Physical-Layer Security of a Binary Data Sequence Transmitted With Bessel–Gaussian Beams Over an Optical Wiretap Channel

Abstract

When an eavesdropper performs an optical beam-splitting attack in a freespace optical communications channel, it is referred to as an optical wiretap channel, which is an extension of Wyner's wiretap channel model. Even though physical-layer security can be compromised, it is possible to exploit the noisy and degraded channel conditions experienced by the eavesdropper to obtain positive secrecy capacity even when a shared secret key is not used. In our previous work, we found that employing Bessel-Gaussian beams can help to improve physical-layer security and provide higher secrecy capacity over that of Laguerre-Gaussian beams in a turbulent free-space optical communications channel. In this companion paper, we conducted an experiment exclusively with Bessel-Gaussian beams onto which we encoded a pseudorandom binary sequence to emulate data transmission over this optical wiretap channel. Bit-error rate curves for the intended receiver and the eavesdropper were calculated from which estimates of secrecy capacity were derived. We found that the bit-error rate curves for the eavesdropper were consistently worse than those of the intended receiver under several turbulence conditions and that further evidence of an error floor even when the eavesdropper uses an optical amplifier is promising for secure communications.

A Survey on Physical Layer Security for FSO Communication Systems

“…[27] investigates throughput of MIMO under-attack of a multiple-apertures eavesdropper (MIMO-ME) for coherent FSO.Furthermore, to analyse the overall system performance across the turbulence fading channel, adaptive and fixed transmission rate techniques are examined depended on the availability of the CSI at the transmission side constrained by the probability of a secrecy outage [27]. The authors of [28] performed an experiment utilizing Bessel-Gaussian (BS) beams to emulate data transmission across an eavesdropping channel under various AT conditions. Even when the eavesdropper can perform optical beam-splitting attacks in the channel to compromise PLS, and even when the legitimate transmitter and receiver do not use a shared key for communications, this study focused on achieving secure FSO communication by exploiting the noisy and degraded channel conditions [28].…”

“…The authors of [28] performed an experiment utilizing Bessel-Gaussian (BS) beams to emulate data transmission across an eavesdropping channel under various AT conditions. Even when the eavesdropper can perform optical beam-splitting attacks in the channel to compromise PLS, and even when the legitimate transmitter and receiver do not use a shared key for communications, this study focused on achieving secure FSO communication by exploiting the noisy and degraded channel conditions [28]. Under diverse AT settings, the authors of [19] combine FSO with the secret key agreement (SKA) to identify information security concerns and achieve secret key rates high-speed communications via FSO link.…”

Position‐sensitivity security transmission with orbital angular momentum directional modulation based on frequency diverse array

“…Thus OAM transmission technique is promising for communication schemes 25 . For quantum and optical fields, OAM physical‐layer security mainly employs the quantum key distribution protocol of entangled photon pairs, hybrid free space optics‐THz technology and OAM multiplexing 26‐30 . So far, there are many methods to generate OAM beam, 31‐35 where the uniform circular array antenna (UCA) has been extensively studied for its flexibility in generating OAM modes.…”

“…25 For quantum and optical fields, OAM physical-layer security mainly employs the quantum key distribution protocol of entangled photon pairs, hybrid free space optics-THz technology and OAM multiplexing. [26][27][28][29][30] So far, there are many methods to generate OAM beam, [31][32][33][34][35] where the uniform circular array antenna (UCA) has been extensively studied for its flexibility in generating OAM modes. Since the message can be encoded on the OAM mode generated by the uniform circular FDA and OAM mode can be observed in the desired region only, the security with OAM mode modulation is enhanced.…”

Multitarget Position-Sensitivity Security Transmission with OAM-DM Based on FDA

“…us, OAM transmission technique is promising for communication scheme [25,26]. In the field of quantum and optics, OAM physical-layer security mainly employs the quantum key distribution protocol of entangled photon pairs, hybrid free space optics-THz technology, and OAM multiplexing [27][28][29][30]. So far, there are many methods to generate OAM beam [31][32][33][34][35][36], where the uniform circular array antenna (UCA) has been extensively studied for its flexibility in generating different OAM modes.…”