4
type: MusicGroup
description: thumb|120px|right|Two modern handwritten fours 4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and compo
popularity: 4
followers: 273
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0xbb25cfc932f58e53d53e7e0649c5842c6309d7736e8d9b851262437b4c3219c7
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 953879
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/953879
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/09d62da3-18b6-4f5e-8968-9b3dc7d9ca5c.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/09d62da3-18b6-4f5e-8968-9b3dc7d9ca5c.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/09d62da3-18b6-4f5e-8968-9b3dc7d9ca5c
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-16T02:57:35Z
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 0xbb25cfc932f58e53d53e7e0649c5842c6309d7736e8d9b851262437b4c3219c7. Chain 2 (Bitcoin): anchored in block 953949 (2026-06-16T13:28:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/09d62da3-18b6-4f5e-8968-9b3dc7d9ca5c.json and https://artists.proofprofile.net/proofs/artist/09d62da3-18b6-4f5e-8968-9b3dc7d9ca5c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-16T13:28:01Z
album: Kluczyki do Muzyki
  type: MusicAlbum
  date published: 2020-05-15
album: Kluczyki do Muzyki
  type: MusicAlbum
  date published: 2020-07-16
album: Kluczyki do Muzyki
  type: MusicAlbum
  date published: 2020-07-16
album: Para Wyjątkowa
  type: MusicAlbum
  date published: 2020-07-16
album: Biało-czerwone
  type: MusicAlbum
  date published: 2020-11-14
album: Biało-czerwone
  type: MusicAlbum
  date published: 2020-11-14
album: Uśmiech
  type: MusicAlbum
  date published: 2022-04-04