thumb|upright|Scottish dirk, blade by Andrew Boog, Edinburgh, c. 1795, Royal Ontario Museum A dirk is a long-bladed thrusting dagger.Chisholm, Hugh (ed.); "Dagger", Encyclopædia Britannica, 11th ed.,
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 0x9df6885fd905d8acfce77ff6672ee4a935217352a68322e3371a3ab0cfe43024. Chain 2 (Bitcoin): anchored in block 953596 (2026-06-14T06:21:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0af5ff49-83a4-4009-8af6-44336c2469c5.json and https://artists.proofprofile.net/proofs/artist/0af5ff49-83a4-4009-8af6-44336c2469c5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).