diff --git a/client/client.go b/client/client.go
index a6e88f72..807629ea 100644
--- a/client/client.go
+++ b/client/client.go
@@ -6,6 +6,8 @@ import (
 	"errors"
 	"io"
 	"io/ioutil"
+	"reflect"
+	"sort"
 
 	"github.com/theupdateframework/go-tuf/data"
 	"github.com/theupdateframework/go-tuf/util"
@@ -14,11 +16,11 @@ import (
 
 const (
 	// This is the upper limit in bytes we will use to limit the download
-	// size of the root/timestamp roles, since we might not don't know how
-	// big it is.
+	// size of the root/timestamp roles, since the size is unknown.
 	defaultRootDownloadLimit      = 512000
 	defaultTimestampDownloadLimit = 16384
 	defaultMaxDelegations         = 32
+	defaultMaxRoots               = 10000
 )
 
 // LocalStore is local storage for downloaded top-level metadata.
@@ -86,13 +88,19 @@ type Client struct {
 	// MaxDelegations limits by default the number of delegations visited for any
 	// target
 	MaxDelegations int
+
+	// ChainedRootUpdater enables https://theupdateframework.github.io/specification/v1.0.19/index.html#update-root
+	ChainedRootUpdater bool
+	// UpdaterMaxRoots limits the number of downloaded roots in 1.0.19 root updater
+	UpdaterMaxRoots int
 }
 
 func NewClient(local LocalStore, remote RemoteStore) *Client {
 	return &Client{
-		local:          local,
-		remote:         remote,
-		MaxDelegations: defaultMaxDelegations,
+		local:           local,
+		remote:          remote,
+		MaxDelegations:  defaultMaxDelegations,
+		UpdaterMaxRoots: defaultMaxRoots,
 	}
 }
 
@@ -144,6 +152,13 @@ func (c *Client) Init(rootKeys []*data.Key, threshold int) error {
 //
 // https://github.com/theupdateframework/tuf/blob/v0.9.9/docs/tuf-spec.txt#L714
 func (c *Client) Update() (data.TargetFiles, error) {
+	if c.ChainedRootUpdater {
+		if err := c.updateRoots(); err != nil {
+			return data.TargetFiles{}, err
+		}
+		return c.update(true)
+	}
+
 	return c.update(false)
 }
 
@@ -249,6 +264,138 @@ func (c *Client) update(latestRoot bool) (data.TargetFiles, error) {
 	return updatedTargets, nil
 }
 
