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 0x434dbbf196cf5c7962e20e4de5758bbde3b0a8f851a59b711e5b08e62f030205. Chain 2 (Bitcoin): anchored in block 954115 (2026-06-17T15:44:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/78b86c90-3e52-42bc-83b8-cb43ade7d9c4.json and https://artists.proofprofile.net/proofs/artist/78b86c90-3e52-42bc-83b8-cb43ade7d9c4.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
F. Chopin: 4 Impromptus - F. Chopin: Piano Sonata No 3 in B Minor, Op. 58 - F. Chopin: Ballade No. 3 in a Flat Major, Op. 47 - F. Chopin: Scherzo No 2 in B-Flat Minor, Op. 31