Summary

Abstract

This chapter presents a summary about wireless physical-layer security for cooperative relay networks. We discuss the challenges and solutions of physical-layer security and their applications for cooperative relay networks. Specifically, the relay selection is studied for enhancing the physical-layer security of wireless communications in the presence of an eavesdropper. Also, a joint relay and jammer selection scheme is presented for wireless physical-layer security, where a relay is used to assist the transmission from the source to destination and meanwhile, a jammer is employed to transmit an artificial noise for confusing the eavesdropper. Additionally, the security-reliability tradeoff (SRT) is analytically formulated for wireless communications, where the security and reliability are measured by using the intercept probability encountered at the eavesdropper and the outage probability experienced at the legitimate destination, respectively. It is demonstrated that as the intercept probability increases, the outage probability decreases accordin3ly and vice versa, showing a tradeoff between the security and reliability. Moreover, two relay selection mechanisms, namely the singe-relay selection and multi-relay selection are devised for enhancing the wireless SRT performance. Finally, the joint relay and jammer selection is re-examined from the SRT perspective, which is capable of improving the wireless security and reliability concurrently.