Tracing Illegal Users of Video: Reconsideration of Tree-Specific and Endbuyer-Specific Methods

In our recent study, we have presented an approach for tracing illegal users in content distribution networks using watermarking and fingerprinting techniques [1][2]. In this paper we generalize our previous work, further the collusion robustness is supplemented by additional security and practical experiment. This includes a more efficient tree decision method, generalization of the fingerprinting system and detailed investigation of the robustness against collusion attacks. Content is distributed along a specified tree, with the seller as the root, and the buyers as the internal nodes or leaves. The fingerprinting step is achieved by the insertion of unique information in the video wavelet coefficients by temporal wavelet transform. Our system is able to detect the fingerprint even if the video content has been distorted by collusion attacks.