thumb|Sailor bag made of canvas thumb|Canvas roof at the Erasmus station of the Brussels Metro thumb|300px|One of Poland's biggest canvas paintings, the Battle of Grunwald, 1878, by Jan Matejko (426 c
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 0x5b699e95524ab81120eba1057806e56fd32bdd3f91be7aa292fc280721d31316. 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/dda72195-ab70-445d-b271-cf57a4bccc2d.json and https://artists.proofprofile.net/proofs/artist/dda72195-ab70-445d-b271-cf57a4bccc2d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).