I'd like to encrypt my disks. My problem is that I've installed Gentoo at school to show my Comp. Sci. teacher how good it is, but there's this kid that keeps booting into it with a livecd and changing the root password. I'm going to password-protect grub, so he can't just change into single-user mode, but he still has his live cds. I don't know how feasible this is, especially if I want to keep what I have on my disks. It would be a pain to reinstall what I have already, since the school has a slow (read 2-5 kbps) connection.
Many thanks in advance.