Fully onchain ticketing with ZK proofs

The author, writing about ETHDenver ticketing, argues that fully onchain ticketing with zero-knowledge proofs can let event organizers check in attendees without learning their identity, as long as the ticket implies identity without requiring an integrity check of the ID. The author describes collecting a passport or ID at reception for large events, and says they were not asked for identification when collecting their ticket. In the proposed flow, attendees self-attest personal information onchain with a zk proof, include that attestation in the ticket payment transaction, and show the ticket's QR code at reception. The author notes this model does not verify whether a document is genuine, which would require solving the harder problem of identity issuance.