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 0x2286f5a17d7c53c8fbb807a33db7652acf0a0a003c57396168d23c14eefa65b1. Chain 2 (Bitcoin): anchored in block 954647 (2026-06-21T04:36:58Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d7ba6cf0-e4e2-4bfd-9ce2-d3ff018ccde6.json and https://artists.proofprofile.net/proofs/artist/d7ba6cf0-e4e2-4bfd-9ce2-d3ff018ccde6.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.