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

Prerequisites

1. Node.js: Ensure you have Node.js installed (version 14 or later).
2. Circom: Install Circom for circuit compilation.
3. snarkjs: Install snarkjs for ZKP setup and proof generation.
4. npm packages:
   • bitcoinjs-lib
   • commander
   • qrcode
   • snarkjs
   • bip39 (if mnemonic support is needed)
   • wif

Install dependencies using:

npm install bitcoinjs-lib commander qrcode snarkjs wif

Installation

Clone the repository and navigate to the project directory:

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

Project Structure

.
├── privateKeyVerification.circom  # The ZKP circuit definition
├── privateKeyVerification_js/     # Compiled WASM file and metadata
├── zkk.js                         # Main script for ZKP generation
├── README.md                      # Project documentation
└── package.json                   # Node.js project configuration

How It Works

1. Validate and Derive Public Key:

   • The script validates a given Bitcoin private key (in WIF format).
   • It derives the corresponding public key and Bitcoin address.

2. Generate ZKP:

   • Using snarkjs, the private key is input into a Circom circuit (privateKeyVerification.circom).
   • The circuit verifies that the private key corresponds to the public key.
   • 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 displayed in the terminal and saved as an SVG image.

Usage

1. Compile the Circuit

Ensure privateKeyVerification.circom is correctly defined. Then compile:

circom privateKeyVerification.circom --r1cs --wasm --sym

2. Perform Trusted Setup

Run the trusted setup for zk-SNARKs:

snarkjs groth16 setup privateKeyVerification.r1cs pot12_final.ptau circuit_final.zkey

Export the verification key:

snarkjs zkey export verificationkey circuit_final.zkey verification_key.json

3. Generate ZKP

Run the script to generate the ZKP and encode it in a QR code:

node zkk.js <BitcoinPrivateKeyWIF>

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

Generated QR Code (in Terminal):

█████████████████████████████
████ ▄▄▄▄▄ █▄▀█▄▄▄ ▄▄▄▄▄ ████
████ █   █ █▀▄ ▄▄▄ █   █ ████
████ █▄▄▄█ █▄▀▄▀▄█ █▄▄▄█ ████
████▄▄▄▄▄▄▄█▄█▄█▄█▄▄▄▄▄▄▄████
████ ▄▄▄▄▄ ██▄▄ ▀▄▄ ▄█▄█▄████
████ █   █ █ ▀▀▄█▄▀█▀▄▀▄ ████
████ █▄▄▄█ █ ▀▄█▄▀ ▄█▀ ▄█████
████▄▄▄▄▄▄▄█▄█▄█▄▄█▄▄▄██▄████
████ ▄▄▄▄▄ ██ ▀█▄ ▄▄█ ▄▀█████
████ █   █ █▄▄▄█ ▀█ ▀▄██▀████
████ █▄▄▄█ █ ▄▄▄▄ ▀ ▄▄▄▄█████
████▄▄▄▄▄▄▄█▄▄▄▄▄█▄█▄▄▄▄▄████
█████████████████████████████

Contributing

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

License

This project is licensed under the MIT License.

Made with ❤️ by fabohax