ZK + OpenID4VP for EU Compliance: Privacy-First Age Verification
How zero-knowledge proofs and OpenID4VP enable GDPR-compliant age verification without collecting personal data
v0.7.0 · Age + Residency Proofs
Age verification without your ID.
States and countries are mandating age checks for websites, apps, and services. Most solutions ask you to upload a photo of your driver's license or passport — trading one privacy problem for a worse one. zk-id is the escape hatch: prove you're 18+ without revealing your name, birthday, or ID number. Only a cryptographic proof leaves your device.
Your data stays on your device. Only the proof leaves.
Why This Exists
Age‑verification laws are accelerating. The UK's Online Safety Act, state laws in Louisiana and Texas (plus many more), and incoming EU rules all push platforms to confirm users are adults. Compliance isn't optional, and the deadline pressure is real.
The default solution—uploading a government ID for a third‑party scan—creates a permanent record that links identity to browsing. The cure is worse than the disease. Centralized ID checks become honeypots: they're breached, subpoenaed, and sold.
zk‑id uses zero‑knowledge proofs so users can prove a fact ("I'm over 18," "I'm a US resident") without exposing the underlying data. Verifiers learn only what they asked for—nothing else. No name, no birthday, no ID scan, no persistent identifier. It's the least invasive way we know to comply with these laws.
The Wallet
zk-id Wallet
✓ Native iOS app (SwiftUI) — built and working
✓ Credentials stored only on your device
✓ ~300ms proof generation via hybrid rapidsnark
✓ OpenID4VP deep-link verification flow
TestFlight beta and Android support coming soon.
Screenshots coming soon
See It In Action
Demo video coming soon
Try the live playground instead
Add Age Verification in 3 Lines
// 1. Import the SDK
import { ZkIdClient } from '@zk-id/sdk';
// 2. Initialize and verify
const client = new ZkIdClient({
verificationEndpoint: 'https://your-verifier.com/verify'
});
await client.verifyAge(18);
// 3. That's it! 🎉Features
Selective Disclosure
Prove you're 18+ without revealing your exact birth year. Verify citizenship without exposing other attributes.
Browser-Based Proofs
Generate ZK proofs entirely in the browser using snarkjs. No server round-trips for proof generation.
Production-Ready Security
Groth16 ZK-SNARKs with trusted setup from Powers of Tau. Poseidon hash-based credentials.
TypeScript SDK
Simple integration with TypeScript SDK. RESTful API for verification from any language.
User-Controlled Revocation
Kill any credential from the wallet at any time. You issued it; you can revoke it. Verifiers see the credential as invalid immediately.
Quick Links
🚀 Quick Start
Interactive 4-step guide to issue credentials and generate proofs in under 5 minutes
🎮 Playground
Live sandbox for generating ZK proofs in your browser
📖 API Reference
Complete API documentation with TypeScript, Python, and Go examples
📚 Documentation
Architecture, protocol details, compliance, and deployment guides
Latest from the Blog
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Zero-knowledge identity verification for your stack
OpenID4VP
Standards-compliant verifiable presentations with W3C and DIF
Mobile SDK
Native iOS wallet (SwiftUI) — built and shipping. Cross-platform SDK planned.
REST API
Language-agnostic HTTP API for verification servers
US/EU Residency Proofs
Prove US or EU residency without revealing your specific country. The nationality-set-verify circuit supports up to 32 allowed nationality codes including all 27 EU member states.
EUDI Wallet
EU Digital Identity Wallet integration (Coming Q2 2026)
Digital Credentials API
Browser-native credential storage (Coming Q3 2026)