thumb|275px| Cumbia festivities Corporation, José Barros house in El Banco. José Benito Barros or simply José Barros (March 21, 1915 – May 12, 2007) was a Colombian musician and composer. He composed
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 0xfdc2a06efeeeb74c44ea76bcb569ff90284cf388d63998c9b42b8576517aa611. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/63a26149-ca09-4876-9677-daad1607d43b.json and https://artists.proofprofile.net/proofs/artist/63a26149-ca09-4876-9677-daad1607d43b.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.