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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ef05d0054aee69aaca3cc206471f799d45e2c36fa32851d67a0430b5ca19f64. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c451194c-c6d5-4bbd-a166-b835560cc0f3.json and https://artists.proofprofile.net/proofs/artist/c451194c-c6d5-4bbd-a166-b835560cc0f3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Ammerbach: Harpsichord Works From the Tabulaturbuch (1571)
Richardson: Complete Works for Harpsichord
Cavazzoni: Complete Works – Italian Ricercars
Harpsichord Works Published by Pierre Attaingnant