1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcaf0d90633f9c5abcc5ac6bde33d1c13c007cfc2689f89526a41c3d23b13b5bc. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ebe9e51a-c593-4325-884e-7eb89125d8af.json and https://artists.proofprofile.net/proofs/artist/ebe9e51a-c593-4325-884e-7eb89125d8af.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.