zkMPA - Zero-Knowledge Multi-Party Approval for Verifiable Credentials

A comprehensive implementation of zkMPA (Zero-Knowledge Multi-Party Approval) for verifiable credentials using Semaphore zero-knowledge proofs.

🏗️ Project Structure

.
├── docs/           # Protocol documentation and specifications
├── examples/       # Example implementations
│   └── zkmpa-demo/              # Full-stack zkMPA demo application
└── packages/       # Core zkMPA packages
    ├── @zkmpa/core       # Main protocol implementation
    ├── @zkmpa/identity   # Identity management
    ├── @zkmpa/group      # Group management
    ├── @zkmpa/proposal   # Proposal and voting
    ├── @zkmpa/credential # VC issuance/verification
    ├── @zkmpa/proof      # ZK proof generation
    └── @zkmpa/storage    # Storage adapters

🚀 Quick Start

Run the Demo Example

# Install dependencies
pnpm install

# Run the full-stack demo
pnpm dev:example

# Or navigate to the example directly
cd examples/zkmpa-demo
pnpm dev:all

📚 Documentation

• Protocol Documentation
• Example Implementation
• API Reference

🔑 Key Features

Anonymous Voting

• Zero-knowledge proofs via Semaphore protocol
• Privacy-preserving member participation
• Cryptographic nullifier prevention of double voting

Dynamic Approval Policies

• Per-credential approval thresholds
• Flexible governance models
• Context-aware policy application

Group DIDs

• Collective entity representation
• W3C DID standard compliance
• Veramo integration

Verifiable Credentials

• W3C VC standard
• Cryptographic evidence of approval
• JWT-based proof format

🛠️ Technology Stack

• Frontend: Next.js, React, TypeScript
• Backend: NestJS, TypeScript
• Cryptography: Semaphore Protocol, snarkjs
• Identity: Veramo, DIDs
• Database: MongoDB
• Blockchain: Ethereum (Sepolia testnet)

📦 Reference Implementation

This repository provides a reference implementation of zkMPA (Zero-Knowledge Multi-Party Approval), including core packages to make it easier to implement this protocol:

• Core packages (@zkmpa/*) provide reusable components and protocol implementation
• Protocol specification documented in ./docs/README.md
• Working demo available in ./examples/zkmpa-demo/

The zkMPA packages are designed to simplify the implementation of the protocol by handling complex cryptographic operations, DID document management, and verification workflows.

🤝 Contributing

Contributions are welcome! Please read our contributing guidelines and submit PRs.

📄 License

MIT License - see LICENSE file for details.

🔗 Links

• Semaphore Protocol
• Veramo Framework
• W3C Verifiable Credentials
• W3C Decentralized Identifiers

🙏 Acknowledgments

This project builds upon the work of:

• Semaphore Protocol team
• Veramo Framework team
• W3C DID and VC Working Groups