+func (c *Client) updateRoots() error {
+	// https://theupdateframework.github.io/specification/v1.0.19/index.html#load-trusted-root
+
+	// 5.2 Load the trusted root metadata file. We assume that a good,
+	// trusted copy of this file was shipped with the package manager
+	// or software updater using an out-of-band process. Note that
+	// the expiration of the trusted root metadata file does not
+	// matter, because we will attempt to update it in the next step.
+	if err := c.getLocalMeta(); err != nil {
+		if _, ok := err.(verify.ErrExpired); !ok {
+			return err
+		}
+	}
+
+	// Prepare for 5.3.11: If the timestamp and / or snapshot keys have been rotated,
+	// then delete the trusted timestamp and snapshot metadata files.
+	getKeyIDs := func(role string) []string {
+		keyIDs := make([]string, 0, len(c.db.GetRole("timestamp").KeyIDs))
+		for k := range c.db.GetRole(role).KeyIDs {
+			keyIDs = append(keyIDs, k)
+		}
+		sort.Strings(keyIDs)
+		return keyIDs
+	}
+	startTimestampKeyIDs := getKeyIDs("timestamp")
+	startSnapshotKeyIDs := getKeyIDs("snapshot")
+
+	// 5.3.1 Temorarily turn on the consistent snapshots in order to download
+	// versioned root metadata files as described next.
+	consistentSnapshot := c.consistentSnapshot
+	c.consistentSnapshot = true
+
+	// https://theupdateframework.github.io/specification/v1.0.19/index.html#update-root
+
+	// 5.3.1 Since it may now be signed using entirely different keys,
+	// the client MUST somehow be able to establish a trusted line of
+	// continuity to the latest set of keys (see § 6.1 Key
+	// management and migration). To do so, the client MUST
+	// download intermediate root metadata files, until the
+	// latest available one is reached. Therefore, it MUST
+	// temporarily turn on consistent snapshots in order to
+	// download versioned root metadata files as described next.
+
+	// This loop returns on error or breaks after downloading the lastest root metadata.
+	// 5.3.2 Let N denote the version number of the trusted root metadata file.
+	for i := 0; i < c.UpdaterMaxRoots; i++ {
+		// 5.3.3 Try downloading version nPlusOne of the root metadata file.
+		// NOTE: as a side effect, we do update c.rootVer to nPlusOne between iterations.
+		nPlusOne := c.rootVer + 1
+		nPlusOneRootPath := util.VersionedPath("root.json", nPlusOne)
+		nPlusOneRootMetadata, err := c.downloadMetaUnsafe(nPlusOneRootPath, defaultRootDownloadLimit)
+		//fmt.Println(string(nPlusOneRootMetadata[:]))
+		if err != nil {
+			if _, ok := err.(ErrMissingRemoteMetadata); ok {
+				// stop when the next root can't be downloaded
+				break
+			} else {
+				return err
+			}
+		}
+
+		// 5.3.4 Check for an arbitrary software attack.
+		nPlusOneRootMetadataSigned := &data.Root{}
+		// 5.3.4.1 Check that N signed N+1
+		// 5.3.5 Check for a rollback attack. Here, we check that nPlusOneRootMetadataSigned.version >= nPlusOne.
+		if err := c.db.UnmarshalExpired(nPlusOneRootMetadata, nPlusOneRootMetadataSigned, "root", nPlusOne); err != nil {
+			// 5.3.6 Note that the expiration of the new (intermediate) root
+			// metadata file does not matter yet, because we will check for
+			// it in step 5.3.10.
+			if _, ok := err.(verify.ErrExpired); !ok {
+				return err
+			}
+		}
+
+		// 5.3.5 Following up, we check for a fast-forward attack: here, we check for that nPlusOneRootMetadataSigned.version >= nPlusOne.
+		if nPlusOneRootMetadataSigned.Version != nPlusOne {
+			return verify.ErrWrongVersion{
+				Given:    nPlusOneRootMetadataSigned.Version,
+				Expected: nPlusOne,
+			}
+		}
+
+		// 5.3.7 Set the trusted root metadata file to the new root metadata file.
+		c.rootVer = nPlusOneRootMetadataSigned.Version
+		// NOTE: following up on 5.3.1, we want to always have consistent snapshots on for the duration
+		// of root rotation. AFTER the rotation is over, we will set it to the value of the last root.
+		consistentSnapshot = nPlusOneRootMetadataSigned.ConsistentSnapshot
+		// 5.3.8 Persist root metadata. The client MUST write the file to non-volatile storage as FILENAME.EXT (e.g. root.json).
+		// NOTE: Internally, setMeta stores metadata in LevelDB in a persistent manner.
+		if err := c.local.SetMeta("root.json", nPlusOneRootMetadata); err != nil {
+			return err
+		}
+
+		// 5.3.4.2 check that N+1 signed itself.
+		if err := c.getLocalMeta(); err != nil {
+			// 5.3.6 Note that the expiration of the new (intermediate) root
+			// metadata file does not matter yet, because we will check for
+			// it in step 5.3.10.
+			if _, ok := err.(verify.ErrExpired); !ok {
+				return err
+			}
+		}
+
+		// 5.3.9 Repeat steps 5.3.2 to 5.3.9
+	}
+
+	// 5.3.10 Check for a freeze attack.
+	// NOTE: this will check for any, including freeze, attack.
+	if err := c.getLocalMeta(); err != nil {
+		return err
+	}
+
+	// 5.3.11 If the timestamp and / or snapshot keys have been rotated,
+	// then delete the trusted timestamp and snapshot metadata files.
+	// To figure out if the keys are rotated, compare the timestamp/snapshot keys
+	// of start root and end root.
+	//endTimestampKeyIDs := someFunc(c.db.GetRole("timestamp").KeyIDs)
+	endTimestampKeyIDs := getKeyIDs("timestamp")
+	endSnapshotKeyIDs := getKeyIDs("snapshot")
+
+	if !reflect.DeepEqual(startTimestampKeyIDs, endTimestampKeyIDs) ||
+		!reflect.DeepEqual(startSnapshotKeyIDs, endSnapshotKeyIDs) {
+		c.local.SetMeta("snapshot", json.RawMessage{})
+		c.local.SetMeta("timestamp", json.RawMessage{})
+		return ErrEmptyTimestampOrSnapshot
+	}
+
+	// 5.3.12 Set whether consistent snapshots are used as per the trusted root metadata file.
+	c.consistentSnapshot = consistentSnapshot
+	return nil
+}
+
 func (c *Client) updateWithLatestRoot(m *data.SnapshotFileMeta) (data.TargetFiles, error) {
 	var rootJSON json.RawMessage
 	var err error
diff --git a/client/client_test.go b/client/client_test.go
index a8ca536f..eb1a0d67 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -3,6 +3,7 @@ package client
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -11,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
 	cjson "github.com/tent/canonical-json-go"
 	tuf "github.com/theupdateframework/go-tuf"
 	"github.com/theupdateframework/go-tuf/data"
@@ -360,6 +362,83 @@ func (s *ClientSuite) TestNewRoot(c *C) {
 	}
 }
 
