The Case Against Steganography In Perceptually Encoded Media

[Mike Rosing]

On Fri, 13 Sep 2002, David E. Weekly wrote:

> The conclusion is remarkable (to my little mind, at any rate): since most
> media transmitted over the Internet is perceptually compressed (JPG, MOV,
> AVI, MP3, etc.) the efforts to steganographically encode data within most
> Internet media are fundamentally doomed.

Since MP3 and JPG are lossy compression you don't want to use them in
any case - you really screw up the image if you attach random data
to the compressed values, and you lose the data completely if you
try to compress the stegonagraphic info.  So it's not useful for more
basic reasons.

> Where, then, can one hide information streams? The answer is wherever
> *random* information is communicated. (Even just partial randomness is okay;
> I've got a paper on this I hope to be presenting soon!)

It doesn't have to be random, it has to be complete.  Random is definitly
better, but it's unlikely that steganography would be needed if one could
send random data for any reason to begin with.  You want the message to be
invisible, and anyone looking for hidden messages is certain to scan
"random" data and check it for statistics.  The power of statistics makes
steganography really hard.

Patience, persistence, truth,
Dr. mike