Metz ( ; ; , then ) is a city in northeast France located at the confluence of the Moselle and the Seille rivers. Metz is the prefecture of the Moselle department and the seat of the parliament of 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 0xc9ec71252dcbfed9528db84c6186b65b81228d65a14762caae44132e0d497b73. Chain 2 (Bitcoin): anchored in block 954638 (2026-06-21T03:45:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d437f5b3-247b-46a1-8557-9c9f450f84e9.json and https://artists.proofprofile.net/proofs/artist/d437f5b3-247b-46a1-8557-9c9f450f84e9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).