+// Test helper
+func initTestClient(c *C, baseDir string, initWithLocalMetadata bool, ignoreExpired bool) (*Client, func() error) {
+	l, err := initTestTUFRepoServer(baseDir, "server")
+	c.Assert(err, IsNil)
+	e := verify.IsExpired
+	if ignoreExpired {
+		verify.IsExpired = func(t time.Time) bool { return false }
+	}
+	tufClient, err := initTestTUFClient(baseDir, "client/metadata/current", l.Addr().String(), initWithLocalMetadata)
+	verify.IsExpired = e
+	c.Assert(err, IsNil)
+	return tufClient, l.Close
+}
+
+// Tests updateRoots method.
+func (s *ClientSuite) TestUpdateRoot(c *C) {
+	var tests = []struct {
+		fixturePath                   string
+		rootUpdater                   bool
+		isExpired                     bool // Value retuned by verify.IsExpired.
+		extpectedError                error
+		expectedRootVersion           int // -1 means no check is performed on this.
+		expectNonRootMetadataDeletion bool
+	}{
+		// Good new root update succeeds (the timestamp check disabled).
+		{"testdata/PublishedTwiceWithRotatedKeys_root", true, false, nil, 2, false},
+		// Good new root update with a new key for timestamp succeeds (the timestamp check disabled), and timestamp and snapshot metadata deleted.
+		{"testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root", true, false, ErrEmptyTimestampOrSnapshot, 2, true},
+		// Good update but with an expired root fails.
+		{"testdata/PublishedTwiceWithRotatedKeys_root", true, true, verify.ErrExpired{}, -1, false},
+		// Bad update does not happen with rootUpdater set to false.
+		{"testdata/PublishedTwiceWithStaleVersion_root", false, false, nil, 1, false},
+		// Bad root update with a rollback attack fails.
+		{"testdata/PublishedTwiceWithStaleVersion_root", true, false, verify.ErrLowVersion{Actual: 1, Current: 2}, -1, false},
+		//Bad root update with fast forward attack fails.
+		{"testdata/PublishedTwiceForwardVersionWithRotatedKeys_root", true, false, verify.ErrWrongVersion(verify.ErrWrongVersion{Given: 3, Expected: 2}), -1, false},
+		// Bad root with invalid new root signature fails.
+		{"testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root", true, false, errors.New("tuf: signature verification failed"), -1, false},
+		// Bad root with invalid old root signature fails.
+		{"testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root", true, false, errors.New("tuf: signature verification failed"), -1, false},
+	}
+
+	for _, test := range tests {
+		fmt.Println(test.fixturePath)
+		e := verify.IsExpired
+		verify.IsExpired = func(t time.Time) bool { return test.isExpired }
+
+		tufClient, closer := initTestClient(c, test.fixturePath /* initWithLocalMetadata = */, true /* ignoreExpired = */, true)
+		tufClient.ChainedRootUpdater = test.rootUpdater
+		_, err := tufClient.Update()
+		if test.extpectedError == nil {
+			c.Assert(err, IsNil)
+			// Check if the root.json is being saved in non-volatile storage.
+			tufClient.getLocalMeta()
+			assert.Equal(c, test.expectedRootVersion, tufClient.RootVersion())
+			// Check the timestamp and metadata deletion.
+			if test.expectNonRootMetadataDeletion {
+				if m, err := tufClient.local.GetMeta(); err == nil {
+					assert.Equal(c, m["timestamp"], json.RawMessage{})
+					assert.Equal(c, m["snapshot"], json.RawMessage{})
+				}
+			}
+
+		} else {
+			if _, ok := err.(verify.ErrExpired); ok {
+				_, ok := test.extpectedError.(verify.ErrExpired)
+				assert.True(c, ok)
+			} else {
+				assert.Equal(c, test.extpectedError, err)
+			}
+		}
+		closer()
+		verify.IsExpired = e
+	}
+
+}
+
 func (s *ClientSuite) TestNewTargets(c *C) {
 	client := s.newClient(c)
 	files, err := client.Update()
diff --git a/client/clienttest.go b/client/clienttest.go
new file mode 100644
index 00000000..0b2e283f
--- /dev/null
+++ b/client/clienttest.go
@@ -0,0 +1,126 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"path/filepath"
+	"strings"
+
+	"github.com/theupdateframework/go-tuf/data"
+	"github.com/theupdateframework/go-tuf/verify"
+)
+
+//Initializes a local HTTP server and serves TUF Repo.
+func initTestTUFRepoServer(baseDir string, relPath string) (net.Listener, error) {
+	serverDir := filepath.Join(baseDir, relPath)
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	go http.Serve(l, http.FileServer(http.Dir(serverDir)))
+	return l, err
+}
+
+// Initializes the client object with local files without fetching
+// the latest version from the server.
+func (c *Client) initWithLocal(rootKeys []*data.Key, threshold int, localrootpath string) error {
+	if len(rootKeys) < threshold {
+		return ErrInsufficientKeys
+	}
+	rootJSON, err := ioutil.ReadFile(localrootpath) //c.downloadMetaUnsafe("root.json", defaultRootDownloadLimit)
+	if err != nil {
+		return err
+	}
+	// create a new key database, and add all the public `rootKeys` to it.
+	c.db = verify.NewDB()
+	rootKeyIDs := make([]string, 0, len(rootKeys))
+	for _, key := range rootKeys {
+		for _, id := range key.IDs() {
+			rootKeyIDs = append(rootKeyIDs, id)
+			if err := c.db.AddKey(id, key); err != nil {
+				return err
+			}
+		}
+	}
+
+	// add a mock "root" role that trusts the passed in key ids. These keys
+	// will be used to verify the `root.json` we just fetched.
+	role := &data.Role{Threshold: threshold, KeyIDs: rootKeyIDs}
+	if err := c.db.AddRole("root", role); err != nil {
+		return err
+	}
+
+	// verify that the new root is valid.
+	if err := c.decodeRoot(rootJSON); err != nil {
+		return err
+	}
+
+	return c.local.SetMeta("root.json", rootJSON)
+}
+
+//Initializes a TUF Client based on metadata in a given path.
+func initTestTUFClient(baseDir string, relPath string, serverAddr string, initWithLocalMetadata bool) (*Client, error) {
+	initialStateDir := filepath.Join(baseDir, relPath)
+	opts := &HTTPRemoteOptions{
+		MetadataPath: "metadata",
+		TargetsPath:  "targets",
+	}
+	rawFile, err := ioutil.ReadFile(initialStateDir + "/" + "root.json")
+	if err != nil {
+		return nil, err
+	}
+	s := &data.Signed{}
+	root := &data.Root{}
+	if err := json.Unmarshal(rawFile, s); err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(s.Signed, root); err != nil {
+		return nil, err
+	}
+	var keys []*data.Key
+	for _, sig := range s.Signatures {
+		k, ok := root.Keys[sig.KeyID]
+		if ok {
+			keys = append(keys, k)
+		}
+	}
+
+	remote, err := HTTPRemoteStore(fmt.Sprintf("http://%s/", serverAddr), opts, nil)
+	if err != nil {
+		return nil, err
+	}
+	c := NewClient(MemoryLocalStore(), remote)
+
+	if initWithLocalMetadata {
+		if err := c.initWithLocal(keys, 1, initialStateDir+"/"+"root.json"); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := c.Init(keys, 1); err != nil {
+			return nil, err
+		}
+	}
+	files, err := ioutil.ReadDir(initialStateDir)
+	if err != nil {
+		return nil, err
+	}
+
+	// load local files
+	for _, f := range files {
+		if f.IsDir() {
+			continue
+		}
+		name := f.Name()
+		// ignoring consistent snapshot when loading initial state
+		if len(strings.Split(name, ".")) == 1 && strings.HasSuffix(name, ".json") {
+			rawFile, err := ioutil.ReadFile(initialStateDir + "/" + name)
+			if err != nil {
+				return nil, err
+			}
+			if err := c.local.SetMeta(name, rawFile); err != nil {
+				return nil, err
+			}
+		}
+	}
+	return c, nil
+}
diff --git a/client/delegations_test.go b/client/delegations_test.go
index 1ed3cf3b..cf32d0b5 100644
--- a/client/delegations_test.go
+++ b/client/delegations_test.go
@@ -2,12 +2,7 @@ package client
 
