2Eyes (), stylized in all caps, was a South Korean girl group formed by SidusHQ. They made their debut in 2013 as a five-member group and consisted of Hyangsuk, Hyerin, Dasom, Daeun and Yeonjun. Follo
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 0x580e1b936a1779bd357d3bdeaa9d6c2199245fbcffef9b3001ac9b1a51f29ae7. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/69e758f8-b2b9-4b39-8bc6-24a8d018a755.json and https://artists.proofprofile.net/proofs/artist/69e758f8-b2b9-4b39-8bc6-24a8d018a755.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.