K9 or K-9 most commonly refers to: K9, the nickname of police dogs and the police dog unit itself Canine or Canis, a genus including dogs, wolves, coyotes, and jackals K9 or K-9 may also refer to:
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 0xa7db2e7934211bf789ce11952166ca5ae4a4bcf5f551c7daeba96cea62a1407e. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8c0538be-0e32-46ca-a6e1-1b31c646be0a.json and https://artists.proofprofile.net/proofs/artist/8c0538be-0e32-46ca-a6e1-1b31c646be0a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).