Strategic Status Updates in an Eavesdropping Game

Abstract:
We analyze a system where a transmitter (Alice) sends status updates to a legitimate receiver (Bob), but a fraction of them can be captured by an eavesdropper (Eve). Alice is modeled as a strategic agent that follows a two-fold objective. First of all, she wants to minimize the average age of information at Bob’s side. Yet, she also simultaneously attempts to maximize Eve’s average age of information, so as to avoid that the eavesdropper captures valuable information. Both objectives are combined in a bargaining framework, so as to obtain their tradeoff that ultimately depends on the injection rate of Alice and the probability that Eve intercepts data. At the same time, Eve is also seen as a strategic agent that aims to minimize its own AoI, coming from stolen data, by tuning the eavesdropping probability but subject to a cost. We frame the interaction between Alice and Eve as a static adversarial game of complete information, and we derive and discuss the resulting equilibria. This extension of security aspects to the age of information framework enables a quantitative perspective with possible practical conclusions.