Black Lagoon (stylized in all caps) is a Japanese manga series written and illustrated by Rei Hiroe. It has been published in Shogakukan's manga magazine Monthly Sunday Gene-X since April 2002, with
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 0xc0caa9575787c5490d65266205090fb20434d9b8110d7dc8aadc7c4277e0ebd6. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/db5b2622-c354-4186-8555-c67f0852ed21.json and https://artists.proofprofile.net/proofs/artist/db5b2622-c354-4186-8555-c67f0852ed21.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).