[6510] in cryptography@c2.net mail archive
Re: The problem with Steganography
daemon@ATHENA.MIT.EDU (Marc Horowitz)
Wed Jan 26 23:15:33 2000
From: Marc Horowitz <marc@MIT.EDU>
To: Dan Geer <geer@world.std.com>
Cc: cryptography@c2.net
Date: 26 Jan 2000 22:27:58 -0500
In-Reply-To: Dan Geer's message of "Wed, 26 Jan 2000 10:54:45 -0500"
Message-ID: <t53901c42ip.fsf@horowitz.ne.mediaone.net>
Dan Geer <geer@world.std.com> writes:
>> My knowledge of media reproduction technology in the large is
>> near zero, but if a color copier can identify itself what is to
>> keep it from identifying the time of day or serial numbering
>> the individual copy or silently including a photo of the
>> operator? Larger still, what's to prevent adding such a
>> fingerprint to every copy of National Geographic, to every film
>> processing lab's printing system, to every copy of every MP3
>> file, to the transmission of every PCS phone, etc., etc.?
This is, more or less, what watermarking tries to do.
>> In short, is steganography the ultimate surveillance tool?
Like most surveillance technologies, this is a game of constant
incremental improvements. You watch me through a window, I put up
curtains. You listen through a hidden microphone, I increase the
background noise. Etc.
As was discussed here a few weeks ago, it's very difficult to do
undefeatable watermarking, and I'd say it's impossible to do
undetectable watermaking in a digital medium (just compare the
documents). My point is that stego could be used as a surveillance
tool, but it would be difficult, and defeating it would be feasible.
Therefore, I don't believe it is the "ultimate" surveillance tool.
Marc
