Routing Security in Mobile Ad-hoc Networks

The role of infrastructure-less mobile ad hoc networks (MANETs) in ubiquitous networks is outlined. In a MANET there are no dedicated routers and all network nodes must contribute to routing. Classification of routing protocols for MANET is based on how routing information is acquired and maintained by mobile nodes and/or on roles of network nodes in a routing. According to the first classification base, MANET routing protocols are proactive, reactive, or hybrid combinations of proactive and reactive protocols. According to the role-based classification, MANET routing protocols are either uniform when all network nodes have the same role or non-uniform when the roles are different and dedicated. A contemporary review of MANET routing protocols is briefly presented. Security attacks against MANET routing can be passive and or active. The purpose of the former is information retrieval, for example network traffic monitoring, while the latter is performed by malicious nodes with the express intention of disturbing, modifying or interrupting MANET routing. An overview of active attacks based on modification, impersonation/spoofing, fabrication, wormhole, and selfish behavior is presented. The importance of cryptography and trust in secure MANET routing is also outlined, with relevant security extensions of existing routing protocols for MANETs described and assessed. A comparison of existing secure routing protocols form the main contribution in this paper, while some future research challenges in secure MANET routing are discussed.