@webb-tools/semaphore-proof

Semaphore proof

A library to generate and verify Semaphore proofs.

👥 Contributing   |   🔎 Issues 🗣️ Chat & Support

This library provides utility functions to generate and verify Semaphore proofs compatible with the Semaphore circuits. Generating valid zero-knowledge proofs requires files that can only be obtained in an attested trusted-setup ceremony. For a complete list of ready-to-use files visit trusted-setup-pse.org.

🛠 Install

npm or yarn

Install the @webb-tools/semaphore-proof package and its peer dependencies with npm:

npm i @webb-tools/semaphore-identity @webb-tools/semaphore-group @webb-tools/semaphore-proof

or yarn:

yarn add @webb-tools/semaphore-identity @webb-tools/semaphore-group @webb-tools/semaphore-proof

📜 Usage

# generateProof(identity: Identity, group: Group, externalNullifier: BigNumberish, signal: string, snarkArtifacts?: SnarkArtifacts): Promise<SemaphoreFullProof>

import { Identity } from "@webb-tools/semaphore-identity"
import { Group } from "@webb-tools/semaphore-group"
import { generateProof } from "@webb-tools/semaphore-proof"

const identity = new Identity()
const group = new Group()
const externalNullifier = BigInt(1)
const signal = "Hello world"

group.addMembers([...identityCommitments, identity.generateCommitment()])

const fullProof = await generateProof(
    identity,
    merkleProof,
    externalNullifier,
    signal,
    {
        zkeyFilePath: "./semaphore.zkey",
        wasmFilePath: "./semaphore.wasm"
    }
)

// You can also use the default zkey/wasm files (only for browsers!).
// const fullProof = await generateProof(identity, merkleProof, externalNullifier, signal)

# verifyProof(verificationKey: any, fullProof: FullProof): Promise<boolean>

import { verifyProof } from "@webb-tools/semaphore-proof"

const verificationKey = JSON.parse(fs.readFileSync("/semaphore.json", "utf-8"))

await verifyProof(verificationKey, fullProof)

# packToSolidityProof(proof: Proof): SolidityProof

import { packToSolidityProof } from "@webb-tools/semaphore-proof"

const solidityProof = packToSolidityProof(fullProof.proof)

# generateNullifierHash(externalNullifier: BigNumberish, identityNullifier: BigNumberish): bigint

import { generateNullifierHash } from "@webb-tools/semaphore-proof"

const nullifierHash = generateNullifierHash(
    externalNullifier,
    identity.getNullifier()
)

# generateSignalHash(signal: string): bigint

import { generateSignalHash } from "@webb-tools/semaphore-proof"

const signalHash = generateSignalHash(signal)