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 0x895d9471bd92a03052df94f7b23ecabccb6212abbcbc5aeb2ae5c279558474cc. Chain 2 (Bitcoin): anchored in block 953657 (2026-06-14T16:43:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4d954891-982d-48e8-97ae-7a10cfb9a0b1.json and https://artists.proofprofile.net/proofs/artist/4d954891-982d-48e8-97ae-7a10cfb9a0b1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Tchaikovsky, P.I.: Piano Trio, Op. 50 / Arensky, A.S.: Piano Trio No. 1 (The Rembrandt Trio)
Brahms, J.: Piano Trio No. 1 / Dvorak, A.: Piano Trio No. 4, "Dumky" (The Rembrandt Trio)
Chaminade, C.: Piano Trio No. 1 / Saint-Saens, C.: Piano Trio No. 1 / Ravel, M.: Piano Trio in A Minor (The Rembrandt)
Chamber Music - Brahms, J. / Schumann, R. / Dvorak, A. / Suk, J. / Kreisler, F. / Grieg, E. / Liszt, F. (Salon Classics) (The Rembrandt Trio)
Mendelssohn, Felix: Piano Trio No. 1 / Schubert, F.: Piano Trio No. 1