Initial commit

.gitignore

@@ -0,0 +1,117 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+
+# Next.js build output
+.next
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and *not* Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+node_modules
+.env
+coverage
+coverage.json
+typechain
+
+#Hardhat files
+cache
+artifacts
+deployments
+circuits/build
+*.ptau

README.md

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+# zkPuzzles
+
+Run `npm i` to install. 
+
+To compile the circuits, generate proofs, and test the contracts using the sample `input.json` locally, run
+
+```shell
+npm run test:fullProof
+```

circuits/input.json

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+{
+    "puzzle": [
+      ["1", "0", "0", "0", "0", "0", "0", "0", "0"],
+      ["0", "8", "0", "0", "0", "0", "0", "0", "0"],
+      ["0", "0", "6", "0", "0", "0", "0", "0", "0"],
+      ["0", "0", "0", "5", "0", "0", "0", "0", "0"],
+      ["0", "0", "0", "0", "3", "0", "0", "0", "0"],
+      ["0", "0", "0", "0", "0", "1", "0", "0", "0"],
+      ["0", "0", "0", "0", "0", "0", "9", "0", "0"],
+      ["0", "0", "0", "0", "0", "0", "0", "7", "0"],
+      ["0", "0", "0", "0", "0", "0", "0", "0", "5"]
+    ],
+    "solution": [
+      ["0", "7", "4", "2", "8", "5", "3", "9", "6"],
+      ["2", "0", "5", "3", "9", "6", "4", "1", "7"],
+      ["3", "9", "0", "4", "1", "7", "5", "2", "8"],
+      ["4", "1", "7", "0", "2", "8", "6", "3", "9"],
+      ["5", "2", "8", "6", "0", "9", "7", "4", "1"],
+      ["6", "3", "9", "7", "4", "0", "8", "5", "2"],
+      ["7", "4", "1", "8", "5", "2", "0", "6", "3"],
+      ["8", "5", "2", "9", "6", "3", "1", "0", "4"],
+      ["9", "6", "3", "1", "7", "4", "2", "8", "0"]
+    ]
+  }

circuits/sudoku.circom

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+pragma circom 2.0.3;
+
+include "../node_modules/circomlib-matrix/circuits/matAdd.circom";
+include "../node_modules/circomlib-matrix/circuits/matElemMul.circom";
+include "../node_modules/circomlib-matrix/circuits/matElemSum.circom";
+include "../node_modules/circomlib-matrix/circuits/matElemPow.circom";
+include "../node_modules/circomlib/circuits/poseidon.circom";
+
+template sudoku() {
+    signal input puzzle[9][9]; // 0  where blank
+    signal input solution[9][9]; // 0 where original puzzle is not blank
+    signal output out;
+
+    // check whether the solution is zero everywhere the puzzle has values (to avoid trick solution)
+
+    component mul = matElemMul(9,9);
+    
+    for (var i=0; i<9; i++) {
+        for (var j=0; j<9; j++) {
+            assert(puzzle[i][j]>=0);
+            assert(puzzle[i][j]<=9);
+            assert(solution[i][j]>=0);
+            assert(solution[i][j]<=9);
+            mul.a[i][j] <== puzzle[i][j];
+            mul.b[i][j] <== solution[i][j];
+        }
+    }
+    for (var i=0; i<9; i++) {
+        for (var j=0; j<9; j++) {
+            mul.out[i][j] === 0;
+        }
+    }
+
+    // sum up the two inputs to get full solution and square the full solution
+
+    component add = matAdd(9,9);
+    
+    for (var i=0; i<9; i++) {
+        for (var j=0; j<9; j++) {
+            add.a[i][j] <== puzzle[i][j];
+            add.b[i][j] <== solution[i][j];
+        }
+    }
+
+    component square = matElemPow(9,9,2);
+
+    for (var i=0; i<9; i++) {
+        for (var j=0; j<9; j++) {
+            square.a[i][j] <== add.out[i][j];
+        }
+    }
+
+    // check all rows and columns and blocks sum to 45 and sum of sqaures = 285
+
+    component row[9];
+    component col[9];
+    component block[9];
+    component rowSq[9];
+    component colSq[9];
+    component blockSq[9];
+
+
+    for (var k=0; k<9; k++) {
+        row[k] = matElemSum(1,9);
+        col[k] = matElemSum(1,9);
+        block[k] = matElemSum(3,3);
+
+        rowSq[k] = matElemSum(1,9);
+        colSq[k] = matElemSum(1,9);
+        blockSq[k] = matElemSum(3,3);
+
+        for (var i=0; i<9; i++) {
+            row[k].a[0][i] <== add.out[k][i];
+            col[k].a[0][i] <== add.out[i][k];
+
+            rowSq[k].a[0][i] <== square.out[k][i];
+            colSq[k].a[0][i] <== square.out[i][k];
+        }
+        var x = 3*(k%3);
+        var y = 3*(k\3);
+        for (var i=0; i<3; i++) {
+            for (var j=0; j<3; j++) {
+                block[k].a[i][j] <== add.out[x+i][y+j];
+                blockSq[k].a[i][j] <== square.out[x+i][y+j];
+            }
+        }
+        row[k].out === 45;
+        col[k].out === 45;
+        block[k].out === 45;
+
+        rowSq[k].out === 285;
+        colSq[k].out === 285;
+        blockSq[k].out === 285;
+    }
+
+    // hash the original puzzle and emit so that the dapp can listen for puzzle solved events
+
+    component poseidon[9];
+    component hash;
+
+    hash = Poseidon(9);
+    
+    for (var i=0; i<9; i++) {
+        poseidon[i] = Poseidon(9);
+        for (var j=0; j<9; j++) {
+            poseidon[i].inputs[j] <== puzzle[i][j];
+        }
+        hash.inputs[i] <== poseidon[i].out;
+    }
+
+    out <== hash.out;
+}
+
+component main = sudoku();

