Skeleton

.eslintrc.js

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+module.exports = {
+    "plugins": [
+        "mocha"
+    ],
+    "env": {
+        "es6": true,
+        "node": true,
+        "mocha": true
+    },
+    "parserOptions": {
+        "ecmaVersion": 2017
+    },
+    "extends": "eslint:recommended",
+    "rules": {
+        "indent": [
+            "error",
+            4
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "quotes": [
+            "error",
+            "double"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ],
+        "mocha/no-exclusive-tests": "error"
+    }
+};

.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# 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
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://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/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+# next.js build output
+.next
+
+tmp

README

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+# javascript implementation of zkSnark
+
+This is a javascript implementation of zkSnarks.
+
+This library allows to do the trusted setup,  generate proofs and verify the proofs.
+
+This library uses the compiled circuits generated by the jaz compiler.
+
+## Install
+
+```
+npm install zkSnark
+```
+
+## Usage
+
+### import
+
+```
+const zkSnark = require("zksnark");
+```
+
+### Load a circuit.
+
+```
+// "myCircuit.cir" is the output of the jaz compiler
+
+const circuitDef = JSON.parse(fs.readFileSync("myCircuit.cir", "utf8"));
+const circuit = new zkSnark.Circuit(circuitDef);
+```
+
+### Inspect the circuit.
+
+```
+    // `signalId` can always be a number or an alias string
+
+    circuit.m; // number of constrains
+    circuit.n; // number of signals
+    circuit.p; // number of public signals (nPublicInputs + nOutputs)
+
+    // The array of signals is always sorted in this order:
+    // [ outputs, publicInputs, privedInputs, internalSignals, constants]
+
+    // returns a,b and c coeficients of the `signalId` on a given `constrain`
+    circuit.a(constrain, signalId)
+    circuit.b(constrain, signalId)
+    circuit.c(constrain, signalId)
+
+    circuit.nOutputs           // number of public outputs
+    circuit.nPublicInputs      // number of public inputs
+    circuit.nPrivateInputs     // number of private inputs
+    circuit.nInputs            // number of inputs ( nPublicInputs + nPrivateInputs)
+
+    circuit.outputIdx(i)       // returns the index of the i'th output
+    circuit.inputIdx(i)        // returns the index of the i'th input
+    circuit.inputPublicIdx(i)  // returns the index of the i'th public input
+    circuit.inputPrivateIdx(i) // returns the index of the i'th private input
+
+    // returns signal Idx given a signalId
+    // if the idx >= n , it is a constant
+    // if the idx == -1, the signal does not exist
+    circuit.signalId2idx(signalId);
+
+    // returns an array aliases names for a given signalId
+    circuit.signalNames(signalId)
+
+    // input is a key value object where keys are the signal names
+    //   of all the inputs (public and private)
+    // returns an array of values that represent the witness
+    circuit.generateWitness(input)
+```
+
+### Trusted setup
+
+```
+const setup = zkSnark.setup(circuit);
+fs.writeFileSink("myCircuit.vk_proof", JSON.stringify(setup.vk_proof), "utf8");
+fs.writeFileSink("myCircuit.vk_verifier", JSON.stringify(setup.vk_verifier), "utf8");
+setup.toxic  // Must be discarded.
+```
+
+### Generate proof
+
+```
+const circuitDef = JSON.parse(fs.readFileSync("myCircuit.cir", "utf8"));
+const circuit = new zkSnark.Circuit(circuitDef);
+const input = {
+    "main.pubIn1": "123",
+    "main.out1": "456"
+}
+const witness = circuit.generateWitness(input);
+const vk_proof = JSON.parse(fs.readFileSync("myCircuit.vk_proof", "utf8"));
+
+const {proof, publicSignals} = zkSnark.genProof(vk_proof, witness);
+```
+
+### Verifier
+
+```
+const vk_verifier = JSON.parse(fs.readFileSync("myCircuit.vk_verifier", "utf8"));
+
+if (zkSnark.isValid(vk_verifier, proof, publicSignals)) {
+    console.log("The proof is valid");
+} else {
+    console.log("The proof is not valid");
+}
+```

