The Next UPI Moment is Here — For Identity

In 2016, UPI revolutionized how India moved money.
Now, it’s time to revolutionize how India moves identity.

What UPI did for payments, Self-Sovereign Identity (SSI) will do for digital trust:
Instant, verifiable, and under user control.

In today’s world, your Aadhaar, PAN, and income data are handed over to dozens of apps without audit, limits, or proof of consent.
But imagine a future where you can prove who you are, without revealing everything you are.

This project is our vision for that future:
A privacy-first, DPDP-compliant identity layer for India, built using:

• BBS+ cryptographic signatures
• Verifiable Credentials (W3C VC)
• User-owned consent trails

We call it:

• SSI Wallet — A decentralized identity wallet with selective disclosure.
• ConsentCast — A verifiable, tamper-proof consent logger.

Together, they flip the model:
From data extraction ➜ to data empowerment.

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✨ Vision: Redefining Identity for Bharat

India took a leap in financial inclusion with UPI.
We believe the next leap is in identity autonomy.

With SSI Wallet + ConsentCast:

• You don’t submit full KYC everywhere — you prove only what’s required
• Every share is logged, signed, and auditable
• Verifiers get cryptographic proof — not PDFs or screenshots

This isn't just a better system.
It's a new social contract for identity in the digital age.

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🔍 The Problem with Digital Identity Today

• You upload your Aadhaar. Again. And again.
• Apps store full KYC documents they don’t need.
• No way to audit what you shared, when, and with whom.
• Companies collect, but don’t always protect, your identity.

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💡 Our Solution: Consent-Driven, Cryptographically Verified Identity

Powered by open standards (W3C VC), advanced cryptography (BBS+), and Indian regulation (DPDP).

✅ Users store credentials issued by banks/authorities
✅ They generate zero-knowledge proofs to share just needed data
✅ Every data-sharing event is signed and logged
✅ Regulators can audit trails, and users stay in control

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System Diagram

Flow:

1. Bank signs credential using BBS+
2. User (holder) stores it in a wallet
3. When asked, user shares only required fields with a zero-knowledge proof
4. Verifier checks the proof and logs the interaction in ConsentCast

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🔬 Proof-of-Concept Flow

1. Verifiable Credential Issuance UI

The bank issues a VC signed with BBS+.

2. Issued Credential JSON

The generated credential is returned with the signature.

3. Verifier Portal - Field Selection + Proof

User selectively shares fields, proof is generated and verified.

4. ConsentCast - Logs consent event (CLI tool)

Each time a third-party app receives user consent to access data, the logger records the event in consent_logs.json . It also cryptographically signs the entry, ensuring tamper-proof audit trails — fully aligned with DPDP requirements for traceability and accountability.

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What is BBS+? Why BBS+?

BBS+ is a digital signature scheme enabling:

• Multi-message signing: One signature for many fields
• Selective disclosure: Prove a subset of signed data without leaking the rest
• Zero-Knowledge Proofs: Non-interactive, compact, and efficient
• Privacy-Preserving Verification: Reveal only what’s needed, nothing else

Bottom Line:
BBS+ = Single signature ➜ Multiple zero-knowledge proofs ➜ Privacy-preserving verification

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Architecture Breakdown

Component	Role
ssi_wallet	Wallet logic for storing credentials and generating BBS+ proofs
bank-vc-issuer	Issues Verifiable Credentials, signs them using BBS+
verifier-portal	Requests proof for specific fields, verifies using public key
consentcast	Logs who accessed what, when, and why — using Ed25519 for integrity

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UPI vs SSI: Identity is the New Payments

Aspect	UPI	SSI Wallet + ConsentCast
Problem Solved	Fragmented, slow payments	Insecure, all-or-nothing identity sharing
Beneficiaries	Banks, fintechs, users	Banks, fintechs, users, regulators
Bank's Role	Payment processor	Credential issuer, trust anchor
Speed Impact	Payments: 3 days ➜ 3 seconds	ID checks: KYC ➜ instant proof-based access
Standards Used	IMPS APIs ➜ UPI protocol	Aadhaar/PAN APIs ➜ W3C VC + BBS+ signatures
Regulatory Push	RBI, NPCI	DPDP Act, RBI Cybersecurity Guidelines
Auditability	Partial, transaction-level	Full: cryptographic proof + signed consent log

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Regulatory Mapping (DPDP Act)

Clause	Our Compliance Mechanism
Section 6(1)	Consent is explicit, signed, and logged
Section 6(3)	Consent revocation via wallet possible
Section 11	ConsentCast logs provide full data-sharing transparency
Section 13	Wallet enables data portability

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Features

SSI Wallet

• BBS+ based Verifiable Credentials
• CLI and Streamlit UI
• Zero-Knowledge Proof generation for disclosed fields

ConsentCast

• Logs signed by Ed25519 (tamper-proof)
• Verifiable audit trail of data sharing
• Supports filtering by user, recipient, or time

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Getting Started

# Step 1: Set up the Python environment (only once)
cd bank-vc-issuer
python3 -m venv env
source env/bin/activate
pip install -r requirements.txt
cd ..

# Step 2: Launch everything with one command
bash setup.sh

What setup.sh Does

• Kills any existing processes on ports 8501, 8502, 8060, and 8090
• Activates the virtual environment in bank-vc-issuer/env
• Launches the VC Issuer and Verifier portals via Streamlit
• Runs the compiled Rust CLI tools: wallet and verifier_cli
• Automatically backgrounds all services and deactivates the virtual environment