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 0xb647126a62f7f91ccabbaa218810e5638ef8e8baba7670f8ce5d5f779c9b543f. Chain 2 (Bitcoin): anchored in block 953618 (2026-06-14T09:16:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1cf1b22e-f4c7-4372-afda-fdcdb2b43dab.json and https://artists.proofprofile.net/proofs/artist/1cf1b22e-f4c7-4372-afda-fdcdb2b43dab.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.