Lightsum (, stylized in all caps) is a South Korean girl group formed by Cube Entertainment. The group is composed of six members: Sangah, Chowon, Nayoung, Hina, Juhyeon, and Yujeong. Originally an ei
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85d6abb9e2b89b5dd1cd56161cdc5c6127cffcb43499c4cf2aeb381edf030e8d. 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/bd4ceaf8-970f-48bd-940b-2ba21da412fc.json and https://artists.proofprofile.net/proofs/artist/bd4ceaf8-970f-48bd-940b-2ba21da412fc.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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31d26a029556d76467d90882f58e02296762793ebf218741146a31dc8b1106a3. 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/KRA392300014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x441f46ea5ed6c84041ff9714eedf362f3c0cfe77a9512be4f4000a3c1ae3a06a. 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/KRA392300015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb3a73503130bd7321df42888016c57944e5187864a938509376169ce3de73205. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/KRA392300016.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa04dd01bee121511b98bc57b23aafddf08ec3c07b789fde71d303a45afce02ca. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/KRA392300017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5ef5a465e8ee14f2f06e22ebacfe0671113d34f573196cd1a91717799c6a212. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/KRA392300018.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4da0ccaa104597a5578d5cc8a75ed4eae00938ef4d8fd208cb5bb9bc3fe9570. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/KRA392300019.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b685e14f1e065dcac89e477740633a9d8ab602d744e4371ab0b9a3f43500118. 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/KRA392200014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65ac7d70fb8e36b972d07c1a8c73f1eea688d5f94089c736d115bb14530c35b5. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/KRA392200015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8ef59f1a94760b347c645e0b9f3ee18bd67e82cf8b3e237918c5292a71427db8. 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/KRA392200016.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd3fb60615f91d2344339ea5df7d3321fe3e86a289cb54b9fe937b1f251f0094d. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/KRA392200017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x06954d0d31da346a5a7992f8d0681456e119c9604f4dbf2ca123b41286acb475. 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/KRA392200018.
Dance Dance (from ″Go Go Bella″, Bella Theme)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x07bf682fd2f4aac89b019769d6476797ac22c5f88cd6ac559df63c08a242df9e. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/KRA492101489.
Dance Dance (from ″Go Go Bella″, Bella Theme) - Instrumental
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6dbaf2040c72b382c9d883a3088233f899eea5feb429392678b134d676509e5. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/KRA492101490.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xadc28cc1fbda40484dd896b3f48cf9b00a5a94201443fe6aba45b4f7cd2e6184. 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/KRA392100031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf87adccd3637099422badc275380888532900a54b30358a76c1b4dc436aa1ea4. 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/KRA392100032.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62aa856a64cf537850393dfda4631ce8f28ade520f4144fd5a83acde0581ca42. 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/KRA392100033.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe49335ce91fd3a4547a23413ee5f48a3f1158fcec17305ebc02051a08fb7aee9. 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/KRA392100018.