Twice (; commonly stylized in all caps) is a South Korean girl group formed by JYP Entertainment. The group is composed of nine members: Nayeon, Jeongyeon, Momo, Sana, Jihyo, Mina, Dahyun, Chaeyoung,
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 0xfbb202b5d76760104ad37a345319a6e85a5ba02feb35382c8a8660be082cf393. 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/c906cdd8-306d-44d3-823e-f291a4a6332e.json and https://artists.proofprofile.net/proofs/artist/c906cdd8-306d-44d3-823e-f291a4a6332e.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 0xeacbba4a826f8e8ae0791171ebc86ab9e5c3c0316f88200df661657edf63f2c0. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA1700047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6d70507d661526fb4a5e1b5eaef26da023231cd4d2144ee87c024d5ed2466e0a. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA1600082.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x67b753968549fe4c42eb4eb2adeae98a40cf9b315906d5d3a9021fee0001d0d9. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA1800053.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe931142cb042d5d256f7df7a35dd56375cbb597108300116194d0413eaf3149b. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2300197.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92f86a4d47b683c8807f938ee7f5251e7f50638cf5e91ba5399ba484b17dacf1. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA2400297.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bd69cc126995e22161bbf65588dbc98f70149bf284e807b778d493f8455f66c. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA2400023.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0a83e831f59c97ed1defe9f3f9dcaed2dacc0c9d920c389a84e4f31cdd7d1ff. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/US5TA2300237.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xad9b7fa25994bb3d9352e45174c49aeca1259e05065f607868adc9e8057d033d. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/US5TA2400012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x42a6781bd976518ea5ad0328ffde668d658cdafdf052db2562b3a52ae035fab4. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/US5TA2400013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1bf066e4599454c1652ddb734ccdd5a8062dd0fe79857744b7129e41a0e90ef1. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/US5TA2400014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd5f41590db3d5a6401122efa34df671677f7ef187c9327721dca4f64a3305bde. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/US5TA2400015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4dba8322f40eccf1709b9d21b28afd29e26c55c832bbae725a23a41ded8dc9a. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2400024.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x753ae82670b72055d0972c3ab52b82e85d887a1fe7ab5b541995302405989098. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/US5TA2300238.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38933936c1b05bd11eeac35573f5721e63eaf5823b549aa46384909b5100fcc6. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2400025.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x32f0923ea4a5c66fe1d8cd9f4a3502e04f8157671a4a5707dedf5cc16f2f34b7. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2400026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3454dbb97cb5be74ba604715575b54c050f22c3b351a0bb773d3aa84dceca18b. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2400027.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa26badd31998ad66107ea87aaca5c269cd99d9bc1cd0ff034b50a83396204a7f. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US5TA2400028.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5f751c479e5e7974f9bf96e791a07006359a3b766e3c70bf2c9d11d2ef481b8. Chain 2 (Bitcoin): anchored in block 960153 (2026-07-29T21:57:12Z), 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/DEM090100040.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcc6632d1760160f5937fad6cf8f85e1f3e6c05a94fdd9e0800f7c13a505ab248. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/USAT22409895.