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 0x21fc0d8ab823db7ec221034c85a5854a192a31ca3854cc0cf9e6b261a7364b41. Chain 2 (Bitcoin): anchored in block 953625 (2026-06-14T11:37:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/27d0f235-6257-4f97-8557-4a16a42276d7.json and https://artists.proofprofile.net/proofs/artist/27d0f235-6257-4f97-8557-4a16a42276d7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Jesushernandez D.E.P. (Don Chuy de Lainfona)