"Ctrl-Alt-Del to login" important for security?

[Tristan Wibberley]

Eduard Giménez wrote:

> Anyway, any computer which is physically accessible is vulnerable (you
> always can stole the HD and work at home ;)).

You can pull a hard disk out through the keyboard or monitor? I'd love 
to see that party trick - it'd be better than taking your underpants off 
without taking your trousers off first :)

A keyboard is only connected to the computer by a cable, just like any 
network terminal, so I don't see the difference between network shell 
security and console security.

 > But with the current system how will you force an user to do some kind
 > of key-combination?
 >
 > I mean, by default we can force the user doing it but it won't stop a
 > malicious user to launch a full screen gdm-like program. Probably the
 > victim user will not press the key combination if he's not prompted to
 > do it, and the malicious user is not going to prompt for it. So we are
 > at the same point.

This can only be done by having the console or X server recognise when a 
trusted binary (running as root) is displaying full screen, not allowing 
any other programs to display over the top of it, and not passing 
keyboard/mouse input on to any other windows - then making a user 
interface change that cannot be duplicated by a non-privileged program.

-- 
Tristan Wibberley