Re: [dm-crypt] cryptsetup, LUKS, plausible deniability

[Arno Wagner <arno@wagner.name>]

On Sun, Sep 13, 2009 at 10:56:53AM +0200, Tommaso wrote:
> > On Sat, Sep 12, 2009 at 11:53:45PM +0200, Ivan Stankovic wrote:
> >> I'd like to start a discussion about plausible deniability for LUKS (see
> >> http://code.google.com/p/cryptsetup/issues/detail?id=7).
> 
> I think that plausible deniability would be a good thing, even if it is
> somewhat difficult to rely upon (the xkcd strip explains this well
> ihih), and maybe it goes beyond the scopes of LUKS. Nonetheless it would
> be nice to have such an option.

I agree, but "nice" and "worth the effort" are two different things.
Andin addition, with LUKS is very likely not possible to go beyond
what plain dm-crypt offers. Use that.

> One thing I'd like to address however, regarding a possible future
> implementation of truecrypt-style "hidden devices". If you'll ever plan
> to do such a thing, remember that they are absolutely useless (except
> maybe for USB sticks) until it will be not possible to use something
> different from FAT16 for the host device. I tell you this because I had
> many, many difficulties using a hidden device for my home, until at last
> I had to abandon the idea.

It is basically not possible to have a hidden volume or any hidden
datya without raising suspicion. The entropy of the encryoted data
cannopt be hidden and some seemingly random data will always be
presend in the presence of a hidden volume. You can only claim
that this data is not a hidden volume, and you can do the same
already with a plain dm-crypt device. 

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name 
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