contracts/verifier.sol

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+//
+// Copyright 2017 Christian Reitwiessner
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+// 2019 OKIMS
+//      ported to solidity 0.6
+//      fixed linter warnings
+//      added requiere error messages
+//
+//
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity ^0.8.4;
+library Pairing {
+    struct G1Point {
+        uint X;
+        uint Y;
+    }
+    // Encoding of field elements is: X[0] * z + X[1]
+    struct G2Point {
+        uint[2] X;
+        uint[2] Y;
+    }
+    /// @return the generator of G1
+    function P1() internal pure returns (G1Point memory) {
+        return G1Point(1, 2);
+    }
+    /// @return the generator of G2
+    function P2() internal pure returns (G2Point memory) {
+        // Original code point
+        return G2Point(
+            [11559732032986387107991004021392285783925812861821192530917403151452391805634,
+             10857046999023057135944570762232829481370756359578518086990519993285655852781],
+            [4082367875863433681332203403145435568316851327593401208105741076214120093531,
+             8495653923123431417604973247489272438418190587263600148770280649306958101930]
+        );
+
+/*
+        // Changed by Jordi point
+        return G2Point(
+            [10857046999023057135944570762232829481370756359578518086990519993285655852781,
+             11559732032986387107991004021392285783925812861821192530917403151452391805634],
+            [8495653923123431417604973247489272438418190587263600148770280649306958101930,
+             4082367875863433681332203403145435568316851327593401208105741076214120093531]
+        );
+*/
+    }
+    /// @return r the negation of p, i.e. p.addition(p.negate()) should be zero.
+    function negate(G1Point memory p) internal pure returns (G1Point memory r) {
+        // The prime q in the base field F_q for G1
+        uint q = 21888242871839275222246405745257275088696311157297823662689037894645226208583;
+        if (p.X == 0 && p.Y == 0)
+            return G1Point(0, 0);
+        return G1Point(p.X, q - (p.Y % q));
+    }
+    /// @return r the sum of two points of G1
+    function addition(G1Point memory p1, G1Point memory p2) internal view returns (G1Point memory r) {
+        uint[4] memory input;
+        input[0] = p1.X;
+        input[1] = p1.Y;
+        input[2] = p2.X;
+        input[3] = p2.Y;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(sub(gas(), 2000), 6, input, 0xc0, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require(success,"pairing-add-failed");
+    }
+    /// @return r the product of a point on G1 and a scalar, i.e.
+    /// p == p.scalar_mul(1) and p.addition(p) == p.scalar_mul(2) for all points p.
+    function scalar_mul(G1Point memory p, uint s) internal view returns (G1Point memory r) {
+        uint[3] memory input;
+        input[0] = p.X;
+        input[1] = p.Y;
+        input[2] = s;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(sub(gas(), 2000), 7, input, 0x80, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require (success,"pairing-mul-failed");
+    }
+    /// @return the result of computing the pairing check
+    /// e(p1[0], p2[0]) *  .... * e(p1[n], p2[n]) == 1
+    /// For example pairing([P1(), P1().negate()], [P2(), P2()]) should
+    /// return true.
+    function pairing(G1Point[] memory p1, G2Point[] memory p2) internal view returns (bool) {
+        require(p1.length == p2.length,"pairing-lengths-failed");
+        uint elements = p1.length;
+        uint inputSize = elements * 6;
+        uint[] memory input = new uint[](inputSize);
+        for (uint i = 0; i < elements; i++)
+        {
+            input[i * 6 + 0] = p1[i].X;
+            input[i * 6 + 1] = p1[i].Y;
+            input[i * 6 + 2] = p2[i].X[0];
+            input[i * 6 + 3] = p2[i].X[1];
+            input[i * 6 + 4] = p2[i].Y[0];
+            input[i * 6 + 5] = p2[i].Y[1];
+        }
+        uint[1] memory out;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(sub(gas(), 2000), 8, add(input, 0x20), mul(inputSize, 0x20), out, 0x20)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require(success,"pairing-opcode-failed");
+        return out[0] != 0;
+    }
+    /// Convenience method for a pairing check for two pairs.
+    function pairingProd2(G1Point memory a1, G2Point memory a2, G1Point memory b1, G2Point memory b2) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](2);
+        G2Point[] memory p2 = new G2Point[](2);
+        p1[0] = a1;
+        p1[1] = b1;
+        p2[0] = a2;
+        p2[1] = b2;
+        return pairing(p1, p2);
+    }
+    /// Convenience method for a pairing check for three pairs.
+    function pairingProd3(
+            G1Point memory a1, G2Point memory a2,
+            G1Point memory b1, G2Point memory b2,
+            G1Point memory c1, G2Point memory c2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](3);
+        G2Point[] memory p2 = new G2Point[](3);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        return pairing(p1, p2);
+    }
+    /// Convenience method for a pairing check for four pairs.
+    function pairingProd4(
+            G1Point memory a1, G2Point memory a2,
+            G1Point memory b1, G2Point memory b2,
+            G1Point memory c1, G2Point memory c2,
+            G1Point memory d1, G2Point memory d2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](4);
+        G2Point[] memory p2 = new G2Point[](4);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p1[3] = d1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        p2[3] = d2;
+        return pairing(p1, p2);
+    }
+}
+contract Verifier {
+    using Pairing for *;
+    struct VerifyingKey {
+        Pairing.G1Point alfa1;
+        Pairing.G2Point beta2;
+        Pairing.G2Point gamma2;
+        Pairing.G2Point delta2;
+        Pairing.G1Point[] IC;
+    }
+    struct Proof {
+        Pairing.G1Point A;
+        Pairing.G2Point B;
+        Pairing.G1Point C;
+    }
+    function verifyingKey() internal pure returns (VerifyingKey memory vk) {
+        vk.alfa1 = Pairing.G1Point(
+            20491192805390485299153009773594534940189261866228447918068658471970481763042,
+            9383485363053290200918347156157836566562967994039712273449902621266178545958
+        );
+
+        vk.beta2 = Pairing.G2Point(
+            [4252822878758300859123897981450591353533073413197771768651442665752259397132,
+             6375614351688725206403948262868962793625744043794305715222011528459656738731],
+            [21847035105528745403288232691147584728191162732299865338377159692350059136679,
+             10505242626370262277552901082094356697409835680220590971873171140371331206856]
+        );
+        vk.gamma2 = Pairing.G2Point(
+            [11559732032986387107991004021392285783925812861821192530917403151452391805634,
+             10857046999023057135944570762232829481370756359578518086990519993285655852781],
+            [4082367875863433681332203403145435568316851327593401208105741076214120093531,
+             8495653923123431417604973247489272438418190587263600148770280649306958101930]
+        );
+        vk.delta2 = Pairing.G2Point(
+            [10515086783844107152789961699805167402839445155551290866755378361779597206636,
+             20478456925122158080847030251895987938966516050421151623379311617589944939390],
+            [5059157857734773241138674055892559481347493446864703000034272295347021788281,
+             14375011299792210542379807625683890344610459290324370915641446570290648004409]
+        );
+        vk.IC = new Pairing.G1Point[](2);
+        
+        vk.IC[0] = Pairing.G1Point( 
+            19246401383474815178724831592580205870572552563426897177365900472878611385139,
+            15806836004560695814718000473351994090404873219496981471859448532750920040149
+        );                                      
+        
+        vk.IC[1] = Pairing.G1Point( 
+            12657598428614834242888308785597800310795156498501122220767637608477504884849,
+            19622962299416559836650067051023594316951893502423743678057735721709394897276
+        );                                      
+        
+    }
+    function verify(uint[] memory input, Proof memory proof) internal view returns (uint) {
+        uint256 snark_scalar_field = 21888242871839275222246405745257275088548364400416034343698204186575808495617;
+        VerifyingKey memory vk = verifyingKey();
+        require(input.length + 1 == vk.IC.length,"verifier-bad-input");
+        // Compute the linear combination vk_x
+        Pairing.G1Point memory vk_x = Pairing.G1Point(0, 0);
+        for (uint i = 0; i < input.length; i++) {
+            require(input[i] < snark_scalar_field,"verifier-gte-snark-scalar-field");
+            vk_x = Pairing.addition(vk_x, Pairing.scalar_mul(vk.IC[i + 1], input[i]));
+        }
+        vk_x = Pairing.addition(vk_x, vk.IC[0]);
+        if (!Pairing.pairingProd4(
+            Pairing.negate(proof.A), proof.B,
+            vk.alfa1, vk.beta2,
+            vk_x, vk.gamma2,
+            proof.C, vk.delta2
+        )) return 1;
+        return 0;
+    }
+    /// @return r  bool true if proof is valid
+    function verifyProof(
+            uint[2] memory a,
+            uint[2][2] memory b,
+            uint[2] memory c,
+            uint[1] memory input
+        ) public view returns (bool r) {
+        Proof memory proof;
+        proof.A = Pairing.G1Point(a[0], a[1]);
+        proof.B = Pairing.G2Point([b[0][0], b[0][1]], [b[1][0], b[1][1]]);
+        proof.C = Pairing.G1Point(c[0], c[1]);
+        uint[] memory inputValues = new uint[](input.length);
+        for(uint i = 0; i < input.length; i++){
+            inputValues[i] = input[i];
+        }
+        if (verify(inputValues, proof) == 0) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

