thumb|upright|Frontispiece of the 1595 Atlas of Mercator An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a continent or region of Earth. Advances in astronomy have a
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 0xfb9bbc7b4fa1a4fd3af14fc0e5f6631350e07f5d1b243e4e8a163e357c6df4ba. Chain 2 (Bitcoin): anchored in block 954028 (2026-06-17T01:08:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/39cdec1d-6f0c-4f4c-9451-e4e060a98897.json and https://artists.proofprofile.net/proofs/artist/39cdec1d-6f0c-4f4c-9451-e4e060a98897.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.