From: ph@netcom.com (Peter Hendrickson)
Date: Fri, 8 Nov 1996 09:02:42 -0800 (PST)
To: Jim McCoy <cypherpunks@toad.com
Subject: Re: Why is cryptoanarchy irreversible?
Message-ID: <v02140b04aea905f722f8@[192.0.2.1]>
MIME-Version: 1.0
Content-Type: text/plain


At 12:29 AM 11/8/1996, Jim McCoy wrote:
>Peter Hendrickson writes:
>[...]
>>> Get a warrant, search my system, find nothing but a bunch of applications
>>> and a collection of risque (but definitely legal) pictures which I exchange
>>> with a few friends.  You may suspect that when the images are concatenated
>>> in a particular way the low-order bits form a stego filesystem but no one
>>> will be able to prove it in court.

>> Are you concatenating these images by hand?  If so, the level of entropy
>> is probably low enough to recover the information through brute force
>> methods or you are hiding a very small amount of information.

> I hide the relatively small amount of data within a very large amount of
> data which makes it impossible to find.  Data from analog sources, like
> the "real world" (images, sounds, etc) is noisy.  This is a fact of life.
> Because this data is noisy I can hide information in the noise.  As long
> as the information I am hiding maintains the same statistical properties
> of noise it is impossible to pull the information out of the data file unless
> you have the key.  If I am paranoid enough I can make this key impossible
> to discover without a breakthrough in factoring.

Where will you keep your secret key?  Remember, when they go through your
house they bring 20 young graduates from MIT who are just dying to show
how clever they are and save the world at the same time.

> This is the essence of steganography and the nature of signal and noise are
> fundemental principles of information theory.

The concept of noise is not all that well defined, however.  There is no
way to look at a signal and say "this is all noise."  Sometimes physical
theories may lead you to believe that it is all noise.  That is fine
for many applications, but when becomes less convinced of things if
the consequences are severe.

>> If you are not doing it by hand, you own terrorist software and will pay
>> the price.

> Ah yes, terrorist programs like cat and perl and operating systems like
> Linux which contain a loopback filesystem that I can hook a perl
> interpreter into at compile-time (which is enough for me to rewrite the
> program from scratch each time if necessary, unless things like math
> libraries are also outlawed on computers :)  I think that the crypto
> concentration camps are going to be very crowded places.

Can you elaborate on this?  I am curious to know exactly what you are going
to keep in your head and what goes on the disk.  Please post the Perl
code that you would type in from scratch every time.

Peter Hendrickson
ph@netcom.com