Game theory can provide a useful tool to study the security problem in mobile ad hoc networks (MANETs). Most existing
work on applying game theories to security only considers two players in the security game model: an attacker and a
defender. While this assumption is valid for a network with centralized administration, it may not be realistic in MANETs,
where centralized administration is not available. Consequently, each individual node in a MANET should be treated
separately in the security game model. In this paper, using recent advances in mean field game theory, we propose a novel
game theoretic approach for security in MANETs. Mean field game theory provides a powerful mathematical tool for
problems with a large number of players. Since security defence mechanisms consume precious system resources (e.g.,
energy), the proposed scheme considers not only the security requirement of MANETs but also the system resources.
In addition, each node only needs to know its own state information and the aggregate effect of the other nodes in the
MANET. Therefore, the proposed scheme is a fully distributed scheme. Simulation results are presented to illustrate the
effectiveness of the proposed scheme.