How do you stop outgoing spam?

Tue Sep 10 20:06:22 UTC 2002

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