deploy/deploy.js

@@ -0,0 +1,10 @@
+module.exports = async ({ getNamedAccounts, deployments }) => {
+    const { deploy } = deployments;
+    const { deployer } = await getNamedAccounts();
+
+    await deploy('Verifier', {
+        from: deployer,
+        log: true
+    });
+};
+module.exports.tags = ['complete'];

hardhat.config.js

@@ -0,0 +1,47 @@
+require("@nomiclabs/hardhat-waffle");
+require("@nomiclabs/hardhat-ethers");
+require("hardhat-deploy");
+require("hardhat-contract-sizer");
+require("hardhat-gas-reporter");
+
+// Replace this private key with your Harmony account private key
+// To export your private key from Metamask, open Metamask and
+// go to Account Details > Export Private Key
+// Be aware of NEVER putting real Ether into testing accounts
+//const HARMONY_PRIVATE_KEY = "insert private key here";
+
+module.exports = {
+    solidity: {
+        version: "0.8.4",
+        optimizer: {
+            enabled: true,
+            runs: 200
+        }
+    },
+    networks: {
+        hardhat: {
+            gas: 100000000,
+            blockGasLimit: 0x1fffffffffffff
+        }/*,
+        testnet: {
+            url: "https://api.s0.b.hmny.io",
+            chainId: 1666700000,
+            accounts: [`${HARMONY_PRIVATE_KEY}`]
+        },
+        mainnet: {
+            url: "https://api.s0.t.hmny.io",
+            chainId: 1666600000,
+            accounts: [`${HARMONY_PRIVATE_KEY}`]
+        },*/
+    },
+    namedAccounts: {
+        deployer: 0,
+    },
+    paths: {
+        deploy: "deploy",
+        deployments: "deployments",
+    },
+    mocha: {
+        timeout: 1000000
+    }
+};

