Copy attack

The copy attack is an attack on certain digital watermarking systems proposed by M. Kutter, S. Voloshynovskiy, and A. Herrige in a paper presented in January, 2000 at the Photonics West SPIE convention.^[1]

In some scenarios, a digital watermark is added to a piece of

may prohibit making copies of a film which contained a watermark.

The copy attack attempts to thwart the effectiveness of such systems by estimating the watermark given in an originally watermarked piece of media, and then adding that watermark to an un-watermarked piece.^[2] In the first scenario listed above, this would allow an attacker to have an inauthentic image declared authentic, since it contains a watermark. In the second scenario, an attacker could flood the market with content which ordinarily would allow a user to manipulate it as he saw fit, but due to the presence of the watermark, limitations would be imposed. In this way, schemes which sought to limit use of watermarked media may prove to be too unpopular for wide distribution.

In a 2003 paper presented at the

system would not authenticate it.

References