 import (
 	"encoding/json"
-	"fmt"
 	"io"
-	"io/ioutil"
-	"net"
-	"net/http"
-	"strings"
 	"testing"
 	"time"
 
@@ -285,113 +280,117 @@ func TestUnverifiedTargets(t *testing.T) {
 
 func TestPersistedMeta(t *testing.T) {
 	verify.IsExpired = func(t time.Time) bool { return false }
-	c, closer := initTestDelegationClient(t, "testdata/php-tuf-fixtures/TUFTestFixture3LevelDelegation")
-	defer closer()
-	_, err := c.Update()
-	assert.Nil(t, err)
+	for _, rootUpdater := range []bool{false, true} {
+		c, closer := initTestDelegationClient(t, "testdata/php-tuf-fixtures/TUFTestFixture3LevelDelegation")
+		defer closer()
+		c.ChainedRootUpdater = rootUpdater
 
-	_, err = c.local.GetMeta()
-	assert.Nil(t, err)
+		_, err := c.Update()
+		assert.Nil(t, err)
 
-	type expectedTargets struct {
-		name    string
-		version int
-	}
-	var persistedTests = []struct {
-		file          string
-		targets       []expectedTargets
-		downloadError error
-		fileContent   string
-	}{
-		{
-			file: "unknown",
-			targets: []expectedTargets{
-				{
-					name:    "targets.json",
-					version: 2,
+		_, err = c.local.GetMeta()
+		assert.Nil(t, err)
+
+		type expectedTargets struct {
+			name    string
+			version int
+		}
+		var persistedTests = []struct {
+			file          string
+			targets       []expectedTargets
+			downloadError error
+			fileContent   string
+		}{
+			{
+				file: "unknown",
+				targets: []expectedTargets{
+					{
+						name:    "targets.json",
+						version: 2,
+					},
 				},
+				downloadError: ErrUnknownTarget{Name: "unknown", SnapshotVersion: 2},
+				fileContent:   "",
 			},
-			downloadError: ErrUnknownTarget{Name: "unknown", SnapshotVersion: 2},
-			fileContent:   "",
-		},
-		{
-			file: "b.txt",
-			targets: []expectedTargets{
-				{
-					name:    "targets.json",
-					version: 2,
-				},
-				{
-					name:    "a.json",
-					version: 1,
-				},
-				{
-					name:    "b.json",
-					version: 1,
+			{
+				file: "b.txt",
+				targets: []expectedTargets{
+					{
+						name:    "targets.json",
+						version: 2,
+					},
+					{
+						name:    "a.json",
+						version: 1,
+					},
+					{
+						name:    "b.json",
+						version: 1,
+					},
 				},
+				downloadError: nil,
+				fileContent:   "Contents: b.txt",
 			},
-			downloadError: nil,
-			fileContent:   "Contents: b.txt",
-		},
-		{
-			file: "f.txt",
-			targets: []expectedTargets{
-				{
-					name:    "targets.json",
-					version: 2,
-				},
-				{
-					name:    "a.json",
-					version: 1,
-				},
-				{
-					name:    "b.json",
-					version: 1,
-				},
-				{
-					name:    "c.json",
-					version: 1,
-				},
-				{
-					name:    "d.json",
-					version: 1,
-				},
-				{
-					name:    "e.json",
-					version: 1,
-				},
-				{
-					name:    "f.json",
-					version: 1,
+			{
+				file: "f.txt",
+				targets: []expectedTargets{
+					{
+						name:    "targets.json",
+						version: 2,
+					},
+					{
+						name:    "a.json",
+						version: 1,
+					},
+					{
+						name:    "b.json",
+						version: 1,
+					},
+					{
+						name:    "c.json",
+						version: 1,
+					},
+					{
+						name:    "d.json",
+						version: 1,
+					},
+					{
+						name:    "e.json",
+						version: 1,
+					},
+					{
+						name:    "f.json",
+						version: 1,
+					},
 				},
+				downloadError: nil,
+				fileContent:   "Contents: f.txt",
 			},
-			downloadError: nil,
-			fileContent:   "Contents: f.txt",
-		},
-	}
+		}
 
-	for _, tt := range persistedTests {
-		t.Run("search "+tt.file, func(t *testing.T) {
-			var dest testDestination
-			err = c.Download(tt.file, &dest)
-			assert.Equal(t, tt.downloadError, err)
-			assert.Equal(t, tt.fileContent, dest.String())
+		for _, tt := range persistedTests {
+			t.Run("search "+tt.file, func(t *testing.T) {
+				var dest testDestination
+				err = c.Download(tt.file, &dest)
+				assert.Equal(t, tt.downloadError, err)
+				assert.Equal(t, tt.fileContent, dest.String())
 
