Double Umpiring System for Ad Hoc Wireless Mobile Network Security

Protecting the network layer from malicious attacks is an important and challenging issue in both wired and wireless networks. Protection becomes even more challenging in the case of MANET. In this paper we propose a solution based on a double umpiring system (DUS) to provide security for routing and data forwarding operations. In our system each node in the path from source to destination performs both packet forwarding and umpiring. In the umpiring role, each node in the path closely monitors the behavior of the succeeding node and immediately flags the offending node if any misbehavior is noticed. The double umpiring system is sufficiently general to be applied to any networking protocol. As a demonstration, we implemented the double umpiring system as a modification of the popular AODV protocol. Simulations demonstrated that even when 40% of the nodes were malicious and the maximum speed was 20 m/s, DUS throughput was increased by 161.25% and communication overhead increased by 18.5%. This is a vast improvement over the performance of the conventional AODV protocol, with only a nominal increase in overhead.