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 0x73ada0fe2eeda6fd370ef4d3454e48e5b61308bcd7820435e7aa4b387e66457e. 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/fa4d7614-3ef5-4f90-a04e-33ef8f9dfa30.json and https://artists.proofprofile.net/proofs/artist/fa4d7614-3ef5-4f90-a04e-33ef8f9dfa30.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Mozart: String Quintets, K. 593 & K. 614
Mozart: Clarinet Quintet, K. 581 / String Quintet, K. 515
Clarinet Quintet in A Major, K. 581: I. Allegro
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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 0x556702d87912e4547f570361f5506ecdef5ddbf2a259906fa3fb91b0b6d2edf0. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/HKI199505701.
Clarinet Quintet in A Major, K. 581: II. Larghetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd0a564f083948b6d612d75b38d9982d759054f271443d6020620d66452b35b72. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/HKI199505702.
Mozart: String Quintets, K. 174 and K. 515