thumb|right|300px|True, visible, and astronomical horizons. Not shown: refracted horizon. Most commonly, the horizon is the border between the surface of a celestial body and its sky when viewed from
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 0x9cc64492c7e2080b749b9f330f1cae8467b3a40df9951bbc58c86de96ecea263. Chain 2 (Bitcoin): anchored in block 954603 (2026-06-20T21:47:54Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c3375a97-a37c-4222-a2be-39326e05661d.json and https://artists.proofprofile.net/proofs/artist/c3375a97-a37c-4222-a2be-39326e05661d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).