Shifu is a Chinese cultural term. Although its pronunciation always sounds the same, there are two ways of writing it using Chinese characters, and they bear two different meanings. The first variatio
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 0x075c6627953731e9d6795db76175c7529057ac6186f0a2a08ec52450743672b6. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e1489313-2338-4a0d-9787-b3587d14fdb9.json and https://artists.proofprofile.net/proofs/artist/e1489313-2338-4a0d-9787-b3587d14fdb9.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.