thumb|right|275px|Old Ship Church, 1681, Hingham, Massachusetts Deacon John Leavitt (1608–1691) was a tailor, public officeholder, and founding deacon of Old Ship Church in Hingham, Plymouth County, M
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 0x7dfd71a6ad2d7788b2df9d3def05ed96a2a79485f7efc227af7b56c046e4ddec. Chain 2 (Bitcoin): anchored in block 954638 (2026-06-21T03:45:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d444012c-cc2c-479a-8dd4-160ff87b3704.json and https://artists.proofprofile.net/proofs/artist/d444012c-cc2c-479a-8dd4-160ff87b3704.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.