Security pairings using physical layer properties of wireless communications

Abstract

New security solutions in the physical communication layer - secret key extraction from the radio channel and information-theoretic secrecy - protect confidentiality of communication without cryptographic establishment of secret keys. Unfortunately, they currently lack authentication. Cryptographic mechanisms are still needed to secure the first contact between previously unknown devices - to guarantee that security pairings are made as the user intends. In this paper, we contribute by analyzing how five different security pairing approaches can be realized or complemented with physical layer solutions. We propose new solutions for replacing the use of expensive crypto algorithms with secret key extraction. We note that information-theoretic secrecy solutions are less capable of surviving without cryptographic authentication. However, in some information-theoretic secrecy approaches, secure out-of-band delivery of channel state information can authenticate receivers.