University of Bristol
Information security has become a pivotal concern in wireless communications, due to the fact that the broadcast nature of the wireless medium allows eavesdroppers to intercept transmissions in the network. Traditionally, cryptographic protocols have been designed and implemented to provide security in the upper layers (e.g., the network layer), based on the assumption of an error-free link in the physical layer. In wireless scenarios, the secret key distribution and management may be expensive and vulnerable to attacks. Therefore, research efforts have been devoted to physical layer security, which exploits the characteristics of wireless channels to provide secure data transmission. Pioneering work on physical layer security considered a wiretap channel with single antennas at the transmitter, the receiver, and the eavesdropper.