So you're working on a system where people you don't trust have root? You're basically screwed. Since they have root there's nothing they can't do. For example, suppose you succeed in hiding the password in your script - what's to stop your adversary from making a copy of your script and changing it to do whatever she wants, using your password?

I suggest you find a different machine to work on or convince the powers that be to restrict access to root.

-sam