GZ or gz may refer to: .gz, the file extension for gzip files (GNU zip, an open source file compression program) GZ, an HCPCS Level II modifier meaning an item or service is expected to be denied a
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 0xf02a8a25f3f49247ad6ab441ffab2ecc542687daadce7d75072b0d89bb263a5e. Chain 2 (Bitcoin): anchored in block 954549 (2026-06-20T10:56:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a815d8d3-3ce6-439d-bb78-05372c08c475.json and https://artists.proofprofile.net/proofs/artist/a815d8d3-3ce6-439d-bb78-05372c08c475.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).