Sjoerd
type: MusicGroup
genre: nederpop
description: Sjoerd () is a Dutch masculine given name of West Frisian origin. It is derived via Sieuwerd from the Germanic Sigiward ("victory warden"). Sjoerd gained some popularity as a baby name between 1975 an
popularity: 4
followers: 270
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x700aabb88600204b4c343f6919a2a7c162f097b2090e9196bfef2d9a09eff4ab
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954618
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954618
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/c8eec0c9-192e-4ee4-a158-35a92d8fa4b6.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/c8eec0c9-192e-4ee4-a158-35a92d8fa4b6.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/c8eec0c9-192e-4ee4-a158-35a92d8fa4b6
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-20T23:05:13Z
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 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 0x700aabb88600204b4c343f6919a2a7c162f097b2090e9196bfef2d9a09eff4ab. Chain 2 (Bitcoin): anchored in block 954618 (2026-06-20T23:05:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c8eec0c9-192e-4ee4-a158-35a92d8fa4b6.json and https://artists.proofprofile.net/proofs/artist/c8eec0c9-192e-4ee4-a158-35a92d8fa4b6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-20T23:05:13Z
album: Live in het Praethuys
  type: MusicAlbum
  date published: 2017-03-10
album: Live in het Praethuys
  type: MusicAlbum
  date published: 2017-03-10
album: Live @ Café De Zeevaert
  type: MusicAlbum
  date published: 2017-03-21
album: Live @ Café de Zeevaert
  type: MusicAlbum
  date published: 2017-03-21
album: Laat me maar op Vlieland zijn
  type: MusicAlbum
  date published: 2017-03-22
album: Laat me maar op Vlieland zijn
  type: MusicAlbum
  date published: 2017-03-22
album: Elsinga/Kardaun Recordings
  type: MusicAlbum
  date published: 2021-11-15
album: Elsinga/Kardaun Recordings
  type: MusicAlbum
  date published: 2021-11-15