[6410] in cryptography@c2.net mail archive
Re: Blue Spike and Digital Watermarking with Giovanni
daemon@ATHENA.MIT.EDU (Eugene Leitl)
Sun Jan 16 20:50:26 2000
From: Eugene Leitl <eugene.leitl@lrz.uni-muenchen.de>
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Message-ID: <14466.29438.495177.107191@lrz.uni-muenchen.de>
Date: Sun, 16 Jan 2000 17:40:14 -0800 (PST)
To: Paul Crowley <paul@hedonism.demon.co.uk>
Cc: Kevin Milani <kevin@zoetics.com>, cryptography@c2.net
In-Reply-To: <87901qvz0u.fsf@hedonism.demon.co.uk>
Well, the deformations must be smooth, so this just describes an
attack against a certain type of watermarks.
As I said, it is difficult to resiliently watermark a single image.
Paul Crowley writes:
> As far as I know, all fielded watermarking schemes can be defeated
> with simple, invisible distortions of the image - see
>
> http://www.cl.cam.ac.uk/~fapp2/steganography/
>
> for work done by Fabien Petitcolas and Ross Anderson. You don't even
> have to have more than one copy of the picture or know very much about
> the scheme in use.
