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 0x9e10a604594fe2be528a6bccdd66e9a01e77b29a66a1cccc8f0c009e02d72a20. Chain 2 (Bitcoin): anchored in block 953947 (2026-06-16T13:14:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/22d6ea85-b4ba-4120-82dd-3fc8b848170f.json and https://artists.proofprofile.net/proofs/artist/22d6ea85-b4ba-4120-82dd-3fc8b848170f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Ferrandini, G.B.: Catone in Utica [Opera]
Torri, P.: Baviera (La) / La Publica Felicita / Egloga Pastorale
Bach, J.S.: Tilge, Hochster, Meine Sunden / Keyboard Concerto, Bwv 974 / Languet Anima Mea
Haydn: Mass No. 3 in C Major, "Missa Cellensis"