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 0xdbf4ad88035e0f1ad9161a8583b3f9a289d45bf3f1117221ff552052a3ec93b8. Chain 2 (Bitcoin): anchored in block 953697 (2026-06-14T21:49:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/50cb7354-fd23-4da1-aa4f-345ab59334ba.json and https://artists.proofprofile.net/proofs/artist/50cb7354-fd23-4da1-aa4f-345ab59334ba.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Hindemith, Honegger: String Quartet Nos. 2 & 3
String Quartet No. 6 / String Quartet No. 3
Tchaikovsky: String Quartet No. 1 - Borodin: String Quartet No. 2
Tchaikovsky: String Quartet No. 1 in D major, Op.11, Borodin: String Quartet No. 2 in D major