Margriet Sjoerdsma
type: MusicGroup
genre: pop soul
popularity: 6
followers: 874
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x42c9104b62e2873940f2dcd9dc32889372e8e3c0b51c530731d7b90c4550a7c8
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954010
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954010
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/341651a1-1734-4ed7-a890-6c604d0e71a1.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/341651a1-1734-4ed7-a890-6c604d0e71a1.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/341651a1-1734-4ed7-a890-6c604d0e71a1
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-16T21:41:36Z
additional property: OTSCanonicalRecord
  type: PropertyValue
  value: {"copyright_id":"0x42c9104b62e2873940f2dcd9dc32889372e8e3c0b51c530731d7b90c4550a7c8","name":"Margriet Sjoerdsma","registered_at":"2026-06-16T07:45:29Z","symbol":"NIM0984552","token_address":"0xc00ee8489ae4fbb7c91754a1f1e96e6802abd99b","type":"artist","uuid":"341651a1-1734-4ed7-a890-6c604d0e71a1"}
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 0x42c9104b62e2873940f2dcd9dc32889372e8e3c0b51c530731d7b90c4550a7c8. 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/341651a1-1734-4ed7-a890-6c604d0e71a1.json and https://artists.proofprofile.net/proofs/artist/341651a1-1734-4ed7-a890-6c604d0e71a1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-16T22:46:20Z
  text: {"copyright_id":"0x42c9104b62e2873940f2dcd9dc32889372e8e3c0b51c530731d7b90c4550a7c8","name":"Margriet Sjoerdsma","registered_at":"2026-06-16T07:45:29Z","symbol":"NIM0984552","token_address":"0xc00ee8489ae4fbb7c91754a1f1e96e6802abd99b","type":"artist","uuid":"341651a1-1734-4ed7-a890-6c604d0e71a1"}
album: Bloom
  type: MusicAlbum
  date published: 2008-05-23
album: Bloom
  type: MusicAlbum
  date published: 2008-05-23
album: Let It All Out
  type: MusicAlbum
  date published: 2011-07-08
album: Drawing Circles
  type: MusicAlbum
  date published: 2011-09-16
album: Drawing Circles
  type: MusicAlbum
  date published: 2011-09-16
album: No More Goodbyes
  type: MusicAlbum
  date published: 2013-11-21
album: A Tribute To Eva Cassidy
  type: MusicAlbum
  date published: 2014-04-11
album: A Tribute To Eva Cassidy
  type: MusicAlbum
  date published: 2014-04-11
album: With The Whisper Of A Morning
  type: MusicAlbum
  date published: 2020-12-01