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 0x0e9ef94faa2e08af8a61168734affba4240785f447618cd688de4b0c6db9b402. Chain 2 (Bitcoin): anchored in block 954058 (2026-06-17T06:34:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/453e1cd7-ce0e-4262-b512-4fd6b9a0fa22.json and https://artists.proofprofile.net/proofs/artist/453e1cd7-ce0e-4262-b512-4fd6b9a0fa22.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.