thumb|A Greek cross (all arms of equal length) above a saltire, a cross whose limbs are slanted The cross is a geometrical figure consisting of two intersecting lines or bars, usually perpendicular t
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 0xfdbd323b934fef9a19f190f756af8eb5402fcf2da42d51781d990c891363b9fe. Chain 2 (Bitcoin): anchored in block 953968 (2026-06-16T16:01:49Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/286a69a5-4eb5-4c20-998c-9e95b68db56f.json and https://artists.proofprofile.net/proofs/artist/286a69a5-4eb5-4c20-998c-9e95b68db56f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).