@zk-kit/poseidon-proof v1.0.0-beta.3

Originally developed for integration with Semaphore V4, this library also functions effectively as a standalone tool. Notable use cases in connection with Semaphore can be:

• allowing a Semaphore user to prove that they possess the secret value associated with the identity commitment of their Semaphore identity,
• unmasking the identity of zero-knowledge proofs earlier created using Semaphore.

The Snark artifacts (.wasm and .zkey files) can be specified or not in the generate function parameters and can possibly be downloaded using the following URLs:

https://github.com/privacy-scaling-explorations/zk-kit/blob/ee457299d36d2601e5bf520237977a9f16b1b599/packages/poseidon-proof/src/config.ts#L5-L8

!WARNING
The Snark artifacts currently used to generate zero-knowledge proofs are the result of an unsecure trusted setup, and the library has not yet been audited. Therefore, it is advised not to use it in production.

🛠 Install

npm or yarn

Install the @zk-kit/poseidon-proof package:

npm i @zk-kit/poseidon-proof

or yarn:

yarn add @zk-kit/poseidon-proof

📜 Usage

# generate( message: BigNumberish, scope: BigNumberish, snarkArtifacts?: SnarkArtifacts ): Promise\<PoseidonProof>

import { generate } from "@zk-kit/poseidon-proof"

const scope = 1
const message = 2

const fullProof = await generate(message, scope)

// If not specified, the Snark artifacts are downloaded automatically.
// You can also specify them.
const fullProof = await generate(message, scope, {
    zkeyFilePath: "./poseidon-proof.zkey",
    wasmFilePath: "./poseidon-proof.wasm"
})

console.log(fullProof)
/*
{
    scope: '1',
    hash: '8645981980787649023086883978738420856660271013038108762834452721572614684349',
    nullifier: '7853200120776062878684798364095072458815029376092732009249414926327459813530',
    proof: [
        '8439157877715136449451128027974582198942685548176158240742469858289217640295',
        '7742778415084033741154475792823260193410560424636243716622958831215275441500',
        '19005176609208302398813682947612978224483117018101271134113308439452561466691',
        '6209272538382784759793219866517186573065390524051102537220446165983489601194',
        '12222537243697573476419214640884921904066033266502734603198915705889607365883',
        '20066191345466355816238393590466176790809335456890624395337970890893401456064',
        '4851746896803117511000878727783002155680855098198108089136166702412365578625',
        '18391775232946751568173446051923718267369779168471637305003186214102154164036'
    ]
}
*/

# verify(poseidonProof: PoseidonProof): Promise\<boolean>

import { verify } from "@zk-key/poseidon-proof"

const response = await verifyProof(fullProof)

console.log(response) // true or false

// Eventually you may want to check the nullifier.

📈 Benchmarks

Benchmarks were run on an Intel Core i7-1165G7, 16 GB RAM machine, after initializing the BN128 curve with @zk-kit/groth16-buildBn128 (~230ms).

import { generate, verify } from "@zk-kit/poseidon-proof"
import { buildBn128 } from "@zk-kit/groth16"

await buildBn128()

console.time("generate")

const proof = await generate(1, 2)

console.timeEnd("generate")

console.time("verify")

console.log(await verify(proof))

console.timeEnd("verify")