Physical Layer Security in Multiuser VLC Systems with a Randomly Located Eavesdropper

Abstract

This paper proposes a secrecy enhancement mechanism for multiuser visible light communication (VLC) systems. Thanks to the inherent advantages of visible light that it cannot penetrate opaque walls and its channel gain largely depends on the distance, VLC systems can serve multiple users at a time with high security and dense spatial reuse. Nevertheless, in the presence of multiple users, the interference caused by other users' signals should be carefully considered when analyzing the secrecy rate and data rate performance measures. By employing a continuous LED model, we formulate an optimization problem to find the optimal set of LEDs that should be used for communication such that the average secrecy rate for the secured user is maximized while satisfying data rate requirements for the other ordinary users. Numerical results are provided to verify that the relative locations of multiple users, the spatial distribution of a random eavesdropper, and the required data rates are significant factors that affect the secrecy performance in multiuser VLC systems.

Secure Visible Light Communication System via Cooperative Attack Detecting Techniques

“…Protected zone [35] Establishing eavesdropping-free zone as protected areas to improve the confidentiality of legitimate users increase when the semiangle of the transmitters increases. Ijaz et al analyzed vulnerability to active attacks by malicious transmitters installed in the VLC system and suggested defensive methods to prevent spoofing and jamming attacks [21].…”

“…One of the response methods of VLC eavesdropping is to select an appropriate LED [33]- [35]. Gargetal.…”

“…When the secrecy rate of the two LED elements chose a better link than using only one LED, the performance corresponding to eavesdropping was better. Cho et al proposed an optimized method for selecting a suitable number of LEDs in a multiuser VLC system, developing an existing study [35] that selects the nearest LED in a single-user VLC system. If many LEDs are selected, not only legitimate users but also eavesdroppers can receive signals, and if fewer LEDs are selected, legitimate users would not receive enough signals; therefore, it is important to select an optimal LED set.…”

Physical-Layer Security for Mobile Users in NOMA-Enabled Visible Light Communication Networks

“…Taking the adopted mathematical tools into account, stochastic geometry theory was used to derive the average secrecy capacity of system while the users were randomly distributed in the room [22]. Optimization theory can also be used to enhance the secrecy performance of VLC systems while satisfying various constraints, such as the LED optical power constraint [23], the peak power constraint to reduce eye damage [16] and the light energy harvesting and dimming control constraint [17]. Taking the eavesdroppers into account, most researches on PLS for VLC networks were performed against external malicious eavesdroppers [16-18, 22, 23], while several have focused on the transmission of confidential information, that is to say, users are kept ignorant about the information not intended for them [19].…”

Cooperative Full-Duplex V2V-VLC in Rectilinear and Curved Roadway Scenarios

“…V2V-VLC can be easily implemented through light-emitting diode (LED)-based headlamps, nowadays equipped in most modern cars, for short-range optical wireless communications [ 4 , 7 ]. The line-of-sight (LOS) communication between the transmitter (LED) and receiver (usually a photodetector (PD) or an image sensor) constitutes a channel with considerably reduced possibility of packet collision and/or interference, which in turn improves the security by preventing information theft and interception techniques [ 8 , 9 , 10 ]. The highly directional V2V-VLC, with reduced field-of-view (FOV), also enables the accommodation of a great number of simultaneous communications, using the total bandwidth for each communication link, in comparison to its RF counterpart [ 11 ].…”