The pipa () is a traditional Chinese musical instrument belonging to the plucked category of instruments. Sometimes called the "Chinese lute", the instrument has a pear-shaped wooden body with a varyi
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 0x36f92cf8b311ee1a0bde574c46932a6120fc6111bdcac17fe25c2a1eec2c05ed. Chain 2 (Bitcoin): anchored in block 954623 (2026-06-20T23:40:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/cac4152d-8ae0-4c7e-834d-d831d49e5dd3.json and https://artists.proofprofile.net/proofs/artist/cac4152d-8ae0-4c7e-834d-d831d49e5dd3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).