Steganalysis and Game Equilibria

Abstract

Steganography is the study of methods of concealing data in the noise of another data set. Steganalysis is the field of discovering hidden data and disrupting covert channels. We introduce a two-player, zero-sum, matrix game for the purpose of modeling the contest between a data-hider and a data-attacker. We then solve the game for equilibria, demonstrating that the form of the solution depends on whether the permitted distortion is less than or greater than d _c, the critical distortion. This critical point is a simple function of several parameters which define the game. We then solve two example cases to demonstrate the ideas presented in the general solution. The value of the game is the amount of information that may be reliably stored in the data set.