simple Password protect
 

Hi all,
Say i have two hard disks

Disk - A
Disk - B

Now lets assume my friend is working on the linux red hat 2.6 with Disk A mounted with lot of our project files.

Disk -B is of mine , say i wanted to copy some data from Disk-A to Disk-B,
the usally procedure is to mount the Disk -B and use it in my system.

Here are my queries.
1. Say i wanted to secure my friend hard disk with a simple password, what is the
procedure?

I am planning to write simple shell script , should i put that in /rc.d that is at boot time, (if the DISK -A is non bootable && bootable scenario) in DISK -A ? .
So that say if i try to mount DISK -A then try to copy the contents into DISK -B It should prompt for enter password else should not provide access to DISK -A.
I know it is not strong method of protecting, but atleast to start with.


2. If the Disk -B is also bootable disk, then on mounting what will happen?

Regards
Titan:

Bear in mind that if you format any disk with ext3 (the default filesystem) then every file has permission information attached to it, which means that any copy operation from A to B automatically involves a permission check by the active operating system to see whether the current user is allowed to access those files on A.

An attacker may circumvent file permissions on a drive by using an OS which is configured to let them copy anything, i.e. by booting from a Live CD. The defence against this is to encrypt the storage so it cannot be read by any software without being decrypted first: I beleive that the current version of Fedora includes LUKS for encrypting drives, although I haven't played with LUKS yet myself.