Challenges in Physical Layer Security for Visible Light Communication Systems

Abstract

This article highlights challenges associated with securing visible light communication (VLC) systems by using physical layer security (PLS) techniques. Motivated by the achievements in PLS studies for radio frequency (RF) communication, many PLS techniques for VLC systems were also rigorously investigated by tailoring the RF techniques to the VLC environment. However, careful consideration of the inherent differences between RF and VLC systems is still needed. By disregarding these differences, an eavesdropper could be given an opportunity to wiretap the VLC systems, even when PLS techniques are employed to protect them. Crucially, the fact that it is often not possible to know the number and locations of eavesdroppers in real VLC systems may allow eavesdroppers to devise various cooperative eavesdropping methods. By examining a few examples of the possible eavesdropper threats that can occur in VLC systems, this article offers novel insights into the vulnerabilities of state-of-the-art PLS schemes for VLC systems. Although the focus of the paper is mostly on these weaknesses, some potential solutions are also briefly proposed with a view to stimulating discourse in the community.

Enhanced secrecy outage probability for multiple‐input single‐output‐VLC systems through optical beamforming and improved light emitting diodes deployment

“…In recent years, Cho et al have investigated PLS from different angles [3,[22][23][24][25][26][27]. More precisely, in Ref.…”

“…According to (6), the instantaneous SNR at receiver type k ∈ { B , E } using beamforming (denoted γ k ), is written as follows: $$${\gamma }_{k}=\frac{{\alpha }^{2}{P}_{DC}^{2}{\mathbf{h}}_{k}^{T}\mathbf{w}{\mathbf{w}}^{T}{\mathbf{h}}_{k}}{{\sigma }_{n}^{2}}.$$$ Provided that γ B ≤ γ E , the secrecy capacity C S writes [27]. $$${C}_{S}=\underset{\mathrm{Pr}[s(t)]}{\mathrm{max}\,}\left\{\mathbb{I}\left(s;{y}_{B}\right)-\mathbb{I}\left(s;{y}_{E}\right)\right\},$$$ where $$\mathbb{I}\left(s;{y}_{k}\right)$$ is the mutual information between the binary OOK signal s ( t ) and the received signal at the receiver type k ∈ { B , E }, y k , which is defined in (6).…”

“…[3], they used the classical zero‐forcing (ZF) beamforming strategy to simultaneously deal with active and passive EDs in VLC systems. Very recently in [27], the challenges associated with secure VLC systems by using PLS techniques and the susceptibility to various eavesdropping attacks is highlighted. In Ref.…”

Physical layer security based on scrambling of the telecommunication system parameters driven by a quantum key distribution system

“…In terms of confidentiality, Free-Space Optical (FSO) transmission is regarded as less sensitive than the RF transmission. The challenges and advantages of optical mediums have been exposed in [9] - [11].…”

A Monte-Carlo/FDTD Study of High-Efficiency Optical Antennas for LED-Based Visible Light Communication

“…Visible light (VL) [ 14 ], ultraviolet (UV) [ 15 ], and infrared radiation (IR) [ 16 ] are the optical bands used as the propagation medium in OWC technology [ 2 ]. VLC (Visible Light Communication) is one of the most promising areas of OWC technology that utilizes the spectrum of visible light in the electromagnetic spectrum (400–800 THz) as a way to carry data as a carrier wave [ 6 , 14 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”