@vivianjeng/circuits

UniRep circuits package

Client library for circuit related functions which are used in UniRep protocol.

🤖 Chat & Support

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💡 About UniRep

UniRep is a private and non-repudiable data system. Users can receive attestations from attesters, and voluntarily prove facts about their data without revealing the data itself. Moreover, users cannot refuse to receive attestations from an attester.

📘 Documentation

Read the medium article to know more about the concept of UniRep protocol. For more information, refer to the documentation

🛠 Install

npm or yarn

Install the @unirep/circuits package with npm:

npm i @unirep/circuits

or yarn:

yarn add @unirep/circuits

📔 Usage

Prover

Build a prover for UniRep protocol

import * as snarkjs from 'snarkjs'
import { Circuit, Prover } from '@unirep/circuits'
import { SnarkProof, SnarkPublicSignals } from '@unirep/utils'

const buildPath = 'PATH/TO/CIRCUIT/FOLDER/'

const prover: Prover = {
    genProofAndPublicSignals: async (
        proofType: string | Circuit,
        inputs: any
    ): Promise<{
        proof: any,
        publicSignals: any
    }> => {
        const circuitWasmPath = buildPath + `${proofType}.wasm`
        const zkeyPath = buildPath + `${proofType}.zkey`
        const { proof, publicSignals } = await snarkjs.groth16.fullProve(
            inputs,
            circuitWasmPath,
            zkeyPath
        )

        return { proof, publicSignals }
    },

    verifyProof: async (
        name: string | Circuit,
        publicSignals: SnarkPublicSignals,
        proof: SnarkProof
    ): Promise<boolean> => {
        const vkey = require(buildPath +  `${name}.vkey.json`)
        return snarkjs.groth16.verify(vkey, publicSignals, proof)
    },
}

Generate proof and verify it with the above prover

import { Circuit } from '@unirep/circuits'

// See ./test/verifyEpochKey.test.ts for generating circuit inputs
const circuitInputs = {
    state_tree_elements: ...,
    state_tree_indexes: ...,
    ...
}
const { proof, publicSignals } = await prover.genProofAndPublicSignals(
    Circuit.epochKey,
    circuitInputs
)

const isValid = await prover.verifyProof(
    Circuit.epochKey,
    publicSignals,
    proof
)

Circom

Use the unirep circom circuits like so:

pragma circom 2.0.0;

include "PATH/TO/node_modules/@unirep/circuits/circuits/epochKey.circom";

template DataProof(STATE_TREE_DEPTH, EPOCH_KEY_NONCE_PER_EPOCH, FIELD_COUNT) {
    signal input state_tree_indexes[STATE_TREE_DEPTH];
    signal input state_tree_elements[STATE_TREE_DEPTH];
    signal input identity_secret;
    signal input data[FIELD_COUNT];
    signal input sig_data;
    signal input reveal_nonce;
    signal input attester_id;
    signal input epoch;
    signal input nonce;

    signal output epoch_key;
    signal output state_tree_root;    

    component epoch_key_template = EpochKey(STATE_TREE_DEPTH, EPOCH_KEY_NONCE_PER_EPOCH, FIELD_COUNT);
    for (var x = 0; x < STATE_TREE_DEPTH; x++) {
      epoch_key_template.state_tree_indexes[x] <== state_tree_indexes[x];
      epoch_key_template.state_tree_elements[x] <== state_tree_elements[x];
    }
    epoch_key_template.identity_secret <== identity_secret;
    epoch_key_template.reveal_nonce <== reveal_nonce;
    epoch_key_template.attester_id <== attester_id;
    epoch_key_template.epoch <== epoch;
    epoch_key_template.nonce <== nonce;
    epoch_key_template.sig_data <== sig_data;
    control <== epoch_key_template.control;
    epoch_key <== epoch_key_template.epoch_key;

    // add your customized circuits
    ...
}

Proof helpers

Proof helpers can help users query the public signals in each proof.

EpochKeyProof

import { EpochKeyProof } from '@unirep/circuits'

const { proof, publicSignals } = await prover.genProofAndPublicSignals(
    Circuit.epochKey,
    circuitInputs
)
const data = new EpochKeyProof(publicSignals, proof)
const epk = data.epochKey

SignupProof

import { SignupProof } from '@unirep/circuits'

const { proof, publicSignals } = await prover.genProofAndPublicSignals(
    Circuit.signup,
    circuitInputs
)
const data = new SignupProof(publicSignals, proof)
const idCommitment = data.identityCommitment

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Privacy & Scaling Explorations

This project is supported by Privacy & Scaling Explorations in Ethereum Foundation. See more projects on: https://appliedzkp.org/.