Experimental validation of wireless secret key agreement using array antennas

This paper considers the problem of wireless secret key agreement based on radio propagation characteristics, where two legitimate parties generate and share a secret key by exploiting the radio propagation characteristics between them in the presence of an eavesdropper. We developed an experimental system using array antennas to implement the wireless secret key agreement. In this paper, we present the experimental system and validate basic characteristics that are fundamental for the wireless secret key agreement, such as the reciprocity and position dependence of radio propagation characteristics, with the developed system.