OLSR broadcast security in mobile ad hoc networks

A mobile ad hoc network consists of wireless nodes that build a robust radio network without any pre-existing infrastructure or centralized servers. The risk of malicious attacks makes security an important but difficult issue in this type of network. In military tactical scenarios, multicast and broadcast traffic is generally considered very important. However, designing ad hoc networks for multicast traffic is more difficult than the corresponding design for unicast traffic. Advanced signatures is one method that can be used to improve security for the Optimised Link State Routing (OLSR) protocol. In this report we show that the overhead cost of this solution is very high and further work will be needed to tune the method. Local information is simpler to secure, which can be used for MPR flooding. We have also studied the efficieny of broadcasting with different amounts of information. Our results suggest that Multi-Point Relay (MPR) flooding seems to be a good compromise between efficiency, security and robustness in a mobile ad hoc network