Bill or William Madden may refer to: William Madden (piper) (fl. 1855–1857), Irish piper William Madden (sailor) (1843–?), U.S. Navy Medal of Honor recipient Billy Madden (1852–1918), American pugili
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 0xa298cd62d8a859b475946fbfe178cdf1cd7a7f9d7c084fc5dacfb7ca77eb1a7e. Chain 2 (Bitcoin): anchored in block 953885 (2026-06-16T04:12:47Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0c69ed95-8698-49a7-b236-edf8fa911f2e.json and https://artists.proofprofile.net/proofs/artist/0c69ed95-8698-49a7-b236-edf8fa911f2e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).