This publication was made possible by NPRP grant #10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. In this paper, we investigate the physical layer security of a wireless communication with a reconfigurable intelligent surface (RIS) and a full-duplex (FD) legitimate receiver over Rayleigh fading channel in the presence of an eavesdropper. In addition, we examine the scenario where the FD receiver is sending a jamming signal while receiving the required message to confuse the eavesdropper. We derive closed form expressions of the intercept probability of two scenarios with and without jamming signal and we also use the strictly positive secrecy capacity (SPSC) metric to gain more insight on the security of our proposed system. To illustrate the analytical analysis, numerical results are provided under different network parameters to study the effect of RIS and jamming technique on the security of FD receiver.
This publication was made possible by NPRP grant #10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. In this paper, we investigate the physical layer security of a wireless communication with a reconfigurable intelligent surface (RIS) and a full-duplex (FD) legitimate receiver over Rayleigh fading channel in the presence of an eavesdropper. In addition, we examine the scenario where the FD receiver is sending a jamming signal while receiving the required message to confuse the eavesdropper. We derive closed form expressions of the intercept probability of two scenarios with and without jamming signal and we also use the strictly positive secrecy capacity (SPSC) metric to gain more insight on the security of our proposed system. To illustrate the analytical analysis, numerical results are provided under different network parameters to study the effect of RIS and jamming technique on the security of FD receiver.
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.
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.
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.
Unlike prior works assuming perfect attack detection, this paper investigates the physical layer security of a simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided network under a full-duplex active eavesdropper in the more realistic scenario where its jamming remains undetected by the legitimate transmitter. Assuming Nakagami-m fading channels, we first derive the probability density functions (PDFs) of the signal-to-interference ratios (SIRs) at both the legitimate user and the eavesdropper. Then, using the PDFs, we obtain novel closed-form expressions for key secrecy metrics, including the probability of nonzero secrecy capacity (PNSC), secrecy outage probability (SOP), and average secrecy capacity (ASC). Moreover, the asymptotic PNSC, SOP, and ASC at high signal-to noise ratio (SNR) are also derived. Based on those asymptotic expressions, we present compact expressions for several key performance indicators: 1) the secrecy diversity order and the secrecy array gain of the SOP, and 2) the high SNR slope and the high SNR power offset of the ASC. Results demonstrate that, compared to the passive eavesdropper scheme, the active jamming attack carried out by Eve will not cause any loss in secrecy diversity gain and high SNR slope, but only result in the loss of secrecy array gain and high SNR power offset. Finally, we verify our analytical results via simulations.
This paper investigates the mathematical modeling of ergodic secrecy capacity (ESC) in securing wireless communication networks enhanced by reconfigurable intelligent surfaces (RIS). The focus is on scenarios involving an eavesdropper and a legitimate receiver operating over a Rician fading channel. Specifically, a RIS is strategically positioned between the source and the receiver to enhance the security of the communication link. Analytical expressions for the ESC are derived, offering key insights into the security characteristics of the system. A comparative evaluation system with best, with RIS, and without RIS deployment is included. Analytical results show that the RIS significantly enhances the ESC of the proposed model, supporting its practical value and opening pathways for further research and implementation in real-world wireless security applications.
Physical layer security (PLS) technologies are expected to play an important role in the next-generation wireless networks, by providing secure communication to protect critical and sensitive information from illegitimate devices. In this paper, we propose a novel secure communication scheme where the legitimate receiver use full-duplex (FD) technology to transmit jamming signals with the assistance of simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) which can operate under the energy splitting (ES) model and the mode switching (MS) model, to interfere with the undesired reception by the eavesdropper. We aim to maximize the secrecy capacity by jointly optimizing the FD beamforming vectors, amplitudes and phase shift coefficients for the ES-RIS, and mode selection and phase shift coefficients for the MS-RIS. With above optimization, the proposed scheme can concentrate the jamming signals on the eavesdropper while simultaneously eliminating the self-interference (SI) in the desired receiver. To tackle the coupling effect of multiple variables, we propose an alternating optimization algorithm to solve the problem iteratively. Furthermore, we handle the non-convexity of the problem by the the successive convex approximation (SCA) scheme for the beamforming optimizations, amplitudes and phase shifts optimizations for the ES-RIS, as well as the phase shifts optimizations for the MS-RIS. In addition, we adopt a semi-definite relaxation (SDR) and Gaussian randomization process to overcome the difficulty introduced by the binary nature of mode optimization of the MS-RIS. Simulation results validate the performance of our proposed schemes as well as the efficacy of adapting both two types of STAR-RISs in enhancing secure communications when compared to the traditional self-interference cancellation technology.