On Multipath Routing in Multihop Wireless Networks: Security, Performance, and Their Tradeoff

Routing amid malicious attackers in multihop wireless networks with unreliable links is a challenging task. In this paper, we address the fundamental problem of how to choose secure and reliable paths in such environments. We formulate the multipath routing problem as optimization problems and propose algorithms with polynomial complexity to solve them. Game theory is employed to solve and analyze the formulated multipath routing problem. We first propose the multipath routing solution minimizing the worst-case security risk (i.e., the percentage of packets captured by attackers in the worst case). While the obtained solution provides the most security routes, it may perform poorly given the unreliability of wireless links. Hence we then investigate the multipath routing solution maximizing the worst-case packet delivery ratio. As a natural extension, to achieve a tradeoff between the routing security and performance, we derive the multipath routing protocol maximizing the worst-case packet delivery ratio while limiting the worst-case security risk under given threshold. As another contribution, we establish the relationship between the worst-case security risk and packet delivery ratio, which gives the theoretical limit on the security-performance tradeoff of node-disjoint multipath routing in multihop wireless networks.