Trust Establishment Based on Bayesian Networks for Threat Mitigation in Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), security is a challenging research topic due to the special characteristics of MANETs, such as no pre-defined infrastructure, unreliable link connections, and nomadic nature. Trust-based schemes are considered as effective mechanisms associated with cryptographic techniques for thwarting a variety of attacks, e.g., Packet drop attacks. Because of the properties of MANETs, trust establishment needs an intelligent approach to identify attackers' misbehavior. In this paper, we focus on mitigating threat from attackers who deliberately drop and modify packets. We propose a scheme of trust establishment based on Bayesian networks, which can effectively perform causal reasoning. Based on this model, other causes, e.g., Unreliable wireless connections, which also can result in packet dropping, will be distinguished from maliciousness and thus, a more accurate trust can be calculated. Simulation results demonstrate the performance and effectiveness of the proposed scheme in malicious environments.