Kim Hanul (; March 22, 1988 – October 8, 2013), better known by her stage name Rottyful Sky (), formerly known as Hanul, was a South Korean singer and producer. Career Solo career and further singles
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 0xee196dd454ab81336aae0200b446c2d2ae5e394bacac9e62c4d8c787d96d593c. Chain 2 (Bitcoin): anchored in block 954513 (2026-06-20T06:31:18Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9e872913-c89c-43c5-a3a0-b5be3e99aeb8.json and https://artists.proofprofile.net/proofs/artist/9e872913-c89c-43c5-a3a0-b5be3e99aeb8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).