Sjef is a given name. Notable people with the given name include: Sjef Hensgens (1948–2024), Dutch middle-distance runner Sjef Janssen (born 1950), Dutch dressage coach Sjef Mertens (1926–2004), Dut
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 0x07f6e3b1807f04ce20e5d7f3cad07b198507a1ab5694415e6c2e2bce09f8578b. Chain 2 (Bitcoin): anchored in block 954689 (2026-06-21T10:35:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e3091f27-6703-4c30-93ad-be1215f451a1.json and https://artists.proofprofile.net/proofs/artist/e3091f27-6703-4c30-93ad-be1215f451a1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
The Void Digital Series: V.D.009 Sjef ep