🔑 ZKK: Zero-Knowledge Key

ZKK is a proof-of-concept project demonstrating the use of Zero-Knowledge Proofs (ZKP) to validate a Bitcoin private key without exposing its value. The project generates a ZKP proving that a given private key corresponds to a derived public key and encodes the proof in a QR code for easy sharing and validation.

Features

• Validate Bitcoin private keys.
• Derive public keys and addresses from private keys.
• Generate Zero-Knowledge Proofs (ZKP) using zk-SNARKs.
• Encode ZKP into a QR code for secure sharing.
• Display and save QR codes as SVG images.

Prerequisites

1. Python 3.8 or later: Ensure you have Python installed.
2. Environment Setup: Create and activate a virtual environment:

   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate

3. Dependencies:
   • bitcoinlib: For Bitcoin key derivation.
   • qrcode: For QR code generation.
   • snarkjs: For zk-SNARK proof generation.

Install dependencies using:

pip install bitcoinlib qrcode snarkjs

Installation

Clone the repository and navigate to the project directory:

git clone https://github.com/fabohax/zkk.git
cd zkk

Use Cases

ZKK can be used in scenarios where you want to prove knowledge or ownership of a Bitcoin private key without revealing the key itself. Example use cases include:

• Anonymous Authentication: Prove you control a Bitcoin address (or cryptographic identity) without revealing your public key or address. Useful for privacy-preserving logins or gated access.
• Private Ownership Proof: Show you own a specific Bitcoin address to a third party (e.g., for KYC, asset verification, or escrow) without exposing your private key or even your public key.
• Selective Disclosure: Prove you control one address from a set (e.g., “I own one of these addresses”) without revealing which one, useful for anonymous group membership or voting.
• On-chain Privacy Protocols: Integrate with smart contracts or privacy-focused blockchains to prove transaction validity or ownership without leaking sensitive information.
• Credential Systems: Use as a building block for decentralized identity, where you prove attributes (like age, membership, or asset ownership) without revealing your identity.
• Secure Messaging or Signing: Prove you can decrypt or sign messages without revealing your key, enabling secure, private communication channels.

Project Structure

zkk/
├── bin/
│   └── cli.py                 # CLI script for ZKP generation and verification
├── src/
│   ├── snarks/                # zk-SNARK proof-related code
│   │   ├── proof.py           # Proof generation and verification logic
│   │   ├── constraints.circom # Circom circuit for zk-SNARKs
│   │   ├── utils.py           # Utility functions for evaluation
│   │   └── merkle.py          # Merkle tree implementation
│   ├── bitcoin/
│   │   └── key_utils.py       # Functions for key derivation and validation
│   └── qr/
│       └── generate_qr.py     # QR code generation utilities
├── tests/                     # Unit and integration tests
├── examples/                  # Example scripts for usage
├── README.md                  # Project documentation
└── requirements.txt           # Python dependencies

How It Works

1. Validate and Derive Public Key:

   • The script validates a given Bitcoin private key.
   • It derives the corresponding public key and Bitcoin address.

2. Generate ZKP:

   • Using zk-SNARKs, the private key is input into a Circom circuit.
   • The proof is generated via snarkjs based on the circuit constraints.
   • The output is a ZKP that can be validated without exposing the private key.

3. Encode in QR Code:

   • The generated ZKP is serialized and encoded into a QR code for sharing.
   • The QR code is saved as an SVG image.

Usage

1. Run the Script

Generate a proof and QR code for a given Bitcoin private key:

python bin/cli.py generate <BitcoinPrivateKey>

2. Example Output

Console Output:

Validating and deriving public key...
Public Key: 02c2977508521f90683cae95a21824b89e5ee4604869c5e383cb85cdd4c2148c00
Address: 19cf4bxogLyzo3yCEedyLq3nwdy6r43RsF
Generating ZKP...
ZKP Generated Successfully.
QR Code saved as zkp_qr.svg

3. Verify the Proof

Run the verification script to confirm proof validity:

python bin/cli.py --verify <path_to_proof_file>

Contributing

Contributions are welcome! Feel free to submit issues or pull requests.

License

Open Source Code Made With ❤️

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