-			p, err := c.local.GetMeta()
-			assert.Nil(t, err)
-			persisted := copyStore(p)
-			// trim non targets metas
-			for _, notTargets := range []string{"root.json", "snapshot.json", "timestamp.json"} {
-				delete(persisted, notTargets)
-			}
-			for _, targets := range tt.targets {
-				storedVersion, err := versionOfStoredTargets(targets.name, persisted)
-				assert.Equal(t, targets.version, storedVersion)
+				p, err := c.local.GetMeta()
 				assert.Nil(t, err)
-				delete(persisted, targets.name)
-			}
-			assert.Empty(t, persisted)
-		})
+				persisted := copyStore(p)
+				// trim non targets metas
+				for _, notTargets := range []string{"root.json", "snapshot.json", "timestamp.json"} {
+					delete(persisted, notTargets)
+				}
+				for _, targets := range tt.targets {
+					storedVersion, err := versionOfStoredTargets(targets.name, persisted)
+					assert.Equal(t, targets.version, storedVersion)
+					assert.Nil(t, err)
+					delete(persisted, targets.name)
+				}
+				assert.Empty(t, persisted)
+			})
+		}
 	}
 }
 
@@ -411,52 +410,11 @@ func versionOfStoredTargets(name string, store map[string]json.RawMessage) (int,
 	return targets.Version, nil
 }
 
-func initTestDelegationClient(t *testing.T, dirPrefix string) (*Client, func() error) {
-	serverDir := dirPrefix + "/server"
-	initialStateDir := dirPrefix + "/client/metadata/current"
-	l, err := net.Listen("tcp", "127.0.0.1:0")
+func initTestDelegationClient(t *testing.T, baseDir string) (*Client, func() error) {
+	l, err := initTestTUFRepoServer(baseDir, "server")
 	assert.Nil(t, err)
-	addr := l.Addr().String()
-	go http.Serve(l, http.FileServer(http.Dir(serverDir)))
-
-	opts := &HTTPRemoteOptions{
-		MetadataPath: "metadata",
-		TargetsPath:  "targets",
-	}
-	remote, err := HTTPRemoteStore(fmt.Sprintf("http://%s/", addr), opts, nil)
-
-	c := NewClient(MemoryLocalStore(), remote)
-	rawFile, err := ioutil.ReadFile(initialStateDir + "/" + "root.json")
-	assert.Nil(t, err)
-	s := &data.Signed{}
-	root := &data.Root{}
-	assert.Nil(t, json.Unmarshal(rawFile, s))
-	assert.Nil(t, json.Unmarshal(s.Signed, root))
-	var keys []*data.Key
-	for _, sig := range s.Signatures {
-		k, ok := root.Keys[sig.KeyID]
-		if ok {
-			keys = append(keys, k)
-		}
-	}
-
-	assert.Nil(t, c.Init(keys, 1))
-	files, err := ioutil.ReadDir(initialStateDir)
+	c, err := initTestTUFClient(baseDir, "client/metadata/current", l.Addr().String(), false)
 	assert.Nil(t, err)
-
-	// load local files
-	for _, f := range files {
-		if f.IsDir() {
-			continue
-		}
-		name := f.Name()
-		// ignoring consistent snapshot when loading initial state
-		if len(strings.Split(name, ".")) == 1 && strings.HasSuffix(name, ".json") {
-			rawFile, err := ioutil.ReadFile(initialStateDir + "/" + name)
-			assert.Nil(t, err)
-			assert.Nil(t, c.local.SetMeta(name, rawFile))
-		}
-	}
 	return c, l.Close
 }
 
diff --git a/client/errors.go b/client/errors.go
index 3d39e6b2..d68ef091 100644
--- a/client/errors.go
+++ b/client/errors.go
@@ -8,9 +8,10 @@ import (
 )
 
 var (
-	ErrNoRootKeys       = errors.New("tuf: no root keys found in local meta store")
-	ErrInsufficientKeys = errors.New("tuf: insufficient keys to meet threshold")
-	ErrNoLocalSnapshot  = errors.New("tuf: no snapshot stored locally")
+	ErrNoRootKeys               = errors.New("tuf: no root keys found in local meta store")
+	ErrInsufficientKeys         = errors.New("tuf: insufficient keys to meet threshold")
+	ErrNoLocalSnapshot          = errors.New("tuf: no snapshot stored locally")
+	ErrEmptyTimestampOrSnapshot = errors.New("tuf: Timestamp or snapshot is empty")
 )
 
