o1js/src/examples/circuit/ecdsa.ts

TypeScript framework for zk-SNARKs and zkApps

import {
  Circuit,
  circuitMain,
  public_,
  Crypto,
  createEcdsaV2,
  createForeignCurveV2,
  Bytes,
  assert,
} from 'o1js';

export { Secp256k1, Ecdsa, Bytes32, Reserves };

class Secp256k1 extends createForeignCurveV2(Crypto.CurveParams.Secp256k1) {}
class Ecdsa extends createEcdsaV2(Secp256k1) {}
class Bytes32 extends Bytes(32) {}

class Reserves extends Circuit {
  @circuitMain
  static main(
    @public_ message: Bytes32,
    signature: Ecdsa,
    publicKey: Secp256k1
  ) {
    assert(signature.verify(message, publicKey));
  }
}

console.time('generateKeypair');
let kp = await Reserves.generateKeypair();
console.timeEnd('generateKeypair');

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([signature, publicKey], [message], kp);
console.timeEnd('prove');

console.time('verify');
let isValid = await Reserves.verify([message], kp.verificationKey(), proof);
assert(isValid, 'verifies');
console.timeEnd('verify');