Shielded Ledger

A privacy-preserving payment solution using zero-knowledge proofs, built with Solidity smart contracts, Circom ZK circuits, and a Next.js frontend.

Project Structure

DiffiPay/
├── packages/
│   ├── contracts/       # Solidity smart contracts (Foundry)
│   ├── circuits/        # Circom ZK circuits
│   └── frontend/        # Next.js TypeScript frontend
├── package.json         # Monorepo configuration
└── README.md

Prerequisites

• Node.js >= 18.0.0
• npm >= 9.0.0
• Foundry
• Circom
• snarkjs

Quick Start

Install Dependencies

# Install all workspace dependencies
npm run install:all

Development

# Run frontend development server
npm run frontend:dev

# Build contracts
npm run contracts:build

# Run contract tests
npm run contracts:test

# Compile circuits
npm run circuits:compile

# Run circuit tests
npm run circuits:test

Packages

Contracts (packages/contracts)

Solidity smart contracts built with Foundry framework.

• Build: npm run contracts:build
• Test: npm run contracts:test
• See packages/contracts/README.md for details

Circuits (packages/circuits)

Zero-knowledge circuits built with Circom.

• Compile: npm run circuits:compile
• Test: npm run circuits:test
• Generate verifiers: npm run circuits:build:contracts
• See packages/circuits/README.md for details

Frontend (packages/frontend)

Next.js application with TypeScript and Tailwind CSS.

• Dev: npm run frontend:dev
• Build: npm run frontend:build
• Start: npm run frontend:start

Workflow

1. Design and implement ZK circuits in packages/circuits
2. Compile circuits and generate Solidity verifier contracts
3. Integrate verifier contracts into main contracts in packages/contracts
4. Deploy contracts and interact via the Next.js frontend

License

MIT