Identity checks today hand over your entire document when all they need is a single fact. StarkWare thinks there’s a better way.
The company has launched a demo of Private KYC on Starknet, using zero-knowledge STARK proofs to let users prove specific attributes — like being over 18 or holding valid credentials — without revealing their full passport or address.
“Whether you need to prove you’re over 18, hold a valid credential or meet an eligibility rule, verification should only confirm the precise fact,” StarkWare said. Corporations shouldn’t collect the full identity behind it, “because every identity database becomes a liability the moment it exists.”
Users scan their passport on their phone using the camera and NFC chip to confirm it’s genuine. They can then encrypt identity data to their Starknet wallet, register attributes in a public on-chain registry, and submit zero-knowledge proofs for selective checks. Verifiers confirm eligibility by reading the public registry without ever seeing the actual identity data.
The timing isn’t random. The US hit a record 3,322 data compromises in 2025, a 79% increase over five years. The global average cost of a data breach sits at $4.4 million. Healthcare alone saw over 1 billion records breached, with an average cost of $7.42 million.
StarkWare’s approach draws comparisons to Sam Altman’s World ID, which uses zk-proofs to verify humanness via iris scans. But World ID faced criticism over centralized biometric custody. StarkWare’s self-custody model aims to sidestep that problem entirely.
The system is live as a demo for now, but it points toward a future where proving who you are doesn’t mean handing over everything you are.
