Nice idea—sensors are great for precision, but they can be a weak spot if you don’t lock them down. First, give each sensor a unique ID and never let it broadcast that ID openly. Use WPA3 or at least WPA2 with a strong passphrase if you’re connecting over Wi‑Fi. If you can, go mesh‑networked or use a dedicated IoT hub that runs its own isolated VLAN so the sensors stay off your main network. Encrypt the data at rest and in transit; TLS 1.3 is the simplest way to keep eavesdroppers at bay. And don’t forget about firmware updates—set up OTA with signed binaries so you’re not installing a backdoor without noticing. If you want extra paranoia, you can run a tiny, tamper‑evident container on the sensor. That way, if someone pulls it out, they’ll see the logs. Finally, physically, put the sensors in sealed, water‑resistant enclosures and lock the greenhouse’s access. Keeps the plants happy and the data safe.