Mobile Intelligence

18.1 INTRODUCTION

A mobile ad hoc network (MANET) is a shortlived collection of heterogeneous mobile nodes, in which nodes communicate among themselves by forwarding packets through intermediate nodes. Security is paramount in such networks, as they are not conducive for centralized trusted authorities due to mobility and dynamically changing topologies.

Although several secure routing protocols [1–5] have been proposed to authenticate the intermediary nodes and to verify the integrity of discovered path, they are not designed to evaluate the trustworthiness of intermediary nodes. This is so required to isolate previously identified malicious nodes and to dynamically choose trustworthy nodes to enhance the security of communications. Consequently, it has resulted in the development of numerous trust and reputation models [6–16], where a node's trust model captures evidence for the trustworthiness of other nodes in order to execute the decisions such as, whether to send a packet to or forward a packet on behalf of other nodes. Note that this approach is collectively known as detection–reaction approach. It is also noted that the evidence may be captured through passive monitoring, link layer acknowledgements, and recommendations. However, these models either modify basic routing operations or introduce additional issues to capture evidence for the trustworthiness of other nodes. Especially in the context of recommendations, they either struggle to resolve a recommender's bias or ...