@semaphore-extensions/identity-proof

Semaphore Identity Proof

A library to prove the ownership of a Semaphore identity without revealing the private key.

🗣️ Chat & Support   |   📘 Docs

This zero-knowledge library allows you to prove and verify that you have the private key of a Semaphore identity. It will be mainly used on-chain because you can get the same result off-chain using EdDSA signatures with the @semaphore-protocol/identity package. It facilitates the demonstration of having an EdDSA hash pre-image while keeping the pre-image value confidential. Additionally, it offers a mechanism to prevent the same proof from being reused. The circuit that forms the foundation of this library is accessible via this link.

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

🛠 Install

Install the @semaphore-extensions/identity-proof package:

npm i @semaphore-extensions/identity-proof

or yarn:

yarn add @semaphore-extensions/identity-proof

📜 Usage

import { generate, verify } from "@semaphore-extensions/identity-proof"

// Your private key (secret) associated with your commitment.
const privateKey = "secret"
// A public value used to contextualize the cryptographic proof and calculate the nullifier.
const scope = "scope"

// Generate the proof.
const fullProof = await generate(privateKey, scope)

/*
    nb. commitment and scope are always the same - proof is variable.
{
    commitment: '21756852044673293804725356853298692762259855200429755225624171532449447776732',
    scope: '52191664570483756643537362991541193331102618014473399276861326740461293928448',
    proof: [
        '14987543977537638797613616391807211498102534775759297152458980015937921301475',
        '3399335485250714998192957632691923175498432819155620830553382340417897595836',
        '458847933923791518779258584891719351511628278818450523853640641455008133942',
        '9130558865745328382423837376229933835283742789420937388990076948167771186665',
        '2527867303822223913583586720705858457538165210401589969189198821632271648294',
        '870032122185130505849909299495220614500026484724112145131565329210361970548',
        '7499124546917660821334566902083675362480525785493429715971012094306224236446',
        '4681140599918274218600441523225984097742730174371377925026448119492671129895'
    ]
}

*/
console.log(fullProof)

// If not specified, the Snark artifacts are downloaded automatically.
// You can specify them as follows.

// const fullProof = await generate(privateKey, scope, {
//     wasm: "<your-path>/identity-proof.wasm",
//     zkey: "<your-path>/identity-proof.zkey"
// })

// Verify the proof.
const response = await verify(fullProof)

// true.
console.log(response)

📈 Benchmarks

Benchmarks were run on an Intel Core i7-1165G7, 16 GB RAM machine.

Generate proof	Verify proof	Constraints
258ms	15ms	1017

import { generate, verify } from "@semaphore-extensions/identity-proof"

console.time("generate")

const proof = await generate("secret", "scope")

console.timeEnd("generate")

console.time("verify")

console.log(await verify(proof))

console.timeEnd("verify")