Chapman may refer to: Businesses Chapman Entertainment, a former British television production company Chapman Guitars, a guitar company established in 2009 by Rob Chapman Chapman's, a Canadian ic
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 0xbbe253179de383051be4a5fef3509bd8eb4636812ac8b930a7c71a01e1fee5d5. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b7652da8-7b2a-44e6-9a03-18ad3dbcc691.json and https://artists.proofprofile.net/proofs/artist/b7652da8-7b2a-44e6-9a03-18ad3dbcc691.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).