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 0xa05f1e4e2f34cff67f38e07255a380b6142cb8dc46b52118f361809943221344. Chain 2 (Bitcoin): anchored in block 954500 (2026-06-20T04:47:29Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9c095f5c-dd66-4fbf-83a6-917bb4caff0c.json and https://artists.proofprofile.net/proofs/artist/9c095f5c-dd66-4fbf-83a6-917bb4caff0c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Catedra Del Cante, Vol. 41: Niño De La Isla
Seguiriyas Cortas de la Isla y Cantes de la Bahía
Great Interpreters of Flamenco - Niño de la Isla, Fernando el Herrero, Niño Medina [1910 - 1928]