thumb|upright=1|Nor'easter off the New England coast of the United States responsible for the January 2018 North American blizzard A nor'easter (also northeaster; see below) is a large-scale extratro
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 0x8a0929f6f08ce94cb1bdaf557cffdebf5ecf5d4f1aff12a69921d791741e3d4d. Chain 2 (Bitcoin): anchored in block 953869 (2026-06-16T01:20:04Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/06deadd2-97b1-4aad-95a0-c6278f8a4898.json and https://artists.proofprofile.net/proofs/artist/06deadd2-97b1-4aad-95a0-c6278f8a4898.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).