Vulnerabilities of wireless key exchange based on channel reciprocity

Abstract

Wireless key exchange on the physical layer is a key exchange protocol independent of computational assumptions. It relies only on the physical properties of the wireless channels to generate a common secret key between two parties. Precise conditions, however, for such a key exchange to be secure remain unclear. An argument why unconditional security does not hold for general scenarios is provided. Finally, a novel side-channel attack against such key exchange schemes is described and experimentally validated. © 2011 Springer-Verlag.