Robust and Secure Watermarking for Multimedia Traitor Tracing

This thesis focuses on the design of a robust and secure watermarking technique in the contextof multimedia fingerprinting for traitors tracing; and proposes a complete multimediafingerprinting system. Our work builds on a robust zero-bit watermarking technique `BrokenArrows', and we propose two improvements to make it more robust, especially, to prevent A.Westfeld's denoising attack. Its security aspect is also strengthened in view of some knownand published security attacks, such as A. Westfeld's clustering attack and P. Bas's subspaceestimation attack. Furthermore, we extend its security by considering some unpublishedattacks, introducing a novel secure watermarking scheme, which is based on `a contrario'decision test and a maximization embedding method constrained by imperceptibility and bysecurity. Finally, we propose a complete multimedia fingerprinting system, which is based onthe symmetric q-ary Tardos fingerprinting code, and these improved watermarking techniques.As these watermarking techniques are very robust, we can detect multiple fingerprints in oneattacked block; this allows us to propose two extended accusation methods for the Tardoscode. The experimental investigations show the good performance of our design; it can evendeal with the previously poorly managed attacks like the fusion of documents.tel-00592126,version1-11May2011