A BLT is a type of sandwich, named for the initials of its primary ingredients, bacon, lettuce, and tomato. It can be made with varying recipes according to personal preference. Simple variants includ
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 0xdaf3e7278f884bd3ecce73a0ee8c2b31ec987fa1d9b2843ba4e669ccf4d56969. Chain 2 (Bitcoin): anchored in block 954063 (2026-06-17T07:49:29Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4733aedf-d71b-4441-8ac7-08b63bd536d5.json and https://artists.proofprofile.net/proofs/artist/4733aedf-d71b-4441-8ac7-08b63bd536d5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).