thumb|upright=1.8|right|The layout of the Punic city-state Carthage, before its fall in 146 BC Carthage (, ) was an ancient city in Northern Africa, on the eastern side of the Lake of Tunis in what is
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 0x31a6d101340887ceb8da406f780fe3df64d56f62efc35107590f3b1ff9d7c2b0. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/77950cf0-8445-4490-bf49-4db0d5642180.json and https://artists.proofprofile.net/proofs/artist/77950cf0-8445-4490-bf49-4db0d5642180.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).