Today I did the same thing to change the root password and found out the way to stop others from doing it. One way is to use . The other is to use grub password. I chose the later for no particular reason. It was very easy to do and it worked. I think I will stick to that.
The way to do it is :
- start grub shell
- type 'md5crypt'. This will ask you for the new password. Enter the password of your choice.
- This will give you md5encrypted password.
- Put "password --md5
" in /boot/grub/grub.conf.
- Reboot. (You dont have to.. but just to test) :)