o1js/src/examples/zkprogram/program-with-input.ts

TypeScript framework for zk-SNARKs and zkApps

import { SelfProof, Field, ZkProgram, verify, Proof, JsonProof, Provable } from 'o1js';

let MyProgram = ZkProgram({
  name: 'example-with-input',
  publicInput: Field,

  methods: {
    baseCase: {
      privateInputs: [],
      async method(input: Field) {
        input.assertEquals(Field(0));
      },
    },

    inductiveCase: {
      privateInputs: [SelfProof],
      async method(input: Field, earlierProof: SelfProof<Field, void>) {
        earlierProof.verify();
        earlierProof.publicInput.add(1).assertEquals(input);
      },
    },
  },
});
// type sanity checks
MyProgram.publicInputType satisfies typeof Field;
MyProgram.publicOutputType satisfies Provable<void>;
MyProgram.privateInputTypes;
MyProgram.auxiliaryOutputTypes;

console.log('program digest', await MyProgram.digest());

console.log('compiling MyProgram...');
let { verificationKey } = await MyProgram.compile();
console.log('verification key', verificationKey.data.slice(0, 10) + '..');

console.log('proving base case...');
let { proof } = await MyProgram.baseCase(0);
proof = await testJsonRoundtrip(MyProgram.Proof, proof);

// type sanity check
proof satisfies Proof<Field, void>;

console.log('verify...');
let ok = await verify(proof.toJSON(), verificationKey);
console.log('ok?', ok);

console.log('verify alternative...');
ok = await MyProgram.verify(proof);
console.log('ok (alternative)?', ok);

console.log('proving step 1...');
let { proof: proof1 } = await MyProgram.inductiveCase(1, proof);
proof1 = await testJsonRoundtrip(MyProgram.Proof, proof1);

console.log('verify...');
ok = await verify(proof1, verificationKey);
console.log('ok?', ok);

console.log('verify alternative...');
ok = await MyProgram.verify(proof1);
console.log('ok (alternative)?', ok);

console.log('proving step 2...');
let { proof: proof2 } = await MyProgram.inductiveCase(2, proof1);
proof2 = await testJsonRoundtrip(MyProgram.Proof, proof2);

console.log('verify...');
ok = await verify(proof2.toJSON(), verificationKey);

console.log('ok?', ok && proof2.publicInput.toString() === '2');

function testJsonRoundtrip<
  P extends Proof<any, any>,
  MyProof extends { fromJSON(jsonProof: JsonProof): Promise<P> }
>(MyProof: MyProof, proof: P) {
  let jsonProof = proof.toJSON();
  console.log(
    'json proof',
    JSON.stringify({
      ...jsonProof,
      proof: jsonProof.proof.slice(0, 10) + '..',
    })
  );
  return MyProof.fromJSON(jsonProof);
}