John Humbird Duffey Jr. (March 4, 1934 – December 10, 1996) was an American bluegrass musician. Biography Duffey was born on March 4, 1934, in Washington, D.C., and lived nearly all his life in the
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 0xfbf58022c04aba5478ce43b4c13a290018355f3d19eab82c0d002fdd69a71929. Chain 2 (Bitcoin): anchored in block 954587 (2026-06-20T19:10:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b9191171-5fc8-4c7e-b28a-efbc1f6b1894.json and https://artists.proofprofile.net/proofs/artist/b9191171-5fc8-4c7e-b28a-efbc1f6b1894.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).