Secret Key Agreement Over Multipath Channels Exploiting a Variable-Directional Antenna

TL;DR

This paper proposes a new key distribution protocol using variable-directional antennas in multipath channels, analyzing its security and improving key agreement with antenna diversity and error correction.

Contribution

It introduces a generalized mathematical model for key distribution with VDA in multipath environments and evaluates security based on mutual locations.

Findings

Simulation-based statistical characterization of VDA

Security estimation based on information leakage

Enhanced key agreement with antenna diversity and error correction

Abstract

We develop an approach of key distribution protocol (KDP) proposed recently by T. Aono et al. A more general mathematical model based on the use of Variable-Directional Antenna (VDA) under the condition of multipath wave propagation is proposed. Statistical characteristics of VDA were investigated by simulation, that allows us to specify model parameters. The security of the considered KDP is estimated in terms of Shannon's information leaking to an eavesdropper depending on the mutual locations of the legal users and the eavesdropper. Antenna diversity is proposed as a mean to enhance the KDP security. In order to provide a better agreement of the shared keys it is investigated the use of error-correcting codes.