Comprehensive Physical Layer Security Analysis of FSO Communications Over Málaga Channels

Abstract

In this paper, we study the physical layer security of free-space optical (FSO) communications under different eavesdropping scenarios. More specifically, the secrecy performance of FSO communication employing intensity modulation/direct detection detection is analyzed for the wellestablished Málaga channels. Three different realistic scenarios of eavesdropping are considered by assuming different placement locations for the eavesdropper in the paper. Novel expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) are derived for the considered scenarios, and useful insights are also provided through asymptotic analysis. The results show: (i) When the eavesdropper is placed near the transmitter, atmospheric condition imposes a less significant impact on secrecy performance; (ii) Certain level of correlation can potentially enhance the secrecy performance for FSO communications; (iii) The correlation imposes opposite impacts on the ASC and SOP of FSO communications; and the secrecy performance metrics exhibit a non-monotonic impact with the increase of correlation; (v) When the correlation of the FSO links is too small or too large (i.e., the correlation parameter around 0 or 1), the correlation plays a more significant impact on secrecy performance; and (vi) The asymptotic slope of the SOP is 0.5 for all eavesdropping scenarios under practical FSO channels.

Secrecy Performance Analysis of Parallel FSO/mm-wave System Over Unified Fisher-Snedecor Channels

“…The direct links between 𝑇 and 𝑅 are assumed to be severely faded. Due to the limitations of the eavesdropper location in the FSO systems and the practicality of its operating technique, it is assumed that the eavesdropper 𝐸 1 close to the optical terminal of the legitimate receiver 𝑓, since this is possibly the most probable case for eavesdropping in FSO communications [39] because the legitimate receiver serves as a reference for the The ℱ-distribution describes the FSO link, and this model has very successfully approximated the link's atmospheric turbulence and pointing error impairments. Taking into account the heterodyne detection (HD) techniques for optical signal detection, the PDF, and CDF of instantaneous SNR; 𝛾 𝑇𝑘 , (𝑘 ∈ {𝑓, 𝐸 1 }) of the FSO links are described as follows [40], [41] 𝑓 𝛾 𝑇𝑘 (𝛾) = 𝒜 𝑘 𝛾 𝑘 𝑎 𝑘 2 −1 𝐺 2,2 𝑧 𝑠 𝑑𝑠,…”

“…Fig. 17 represents the SOP derived in (39) for different pointing errors and atmospheric conditions when both eavesdroppers 𝐸1 and 𝐸2 are active. As expected, the SOP with lower 𝜀 and stronger turbulence is greater than with the larger value of 𝜀 and weaker turbulence.…”

Communication Technologies for Smart Grid: A Comprehensive Survey

“…Subsequently, the received light is focused on an optical detector and converted to electrical signals for further information extraction [ 98 ]. Besides the advantages of large data rate with unlicensed spectrum, the FSO communication is also considered to be a more secure technique than the RF communication [ 99 , 100 , 101 , 102 ]. Thanks to the various advantages of FSO communications, FSO link can be part of the backhaul communication network for rural or remote substations monitoring applications.…”

Optical Satellite Eavesdropping

“…In recent research, however, a physical layer security (PLS) has been considered as a relevant solution complementary to cryptographicbased schemes to secure information against eavesdroppers relying on channel characteristics [7]. In particular, PLS has been introduced for FSO communication [8]- [10]. In FSO communication, the eavesdropper should be positioned very close to the communicating peers, so that it can capture the beam that is reflected by the aerosols or gases in the atmosphere [8].…”

“…In particular, PLS has been introduced for FSO communication [8]- [10]. In FSO communication, the eavesdropper should be positioned very close to the communicating peers, so that it can capture the beam that is reflected by the aerosols or gases in the atmosphere [8]. However, if the eavesdropper blocks the laser beam while capturing information, the receiver can notice the leakage of power and thus stop the communication for security issues [9].…”