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 0x9d42a1b8dcf0f7c3bf5ca26cbfb6052216e29f3967418d02737a8873d21cfa49. Chain 2 (Bitcoin): anchored in block 954638 (2026-06-21T03:45:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d3c96a28-21c3-4e9c-aa71-6bf3eae010c2.json and https://artists.proofprofile.net/proofs/artist/d3c96a28-21c3-4e9c-aa71-6bf3eae010c2.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Shostakovich & Schubert: String Quartets
Gerald Resch: String Quartet No. 3 - Beethoven: String Quartet No. 7, Op. 59 No. 1