@saurabhchalke/proof

Semaphore proof

A library to generate and verify Semaphore proofs.

👥 Contributing   |   🤝 Code of conduct   |   🔎 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 @saurabhchalke/proof package and its peer dependencies with npm:

npm i @semaphore-protocol/identity @semaphore-protocol/group @saurabhchalke/proof

or yarn:

yarn add @semaphore-protocol/identity @semaphore-protocol/group @saurabhchalke/proof

📜 Usage

# generateProof( identity: Identity, group: Group | MerkleProof, externalNullifier: BytesLike | Hexable | number | bigint, signal: BytesLike | Hexable | number | bigint, snarkArtifacts?: SnarkArtifacts ): Promise<SemaphoreProof>

import { Identity } from "@semaphore-protocol/identity"
import { Group } from "@semaphore-protocol/group"
import { generateProof } from "@saurabhchalke/proof"
import { utils } from "ethers"

const identity = new Identity()
const group = new Group()
const externalNullifier = utils.formatBytes32String("Topic")
const signal = utils.formatBytes32String("Hello world")

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

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

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

# verifyProof(semaphoreProof: SemaphoreProof, treeDepth: number): Promise<boolean>

import { verifyProof } from "@saurabhchalke/proof"

await verifyProof(fullProof, 20)

# calculateNullifierHash( identityNullifier: bigint | number | string, externalNullifier: _BytesLike | Hexable | number | bigint ): bigint

import { Identity } from "@semaphore-protocol/identity"
import { calculateNullifierHash } from "@saurabhchalke/proof"

const identity = new Identity()
const externalNullifier = utils.formatBytes32String("Topic")

const nullifierHash = calculateNullifierHash(identity.nullifier, externalNullifier)