[4875] in cryptography@c2.net mail archive
Re: personal encryption? (fwd)
daemon@ATHENA.MIT.EDU (Arnold G. Reinhold)
Fri Jun 11 10:05:25 1999
In-Reply-To: <t53k8tbhj1x.fsf@horowitz.ne.mediaone.net>
Date: Thu, 10 Jun 1999 21:53:47 -0400
To: Marc Horowitz <marc@mit.edu>
From: "Arnold G. Reinhold" <reinhold@world.std.com>
Cc: William Knowles <erehwon@kizmiaz.dis.org>, cryptography@c2.net
At 4:55 PM -0400 6/10/99, Marc Horowitz wrote:
>"Arnold G. Reinhold" <reinhold@world.std.com> writes:
>
>>> It seems to me that you could use the DNA encodings for common words like
>>> "the" and "and" as a marker for PCR. A soop of such initiators, followed by
>>> a gel for the longest fragments should crack this code quickly. You might
>>> need a second "backwards" PCR step to recover the very begining of the
>>> message.
>
>So you encrypt the message before DNA encoding it. If the scientist's
>assertions are accurate, just include the key alongside the
>ciphertext. Then you have no known text to PCR for. If you have a
>key distribution mechanism in place, then use that instead, and even
>if they do manage to find your message, they can't decrypt it.
The secret region of DNA they use to start the PCR is a key of sorts so you
will need some secure mechanism for distributing keys in any case.
>
>Of course, this DNA system is just yet another way to to
>stegonography, so all the techniques for doing stego well apply here,
>too.
Right. In particular you will need to mimic to some extent the base-pair
distribution in natural DNA, which I believe is not uniform, even in
regions that do not encode genes. I think it might be possible to pull out
a uniformly pseudo-random DNA string from a large amount of natural DNA.
Arnold Reinhold
