thumb|upright=1.1|Pig iron used to manufacture ductile iron Pig iron is an intermediate good used by the iron industry in the production of steel. It is developed by smelting iron ore in a blast furn
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 0xe8303a186f5a7e3aad3e4e58d6d2e359bfeb6fdaaef08afd1d2d86c6db9b7e37. Chain 2 (Bitcoin): anchored in block 953949 (2026-06-16T13:28:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/16ee353e-a83c-4f86-bc09-20a3c4cf44f7.json and https://artists.proofprofile.net/proofs/artist/16ee353e-a83c-4f86-bc09-20a3c4cf44f7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).