15& (, also known as Fifteen And) was a South Korean duo formed by JYP Entertainment in 2012. The duo consisted of Park Ji-min and Baek Ye-rin. The name refers to fifteen being their age at debut, wit
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 0x1098e989ee5611f516d15b4e2dff9cd3d795c1e064f9b12a4c3787492e134b0f. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/630af31f-9258-43e3-b0d9-2a29247c7fc7.json and https://artists.proofprofile.net/proofs/artist/630af31f-9258-43e3-b0d9-2a29247c7fc7.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 0x43556237aa498dcd33d23620a0d9df7f28ffc26c0864fee0fa7c4d50a56065ab. Chain 2 (Bitcoin): anchored in block 959355 (2026-07-24T03:24:16Z), 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/US5TA1200611.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x43556237aa498dcd33d23620a0d9df7f28ffc26c0864fee0fa7c4d50a56065ab. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/US5TA1200611.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbac7663eb2b24579ac42910e1c571c33ca13aeb8747929d8d15e47ba08dc591f. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/US5TA1400043.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb376f2007b4475b66c81e60cc89bffcbc2ffa3499ee86afd8cb7dfde653b8cac. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/US5TA1400044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1dc641e9e64f193202c8e74d75acf6b188a4e33189c1374a811395d9dd1e0c44. Chain 2 (Bitcoin): anchored in block 958300 (2026-07-16T16:14:30Z), 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/US5TA1400045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa1ca9aa9021979c9418b32cc11b3baa8ee5e2672740163591a643e42c4da4ce. Chain 2 (Bitcoin): anchored in block 958621 (2026-07-18T22:59:44Z), 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/US5TA1400047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7075f678abe8a8d6c51805ef5eb77c59a253fb6a3f363026ba5627bd0e4f5c11. Chain 2 (Bitcoin): anchored in block 958410 (2026-07-17T12:18:07Z), 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/US5TA1400049.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x60ce5536b4e9208108e6ba8964c1d2662f1de0eed50d4e4367644b6fd6f64507. Chain 2 (Bitcoin): anchored in block 958211 (2026-07-15T23:24:33Z), 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/US5TA1400050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x76aab5540dd9321bc91b26629a911fdfd418d3f8293ee9a899be15d5ad7f2146. Chain 2 (Bitcoin): anchored in block 958211 (2026-07-15T23:24:33Z), 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/US5TA1300001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b22092c3fc5858b154693abf7df00de440f3a2dcea051f0d803967d77c2d7c5. Chain 2 (Bitcoin): anchored in block 959023 (2026-07-21T15:22:58Z), 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/US5TA1400048.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x43556237aa498dcd33d23620a0d9df7f28ffc26c0864fee0fa7c4d50a56065ab. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/US5TA1200611.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1699fc348942861e79e5446502a89ee000cda671670f10f764f5752ca0ff7039. 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/US5TA1500008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1699fc348942861e79e5446502a89ee000cda671670f10f764f5752ca0ff7039. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/US5TA1500008.