thumb|upright|Four measuring devices having metric calibrations Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In oth
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 0x5148de96e15f6cacc6a970036ecba6fc9a3a38ccb155acb39ecde13c889b7f52. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8463fbd2-1e19-47ef-aabe-5ac79c131190.json and https://artists.proofprofile.net/proofs/artist/8463fbd2-1e19-47ef-aabe-5ac79c131190.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).