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 0xc3797385eca4ae27e2a4757b069ca0076b7d8bbe9ebffa30b984da41f7ae1dda. Chain 2 (Bitcoin): anchored in block 954050 (2026-06-17T05:14:33Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/42cc984b-9a30-4f32-87d0-57750e30e6df.json and https://artists.proofprofile.net/proofs/artist/42cc984b-9a30-4f32-87d0-57750e30e6df.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.