nanog mailing list archives

Re: How do you stop outgoing spam?


From: "Majdi S. Abbas" <msa () samurai sfo dead-dog com>
Date: Tue, 10 Sep 2002 13:06:22 -0700


On Tue, Sep 10, 2002 at 12:45:01PM -0700, Al Rowland wrote:
Steganography looked great in that hollywood movie Along Came a Spider
with Morgan Freeman (or at least the 'screen friendly' version they
portrayed) but a recent study of millions of graphics across USENET
found zero steganographic images. Great theory, no examples found in the
wild, other than in Hollywood scripts and some folk trading porn of the
type not usually posted to the public Internet.

        I was going to stay out of this one, but then this came
along.  It is trivially easy to encrypt, transpose, or otherwise
bury the message inside an image, or what have you.

        If I use a PRNG, prearrangement, or some other selection method 
to decide which bytes, or which files, or some combination of both will
receive a chunk of the data to be hidden, and then encrypt it with
a decent enough algorithm, it will not be easy to determine there is
something there at all, particularly in a medium like USENET where lots
and lots of large binary postings are common.

        Just because someone ran through a pile of images using jpegv4
with the jsteg patches, or some similar commercial application, does
not mean it wasn't there -- it just means it wasn't obviously there.

        I myself have encrypted my PGP key's revocation certificates
and buried them in some images on a website as a fallback storage
method.

        Is it widely used?  Probably not.  Is it safe to say it's not
being used on the basis of a quick check with an off the shelf 
utility or two?  No.

        --msa


Current thread: