right|100px|thumb|Del operator,represented bythe nabla symbol Del, or nabla, is an operator used in mathematics (particularly in vector calculus) as a vector differential operator, usually represented
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 0x26206803f9bea65c2e0dfc95877d2f8293c1142c51a7d16ad9d8283dbb28cb95. Chain 2 (Bitcoin): anchored in block 953699 (2026-06-14T22:00:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/755867a9-5db4-4eef-bf47-9f4b02239cd5.json and https://artists.proofprofile.net/proofs/artist/755867a9-5db4-4eef-bf47-9f4b02239cd5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).