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 0xe0160c6373a5d6ba5e77a10278c5a643757d459b31470a83451c49255ccca93f. Chain 2 (Bitcoin): anchored in block 953660 (2026-06-14T17:20:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/53f7dec9-24c4-4b2f-9a48-db6d949ee1cb.json and https://artists.proofprofile.net/proofs/artist/53f7dec9-24c4-4b2f-9a48-db6d949ee1cb.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.