A library to generate and verify Poseidon proofs.
This zero-knowledge library facilitates the demonstration of having a Poseidon 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. |
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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://snark-artifacts.pse.dev/poseidon/{version}/poseidon-{numberOfInputs}.wasm
- https://snark-artifacts.pse.dev/poseidon/{version}/poseidon-{numberOfInputs}.zkey
[!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 the @zk-kit/poseidon-proof
package:
npm i @zk-kit/poseidon-proof
or yarn:
yarn add @zk-kit/poseidon-proof
import { generate, verify } from "@zk-kit/poseidon-proof"
// A public value used to contextualize the cryptographic proof and calculate the nullifier.
const scope = "scope"
// The message (preimage) to prove (secret).
const messages = [1, 2]
// Generate the proof.
const fullProof = await generate(messages, scope)
/*
nb. scope, digest and nullifier are always the same - proof is variable.
{
scope: '2',
digest: '13713635907739611880977640264956372443229506353728466835599871320028961887800',
nullifier: '4995263610384888704435371233168916617325583088652670186865584118891394144999',
proof: [
'4344680442683455359115899095464919042642166233886432616638435348359080260980',
'20569010229031596977566212621532395450352277701036306316464269899598925981651',
'19318221594436336163085169568471746851468100277321435282188061183430353155289',
'13863222659316400652438453097923451250965656325472339120118358727133180331649',
'2718553541880998786976126630362604850217726344847462841516918030540821216281',
'11960084231774590415377471656397863783771599717615252119734899677642065267169',
'10666072962579546268534775428261696356732715643486735369393626224913301307278',
'4251217137130113647513155953595492143724626859298741948572817563032672674599'
]
}
*/
console.log(fullProof)
// If not specified, the Snark artifacts are downloaded automatically.
// You can specify them as follows.
// const fullProof = await generate(message, scope, {
// wasm: "<your-path>/poseidon-proof.wasm",
// zkey: "<your-path>/poseidon-proof.zkey"
// })
// Verify the proof.
const response = await verify(fullProof)
// true.
console.log(response)
// Eventually you may want to check the nullifier.
Benchmarks were run on an Intel Core i7-1165G7, 16 GB RAM machine (with two inputs).
Generate proof | Verify proof | Constraints |
---|---|---|
170ms |
12ms |
214 |
import { generate, verify } from "@zk-kit/poseidon-proof"
console.time("generate")
const proof = await generate([1, 2], "scope")
console.timeEnd("generate")
console.time("verify")
console.log(await verify(proof))
console.timeEnd("verify")