Verifiable JS

JavaScript/TypeScript WebAssembly bindings for the Parity Verifiable crate.

Anonymous membership proofs using ring VRFs on the Bandersnatch elliptic curve. Prove you belong to a group without revealing which member you are.

Full documentation, API reference, and examples: github.com/paritytech/verifiablejs

Installation

npm install verifiablejs

Quick Start

import { encode_members, member_from_entropy, one_shot, validate, validate_with_commitment } from 'verifiablejs/nodejs'
// or 'verifiablejs/bundler' for browsers

// Create a ring of members
const members = []
for (let i = 0; i < 10; i++) {
  members.push(member_from_entropy(new Uint8Array(32).fill(i)))
}
const encodedMembers = encode_members(members) // SCALE-encode Vec<Member>

// Create an anonymous ring proof
const entropy = new Uint8Array(32).fill(5)
const context = new TextEncoder().encode('my-app')
const message = new TextEncoder().encode('hello')

const RING_EXPONENT = 9 // R2e9 — capacity 255 (also: 10 → 767, 14 → 16,127)
const result = one_shot(RING_EXPONENT, entropy, encodedMembers, context, message)

// Verify the proof from the raw member list
const alias = validate(RING_EXPONENT, result.proof, encodedMembers, context, message)

// Recommended pre-flight before any on-chain submission: validate against the
// 288-byte ring root (MembersCommitment) the chain exposes, rather than the
// full member list. Catches proof/ring/message mismatches locally.
// const ringRoot = /* 288 bytes fetched via RPC */
// const alias = validate_with_commitment(RING_EXPONENT, result.proof, ringRoot, context, message)

Tip: validate rebuilds the ring commitment on every call, which is the expensive part of verification. If you already have the finalized commitment — e.g. fetched from pallet-members on chain — use validate_with_commitment instead. See the full docs for details.

API Overview

| Function | Description | | -------------------------- | --------------------------------------------------- | | member_from_entropy | Derive a public key from entropy | | is_member_valid | Check if a public key is valid | | encode_members | SCALE-encode Member[] → Vec<Member> | | one_shot | Create an anonymous ring proof | | validate | Validate a proof from the member list | | validate_with_commitment | Validate against a pre-built commitment (preferred) | | is_valid | Check proof validity with known alias | | batch_validate | Validate multiple proofs efficiently | | alias_in_context | Compute alias without a proof | | sign | Non-anonymous message signature | | verify_signature | Verify a signature | | members_root | Compute ring commitment (288 bytes) | | members_intermediate | Compute intermediate state (848 bytes) |

All ring functions require a ring_exponent parameter matching the on-chain RingExponent: 9 (R2e9, ~255 members), 10 (R2e10, ~767), or 14 (R2e14, ~16,127).

License

GPL-3.0-or-later WITH Classpath-exception-2.0