Jamming Games in the MIMO Wiretap Channel With an Active Eavesdropper

TL;DR

This paper explores strategies for secure and covert MIMO communication in the presence of an active eavesdropper capable of jamming or passive listening, modeling their interaction as a strategic game.

Contribution

It introduces a game-theoretic framework to analyze the interaction between transmitter and eavesdropper, deriving equilibrium strategies under various information scenarios.

Findings

Existence conditions for pure-strategy Nash equilibria.

Characterization of mixed-strategy Nash equilibria.

Optimal strategies under perfect and imperfect information.

Abstract

This paper investigates reliable and covert transmission strategies in a multiple-input multiple-output (MIMO) wiretap channel with a transmitter, receiver and an adversarial wiretapper, each equipped with multiple antennas. In a departure from existing work, the wiretapper possesses a novel capability to act either as a passive eavesdropper or as an active jammer, under a half-duplex constraint. The transmitter therefore faces a choice between allocating all of its power for data, or broadcasting artificial interference along with the information signal in an attempt to jam the eavesdropper (assuming its instantaneous channel state is unknown). To examine the resulting trade-offs for the legitimate transmitter and the adversary, we model their interactions as a two-person zero-sum game with the ergodic MIMO secrecy rate as the payoff function. We first examine conditions for the existence of pure-strategy Nash equilibria (NE) and the structure of mixed-strategy NE for the strategic form of the game.We then derive equilibrium strategies for the extensive form of the game where players move sequentially under scenarios of perfect and imperfect information. Finally, numerical simulations are presented to examine the equilibrium outcomes of the various scenarios considered.