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 0x479fecaff3ce30ecf9f52890bd0b33f943278b65de45ce2bc83b243e10da9cac. Chain 2 (Bitcoin): anchored in block 953947 (2026-06-16T13:14:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/229e8eac-1d13-454b-8b03-e0eff77c3f67.json and https://artists.proofprofile.net/proofs/artist/229e8eac-1d13-454b-8b03-e0eff77c3f67.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.