thumb|350px|right|Facsimile of Ribeiro's original 1527 world map, now held by the Anna Amalia Bibliothek in Weimar, Germany. thumb|350px|right|William Griggs's facsimile of Ribeiro's 1529 original wo
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 0xcaad6684bdd74f73f8c6c330c7a682b6c14c83ac40e48a2f0f7cd34befac5adc. Chain 2 (Bitcoin): anchored in block 953947 (2026-06-16T13:14:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2285a588-8541-477e-8054-c00f057b9b46.json and https://artists.proofprofile.net/proofs/artist/2285a588-8541-477e-8054-c00f057b9b46.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).