L9 may refer to: __NOTOC__ Military HMS L9, a British L class submarine L9 Bar Mine, a large rectangular British anti-tank landmine L9A1 51 mm light mortar, used by the British Army Royal Ordna
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 0x86700989d84ecb10935129a9651dd4a555b5b461b61db4db2dabb819f620f337. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/922fcfd5-641b-4323-8e47-33b330255c42.json and https://artists.proofprofile.net/proofs/artist/922fcfd5-641b-4323-8e47-33b330255c42.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).