Ch'asu () is a superior military rank of North Korea, often translated as Vice Marshal. The rank is senior to that of Daejang (General) and junior to that of Wonsu (Marshal). The rank is seldom best
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 0xe7b548e81c6cbec0cf7bb1b15d9050aacb1087583567eea0301c852cb7c1d956. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ed7d0a97-99ba-4c18-8856-bddcf6490b3b.json and https://artists.proofprofile.net/proofs/artist/ed7d0a97-99ba-4c18-8856-bddcf6490b3b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).