SimpleBase

This is my own take for exotic base encodings like Base32, Base58 and Base85. I started to write it in 2013 as coding practice and kept it as a small pet project. I suggest anyone who wants to brush up their coding skills to give those encoding problems a shot. They turned out to be more challenging than I expected. To grasp the algorithms I had to get a pen and paper to see how the math worked.

Features

• Multibase support. All formats covered by SimpleBase including a few Base64 variants are supported. Base2, Base8, and Base10 are also supported.
• Base32: RFC 4648, BECH32, Crockford, z-base-32, Geohash, FileCoin and Extended Hex (BASE32-HEX) flavors with Crockford character substitution, or any other custom flavors.
• Base36: Both lowercase and uppercase alphabets are supported.
• Base45: RFC 9285 is supported.
• Base58: All the standard (Bitcoin (BTC), Ripple (XRP), Monero (XMR)) and custom Base58 encoding methods are supported. Also provides Base58Check and Avalanche (AVAX) CB58 encoding/decoding helpers.
• Base62: The standard Base62 encoding/decoding supported along with a custom alphabet.
• Base85: Ascii85, Z85 and custom flavors. IPv6 encoding/decoding support.
• Base16: UpperCase, LowerCase and ModHex flavors. An experimental hexadecimal encoder/decoder just to see how far I can take the optimizations compared to .NET's implementations. It's quite fast now, but .NET has Convert.FromHexString() method since .NET 5. This is mostly a baseline implementation now (except for when you need ModHex).
• Base256 Emoji🚀: Supported by Multibase, and can also be used individually.
• One-shot memory buffer based APIs for simple use cases.
• Stream-based async APIs for more advanced scenarios.
• Lightweight: No dependencies.
• Support for big-endian CPUs like IBM s390x (zArchitecture).
• Thread-safe.
• Simple to use.

NuGet

To install it from NuGet:

Install-Package SimpleBase

Usage

The basic usage for encoding a buffer into, say, Base32, is as simple as:

using SimpleBase;

byte[] myBuffer;
string result = Base32.Crockford.Encode(myBuffer, padding: true);
// you can also use "ExtendedHex" or "Rfc4648" as encoder flavors

Decoding is also similar:

using SimpleBase;

string myText = ...
byte[] result = Base32.Crockford.Decode(myText);

See the wiki for more types of examples and full documentation.

Benchmark Results

Small buffer sizes are used (64 characters). They are closer to real life applications. Base58 performs really bad in decoding of larger buffer sizes, due to polynomial complexity of numeric base conversions.

BenchmarkDotNet v0.14.0, Windows 11 (10.0.26100.4061) AMD Ryzen 9 5950X, 1 CPU, 32 logical and 16 physical cores .NET SDK 9.0.300 [Host] : .NET 8.0.16 (8.0.1625.21506), X64 RyuJIT AVX2 DefaultJob : .NET 8.0.16 (8.0.1625.21506), X64 RyuJIT AVX2

Encoding (64 byte buffer)

Method	Mean	Error	StdDev	Gen0	Allocated
DotNet_Base64	29.82 ns	0.644 ns	0.924 ns	0.0119	200 B
Base2_Default	235.29 ns	4.472 ns	6.413 ns	0.0625	1048 B
Base8_Default	126.04 ns	2.556 ns	3.903 ns	0.0224	376 B
Base16_UpperCase	82.37 ns	1.667 ns	1.920 ns	0.0167	280 B
Multibase_Base16_UpperCase	107.22 ns	2.102 ns	4.197 ns	0.0334	560 B
Base32_CrockfordWithPadding	156.90 ns	1.599 ns	1.335 ns	0.0138	232 B
Base36_LowerCase	47.26 ns	0.874 ns	0.898 ns	0.0091	152 B
Base45_Default	123.42 ns	1.853 ns	1.642 ns	0.0129	216 B
Base58_Bitcoin	47.16 ns	0.989 ns	1.177 ns	0.0091	152 B
Base58_Monero	207.06 ns	1.920 ns	1.796 ns	0.0119	200 B
Base62_Default	46.39 ns	0.509 ns	0.476 ns	0.0091	152 B
Base85_Z85	163.01 ns	1.226 ns	1.024 ns	0.0110	184 B
Base256Emoji_Default	230.50 ns	4.505 ns	4.214 ns	0.0167	280 B

Decoding (80 character string, except Base45 which must use an 81 character string)

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
DotNet_Base64	102.24 ns	0.234 ns	0.219 ns	0.0052	-	88 B
Base2_Default	102.95 ns	0.074 ns	0.070 ns	0.0024	-	40 B
Base8_Default	103.41 ns	0.199 ns	0.176 ns	0.0024	-	40 B
Base16_UpperCase	50.60 ns	0.931 ns	0.777 ns	0.0038	-	64 B
Base16_UpperCase_TextReader	275.90 ns	2.852 ns	2.381 ns	0.5007	0.0153	8376 B
Multibase_Base16_UpperCase	51.73 ns	0.254 ns	0.238 ns	0.0038	-	64 B
Multibase_TryDecode_Base16_UpperCase	46.95 ns	0.265 ns	0.235 ns	-	-	-
Base32_Crockford	126.78 ns	1.751 ns	1.552 ns	0.0048	-	80 B
Base36_LowerCase	4,160.01 ns	65.532 ns	54.722 ns	-	-	80 B
Base45_Default	73.56 ns	1.248 ns	1.167 ns	0.0048	-	80 B
Base58_Bitcoin	4,544.46 ns	89.449 ns	133.882 ns	-	-	88 B
Base58_Monero	107.88 ns	0.408 ns	0.341 ns	0.0052	-	88 B
Base62_Default	4,500.24 ns	7.457 ns	6.610 ns	-	-	88 B
Base85_Z85	256.92 ns	0.580 ns	0.514 ns	0.0052	-	88 B
Base256Emoji_Default	287.68 ns	1.634 ns	1.528 ns	0.0062	-	104 B

Notes

I'm sure there are areas for improvement. I didn't want to go further in optimizations which would hurt readability and extensibility. I might experiment on them in the future.

Test suite for Base32 isn't complete, I took most of it from RFC4648. Base58 really lacks a good spec or test vectors needed. I had to resort to using online converters to generate preliminary test vectors.

Base85 tests are also makseshift tests based on what output Cryptii produces. Contribution to missing test cases are greatly appreciated.

It's interesting that I wasn't able to reach .NET Base64's performance with Base16 with a straightforward managed code despite that it's much simpler. I was only able to match it after I converted Base16 to unsafe code with good independent interleaving so CPU pipeline optimizations could take place. Still not satisfied though. Is .NET's Base64 implementation native? Perhaps.

Thanks

Thanks to all contributors who provided patches, and reported bugs.

Chatting about this pet project with my friends @detaybey, @vhallac, @alkimake and @Utopians at one of our friend's birthday encouraged me to finish this. Thanks guys.