Physical characteristics of wireless communication channels for secret key establishment: A survey of the research

Physical layer security protocols have recently been deployed in the context of Wireless communications. These are derived from the intrinsic characteristics of the communication media for key generation, sharing and randomness extraction. These protocols always seek to exhibit both low computational complexity and energy efficiency, whilst also maintain unconditionally secure communications. We present herein, a comprehensive literature review of existing “state-of-the-art” quantisation schemes for physical layer security, with a strong emphasis upon key performance metrics and intrinsic channel characteristics. Our survey seeks not only to concentrate upon the most common quantisation methods, hence their efficiency during key generation; but also crucially, describes the inherent trade-offs as between these standardised metrics. The exact way(s) in which these metrics are duly influenced by quantisation schemes is also discussed, by means of a comprehensive critical narrative of both existing and future developments in the field.