o1js/src/examples/zkfunction/ecdsa.ts

TypeScript framework for zk-SNARKs and zkApps

import { Bytes, Crypto, Experimental, createEcdsa, createForeignCurve } from 'o1js';
const { ZkFunction } = Experimental;

export { Bytes32, Ecdsa, Secp256k1, reserves };

class Secp256k1 extends createForeignCurve(Crypto.CurveParams.Secp256k1) {}
class Ecdsa extends createEcdsa(Secp256k1) {}
class Bytes32 extends Bytes(32) {}

const reserves = ZkFunction({
  name: 'Reserves',
  publicInputType: Bytes32,
  privateInputTypes: [Ecdsa, Secp256k1],
  main: (message: Bytes32, signature: Ecdsa, publicKey: Secp256k1) => {
    signature.verify(message, publicKey).assertTrue();
  },
});

console.time('compile');
let { verificationKey } = await reserves.compile();
console.timeEnd('compile');

let message = Bytes32.random();
let privateKey = Secp256k1.Scalar.random();
let publicKey = Secp256k1.generator.scale(privateKey);
let signature = Ecdsa.sign(message.toBytes(), privateKey.toBigInt());

console.time('prove');
let proof = await reserves.prove(message, signature, publicKey);
console.timeEnd('prove');

console.time('verify');
let isValid = await reserves.verify(proof, verificationKey);
console.timeEnd('verify');

if (!isValid) throw Error('verification failed!');