Effect of Intrusion Detection on Reliability of Mission-Oriented Mobile Group Systems in Mobile Ad Hoc Networks

For mission-oriented mobile group systems designed to continue mission execution in hostile environments in the presence of security attacks, it is critical to properly deploy intrusion detection techniques to cope with insider attacks to enhance the system reliability. In this paper, we analyze the effect of intrusion detection system (IDS) techniques on the reliability of a mission-oriented group communication system consisting of mobile groups set out for mission execution in mobile ad hoc networks. Unlike the common belief that IDS should be executed as often as possible to cope with insider attacks to prolong the system lifetime, we discover that IDS should be executed at an optimal rate to maximize the mean time to failure of the system. Further, the optimal rate at which IDS is executed depends on the operational conditions, system failure definitions, attacker behaviors, and IDS techniques used. We develop mathematical models based on Stochastic Petri nets to identify the optimal rate for IDS execution to maximize the mean time to failure of the system, when given a set of parameter values characterizing the operational conditions, and attacker behaviors.