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 0xeeb22a5ee3f0dbd3c50eb818ea2520f1335e4cbe75ed55eb06d6ac6783aeaa61. Chain 2 (Bitcoin): anchored in block 954693 (2026-06-21T11:50:32Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e6008842-1615-4dd4-b443-851f6451b3f3.json and https://artists.proofprofile.net/proofs/artist/e6008842-1615-4dd4-b443-851f6451b3f3.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Landes (Bande originale du film de François-Xavier Vives)
Pop Redemption (Bande originale du film)
Wara (Bande originale de la série télévisée)
Les engagés - Saisons 1 & 2 (Bande originale de la série)
Les engagés - XAOC (Bande originale de la série télévisée)
Science grand format : Voyage sur les flots célestes - Les cartographes de l'univers (Bande originale du film)