Physical-layer wireless security of reconfigurable antennas in line-of-sight channels

Secure transmission is one of the most important aspects of wireless communications systems. In contrast to traditional cryptographic methods, physical layer security exploits the propagation channel to ensure security. It has been proven that a time-varying reciprocal channel can be used to generate secret keys which are secure even when an eavesdropper is located near one of the communicating nodes [1]. For line-of-sight (LOS) and slow-fading channels, reconfigurable aperture (RECAP) antennas have demonstrated their utility for physical layer security [2].