johnson86tw

describe("ZK", function () {
  it("should process", async () => {
    const secret = 42;
    const input = { secret };
    const output = secret * secret + 6;
    const publicSignals = [BigInt(output)];

    let { proof } = await groth16.fullProve(input, wasmPath, zkeyPath);
    const calldata = await groth16.exportSolidityCallData(unstringifyBigInts(proof), publicSignals);
    const args = JSON.parse("[" + calldata + "]");

johnson86tw

interface IVerifier {
    function verifyProof(
        uint256[2] memory a,
        uint256[2][2] memory b,
        uint256[2] memory c,
        uint256[1] memory input // publicSignals
    ) external view returns (bool r);
}

contract ZK {

johnson86tw

template Square() {
    signal input in;
    signal output out;

    out <== in * in;
}

template Add() {
    signal input in;
    signal output out;

johnson86tw

contract WithoutZK {
  string greeting = "hello world";
  uint256 answer = 1770;

  function greet() public view returns (string memory) {
    return greeting;
  }

  function _setGreeting(string memory _greeting) internal {
    greeting = _greeting;

johnson86tw

...
 proof(indexOfLeaf: number) {
    let pathElements: string[] = [];
    let pathIndices: number[] = [];
    const leaf = this.storage.get(MerkleTree.indexToKey(0, indexOfLeaf));
    if (!leaf) throw new Error("leaf not found");
    // store sibling into pathElements and target's indices into pathIndices
    const handleIndex = (level: number, currentIndex: number, siblingIndex: number) => {
      const siblingValue = this.storage.get(MerkleTree.indexToKey(level, siblingIndex)) || this.zeros[level];
      pathElements.push(siblingValue);

johnson86tw

const circomlib = require("circomlib");
const mimcsponge = circomlib.mimcsponge;
export function MiMCSponge(left: string, right: string): string {
  return mimcsponge.multiHash([BigInt(left), BigInt(right)]).toString();
}
export interface IMerkleTree {
  root: () => string;
  proof: (index: number) => {
    root: string;
    pathElements: string[];

johnson86tw

proof = {
    root: "117086588437903260255921638146322982",
    pathElements: [
    '40',
    '1978699832413026196628606142134435304247'
    ],
    pathIndices: [ 0, 1 ],
    leaf: '30'
}

johnson86tw

// prover
const levels = 2;
const leaves = [10, 20 ,30 ,40];
const tree = new MerkleTree(levels, leaves);
const index = 2;
const proof = tree.proof(index);
// verifier
const root = "117086588437903260255921638146322982"
console.log(verify(proof, root)); // true

johnson86tw

const circomlib = require("circomlib");
const mimcsponge = circomlib.mimcsponge;

export function MiMCSponge(left: string, right: string): string {
  return mimcsponge.multiHash([BigInt(left), BigInt(right)]).toString();
}

export interface IMerkleTree {
  root: () => string;
  proof: (index: number) => {

johnson86tw

pragma solidity ^0.7.0;

// 這是一個叫做 Token 的合約
contract Token {

    // 貨幣的名稱叫做...
    string public name = "My Awesome Token";
    
    // 貨幣的代號是...
    string public symbol = "MAT";