>It's not meant to be a physical means of copy prevention. What it does
>is give the real owner the legal proof necessary to prove the
>copywritten image was stolen.


This is the goal. But unfortunately, as I said in a previous post, the
technology is not ready yet so you cannot use it to prove anything. People
are working hard on this problem but no theory for "perfect covertness" is
available yet so everything is based on experiments: some propose new
marking schemes others write software to destroy these... just like for
cryptography.

Fabien.
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Fabien Petitcolas, Computer Laboratory, University of Cambridge
Cambridge CB2 3QG, [log in to unmask], http://www.cl.cam.ac.uk/~fapp2/