On the Secrecy Capacity of Wiretap Visible Light Communication Channels

Abstract

With the rapid increase of data traffic on the network, expected to triple between 2016 and 2021, which also drives a larger security concern, it becomes essential to explore ways to increase the bandwidth of the network. Given that the RF spectrum is scarse and fully licensed, we explore the optical spectrum as a new and unexplored resource. Visible Light Communicatiin (VLC) uses optical waves to transmit data wirelessly in the optical spectrum, which is currently underutilized and readily available for the network, and offers faster data rates and better security guarantees. In this paper, we investigate the secrecy capacity of VLC systems, which is the maximum rate of information that can be sent through a VLC channel while keeping that information secure from an adversary. While finding closed form expressions for secrecy capacity of the VLC channel is difficult, tight upper and lower bounds for the single-input-single- output (SISO) VLC channel are found, and high secrecy rates are achieved using discrete input distributions. Optical Space Shift Keying (OSSK) is also proposed as a novel multiple-input-multiple-output (MIMO) modulation scheme, and is proven through computer simulations to provide substantial security perfromances.