veil-zk

Zero-knowledge predicate proofs for Veil: prove age >= 18 or balance >= 100 over a numeric claim without revealing the value. The verifier learns only true or false.

A composite proof binds a BBS proof-of-knowledge to a Bulletproofs++ range proof (transparent, no trusted setup), so the bound is checked against the signed claim. Built on @docknetwork/crypto-wasm-ts; runs in Node and, with a WASM-aware bundler, in the browser.

npm install veil-zk veil-core

import { ZkAgeIssuer, ZkAgeProver, ZkAgeVerifier } from 'veil-zk';

const issuer = await ZkAgeIssuer.create();
const credential = await issuer.issue({ user_id: 'u1', age: 25 });
const ctx = { nonce: crypto.randomUUID(), audience: 'https://bar.example' };

const proof = await new ZkAgeProver().proveAgeAtLeast(credential, 18, ctx);
const ok = await new ZkAgeVerifier(issuer.publicKey).verifyAgeAtLeast(proof, 18, ctx); // true

For other claims use the generic ZkPredicateIssuer / ZkPredicateProver / ZkPredicateVerifier.

Status

Not production-ready; the cryptography has not been independently audited, and ciphersuite conformance/interop is unverified. See the repository and its SECURITY.md.

License

Apache-2.0