thumb|right|75px|Variant kappa|class=skin-invert-image thumb|right|Greek word καί written with a handwritten variant of kappa, from the Byzantine period|class=skin-invert-image Kappa (; uppercase Κ, l
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 0xb2a7e98bda6e7b17ec874dbad5b36b1f7716055bdf0ecd23cca00661d1d05886. 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/a4bd3875-4ab8-453c-b5f9-0f5d169edc4f.json and https://artists.proofprofile.net/proofs/artist/a4bd3875-4ab8-453c-b5f9-0f5d169edc4f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).