[11142] in cryptography@c2.net mail archive
Re: Maybe no stego on eBay afterall
daemon@ATHENA.MIT.EDU (Nelson Minar)
Fri Jul 19 16:00:59 2002
Date: Fri, 19 Jul 2002 11:14:50 -0700
From: Nelson Minar <nelson@monkey.org>
To: Peter Wayner <pcw2@flyzone.com>
Cc: Hadmut Danisch <hadmut@danisch.de>,
cryptography@wasabisystems.com
In-Reply-To: <E17Vc2C-00022m-00@smtp10.atl.mindspring.net>
>The basic scheme is very simple. Generally the inserted message has
>higher entropy than the raw LSBs of an image. So the entropy of the
>picture/message combo should be higher than the picture alone.
That's only for lousy steganography. If you really want to mask your
message, you match it to the statistical profile of the source data.
Of course that's difficult to do perfectly and so is potentially
detectable, but you can make detection much harder than "look for
white noise in the LSB".
>So even though there's some cool science in the process, there's no
>scientific way to draw the line.
I agree. Maybe the good folks at WetStone just draw the line in
whatever place is best for their business at the time. Or maybe they
made an honest mistake. Either way, now their president is on record
drawing the line in two radically different places.
nelson@monkey.org
. . . . . . . . http://www.media.mit.edu/~nelson/
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