A Distributed Trust Model for Securing Mobile Ad Hoc Networks

In mobile ad hoc networks, the security enforcement and its implementation becoming increasingly difficult due to quasi-static nature of the mobile nodes (wireless communication devices), no fixed network topology and more importantly absence of centralized authority. In such networks, communication links between nodes may be bandwidth constrained, messages typically roamed in multi-hoped fashion, nodes may be powered by limited energy source and also have limited physical security. The major challenge in such networks is to give a robust security solution. The complexity of the problem is compounded by the fact that both active and passive attackers may present in the system, and nodes may not function properly in order to save its own energy by selective forwarding of the packets. This paper presents a distributed trust based security framework for ad hoc networks. We have proposed a clustering mechanism and security is enforced by local monitoring system by a new kind of nodes referred as guard nodes. This framework stems from cryptographic computation, which is not suitable in this scenario. The trust is computed depending upon some parameters which have a primary role in enforcing security and cooperation between the nodes. Also this solution conforms graceful leave and dynamic secure allocation of IP of the nodes.