Eddie C. Campbell (May 6, 1939 – November 20, 2018) was an American blues guitarist and singer in the Chicago blues scene. Biography Campbell was born in Duncan, Mississippi. He moved to Chicago at
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 0xf41a8e5de16c0d51a72b9f4792da1c4d172cc686e334b4e823d460a4e2e059ca. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e0c24ab3-6de6-477d-89fa-11f9b148c9ea.json and https://artists.proofprofile.net/proofs/artist/e0c24ab3-6de6-477d-89fa-11f9b148c9ea.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).