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 0x16bc4d0e9d52d4194ce39f5813d68241bf7b2b48f59e8cdcc0f7c8117af78740. Chain 2 (Bitcoin): anchored in block 954659 (2026-06-21T06:14:42Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/dce1d45c-657c-4916-8752-8a0c6d67987b.json and https://artists.proofprofile.net/proofs/artist/dce1d45c-657c-4916-8752-8a0c6d67987b.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.