Cassandre, pseudonym of Adolphe Jean-Marie Mouron Notice d'autorité personne : Cassandre, BnF, according to the international pseudonym convention described in the BnF authority file. (24 January 1901
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 0xfc3d02f71854f3b8b8346998f8fb1b95e31e59df1b2266e539212e5a521fdeac. Chain 2 (Bitcoin): anchored in block 954513 (2026-06-20T06:31:18Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9d0495fe-024f-493c-8724-d11c767f7c47.json and https://artists.proofprofile.net/proofs/artist/9d0495fe-024f-493c-8724-d11c767f7c47.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).