Jacques Coursil (March 31, 1938 – June 26, 2020) was a French composer, jazz trumpeter, scholar, and professor of literature, linguistics, and philosophy. Early life Coursil was born in Paris, France
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 0x603ce62691f8b3d5663e99069142550e170473f1db2f978c61d1fbf7f82d6aea. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/90cbb3f9-6d1f-4f57-82e7-7fa0a3a7761b.json and https://artists.proofprofile.net/proofs/artist/90cbb3f9-6d1f-4f57-82e7-7fa0a3a7761b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).