Le Mans (; ) is a city in northwestern France on the Sarthe River where it meets the Huisne. Traditionally the capital of the province of Maine, it is now the capital of the Sarthe department and the
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 0xdd7fe1caa8f5037eef53888f583d61d3791c04b90f2b8201e942268a8e4e3f65. Chain 2 (Bitcoin): anchored in block 954533 (2026-06-20T08:57:02Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a716a9ce-ac46-4dcf-99f5-7d702efddfc5.json and https://artists.proofprofile.net/proofs/artist/a716a9ce-ac46-4dcf-99f5-7d702efddfc5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).