index.js

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+exports.Circuit = require "./src/circuit.js";
+exports.setup = require "./src/setup.js";
+exports.genProof = require "./src/prover.js";
+exports.isValid = require "./src/verifier.js";

package.json

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+{
+  "name": "zksnark",
+  "version": "0.0.1",
+  "description": "zkSnark implementation in javascript",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [
+    "zksnark",
+    "zcash",
+    "ethereum",
+    "zero",
+    "knowlage",
+    "cryptography",
+    "circuit"
+  ],
+  "author": "Jordi Baylina",
+  "license": "GPL-3.0",
+  "dependencies": {
+    "eslint": "^5.3.0"
+  },
+  "devDependencies": {
+    "eslint-plugin-mocha": "^5.1.0"
+  }
+}

src/circuit.js

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+
+module.exports = class Circuit {
+    constructor(circuitDef) {
+
+    }
+};

src/g1curve.js

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+const bigInt = require("big-integer");
+const ZnField = require("./znfield.js");
+
+module.eports = class G1Curve {
+
+    constructor() {
+        this.F = new ZnField(bigInt("21888242871839275222246405745257275088696311157297823662689037894645226208583"));
+        this.g = [
+
+        ];
+
+    }
+
+    add(p1, p2) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    double(p1) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    mulEscalar(p1, e) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+};

src/g2curve.js

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+const bigInt = require("big-integer");
+const ZnField = require("./znfield.js");
+
+module.eports = class G2Curve {
+
+    constructor() {
+        this.F = new ZnField(bigInt("21888242871839275222246405745257275088696311157297823662689037894645226208583"));
+        this.g = [
+
+        ];
+    }
+
+    add(p1, p2) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    double(p1) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    mulEscalar(p1, e) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+};

src/pairing.js

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+/*
+This module calculate the pairing of p1 and p2 where p1 in G1 and p2 in G2
+ */
+
+const bigInt = require("big-integer");
+
+module.exports = function pairing(p1, p2) {
+    // TODO
+    throw new Error("Not Implementted");
+};

src/polinomial.js

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+/*
+    This library do operations on polinomials where their coefficients are in field F
+
+    The polynomial P(x) = p0 + p1 * x + p2 * x^2 + p3 * x^3, ...
+    is represented by the array [ p0, p1, p2, p3, ...  ]
+ */
+
+class PolField {
+    constructor (F) {
+        this.F = F;
+    }
+
+    _reduce(a) {
+        let i = a.length-1;
+        while ((i>=0) && (this.F.isZero(a[i]))  ) i--;
+        return (i < a.length-1) ? a.slice(0, i+1) : a;
+    }
+
+    add(a, b) {
+        const maxGrade = Math.max(a.length, b.length);
+        const res = new Array(maxGrade);
+        for (let i=0; i<maxGrade; i++) {
+            res[i] = this.F.add(a[i], b[i]);
+        }
+        return this._reduce(res);
+    }
+
+    sub(a, b) {
+        throw new Error("Not Implementted");
+    }
+
+    mul(a, b) {
+        throw new Error("Not Implementted");
+    }
+
+    div(a, b) {
+        throw new Error("Not Implementted");
+    }
+
+    lagrange(points) {
+        throw new Error("Not Implementted");
+    }
+}
+
+
+module.exports = PolField;

src/prover.js

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+
+
+module.exports = function genProof(vk_proof, witness) {
+
+}

src/setup.js

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+
+
+module.exports = function setup(circuit) {
+
+}

src/verifier.js

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+
+module.exports = function isValid(vk_verifier, proof, publicSignals) {
+
+}

src/znfield.js

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+
+
+class ZnField {
+    constructor(n) {
+        this.n = n;
+    }
+
+    add(a, b) {
+        const maxGrade = Math.max(a.length, b.length);
+        const res = new Array(maxGrade);
+        for (let i=0; i<maxGrade; i++) {
+            res[i] = this.F.add(a[i], b[i]);
+        }
+        return this._reduce(res);
+    }
+
+    sub(a, b) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    mul(a, b) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    inverse(a, b) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+    div(a, b) {
+        // TODO
+        throw new Error("Not Implementted");
+    }
+
+}
+
+module.exports = ZnField;