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 0x317cc82d45230585678d3fea135274ce175904619bad5b8baff32128fb944700. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9431b755-6f5a-402a-8763-5a53b3712073.json and https://artists.proofprofile.net/proofs/artist/9431b755-6f5a-402a-8763-5a53b3712073.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Laks: Divertimento, Wind Concertino, Passacaille, String Quartet No. 4, Piano Quintet & Sonatina
Fitelberg: String Quartets Nos. 1 and 2, Serenade, Sonatine & Nachtmusik
Robert Müller-Hartmann: String Quartet No. 2, Op. 38 II. Vivace e scherzando
Hemsi: Three Ancient Airs, from the Coplas Sefardies, Op. 30: I. Ballata