package.json

@@ -0,0 +1,44 @@
+{
+  "name": "zk-puzzles",
+  "version": "0.1.0",
+  "description": "Puzzles using ZKP",
+  "main": "index.js",
+  "scripts": {
+    "compile:contracts": "npx hardhat compile --force",
+    "develop": "npx hardhat node",
+    "deploy:localhost": "npx hardhat deploy --tags complete",
+    "test": "npx hardhat test",
+    "compile:circuits": "bash scripts/compile-circuits.sh",
+    "version:fix": "node scripts/bump-solidity",
+    "generate:proof": "bash scripts/generate-proof.sh",
+    "setup:circom": "bash scripts/setup-circom.sh",
+    "test:fullProof": "npm run compile:circuits && npm run version:fix && npm run generate:proof && npm run compile:contracts && npx hardhat test"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/socathie/zkPuzzles.git"
+  },
+  "author": "Cathie So, PhD",
+  "license": "GPL-3.0",
+  "bugs": {
+    "url": "https://github.com/socathie/zkPuzzles/issues"
+  },
+  "homepage": "https://github.com/socathie/zkPuzzles#readme",
+  "devDependencies": {
+    "@nomiclabs/hardhat-ethers": "^2.0.5",
+    "@nomiclabs/hardhat-waffle": "^2.0.3",
+    "chai": "^4.3.6",
+    "circom_tester": "^0.0.10",
+    "circomlib": "^2.0.2",
+    "circomlib-matrix": "^1.0.0",
+    "circomlibjs": "^0.1.1",
+    "ethereum-waffle": "^3.4.0",
+    "ethers": "^5.6.1",
+    "hardhat": "^2.9.1",
+    "hardhat-contract-sizer": "^2.4.0",
+    "hardhat-deploy": "^0.10.6",
+    "hardhat-gas-reporter": "^1.0.7",
+    "snarkjs": "^0.4.13",
+    "web3-utils": "^1.7.0"
+  }
+}

scripts/bump-solidity.js

@@ -0,0 +1,7 @@
+const fs = require("fs");
+const solidityRegex = /pragma solidity \^\d+\.\d+\.\d+/
+
+let content = fs.readFileSync("./contracts/verifier.sol", { encoding: 'utf-8' });
+let bumped = content.replace(solidityRegex, 'pragma solidity ^0.8.4');
+
+fs.writeFileSync("./contracts/verifier.sol", bumped);

scripts/compile-circuits.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+#export NODE_OPTIONS="--max-old-space-size=16384"
+
+cd circuits
+mkdir -p build
+
+if [ -f ./powersOfTau28_hez_final_14.ptau ]; then
+    echo "powersOfTau28_hez_final_14.ptau already exists. Skipping."
+else
+    echo 'Downloading powersOfTau28_hez_final_14.ptau'
+    wget https://hermez.s3-eu-west-1.amazonaws.com/powersOfTau28_hez_final_14.ptau
+fi
+
+echo "Compiling: sudoku..."
+
+mkdir -p build/sudoku
+
+# compile circuit
+
+if [ -f ./build/sudoku.r1cs ]; then
+    echo "Circuit already compiled. Skipping."
+else
+    circom sudoku.circom --r1cs --wasm --sym -o build
+    snarkjs r1cs info build/sudoku.r1cs
+fi
+
+# Start a new zkey and make a contribution
+
+if [ -f ./build/sudoku/verification_key.json ]; then
+    echo "verification_key.json already exists. Skipping."
+else
+    snarkjs groth16 setup build/sudoku.r1cs powersOfTau28_hez_final_14.ptau build/sudoku/circuit_0000.zkey
+    snarkjs zkey contribute build/sudoku/circuit_0000.zkey build/sudoku/circuit_final.zkey --name="1st Contributor Name" -v -e="random text"
+    snarkjs zkey export verificationkey build/sudoku/circuit_final.zkey build/sudoku/verification_key.json
+fi
+
+# generate solidity contract
+snarkjs zkey export solidityverifier build/sudoku/circuit_final.zkey ../contracts/verifier.sol

scripts/generate-proof.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+cd circuits
+mkdir -p build
+
+mkdir -p build/sudoku
+
+# generate witness
+node "build/sudoku_js/generate_witness.js" build/sudoku_js/sudoku.wasm input.json build/sudoku/witness.wtns
+        
+# generate proof
+snarkjs groth16 prove build/sudoku/circuit_final.zkey build/sudoku/witness.wtns build/sudoku/proof.json build/sudoku/public.json
+
+# verify proof
+snarkjs groth16 verify build/sudoku/verification_key.json build/sudoku/public.json build/sudoku/proof.json
+
+# generate call
+snarkjs zkey export soliditycalldata build/sudoku/public.json build/sudoku/proof.json > build/sudoku/call.json

