Motion-compensated inter-frame collusion attack on video watermarking and a countermeasure
P. Vinod, Prabin Kumar Bora · IEE proceedings. Information security · 2006
One of the challenging issues in video watermarking is its robustness to inter-frame collusion attacks. These attacks exploit the inherent redundancy in the video frames or in the watermark to produce an unwatermarked copy of the video. A basic inter-frame collusion attack is the frame temporal filtering (FTF). In this attack, temporal low-pass filtering is applied to the watermarked frames to remove temporally uncorrelated watermarks. If the video frames contain moving objects and/or there is camera motion, temporal low-pass filtering introduces visually annoying ghosting artifacts in the attacked video. Thus the applicability of the FTF attack is limited by the motion of the objects in the scene and that of the camera. We propose an extended FTF attack which overcomes this limitation by exploiting the motion within the video frames. The attack is based on the motion-compensated redundant temporal wavelet transform (MC-RTWT) of the watermarked frames. The lifting-based MC-RTWT is applied to the video frames in a scene and the resulting low-pass temporal frames constitute the attacked video. Experimental results presented in this paper confirm the effectiveness of the proposed attack over the FTF attack. A motion-coherent video watermarking scheme in the motion-compensated temporal wavelet transform (MC-TWT) domain is also presented as a countermeasure to this extended FTF attack. The proposed watermarking scheme is shown to be resistant to the extended FTF attack and other inter-frame collusion attacks.