Petz is a series of single-player video games dating back to 1995, in which the player can adopt, raise, care for and breed their own virtual pets. Developed by PF.Magic, original Petz (Dogz and Catz)
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 0x5284cc06ef3c33c045ad7a293837f05ff1c1c7d0cbefd72b6071e2577016dc3b. Chain 2 (Bitcoin): anchored in block 953768 (2026-06-15T09:30:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bf8647e8-f39c-42ba-b3e3-fc0c44a49ebd.json and https://artists.proofprofile.net/proofs/artist/bf8647e8-f39c-42ba-b3e3-fc0c44a49ebd.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).