In this letter, we analyze the secrecy performance of a reconfigurable intelligent surface (RIS)-aided communication system with spatially random unmanned aerial vehicles (UAVs) acting as eavesdroppers. We consider the scenarios where the base station (BS) is equipped with single and multiple antennas. The signal-to-noise ratios (SNRs) of the legitimate user and the eavesdroppers are derived analytically and approximated through a computationally effective method. The ergodic secrecy capacity is approximated and derived in closed-form expressions. Simulation results validate the accuracy of the analytical and approximate expressions and show the security-enhanced effect of the deployment of the RIS.
In this letter, we analyze the secrecy performance of a reconfigurable intelligent surface (RIS)-aided communication system with spatially random unmanned aerial vehicles (UAVs) acting as eavesdroppers. We consider the scenarios where the base station (BS) is equipped with single and multiple antennas. The signal-to-noise ratios (SNRs) of the legitimate user and the eavesdroppers are derived analytically and approximated through a computationally effective method. The ergodic secrecy capacity is approximated and derived in closed-form expressions. Simulation results validate the accuracy of the analytical and approximate expressions and show the security-enhanced effect of the deployment of the RIS.
In this paper, we investigate the secrecy performance of a secure wireless communication system configured with reconfigurable intelligent surfaces (RIS). In particular, a legitimate source sends its private message to a legitimate destination with the aid of an RIS, while a passive eavesdropper intercepts this private information from both source and RIS. Considering this system setup, we first study the statistical analysis of the instantaneous signal-to-noise ratios (SNRs) at the destination and eavesdropper by exploiting the method of moments. Then, we deduce the closed-form expression of the ergodic secrecy capacity (ESC) over independent and identically distributed Rayleigh fading channels. Further, we provide the asymptotic ESC analysis in the high SNR regime to reveal some insightful information. Using the asymptotic ESC analysis, we also analytically present the impact of number of RIS elements on the ESC performance. Lastly, the analytical findings are corroborated via numerical and simulation studies, and show the impact of various involved parameters on the ESC performance.
In this letter, we investigate the secrecy performance of a reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) communication network in the presence of randomly positioned eavesdroppers. We derive closed form expressions for the beamforming vector of the base station (BS) and the phase shifts of the RIS. Considering the colluding wiretap strategy, the secrecy outage probability is obtained in closed form by using the theory of stochastic geometry. Numerical results confirm the effectiveness of our theoretical analysis, demonstrating that increasing the number of BS antennas and RIS elements can significantly enhance the secrecy performance of the system.
In this article, the physical layer security (PLS) is investigated for reconfigurable intelligent surface (RIS)-aided wireless communication systems, where one RIS is deployed to assist the communications between a pair of transmitter (Alice) and receiver (Bob), under a passive eavesdropper (Eve) attack. For the Eve, different from the bounded channel state information uncertainty model, the distribution of the Eve’s location is introduced into the wiretap link. In the proposed system, considering that the Eve can overhear signals transmitted from Alice or reflected by the RIS, two scenarios are studied for RIS-aided secure communication systems: one is that the Eve distributes close to Alice without the RIS orientation, and the other is that the Eve locates close to Bob and in the presence of the RIS. After investigating the probability distribution functions of the Eve’s location and the wiretap link, the novel cumulative density functions (CDFs) of the received signal-to-noise ratios (SNRs) at the Eves are, respectively, derived for the two considered scenarios, taking into account the effects of RIS reflection coefficients, pathloss, and Eve’s location distribution. The closed-form expressions for the probability of the nonzero secrecy capacity and the ergodic secrecy capacity are obtained, providing insights into the impact of the Eve’s location uncertainty and the RIS design on the secrecy performance. Moreover, based on the derived CDFs for received SNRs at Eves, the secrecy outage probabilities are, respectively, analyzed. Specifically, under the constraint of the secrecy outage probability, the closed forms of the minimum required SNRs at Bob and the number of RIS elements are also obtained. Simulation and analytical results corroborate the derived expressions and reveal the tradeoff between the system’s energy efficiency and the number of RIS elements.
This paper investigates the enhancement of security in Rayleigh fading channels using the best reconfigurable intelligent surface (RIS). The study focuses on a scenario involving a single legitimate receiver and a single eavesdropper, both operating over a Rayleigh fading channel. The impact of key parameters such as the eavesdroppers average signal-to-noise ratio (SNR), the number of reflecting elements of a RIS, and the number of RIS is thoroughly examined. Analytical expressions for the ergodic secrecy capacity (ESC) are derived to evaluate the systems secrecy performance. Furthermore, a comparative analysis is carried out between systems with and without RIS integration. The results confirm that deploying RIS significantly improves the ergodic secrecy capacity in wireless systems, thereby providing a foundation for further research and potential realworld implementations.
Physical layer security (PLS) is pivotal for beyond 5G networks in response to the escalating demand for secure and reliable communication across various applications, which remain susceptible to eavesdropping and computational attacks. This study presents an innovative aerial reconfigurable intelligent surface (A-RIS) assisted PLS scheme, wherein a RIS-equipped unmanned aerial vehicle (UAV) amplifies the intended legitimate user's signal while concurrently attenuating the eavesdropper's signal to enhance the secrecy outage probability (SOP). We develop closed-form solutions for the SOP and propose an optimal virtual RIS segmentation strategy, which is subsequently employed in a 3D A-RIS deployment approach to minimize the overall SOP. The numerical findings corroborate the analytical derivations and solutions, revealing that the proposed A-RIS partitioning and 3D A-RIS deployment approach yield superior security compared to conventional PLS benchmarks.
Unmanned aerial vehicles (UAVs) have been extensively utilized in various scenarios due to their flexible mobility and rapid on-demand deployment. It becomes necessary and urgent to examine the secrecy performance of the UAV communication systems due to the open characteristics of the transmission technologies employed in UAV systems. In this paper, we investigate the physical layer security of the UAV communication system, in which the ground base station sends secret messages to the UAV hovering in the air, while a random number of eavesdroppers are randomly located around the ground base station. Using the Poisson point process theory, we obtain the exact and approximate expressions of the cumulative distribution function for the signal-to-noise ratio of the ground-to-air link, and then the analytical expressions of the secrecy outage probability and the average secrecy rate are derived. Finally, the accuracy of the analytical results is validated by Monte Carlo simulation.