Guy Van Duser (born September 25, 1948) is an American jazz and folk guitarist. He recorded for Rounder from the 1970s to the 1990s and often appeared on the radio show A Prairie Home Companion. His
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 0x03c417ee907642861310d8316b2c58edd802c2b3ad21f2f81af551c1b1dc52b8. 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/54ab1573-d193-4a8e-bed1-0899b14fcd6f.json and https://artists.proofprofile.net/proofs/artist/54ab1573-d193-4a8e-bed1-0899b14fcd6f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).