LoRa Packet Protocol

AES-128-GCM encrypted, 28 bytes on the wire:

[4B nonce] [8B ciphertext] [16B GCM auth tag]

Plaintext format (8 bytes)

[2B seq] [1B device_id] [1B event_type] [1B f0_bin] [1B rms_db] [2B reserved]

Security features

• Sequence counter prevents replay attacks
• GCM auth tag ensures data integrity and authenticity
• Sync word provides channel isolation at the RF level