From: iang@cs.berkeley.edu (Ian Goldberg)
Date: Sun, 21 Jul 1996 08:14:29 +0800
To: cypherpunks@toad.com
Subject: Re: Opiated file systems
In-Reply-To: <199607172125.RAA09158@unix.asb.com>
Message-ID: <4srkst$2q0@abraham.cs.berkeley.edu>
MIME-Version: 1.0
Content-Type: text/plain


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In article <199607182148.WAA00324@server.test.net>,
Adam Back  <aba@dcs.ex.ac.uk> wrote:
>ie. the attacker can not tell without the hidden file system key (if
>one exists) whether the unused space on your drive is really just
>that: unused space filled with garbage, or whether it is in fact
>another encrytped filesystem.
>
>They might be suspicious, but I don't think they would be able to
>claim you were in comptempt of court, if you provide the 1st key and
>claim there is no other key: the software has support for either 1 or
>2 filesystems.
>
The fixes to the encrypted loopback filesystem support for Linux that
I'll be finishing shortly (hopehopehope) incorporate, among other things,
the following features:

o encrypted filesystems
o stego'ing a filesystem in a large (say audio) file

Now, what if you do this:

Record 1/2 an hour of music from your CD, say at 8k samples/sec, 8 bits/sample,
stereo.  In the _left_ channel, stego your real filesystem.  In the _right_
channel, stego your duress filesystem.  If the cops are suspicious that
you have a huge sound file on your hard drive and they don't believe that
it's just for audio purposes, you could (reluctantly) give up the duress key.

Does this have the properties you want?

   - Ian

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