A postface is the opposite of a preface, a brief article or explanatory information placed at the end of a book. Postfaces are quite often used in books so that the non-pertinent information will appe
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2eb05d6f22b4dff3b4d4b11a25e995dabf5ef3d8ad5c237c68fb065ccb2eb934. Chain 2 (Bitcoin): anchored in block 954015 (2026-06-16T22:55:46Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3474b398-ccdf-4215-bf59-4a78bbac41cc.json and https://artists.proofprofile.net/proofs/artist/3474b398-ccdf-4215-bf59-4a78bbac41cc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).