Resistance of content-dependent video watermarking to watermark-estimation attacks

One of the key challenges for a watermarking scheme to be mandated in a digital right management (DRM) system is the robustness. This paper is focused on exploring the robustness against the watermark-estimation attacks (WEAs) that are clever at disclosing hidden information for unauthorized purposes without sacrificing media\´s quality. In WEAs, the collusion attack naturally occurs in video watermarking while the copy attack adapts to any media watermarking. In view of this, the aim of this study is to deal with the WEAs by means of a video frame-dependent watermark (VFDW). We begin by gaining insight into the WEAs, leading to formal definitions of "optimal watermark prediction" and "perfect cover data recovery". Subject to these definitions, the video-frame hash is addressed as a constituent component of the VFDW for antiestimation of hidden watermarks. Both mathematical analyses and experiment results consistently verify the antidisclosure capability of the video content-dependent watermarking scheme. Our approach is the first work that takes resistance to both the collusion and copy attacks into consideration.