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 0x90a59a86913ae1fd2c3248ded899f7713c3c5f63e57d6c4048b6010a2bac2350. Chain 2 (Bitcoin): anchored in block 953949 (2026-06-16T13:28:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/182522e6-c3d5-4ec8-95bf-b4b3d66fc1f2.json and https://artists.proofprofile.net/proofs/artist/182522e6-c3d5-4ec8-95bf-b4b3d66fc1f2.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.