  A common goal in the areas of secure information flow and privacy is to build
effective defenses against unwanted leakage of information. To this end, one
must be able to reason about potential attacks and their interplay with
possible defenses. In this paper we propose a game-theoretic framework to
formalize strategies of attacker and defender in the context of information
leakage, and provide a basis for developing optimal defense methods. A crucial
novelty of our games is that their utility is given by information leakage,
which in some cases may behave in a non-linear way. This causes a significant
deviation from classic game theory, in which utility functions are linear with
respect to players' strategies. Hence, a key contribution of this paper is the
establishment of the foundations of information leakage games. We consider two
main categories of games, depending on the particular notion of information
leakage being captured. The first category, which we call QIF-games, is
tailored for the theory of quantitative information flow (QIF). The second one,
which we call DP-games, corresponds to differential privacy (DP).
