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 0x16a4cb6c7f73331a603f23beabc283e1f7631f7ea78d839e6302ab4ced8a9d05. Chain 2 (Bitcoin): anchored in block 953875 (2026-06-16T02:12:46Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/080e6557-0298-4068-a99b-b15f3d4db657.json and https://artists.proofprofile.net/proofs/artist/080e6557-0298-4068-a99b-b15f3d4db657.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.