scripts/setup-circom.sh

@@ -0,0 +1,10 @@
+curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sh
+
+git clone https://github.com/iden3/circom.git
+
+cd circom
+
+cargo build --release
+cargo install --path circom
+
+npm install -g snarkjs@latest

test/sudoku.js

@@ -0,0 +1,94 @@
+const chai = require("chai");
+
+const wasm_tester = require("circom_tester").wasm;
+
+const F1Field = require("ffjavascript").F1Field;
+const Scalar = require("ffjavascript").Scalar;
+exports.p = Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617");
+const Fr = new F1Field(exports.p);
+
+const assert = chai.assert;
+
+describe("Sudoku circuit test", function () {
+  this.timeout(100000000);
+
+  it("Should fail for invalid solution", async () => {
+    const circuit = await wasm_tester("circuits/sudoku.circom");
+    await circuit.loadConstraints();
+    assert.equal(circuit.nVars, 4372);
+    assert.equal(circuit.constraints.length, 4332);
+
+    const INPUT = {
+      "puzzle": [
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "0"]
+      ],
+      "solution": [
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"],
+        ["5", "5", "5", "5", "5", "5", "5", "5", "5"]
+      ]
+    }
+
+    const witness = await circuit.calculateWitness(INPUT, true)
+      .catch((error) => {
+        errorString = error.toString();
+      });
+
+    //console.log(errorString);
+
+    assert(errorString=="Error: Error: Assert Failed. Error in template sudoku_79 line: 91");
+  });
+
+  it("Should compute correct solution", async () => {
+    const circuit = await wasm_tester("circuits/sudoku.circom");
+    await circuit.loadConstraints();
+    assert.equal(circuit.nVars, 4372);
+    assert.equal(circuit.constraints.length, 4332);
+
+    const INPUT = {
+      "puzzle": [
+        ["1", "0", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "8", "0", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "6", "0", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "5", "0", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "3", "0", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "1", "0", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "9", "0", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "7", "0"],
+        ["0", "0", "0", "0", "0", "0", "0", "0", "5"]
+      ],
+      "solution": [
+        ["0", "7", "4", "2", "8", "5", "3", "9", "6"],
+        ["2", "0", "5", "3", "9", "6", "4", "1", "7"],
+        ["3", "9", "0", "4", "1", "7", "5", "2", "8"],
+        ["4", "1", "7", "0", "2", "8", "6", "3", "9"],
+        ["5", "2", "8", "6", "0", "9", "7", "4", "1"],
+        ["6", "3", "9", "7", "4", "0", "8", "5", "2"],
+        ["7", "4", "1", "8", "5", "2", "0", "6", "3"],
+        ["8", "5", "2", "9", "6", "3", "1", "0", "4"],
+        ["9", "6", "3", "1", "7", "4", "2", "8", "0"]
+      ]
+    }
+
+    const witness = await circuit.calculateWitness(INPUT, true)
+
+    //console.log(witness);
+
+    assert(Fr.eq(Fr.e(witness[0]),Fr.e(1)));
+    assert(Fr.eq(Fr.e(witness[1]),Fr.e('14859242797732307376594647282705218440328040987055989295014298721628438034438')));
+  });
+});

test/verifier.js

@@ -0,0 +1,26 @@
+const { expect } = require("chai");
+const { ethers } = require("hardhat");
+const fs = require("fs");
+
+describe("Verifier Contract", function () {
+    let Verifier;
+    let verifier;
+
+    beforeEach(async function () {
+        Verifier = await ethers.getContractFactory("Verifier");
+        verifier = await Verifier.deploy();
+        await verifier.deployed();
+    });
+
+    it("Should return true for correct proofs", async function () {
+        var array = JSON.parse("[" + fs.readFileSync("./circuits/build/sudoku/call.json") + "]");
+        expect(await verifier.verifyProof(array[0], array[1], array[2], array[3])).to.be.true;
+    });
+    it("Should return false for invalid proof", async function () {
+        let a = [0, 0];
+        let b = [[0, 0], [0, 0]];
+        let c = [0, 0];
+        let d = [0];
+        expect(await verifier.verifyProof(a, b, c, d)).to.be.false;
+    });
+});