Data Insertion Protection?

[eluser]jamgood96[/eluser]
I'm currently working on a website that displays electrical usage data for a project our company is working on. For the actual data collection I'm using an Arduino that is tied to the internet. I currently having it do a GET request to a function in one of my controllers. This controller then inserts the info into a MySQL database via the proper model. This works fine, but this seems insecure. The Arduino is really limited to just doing a GET or POST request, so I don't know what my options are. Do I have the function require a password prior to allowing submission into the database, then just have the Arduino supply the proper one?

Thanks in advance!