Sina may refer to: Relating to China Chin (China), or Sina (), old Chinese form of the Sanskrit name Cina () Shina (word), or Sina (), archaic Japanese word for China Sinae, Latin name for China
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 0x36f91fa0adea7f28b3ea04e59b64d221deb4dc34b8fbc7b6346a8340812512a2. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/960a96e2-f63f-42f5-aadf-8c989228cf62.json and https://artists.proofprofile.net/proofs/artist/960a96e2-f63f-42f5-aadf-8c989228cf62.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).