Digital Video Watermarking and the Collusion Attack
Roberto Caldelli, Alessandro Piva · IGI Global eBooks · 2011
This chapter is devoted to the analysis of the collusion attack applied to current digital video watermarking algorithms. In particular, we analyze the effects of collusion attacks, with particular attention to the temporal frame averaging (TFA), applied to two basic watermarking systems like spread spectrum (SS) and spread transform dither modulation (STDM). The chapter describes the main drawbacks and advantages in using these two watermarking schemes and, above all, the fundamental issues to be taken into account to grant a certain level of robustness when a collusion attack is carried out by an attacker.