LEN
type: MusicGroup
description: Len or LEN may refer to: People and fictional characters Len (given name), a list of people and fictional characters Lén, a character from Irish mythology Alex Len (born 1993), Ukrainian basketbal
popularity: 4
followers: 63
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x74a24cfe253760650f5abe63365019bad6d9a1597eacbe5b473052c0c04ede88
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954516
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954516
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/9ff8a5d1-1af8-40c0-9a8c-9011d1ffb87a.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/9ff8a5d1-1af8-40c0-9a8c-9011d1ffb87a.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/9ff8a5d1-1af8-40c0-9a8c-9011d1ffb87a
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-20T07:04:44Z
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 0x74a24cfe253760650f5abe63365019bad6d9a1597eacbe5b473052c0c04ede88. Chain 2 (Bitcoin): anchored in block 954516 (2026-06-20T07:04:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9ff8a5d1-1af8-40c0-9a8c-9011d1ffb87a.json and https://artists.proofprofile.net/proofs/artist/9ff8a5d1-1af8-40c0-9a8c-9011d1ffb87a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-20T07:04:44Z
album: 未知
  type: MusicAlbum
  date published: 2020-04-01
album: 未知
  type: MusicAlbum
  date published: 2020-04-01
album: 未知
  type: MusicAlbum
  date published: 2020-04-01
album: 未知
  type: MusicAlbum
  date published: 2020-04-01
album: One&Only
  type: MusicAlbum
  date published: 2022-01-26
album: One&Only
  type: MusicAlbum
  date published: 2022-01-26
album: 君の世界
  type: MusicAlbum
  date published: 2023-05-10
album: the world you are in
  type: MusicAlbum
  date published: 2023-05-10
album: Memory (Ⅲ)
  type: MusicAlbum
  date published: 2024-08-07
album: BOKURANOIRO
  type: MusicAlbum
  date published: 2025-04-09
  track: BOKURANOIRO
    type: MusicRecording
    duration: PT5M0S
    duration ms: 300235
    explicit: false
    by artist: LEN
    in album: BOKURANOIRO
      type: MusicAlbum
      date published: 2025-04-09
    isrc code: JPZ922501923
    additional property: CopyrightID
    additional property: CopyrightStatus
      type: PropertyValue
      value: registered
    additional property: CopyrightRegisteredAt
      type: PropertyValue
      value: 2026-07-22T08:05:13+00:00
    additional property: CopyrightChainExplorerURL
      type: PropertyValue
      value: https://explorer.copyrightchains.com/tx/0x555f856dba4cf184a53316464fa869a4c0c0c52c19d938e6170b6baa3897bbd0
    additional property: OTSHash
    additional property: OTSBitcoinBlock
      type: PropertyValue
      value: 959114
    additional property: OTSBitcoinBlockVerifyURL
      type: PropertyValue
      value: https://blockstream.info/api/block-height/959114
    additional property: OTSVerificationAPI
      type: PropertyValue
      value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/JPZ922501923
    additional property: OTSTimestamp
      type: PropertyValue
      value: 2026-07-22T08:41:42Z
    additional property: OTSVerifyInstructions
      type: PropertyValue
      value: 1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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 0x555f856dba4cf184a53316464fa869a4c0c0c52c19d938e6170b6baa3897bbd0. Chain 2 (Bitcoin): anchored in block 959114 (2026-07-22T08:41:42Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/JPZ922501923.
      date published: 2026-07-22T08:41:42Z
    audio: BOKURANOIRO
      type: AudioObject
      additional property: Tempo (BPM)
        type: PropertyValue
        value: 98.718
      additional property: Musical Key
        type: PropertyValue
        value: 8
      additional property: Mode (Major/Minor)
        type: PropertyValue
        value: 1
      additional property: Time Signature
        type: PropertyValue
        value: 4
      additional property: Danceability
        type: PropertyValue
        value: 0.575
      additional property: Energy
        type: PropertyValue
        value: 0.686
      additional property: Speechiness
        type: PropertyValue
        value: 0.032
      additional property: Acousticness
        type: PropertyValue
        value: 0.171
      additional property: Instrumentalness
        type: PropertyValue
        value: 0
      additional property: Liveness
        type: PropertyValue
        value: 0.309
      additional property: Valence (Positivity)
        type: PropertyValue
        value: 0.354
      additional property: Loudness (dB)
        type: PropertyValue
        value: -4.206
      additional property: Key Name
        type: PropertyValue
        value: Ab
      additional property: Mode Name
        type: PropertyValue
        value: Major
album: 僕らの色
  type: MusicAlbum
  date published: 2025-04-09