Cluster based security scheme for mobile ad hoc networks

Secured communication in mobile ad hoc network is a crucial issue due to dynamic nature of the network topology. Due to lack of centralized control, issuing certificates from a centralized certification agent is not possible in ad hoc network. The major problem in providing security services in such infrastructure less networks is how to manage the cryptographic keys that are needed. The unique characteristics of mobile ad hoc networks causes a number of nontrivial challenges to security design such as open network architecture, shared wireless medium, stringent resource constraints and highly dynamic topology. In MANET any node may compromise the packet routing functionality by disrupting the route discovery process. These challenges make a case for building multi-fence security solution that achieves both extensive protection and desirable network performance. We propose a novel cluster based security scheme to protect mobile ad hoc network link layer and network layer operations of delivering packet over the multihop wireless channel. The dynamic network topology can be managed efficiently by the proposed cluster based architecture. A well-behaving node becomes a cluster member after the initial trust verification process. The membership validity period of a node depends on how long it has stayed and behaved well. Non overlapping clusters are created using the dynamic cluster creation algorithm. The cluster construction is fully distributed so efficiency is not degraded by node mobility.