Jef is a Dutch-language masculine given name primarily used in Belgium. It is a short form of Jozef/Josef, used also in Breton. People with the name include: Jef Billings (1945–2016), American figure
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 0xce11c514da2f2163ef9b4d962cc1824a3f9457523e06a966b142dec3e63e1b58. Chain 2 (Bitcoin): anchored in block 954014 (2026-06-16T22:46:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/27ee5814-1a33-4ff4-9297-76453f79238e.json and https://artists.proofprofile.net/proofs/artist/27ee5814-1a33-4ff4-9297-76453f79238e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).