Pure may refer to: Computing Pure function PureSystems, a family of computer systems introduced by IBM in 2012 Pure Software, a company founded in 1991 by Reed Hastings to support the Purify tool
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 0xadefa0b264ad82ef71f0e63b874d5503c375202e2a73df0d5308e83eafe96476. Chain 2 (Bitcoin): anchored in block 953817 (2026-06-15T18:10:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fdf3c4ea-459f-472d-afe7-5b914d1a58c9.json and https://artists.proofprofile.net/proofs/artist/fdf3c4ea-459f-472d-afe7-5b914d1a58c9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).