vrf-ts

A TypeScript implementation of Verifiable Random Functions (VRFs) based on RFC 9381. This library implements an elliptic curve VRF using the secp256k1 curve.

Features

• Implementation of RFC 9381 VRF specifications for secp256k1
• Deterministic proof generation using RFC 6979 for nonce generation
• Proof verification
• Hash output conversion
• Key pair generation

Installation

npm install vrf-ts
# or
yarn add vrf-ts
# or
bun add vrf-ts

Usage Examples

Basic VRF Operations

import { Secp256k1Vrf } from 'vrf-ts';

// Create a VRF instance
const vrf = new Secp256k1Vrf();

// Generate a key pair
const keyPair = vrf.keygen();
console.log('Secret Key:', keyPair.secretKey);
console.log('Public Key:', keyPair.publicKey);

// Prove a message
const message = Buffer.from('example message');
const privateKey = Buffer.from(keyPair.secretKey, 'hex');
const proof = vrf.prove(privateKey, message);
console.log('VRF Proof:', Buffer.from(proof).toString('hex'));

// Verify a proof
const publicKey = Buffer.from(keyPair.publicKey, 'hex');
const result = vrf.verify(publicKey, proof, message);
if (result.isValid) {
    console.log('VRF Hash:', result.hash);
} else {
    console.error('Verification failed:', result.reason);
}

// Convert proof to hash directly
const hashFromProof = vrf.proofToHash(proof);
console.log('Hash from Proof:', hashFromProof);

API Reference

Secp256k1Vrf Class

Constructor

new Secp256k1Vrf()

Methods

• keygen(): Generate a new key pair

  • Returns: { secretKey: string, publicKey: string } (hex encoded)

• prove(secret: PrivKey, message: Bytes): Generate a VRF proof

  • Returns: Bytes (proof)

• verify(publicKey: Hex, proof: Bytes, message: Bytes): Verify a VRF proof

  • Returns: { isValid: true, hash: string } | { isValid: false, reason: string }

• proofToHash(proof: Bytes): Convert a proof to its output hash

  • Returns: string (hex encoded hash)

Implementation Details

This library implements the secp256k1 curve VRF with SHA-256 (extension beyond RFC 9381). It uses:

• @noble/secp256k1 for elliptic curve operations
• @noble/hashes for cryptographic hashing
• RFC 6979 for deterministic nonce generation

Development

To install dependencies:

bun install

To run tests:

bun test

License

This project is open source and available under the MIT License.