KL, kL, kl, or kl. may refer to: Businesses and organizations KLM, a Dutch airline (IATA airline designator KL) Koninklijke Landmacht, the Royal Netherlands Army Kvenna Listin ("Women's List"), a
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 0xded0186ac106bae1fd62571322a1d8730734eeebafbe714bdbb31f6f6c12ebfe. Chain 2 (Bitcoin): anchored in block 954516 (2026-06-20T07:04:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9f7d1f48-2c2e-4ba5-90cf-7ad7b42adc9e.json and https://artists.proofprofile.net/proofs/artist/9f7d1f48-2c2e-4ba5-90cf-7ad7b42adc9e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).