 type ErrMissingRemoteMetadata struct {
@@ -144,3 +145,12 @@ type ErrTargetsSnapshotVersionMismatch struct {
 func (e ErrTargetsSnapshotVersionMismatch) Error() string {
 	return fmt.Sprintf("tuf: downloaded %s version %d expected %d in snapshot v%d ", e.Role, e.DownloadedTargetsVersion, e.TargetsSnapshotVersion, e.SnapshotVersion)
 }
+
+type ErrWrongRootVersion struct {
+	DownloadedVersion int
+	ExpectedVersion   int
+}
+
+func (e ErrWrongRootVersion) Error() string {
+	return fmt.Sprintf("tuf: wrong root version downloaded expected %d got %d", e.ExpectedVersion, e.DownloadedVersion)
+}
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/hash.txt b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/hash.txt
new file mode 100644
index 00000000..2344c64a
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/hash.txt
@@ -0,0 +1 @@
+6f48551422eae31c39076399d189fdfa8b20204820d3c884c13cdc025e250e53
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/2.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/2.root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/3.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/3.root.json
new file mode 100644
index 00000000..b6800bb5
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/3.root.json
@@ -0,0 +1,95 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "15156589fe9283fddeecb7195e7bdc13cf0e002b4746d10d47f9c98db74e5e10b4092f26b29a1df9eea93fb60648eaf8c6b5f1002621d843bff065dc9d51940a"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "54a8394b644d5bf8444bf6eef070e0f03b0336a451be671da1dc31b13e241bc618f9ead0f4477c622cee928f970c0754fe00bc354c9ba687305933c75de94306"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "b7231c68eb4fa0b13f175b2feb0dbaf27cb14fd8c3c88c52362f33e383752fa158ceca86fd92b5327dcfe5cfbcf30c479aaf60afa9a871dde4197868642e4008"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 3
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..b6800bb5
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/root.json
@@ -0,0 +1,95 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "15156589fe9283fddeecb7195e7bdc13cf0e002b4746d10d47f9c98db74e5e10b4092f26b29a1df9eea93fb60648eaf8c6b5f1002621d843bff065dc9d51940a"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "54a8394b644d5bf8444bf6eef070e0f03b0336a451be671da1dc31b13e241bc618f9ead0f4477c622cee928f970c0754fe00bc354c9ba687305933c75de94306"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "b7231c68eb4fa0b13f175b2feb0dbaf27cb14fd8c3c88c52362f33e383752fa158ceca86fd92b5327dcfe5cfbcf30c479aaf60afa9a871dde4197868642e4008"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 3
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/2.root.json
new file mode 100644
index 00000000..b6800bb5
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/2.root.json
@@ -0,0 +1,95 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "15156589fe9283fddeecb7195e7bdc13cf0e002b4746d10d47f9c98db74e5e10b4092f26b29a1df9eea93fb60648eaf8c6b5f1002621d843bff065dc9d51940a"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "54a8394b644d5bf8444bf6eef070e0f03b0336a451be671da1dc31b13e241bc618f9ead0f4477c622cee928f970c0754fe00bc354c9ba687305933c75de94306"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "b7231c68eb4fa0b13f175b2feb0dbaf27cb14fd8c3c88c52362f33e383752fa158ceca86fd92b5327dcfe5cfbcf30c479aaf60afa9a871dde4197868642e4008"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 3
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/root.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/root.json
new file mode 100644
index 00000000..b6800bb5
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/root.json
@@ -0,0 +1,95 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "15156589fe9283fddeecb7195e7bdc13cf0e002b4746d10d47f9c98db74e5e10b4092f26b29a1df9eea93fb60648eaf8c6b5f1002621d843bff065dc9d51940a"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "54a8394b644d5bf8444bf6eef070e0f03b0336a451be671da1dc31b13e241bc618f9ead0f4477c622cee928f970c0754fe00bc354c9ba687305933c75de94306"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "b7231c68eb4fa0b13f175b2feb0dbaf27cb14fd8c3c88c52362f33e383752fa158ceca86fd92b5327dcfe5cfbcf30c479aaf60afa9a871dde4197868642e4008"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 3
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/targets.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceForwardVersionWithRotatedKeys_root/server/metadata/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/hash.txt b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/hash.txt
new file mode 100644
index 00000000..5fd89358
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/hash.txt
@@ -0,0 +1 @@
+008c20ceb275a7c650b65e865412a9da3b8face9b888a5f11d1b8ed9f55c60e2
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/2.root.json
new file mode 100644
index 00000000..931ad3af
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "000000"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/root.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/targets.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidNewRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/hash.txt b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/hash.txt
new file mode 100644
index 00000000..edc69014
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/hash.txt
@@ -0,0 +1 @@
+9b144ffe6848a231771baa3518301cc78ab496802d259977b11051162d748423
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/2.root.json
new file mode 100644
index 00000000..898f11ba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "000000"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/root.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/targets.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceInvalidOldRootSignatureWithRotatedKeys_root/server/metadata/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/hash.txt b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/hash.txt
new file mode 100644
index 00000000..1c923e38
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/hash.txt
@@ -0,0 +1 @@
+4f14421dd7556a52afaf1e2593dc843654a6606640ada0564ec94b42d9340fc3
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.root.json
new file mode 100644
index 00000000..32220da7
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.root.json
@@ -0,0 +1,103 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "37cb1e3f3a5c8093b68bc7cb449d104a1cc71dc98bcb6cceeb94d3f70710616a5e27ec83130d43b22c653cc91ccb0e6545ff3ba0293015663268524e05253c05"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "0baa29873d41760ff2bd410dcfada466de6132f2c0aeca18cc0f424887b8de298ea5691524aebd6ea1f5632396d6399154563c32c5cfca11f76892b2c2fc640f"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.timestamp.json
new file mode 100644
index 00000000..e4ae39b5
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/2.timestamp.json
@@ -0,0 +1,28 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "e26d60554d72cf2f96ac326f19ddfc1e5cbf2946205b17d080b67712f7e0e9c65e3634fa71aaffb77ef5af97349753626e7ab12adb59a6eae276257998a68e09"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "6f8c5001fb8282d8452f64504d748f83516b80074840aaa9c354767ccf0ba784a1259998dcf6002b6135cc3db40f520e78eb262967aaec9cd32f3dd935c6960b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..32220da7
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/root.json
@@ -0,0 +1,103 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "37cb1e3f3a5c8093b68bc7cb449d104a1cc71dc98bcb6cceeb94d3f70710616a5e27ec83130d43b22c653cc91ccb0e6545ff3ba0293015663268524e05253c05"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "0baa29873d41760ff2bd410dcfada466de6132f2c0aeca18cc0f424887b8de298ea5691524aebd6ea1f5632396d6399154563c32c5cfca11f76892b2c2fc640f"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..e4ae39b5
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,28 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "e26d60554d72cf2f96ac326f19ddfc1e5cbf2946205b17d080b67712f7e0e9c65e3634fa71aaffb77ef5af97349753626e7ab12adb59a6eae276257998a68e09"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "6f8c5001fb8282d8452f64504d748f83516b80074840aaa9c354767ccf0ba784a1259998dcf6002b6135cc3db40f520e78eb262967aaec9cd32f3dd935c6960b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.root.json
new file mode 100644
index 00000000..32220da7
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.root.json
@@ -0,0 +1,103 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "37cb1e3f3a5c8093b68bc7cb449d104a1cc71dc98bcb6cceeb94d3f70710616a5e27ec83130d43b22c653cc91ccb0e6545ff3ba0293015663268524e05253c05"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "0baa29873d41760ff2bd410dcfada466de6132f2c0aeca18cc0f424887b8de298ea5691524aebd6ea1f5632396d6399154563c32c5cfca11f76892b2c2fc640f"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.timestamp.json
new file mode 100644
index 00000000..e4ae39b5
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/2.timestamp.json
