Enhance communication security in wireless ad hoc networks through multipath routing

The specific characteristics of Mobile Ad Hoc Networks (MANETs) make cooperation among all nodes and secure transmission important issues in its research. A number of research studies using single path or multipath transmission to safeguard communication against intermediate node misbehavior have been conducted. In this dissertation, we propose and evaluate a novel secure scheme, MultipAth Routing Single-path transmission (MARS), to secure data transmission in ad hoc networks. The MARS scheme is proposed from the cross-layer perspective. Multipath routing, single path data transmission, and end-to-end feedback mechanism are combined to provide better network performance and more comprehensive protection against misbehavior on data formed by individual or colluding misbehaving nodes. The MARS scheme, its enhancement E-MARS, the secure transmission protocol TWOACK, and the DSR protocol are evaluated by means of simulation under various adverse scenarios. The simulation results show that the MARS and E-MARS provide considerable protection to ad hoc networks at the expense of moderate overhead. In a network with 20% misbehaving nodes, the MARS and E-MARS have up to 45% higher data receive rate than the DSR under individual misbehavior. The data receive rates of MARS and E-MARS are higher up to 50% and 28% respectively under individual or colluded misbehavior with 40% misbehaving nodes in the network.; To compare our protocols with multipath secure schemes, we also assess the impact of interactions between MAC-layer protocols and data forwarding along network-layer paths on multipath data transmission over multihop IEEE 802.11 MAC-based wireless networks. The frame service time at source in 802.11 MAC-based multipath data transmission system under unsaturated conditions is studied. Analytical models have been developed for two packet generation schemes (round robin and batch) with Poisson frame arrival process. Moreover, an analytical model is used to investigate the throughput of multipath transmission system in 802.11-based multihop wireless networks. Two methods have been developed to estimate the impact of cross-layer interactions on the frame service time in such a system. Two bounds of the system throughput are obtained based on these estimation methods. These models are validated by means of simulation under various scenarios.