thumbnail|300 px|Low key oil painting Low key as a term used in describing paintings or photographs is related to but not the same as low-key lighting in cinema or photography. A photographic image, p
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 0x7eae330d5b21b7097320f5bfa614b13e5881b467685f012848becd42a56cc70e. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/cf0d80b7-32ff-483b-9909-58bb9d6fce7d.json and https://artists.proofprofile.net/proofs/artist/cf0d80b7-32ff-483b-9909-58bb9d6fce7d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).