Leon IV or Leo IV may refer to: Leo IV the Khazar (750 – 780), Byzantine Emperor Pope Leo IV, pope from 847 – 855 Leo IV, King of Armenia (1309 – 1341), last Hethumid king of Cilicia Leo IV (dwarf gal
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 0x99fd7836a2b53c3fdf8eb7b2696e7477722d9ccf2d09770dc8e3faf33edb61d1. Chain 2 (Bitcoin): anchored in block 954533 (2026-06-20T08:57:02Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a63f9a4e-e111-4ac8-b0ff-8040d5c0515d.json and https://artists.proofprofile.net/proofs/artist/a63f9a4e-e111-4ac8-b0ff-8040d5c0515d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).