Performance Assessment Of Secure Manet Routing Protocols In Malicious Environment

Mobile Ad-hoc Network (MANET), by virtue of their flexibility and independence of network infrastructures like base stations and unique characteristics such as dynamic network topology, limited bandwidth and limited battery power, routing in this network is a particularly challenging task as compared to a conventional network. In MANET, routing is severely vulnerable to various kinds of routing attacks viz-a-viz:black hole attack, link with holding attack, link spooring attack, replay attack, wormhole attack and colluding mis-relay attack. All of these attacks influence the normal operations of MANET in different ways. With the dynamic network topology in MANET, routing functions are carried out by available nodes since there are fixed base stations. In such routing environment, each node acts both as a router and as a host thus, causes the network to raise security problems for routing processes since nodes in ad hoc cannot be trusted for the non-jeopardized execution of critical network functions. For instance, in a malicious routing environment, a malicious node can launch flooding attack to exhaust the network resources such as bandwidth and to consume legitimate nodes resources such as computational and battery power or to disrupt the routing operation by causing severe degradation in network performance. As a result of all these mentioned above, research in this area became an important and attractive issue to researchers in the recent decades. Our research work is to assess the performance and effectiveness of some secure routing protocols in a malicious environment through by simulating various scenarios of attacks in MANET including ARIADNE and the Secure Ad hoc On-demand Distance Vector routing protocol (SAODV).In achieving the above mentioned goal, we used OPNET (Optimised Network Engineering Tool) simulation tool in our research work to assess and evaluate how malicious nodes can disrupt the routing processes and performances of these four routing protocols:DSR, ARIADNE, AODV and SAODV. In the process, a scenario is set up for data collection and this scenario is run11times with11different values of the mobility pause time ranging from0to100seconds. The data is collected according to two metrics:Packet Delivery Fraction (PDF) and Normalized Routing Load (NLR). In our work, the actual values of the performance metrics in a given scenario are affected by many factors, such as node speed, moving direction of the nodes, the destination of the traffic, data flow, congestion at a specific node, etc. Thus, it was therefore difficult to evaluate the performance of the protocols by directly comparing the acquired metrics from individual scenarios. Hence, we decided to take the average values of multiple simulation runs in order to obtain representative values for the performance metrics. The average values of these11simulation runs are then calculated for the two metrics and used as a baseline to evaluate the performance of routing protocols in a given malicious environments. Furthermore, the simulations are diversified by changing the pause time value of the mobility model from0to100seconds. The average numbers of collected statistics are used to calculate the metrics, and then evaluate the performance of the four routing protocols to determine the impacts of the attacks upon these metrics.According to the analytical results of the simulation experiments, we observed that in a benign environment, given the network setup and mobility model; AODV and SAODV protocols were observed to do better than DSR and ARIADNE. This is due to the high mobility of the nodes, and as such there is a more negative impact upon the operations of the DSR and ARIADNE protocols in such environment. However, the route drop attacks cause the number of received data packets to decrease for all of the protocols and when the number of malicious nodes increases, fewer data packets can get to the destination. The secure protocols such as ARIADNE and SAODV, working in malicious environments with route modification attacks, achieved almost the same high PDF metric as in the benign environments but there is a slight decrease of PDF metric due to more routing packets being generated. As observed in our experiment, in all simulated malicious environments, the normal routing protocols DSR and AODV failed to get data delivered to the destinations and positioning the malicious nodes initially in the middle of the network affects the PDF metrics the most. Furthermore, the ARIADNE protocol did not properly handle the case in which the intermediate nodes return cached routes. We noticed that if this feature is enabled in order to take advantage of faster route discovery time, the protocol may become vulnerable to fabrication attacks and this vulnerability must be removed in order for the cached route feature to be effectively used. However, the SAODV protocol really needs a key management mechanism to work properly in malicious environments.