Investigations on secure on demand multicast routing protocols for MANETs

Abstract

A Mobile Ad hoc NETwork (MANET) is an autonomous collection of mobile users forming a temporary network that communicate over relatively bandwidth constrained wireless links. Multicast Ad hoc On demand Distance Vector Routing protocol (MAODV) and On Demand Multicast Routing Protocol (ODMRP) do not include any provisions for security. The existing routing protocols are optimized to spread updated routing information quickly when network topology changes without considering the security problem. MAODV and ODMRP messages are basically assumed to be trusted. The authentication mechanism suitable for MANET should be feasible for highly changing network topology with low computational complexity and low bandwidth consumption In this context, a certificate based authentication mechanism has been proposed for security enhancement in reactive multicast routing protocols to counter the influence of malicious nodes. Our simulations show that the proposed techniques can greatly improve the network performance in the presence of malicious nodes. Blackhole Secure MAODV (BHS-MAODV), Blackhole Secure ODMRP (BHS-ODMRP), Wormhole Secure MAODV (WHS-MAODV) and Wormhole Secure ODMRP (WHS-ODMRP) are as effective as MAODV and ODMRP in discovering and maintaining routes in addition to providing the required security. Security is implemented on top of the route discovery process of MAODV and ODMRP. There are no modifications made to the RREQ and RREP messages. Certified RREP messages are appended with the certificates to allow authorized nodes to participate in the routing process. This authentication mechanism eliminates the need for a centralized trusted authority which is not practical in MANETs due to their self organizing nature. Our simulation results show that even though the performance of all multicast protocols degrades, in terms of packet delivery as the number of malicious nodes increases, the impact of the attack is more severe in tree based protocols compared to mesh based protocols for almost all scenarios. newline newline newline