Jef
type: MusicGroup
description: 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
popularity: 2
followers: 409
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x0a450c631a1367ed6acc687a43ce6046734c2c41fd6716dec6548a834ee3da62
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954342
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954342
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/8dc995d1-7672-4fe7-9eae-e1eb5ba00995.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/8dc995d1-7672-4fe7-9eae-e1eb5ba00995.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/8dc995d1-7672-4fe7-9eae-e1eb5ba00995
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-19T03:22:39Z
additional property: OTSCanonicalRecord
additional property: OTSVerifyInstructions
  type: PropertyValue
  value: 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
subject of: OpenTimestamps Proof of Existence
  type: DigitalDocument
  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a450c631a1367ed6acc687a43ce6046734c2c41fd6716dec6548a834ee3da62. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8dc995d1-7672-4fe7-9eae-e1eb5ba00995.json and https://artists.proofprofile.net/proofs/artist/8dc995d1-7672-4fe7-9eae-e1eb5ba00995.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-19T03:22:39Z
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