DOHWA Engineering Company Limited is a privately owned engineering, construction company in South Korea. DOHWA is one of the largest engineering design firms in South Korea.DOHWA Engineering Co., Ltd.
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 0xa7b28c6f8c5ccb5aa7689d319c416a9fe94c6420abc8ad661df6b3e2e5a7c0a7. Chain 2 (Bitcoin): anchored in block 953596 (2026-06-14T06:21:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0aca9e20-4813-466d-b179-1b6ca83a6405.json and https://artists.proofprofile.net/proofs/artist/0aca9e20-4813-466d-b179-1b6ca83a6405.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
사랑공식 11M (Original Television Soundtrack)
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 0xca46e8149ed2b0ad66105ec5af417661deecd7c4a90b5b6020ad6161ec4d9b72. 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/KRMIM1920717.