Jan de Hartog
type: MusicGroup
description: Jan de Hartog (April 22, 1914 – September 22, 2002) was a Dutch playwright, novelist and occasional social critic who moved to the United States in the early 1960s and became a Quaker. Early life I
popularity: 10
followers: 421
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0xf0df9b9c99659c2fe305f35a76689f79ca77b719ebc8839cb927c5d1837c3bd7
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954603
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954603
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/c439cdb5-974c-465e-bf23-0be007e127e7.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/c439cdb5-974c-465e-bf23-0be007e127e7.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/c439cdb5-974c-465e-bf23-0be007e127e7
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-20T21:47:54Z
additional property: OTSCanonicalRecord
  type: PropertyValue
  value: {"copyright_id":"0xf0df9b9c99659c2fe305f35a76689f79ca77b719ebc8839cb927c5d1837c3bd7","name":"Jan de Hartog","registered_at":"2026-06-20T20:28:40Z","symbol":"NIM1705703","token_address":"0xd816981b61dc701643248c0206118cc9f79f1ec1","type":"artist","uuid":"c439cdb5-974c-465e-bf23-0be007e127e7"}
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 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
subject of: OpenTimestamps Proof of Existence
  type: DigitalDocument
  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf0df9b9c99659c2fe305f35a76689f79ca77b719ebc8839cb927c5d1837c3bd7. Chain 2 (Bitcoin): anchored in block 954603 (2026-06-20T21:47:54Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c439cdb5-974c-465e-bf23-0be007e127e7.json and https://artists.proofprofile.net/proofs/artist/c439cdb5-974c-465e-bf23-0be007e127e7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-20T21:47:54Z
  text: {"copyright_id":"0xf0df9b9c99659c2fe305f35a76689f79ca77b719ebc8839cb927c5d1837c3bd7","name":"Jan de Hartog","registered_at":"2026-06-20T20:28:40Z","symbol":"NIM1705703","token_address":"0xd816981b61dc701643248c0206118cc9f79f1ec1","type":"artist","uuid":"c439cdb5-974c-465e-bf23-0be007e127e7"}
album: Hollands Glorie
  type: MusicAlbum
  date published: 1977