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 0x78d460b8dd47b172453b7759feda46c92e78fc917dcb6f08fa119a3398f830cd. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4525445a-01f7-4322-ae41-8d64b04b2642.json and https://artists.proofprofile.net/proofs/artist/4525445a-01f7-4322-ae41-8d64b04b2642.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Lachrimae (Mathew Holmes lute book (GB-Cu MS Dd.2.11))