Collusion-Resistant Watermarking Using Modified Barni Method

Collusion attacks are effective against fingerprinting schemes. When a watermark is embedded as part of a fingerprinting schemes, it should be resistant to collusion by multiple users who each have a different version of the watermark. However, there is a limitation to detecting the watermark when classical spread spectrum watermarking is used. In this paper, we propose a negative correlation watermarking scheme to resolve this limitation using a modified Barni’s watermarking scheme, which is a method that can be used in many application areas. In particular, the difference between the frequency coefficients and uniformly distributed real numbers is used as the embedded watermark. This method can also be applied to our previously proposed wavelet-based video fingerprinting system.