F-ve Dolls (; sometimes stylized in all caps, formerly known as 5dolls) was a South Korean girl group formed by Core Contents Media in 2011. The group was composed of six members: Hyoyoung, Seunghee,
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 0x9fb1880dc97b468bc5ef34a2eee39b7a4ab802c600352a0490c76eb989e2eacd. Chain 2 (Bitcoin): anchored in block 953667 (2026-06-14T17:49:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/57a01ad4-c058-46fd-addf-20425fe3615d.json and https://artists.proofprofile.net/proofs/artist/57a01ad4-c058-46fd-addf-20425fe3615d.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 0xcef503aeb26d41f3ef943695724d316297eabd76712fb0443061ea4b4fff1466. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/KRA341561050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcef503aeb26d41f3ef943695724d316297eabd76712fb0443061ea4b4fff1466. 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/KRA341561050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa7a48a741ca5707b37170ab56de8f3ebc8f2b31cd461cf6fa24661b8d73d8fb2. Chain 2 (Bitcoin): anchored in block 956484 (2026-07-03T10:47:44Z), 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/KRA341561051.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2fa137f2c4165ae7416bab8f1019e0935e08110b3bb2e0717d5e86c3840b485e. 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/KRA341561057.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x024fc15a2ed67d84a750d2444861756f69bdeee9ba163d011632525545f4f1be. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/KRA341561060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe41fc89a927bd642a068f0ef640bba84bc97ddc3afa43281b18499c3a1c26406. 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/KRA341561150.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x71d2ee661467d2d35bc3b8f8d3fb2d5dcf65ada9698817317ac021324d194f01. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/KRA341561151.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x71d2ee661467d2d35bc3b8f8d3fb2d5dcf65ada9698817317ac021324d194f01. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/KRA341561151.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd742409e4c8e34278d3c7bfd9862d1f5154e95a4dcc94ead928c73fefee9020e. Chain 2 (Bitcoin): anchored in block 958271 (2026-07-16T09:16:54Z), 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/KRA341561152.