@@ -0,0 +1,28 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "e26d60554d72cf2f96ac326f19ddfc1e5cbf2946205b17d080b67712f7e0e9c65e3634fa71aaffb77ef5af97349753626e7ab12adb59a6eae276257998a68e09"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "6f8c5001fb8282d8452f64504d748f83516b80074840aaa9c354767ccf0ba784a1259998dcf6002b6135cc3db40f520e78eb262967aaec9cd32f3dd935c6960b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/root.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/root.json
new file mode 100644
index 00000000..32220da7
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/root.json
@@ -0,0 +1,103 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "37cb1e3f3a5c8093b68bc7cb449d104a1cc71dc98bcb6cceeb94d3f70710616a5e27ec83130d43b22c653cc91ccb0e6545ff3ba0293015663268524e05253c05"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "0baa29873d41760ff2bd410dcfada466de6132f2c0aeca18cc0f424887b8de298ea5691524aebd6ea1f5632396d6399154563c32c5cfca11f76892b2c2fc640f"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "82f52e4503dbb364fabe8e5567f1cf909d4175d45468a021dfe75653db9ac98c"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+     "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/targets.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..e4ae39b5
--- /dev/null
+++ b/client/testdata/PublishedTwiceRotateTimestampKeysWithRotatedKeys_root/server/metadata/timestamp.json
@@ -0,0 +1,28 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "e26d60554d72cf2f96ac326f19ddfc1e5cbf2946205b17d080b67712f7e0e9c65e3634fa71aaffb77ef5af97349753626e7ab12adb59a6eae276257998a68e09"
+  },
+  {
+   "keyid": "718fedad390b4d0d470b890781eb8c94e5a7e975aebe65fc0862246c945fce68",
+   "sig": "6f8c5001fb8282d8452f64504d748f83516b80074840aaa9c354767ccf0ba784a1259998dcf6002b6135cc3db40f520e78eb262967aaec9cd32f3dd935c6960b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/hash.txt b/client/testdata/PublishedTwiceWithRotatedKeys_root/hash.txt
new file mode 100644
index 00000000..72d6246a
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/hash.txt
@@ -0,0 +1 @@
+f6790e7990e7a5862561d1128322042274a51e8e57c2471e6514ac1d4e605062
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/2.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/2.root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/2.root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/2.root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/root.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/root.json
new file mode 100644
index 00000000..6ba80ef4
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/root.json
@@ -0,0 +1,91 @@
+{
+ "signatures": [
+  {
+   "keyid": "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b",
+   "sig": "309302515543a5b06579cc0cf15cdbaa7eae486e5ae9c2d335926826d069138fcebd21062667eb4a950ccf289824d2de3a221b8f8875f6d29a856f5657542003"
+  },
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "81cb58f9fa43cb41931d1608d980d935b5a6ed34d7240a6987c787cc0c34889f7e019aea47656f2792d5b0868844303b3d205441b79daa94f52c0855db511804"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "f758af464295e62a1da4d3267be6d13f4aba9c7d52166d01b6bd5b4559496c9d"
+    },
+    "scheme": "ed25519"
+   },
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "05e17c1501d627b2597322f80d33aacec6f30a507552d3326a88913422b0e30b"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 2
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/targets.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithRotatedKeys_root/server/metadata/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/current/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/client/metadata/previous/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/hash.txt b/client/testdata/PublishedTwiceWithStaleVersion_root/hash.txt
new file mode 100644
index 00000000..c4204ced
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/hash.txt
@@ -0,0 +1 @@
+ce6dd7ea549940ed3eef235d48bb0cdaa28fa5ec57f0e3dc9f8eadfe6812ecfb
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata.staged/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/1.timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/2.root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/2.root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/2.root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/root.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/root.json
new file mode 100644
index 00000000..08986107
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/root.json
@@ -0,0 +1,87 @@
+{
+ "signatures": [
+  {
+   "keyid": "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129",
+   "sig": "d0bf76a5cfc0aee1b8a1b1bf0ed8ca646a1a6d5f205945c515e8546bfd3c1e6b5e07cc0b93836bd030dd05ba68f177aecb05f6bf90c6702fd178e53310022506"
+  }
+ ],
+ "signed": {
+  "_type": "root",
+  "consistent_snapshot": true,
+  "expires": "2020-12-31T05:48:20Z",
+  "keys": {
+   "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6bac59b8d9e1aae02fae6fba6e7fe3fc9fe5b4a9fe98c3fca255d8c8ec3e5b35"
+    },
+    "scheme": "ed25519"
+   },
+   "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "6400d770c7c1bce4b3d59ce0079ed686e843b6500bbea77d869a1ae7df4565a1"
+    },
+    "scheme": "ed25519"
+   },
+   "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "28bf74baa87ed923f8fa27e3292684f8ec4730ce0bdc65150ed58199206ce089"
+    },
+    "scheme": "ed25519"
+   },
+   "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4": {
+    "keyid_hash_algorithms": [
+     "sha256",
+     "sha512"
+    ],
+    "keytype": "ed25519",
+    "keyval": {
+     "public": "e6ae9d3b67d7b3ce274130291dd90287f32b8fd72bfb4ac5430859ebd1c28a46"
+    },
+    "scheme": "ed25519"
+   }
+  },
+  "roles": {
+   "root": {
+    "keyids": [
+     "d4dab4b4d68b91665a6d0dac5b4e64677aa6d853fc787669168b4b4ba9822129"
+    ],
+    "threshold": 1
+   },
+   "snapshot": {
+    "keyids": [
+     "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93"
+    ],
+    "threshold": 1
+   },
+   "targets": {
+    "keyids": [
+     "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4"
+    ],
+    "threshold": 1
+   },
+   "timestamp": {
+    "keyids": [
+     "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae"
+    ],
+    "threshold": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/snapshot.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/snapshot.json
new file mode 100644
index 00000000..dcbd2f47
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/snapshot.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "77dfdca206c0fe1b8e55d67d21dd0e195a0998a9d2b56c6d3ee8f68d04c21e93",
+   "sig": "61db8765350398f7f750853337d9a55c5d6e790812d29146b5b45d5fd43d2a42c474a7a9fab263c3a50a28114a82f79dbf24ff1f99ae737a8d06f332f9f7d103"
+  }
+ ],
+ "signed": {
+  "_type": "snapshot",
+  "expires": "2020-01-08T00:00:00Z",
+  "meta": {
+   "targets.json": {
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/targets.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/targets.json
new file mode 100644
index 00000000..820691ec
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/targets.json
@@ -0,0 +1,19 @@
+{
+ "signatures": [
+  {
+   "keyid": "e4dae3872d28d29f7624a702bfd25f68453544d597229ee9e0a8569d1f940cf4",
+   "sig": "c150e8ed5d352f366a979f4c4b9d556350c414c2da7ef1279045aaed3438c60872142d0dfe5ddbb627fec2d8fb7c5d8e692e04a87230b78d74714c5db035620a"
+  }
+ ],
+ "signed": {
+  "_type": "targets",
+  "delegations": {
+   "keys": {},
+   "roles": []
+  },
+  "expires": "2020-04-01T07:27:10Z",
+  "spec_version": "1.0.0",
+  "targets": {},
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/timestamp.json b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/timestamp.json
new file mode 100644
index 00000000..aae05fba
--- /dev/null
+++ b/client/testdata/PublishedTwiceWithStaleVersion_root/server/metadata/timestamp.json
@@ -0,0 +1,24 @@
+{
+ "signatures": [
+  {
+   "keyid": "3a05831328273e4b821c3bbe1fed0c5332749d8e071675879af26a401a5c85ae",
+   "sig": "1d668531c7a0960cf90825faa684106a8aef0799c1b47e72301bac45d87f2dd42c14f1a3ac7db862323ca5177dd4fd686573ea92aea99638f17414dde561c00b"
+  }
+ ],
+ "signed": {
+  "_type": "timestamp",
+  "expires": "2020-01-02T00:00:00Z",
+  "meta": {
+   "snapshot.json": {
+    "hashes": {
+     "sha256": "f4ca389c2c9fbc592d91d4e693c31113b8803a11bcb5ecd973581fa0e3d34ce0",
+     "sha512": "92a0989e44c0e9f16d3e56268a3b8dd4e4416ee2ac91a4c871a405f1e426062651ec4effa0078fc4409c8b0422ccad9b1aa197db58f178406f398562b2e98195"
+    },
+    "length": 431,
+    "version": 1
+   }
+  },
+  "spec_version": "1.0.0",
+  "version": 1
+ }
+}
\ No newline at end of file
diff --git a/verify/errors.go b/verify/errors.go
index 6e4587be..376f4219 100644
--- a/verify/errors.go
+++ b/verify/errors.go
@@ -50,6 +50,15 @@ func (e ErrLowVersion) Error() string {
 	return fmt.Sprintf("version %d is lower than current version %d", e.Actual, e.Current)
 }
 
