F.Cuz (, "Focus"), is a South Korean boy band that used to be managed by Tunes-Will Entertainment,Newsway Korea / 남성 5인조 아이돌그룹 포커즈, 새 소속사에서 새로운 출발! . (March 13, 2014). Retrieved on March 21, 2014. and
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7910fe3d0626efa61f6423a9d39a0b5272c5cd12356458d72115c966cf35b40b. Chain 2 (Bitcoin): anchored in block 953602 (2026-06-14T06:58:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0f509e74-1bb0-4087-8a87-74a73b9b7874.json and https://artists.proofprofile.net/proofs/artist/0f509e74-1bb0-4087-8a87-74a73b9b7874.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x73d4d766c2f9db3cd005d972e939ec56e77da30fe3637e11a656142db2a0aa35. Chain 2 (Bitcoin): anchored in block 958689 (2026-07-19T07:11:11Z), 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/SEYOK1128236.
맨발 (Feat. 한겨울) [from 'Ruby Ruby Love' (Original Soundtrack), Pt.1]
맨발 (feat. 한겨울) (from 'Ruby Ruby Love' (Original Soundtrack), Pt.1)