John Preston may refer to: Politicians John Preston (died 1434), Member of Parliament (MP) for Sussex John Preston (c. 1578 – c. 1642), MP for Lancaster John Preston (alderman) (1611–1686), mayor of
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 0xc6c6318985ab50d08a1e35b4b40f7e505f5e9e35f574c8b287205073f6605a52. Chain 2 (Bitcoin): anchored in block 953997 (2026-06-16T20:07:57Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/202d07ce-b2bc-49db-b65f-74c39a111922.json and https://artists.proofprofile.net/proofs/artist/202d07ce-b2bc-49db-b65f-74c39a111922.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).