Security of Watermarking Schemes Against Sensitivity Analysis Attacks

76 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.This conclusion calls for a design framework for watermark detectors encompassing all the requirements on the detector. In order to build such framework, we model sensitivity analysis attacks as a general watermark estimation problem in which the adversary controls how informative the measurements will be about the watermark. We evaluate the fundamental performance limits for the attacker's watermark estimation problem. The inverse of the Fisher information matrix provides an algorithm-independent bound on the covariance matrix of the estimation error. A general strategy for the attacker is to select the distribution of auxiliary test signals that minimizes the trace of the inverse Fisher information matrix. The watermark detector must trade off two conflicting requirements: (1) reliability, and (2) security against sensitivity attacks. We explore this tradeoff and design the detection function that maximizes the trace of the attacker's inverse Fisher information matrix while simultaneously guaranteeing an exponential upper bound on the error probability. Game theory is the natural framework to study this problem, and considerable insights emerge from this analysis. Finally, throughout the thesis, we apply our analysis to image watermarking, for which "good" statistical models are available, and hence the practical value of our work can be illustrated.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD