Docs/SysAdmin/Security/PhysicalSecurity

Physical security is at least as important as system and network security. Consider these security measures and visit this site for more information.

Keep your station in a locked room
Buy a lockable computer case and lock it
Get the hardware to connect the case to the floor so it is difficult to remove.
Ask for a password when accessing your computer's BIOS
Set up a password in your BIOS so it will not boot without it
Ask for a password when passing arguments to your kernel (this can be configured in lilo or grub
Use grub as it can encrypt the above mentioned password using md5, or:
Use lilo with password="" and run lilo -p to generate a hashed password file as /etc/lilo.conf.shs, rather than storing the password in the clear in /etc/lilo.conf