Xdelta is a command line tool for delta encoding, which stores or transmits the difference (deltas) between sequential data, instead of entire files. This is similar to diff and patch, except diff com
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 0x2a819aa68d8f8dc4e7c06b6565510e5f2c05913d363657f97b1c645d75f27e58. Chain 2 (Bitcoin): anchored in block 953978 (2026-06-16T17:11:18Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2c3b2769-7d89-4517-8bea-3c2e8801b6a2.json and https://artists.proofprofile.net/proofs/artist/2c3b2769-7d89-4517-8bea-3c2e8801b6a2.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).