Towards an Integration of Security and Quality of Service in IP-Based Mobile Ad Hoc Networks

Security and quality of service (QoS) are two areas of mobile ad hoc network (MANET) research which have so far been largely carried out separately. Some of the unique characteristics of MANETs make them extremely vulnerable to security attacks, and these attacks have a direct impact on QoS provisioning. We therefore argue that integrating security and QoS may be the most effective way of providing QoS in MANETs which contain malicious nodes, and hypothesize that context-aware adaptive multi-path routing may mitigate the damaging effects of denial of availability (DoA) attacks, thus bettering QoS provisioning. As our first step towards validating this hypothesis, this paper investigates whether a single path should be sought using a reservation-based or a non-reservation-based approach. We compare INSIGNIA, an adaptive, reservation-based approach to QoS in MANETs, with Dynamic Source Routing (DSR), a best-effort MANET routing protocol, using simulation. The performance of these two approaches is evaluated in the presence of a variable number of malicious nodes executing blackhole and grayhole data packet forwarding attacks and a denial of QoS request attack. The simulation results show that INSIGNIA outperforms DSR in terms of packet delivery ratios when the traffic load is at a low-to-medium level and the threat level is at a medium-to-high level, although these delivery ratios are much lower than those achieved in a non-malicious network environment. These findings indicate that under certain conditions, e.g., when the network traffic level is high and the threat level is medium-to-high, INSIGNIA's single-path adaptation mechanism is no longer sufficient, and adaptive multi-path routing may help to better QoS support.