+type ErrWrongVersion struct {
+	Given    int
+	Expected int
+}
+
+func (e ErrWrongVersion) Error() string {
+	return fmt.Sprintf("version %d does not match the extepcted version %d", e.Given, e.Expected)
+}
+
 type ErrRoleThreshold struct {
 	Expected int
 	Actual   int
diff --git a/verify/verify.go b/verify/verify.go
index b6d4162d..9560a69c 100644
--- a/verify/verify.go
+++ b/verify/verify.go
@@ -118,6 +118,29 @@ func (db *DB) Unmarshal(b []byte, v interface{}, role string, minVersion int) er
 	return json.Unmarshal(s.Signed, v)
 }
 
+// UnmarshalExpired is exactly like Unmarshal except ignores expired timestamp.
+func (db *DB) UnmarshalExpired(b []byte, v interface{}, role string, minVersion int) error {
+	s := &data.Signed{}
+	if err := json.Unmarshal(b, s); err != nil {
+		return err
+	}
+	// Note: If verification fails, then we wont attemp to unmarshal
+	// unless when verification error is errExpired.
+	verifyErr := db.Verify(s, role, minVersion)
+	if verifyErr != nil {
+		if _, ok := verifyErr.(ErrExpired); !ok {
+			return verifyErr
+		}
+	}
+	if err := json.Unmarshal(s.Signed, v); err != nil {
+		return err
+	}
+	if verifyErr != nil {
+		return verifyErr
+	}
+	return nil
+}
+
 func (db *DB) UnmarshalTrusted(b []byte, v interface{}, role string) error {
 	s := &data.Signed{}
 	if err := json.Unmarshal(b, s); err != nil {