Prove.Without revealing.
Private identity verification powered by the EUDI Wallet and zero-knowledge proofs.
One process. Four steps.
From EUDI Wallet to on-chain proof in seconds.
1.Open your EUDI Wallet
Use an eIDAS 2.0 compliant EU Digital Identity Wallet.
2.Scan the QR code
Selective disclosure via OpenID4VP. ISO 18013-5 / SD-JWT signature, IACA trust chain.
3.Zero-knowledge proof
Groth16 circuit proving your attributes without revealing them.
4.Ethereum anchoring
Poseidon commitment anchored on-chain. Publicly verifiable forever.
The difference is invisible.
See what websites usually collect, and what Zykay actually reveals.
Stored data (PII)
High riskLast name
DUBOIS
First name
Sophie
Date of birth
15/03/1992
Place of birth
Lyon, France
Address
14 Rue de la République, 69002
Document no.
FRA-2024-0847291
Zero-knowledge proof
100% PrivateZero personal data transmitted.
Why trust us
Government signature
eIDAS 2.0 compliant. Member-state IACA trust chains. Every attribute is signed by its state-issued credential.
Groth16 proofs
BN254 curve, Hermez ceremony setup, and millisecond verification performance.
Ethereum anchoring
Poseidon commitments anchored on-chain for immutable public verification.
Zero PII storage
AES-256-GCM encrypted attributes. No raw identity data persisted.
Anti-Sybil
Per-partner Poseidon nullifiers with no cross-site identity correlation.
Open & Auditable
On-chain Groth16 verifier auditable on Etherscan. Publicly verifiable proofs.
Frequently asked questions
A zero-knowledge proof (ZKP) lets you prove a statement is true without revealing the underlying data. ZYKAY can prove that you are over 18 without exposing your date of birth.
No. Your identity attributes stay inside your EUDI Wallet on your phone. Selective disclosure (OpenID4VP + SD-JWT/mdoc) only transmits the attributes you approve, which are then converted into a cryptographic proof (booleans like isAdult: true) before reaching the partner. Personal data never leaves your device in the clear.
Ethereum provides an immutable public registry for proof commitments. Partners can verify proofs without relying on a central authority.
The European Digital Identity (EUDI) Wallet is the eIDAS 2.0 standard that lets every EU citizen store and share identity attributes from their smartphone. Each member state issues signed credentials (ISO 18013-5 mdoc or SD-JWT) anchored in the IACA trust chain. ZYKAY consumes these credentials via OpenID4VP — the state-issued signature guarantees authenticity, and our ZK circuit extracts only the attributes strictly requested.
Integration has two steps: launch the verification flow on the client and exchange the returned grant_code on your backend to fetch verification attributes.
Proofs are wallet-bound. If you switch wallets, you need to verify again. This prevents proof transfer between users.
Ready to verify without compromising privacy?
Join the next generation of digital identity: secure, private, and verifiable.