4U or 4 U may refer to: Music 4U (album), by Elva Hsiao, 2002 4U (Christina Milian EP), 2015 4 U (Cody Simpson EP), 2010 4U: Outside, an EP by BtoB, 2021 "4U", a song by Aero Chord, 2015 "4U",
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 0xee895b75c5f1f8ae9e776c36196b7336a97f8ed57edd0a8d3c7b724774a5aa59. Chain 2 (Bitcoin): anchored in block 953648 (2026-06-14T15:20:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/456dbee4-cf0c-4371-8b39-47414ae6a67b.json and https://artists.proofprofile.net/proofs/artist/456dbee4-cf0c-4371-8b39-47414ae6a67b.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 0x22aab77a5ad726ef28069f0f2c99339cc83813d68f705d4d3bc2f642dc0e9633. Chain 2 (Bitcoin): anchored in block 958677 (2026-07-19T05:47:23Z), 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/JPVI01734740.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe83bf3bd3a3462739dcb4c33d0173926df128a7d56a36ce4a2e8ce45d80f4e2b. Chain 2 (Bitcoin): anchored in block 957747 (2026-07-12T19:35:06Z), 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/JPVI02000094.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x83928b5b9e27545ea469d4b55f44af09b2705f28a6a419dac6931410e6a45fe1. Chain 2 (Bitcoin): anchored in block 958163 (2026-07-15T14:38:07Z), 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/JPVI02000095.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x207df140fb30b1ff7f1b8783a22b8638bd2b5467957e870b17841305c4c69d36. Chain 2 (Bitcoin): anchored in block 959137 (2026-07-22T14:03:35Z), 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/TCJPS2255089.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52599d19d8b67464cf3d236bd74111a2e42a6fa8509e7df9422f9b28e47107ec. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/TCJPS2255090.