5. Secure Routing

Due to the advantages of low computational complexity, easy implementation in a distributed manner and no need to distribute/manage secret keys, applying the PLS technology to protect transmission security in various wireless communication systems has been attracting considerable academic attention recently. Existing studies on the design of PLS-based schemes mainly focus on either the single-hop (point-to-point) or two-hop relay communication systems. Although these studies have made great progress, they are not applicable to multi-hop network scenarios. In many cases, wireless nodes (devices) adopt short-range communication due to power limitations. Hence, data of a source may need to be forwarded by several intermediate nodes to reach its destination when the distance between the source and destination is far. In this context, it is essential to leverage a routing scheme to establish the route (path) for end-to-end data delivery. However, the PLS-oriented routing design for multi-hop wireless communication systems still remains largely uninvestigated and needs to be addressed carefully. This chapter introduces the PLS-based secure routing design. In Sect. 5.1, we present a security/QoS-aware route selection mechanism in multi-hop wireless ad hoc networks under different forwarding strategies. In Sect. 5.2, we show the PLS-based secure routing schemes that can achieve optimal security-QoS tradeoffs. In Sect. 5.3, we investigate the secure routing design taking into account the selfishness of cooperative jammers. The common performance metrics used in this chapter include SOP and connection outage probability (COP), where the former defines the probability that the SINR at one or more eavesdroppers is above a fixed threshold and the latter represents the probability that the SINR at the intended receiver is below a required threshold. SOP and COP serve as the metrics of security and QoS of the communication, respectively.