thumb|Elkjøp Megastore, Kristiansand (July 2009) Elkjøp, better known as Elgiganten outside Norway, is the largest consumer electronics retailer in the Nordic countries with four hundred stores in si
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 0xf5ffa9e3e3a8d0f74088b0b83033d06238b36308cedd6782fa4291c6b0b3795c. 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/c747f2f0-6504-49bd-ad42-cd49c0100a76.json and https://artists.proofprofile.net/proofs/artist/c747f2f0-6504-49bd-ad42-cd49c0100a76.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).