As 5G mobile communication technologies present new challenges to assuring security and privacy, physical layer security (PLS), which comprises methods to improve data security via physical layer techniques, offers a new pillar of protection. Coordinated multi-point is a transmission technique to enhance signal reception especially for users at cell edges. In this study, we propose a PLS scheme involving CoMP coupled with beamforming and service-based power management. A certain level of geographical isolation for the coverage of the signal for the typical legitimate user is achieved. The proposed scheme is evaluated on simulated scenarios based on real-life mobile network topology data. As a Figure of performance, the secure and successful detection probability is computed with varying antenna array size, number of coordinated transmission points, and different service requirements. The improvement of the area where the legitimate user is vulnerable to security outage is also illustrated.
As 5G mobile communication technologies present new challenges to assuring security and privacy, physical layer security (PLS), which comprises methods to improve data security via physical layer techniques, offers a new pillar of protection. Coordinated multi-point is a transmission technique to enhance signal reception especially for users at cell edges. In this study, we propose a PLS scheme involving CoMP coupled with beamforming and service-based power management. A certain level of geographical isolation for the coverage of the signal for the typical legitimate user is achieved. The proposed scheme is evaluated on simulated scenarios based on real-life mobile network topology data. As a Figure of performance, the secure and successful detection probability is computed with varying antenna array size, number of coordinated transmission points, and different service requirements. The improvement of the area where the legitimate user is vulnerable to security outage is also illustrated.
Wireless networks have become imperative in all areas of human life. As such, one of the most critical concerns in next-generation networks is ensuring the security and privacy of user data/communication. Cryptography has been conventionally used to tackle this, but it may not be scalable (in terms of key exchange and management) with the increasingly heterogeneous network deployments. Physical layer security (PLS) provides a promising alternative, but struggles when an attacker boasts a better wireless channel as compared to the legitimate user. This work leverages the coordinated multipoint concept and its distributed transmission points, in conjunction with channel shortening, to address this problem. Results show significant degradation of the bit-error-rate experienced at the eavesdropper as compared to state-of-the-art channel shortening-based PLS methods.
5G network is expected to support massive user connections and exponentially increasing wireless services, which makes network security unprecedentedly important. Unlike traditional security-guaranteeing techniques which rely heavily on cryptographic approaches at upper layers of the protocol stack, physical-layer security (PLS) solutions fully take advantages of the characteristics of wireless channels to degrade the received signal qualities at the malicious users, and realize keyless secure transmission via signal design and signal processing techniques. PLS avoids the difficulties in the distribution and management of secret keys, and provides flexible security levels through adaptive transmission protocol design. Moreover, PLS techniques match the features of 5G networks well. Therefore, the application of PLS to 5G networks is a promising solution to address the security threats. This article presents a comprehensive review of the state-of-the-art PLS techniques, and discusses their applications in 5G networks. We first summarize the principle and advantages of PLS techniques, and point out the reasons why PLS is suitable for 5G networks. Then, we review the existing PLS methods in literature, and highlight several PLS solutions that are expected to be applied in 5G networks. Finally, we conclude this article and figure out some further research directions.
One benefit of 5G network deployment relates to the smaller size of cells allowing low latency and increased users capacity. The downside is that the potential eavesdroppers could be closer to the victim making the security more challenging. So it is clear the need for enhanced privacy protection in the next generation communications systems even for low power/low complexity IoT devices. The last few years there are numerous research efforts to enhance transmitted information security with complementary techniques that operate in physical layer. In this paper we propose a physical layer scheme that complements the security schemes implemented in the upper layers or/and in the physical layer. The proposed scheme takes advantage of the pilot subcarriers that are part of an OFDM transmission. Pilot subcarriers are essential for the pilot channel estimation process performed at the receiver. In conventional OFDM systems the positions of pilot subcarriers are known. In this paper we propose the positions of the subcarriers to change on every OFDM symbol following a probability distribution known only to the legitimate transmitter and legitimate receiver. This puts a passive eavesdropper at a relative disadvantage compared to a legitimate receiver, because it does not know the position of the pilot subcarriers. To evaluate the security performance of the proposed scheme the secrecy capacity and the outage probability are used as metrics.
Security has become an increasingly significant and urgent issue in wireless networks. The growing computational capability of the eavesdropper (Eve) and more and more complicated secure key management in large scale and heterogeneous networks, pose more and more stringent requirement to the cryptographic protocols. As a new design paradigm, physical layer security has been recognised as a promising solution to enhance the security of wireless links relying on the channel properties and advanced signal processing, and can act as either an alternative or a complementary solution to the conventional cryptographic methods. Without complicated secure key generation and management, physical layer security is quite suitable for the large scale distributed networks. In this thesis, we aim to improve the secrecy performance in emerging wireless communication systems relying on different physical layer security techniques. Firstly, the security of an amplify-and-forward successive relaying network with multiple untrusted relay nodes is investigated, where the conventional detrimental inter-relay interference is exploited to jam the untrusted nodes without assistance of external helpers. Considering different complexity requirements, several relay selection schemes are proposed, and the closed-form expressions of the lower bound of the secrecy outage probability and the maximum secrecy diversity order are derived accordingly. It is shown that the maximum secrecy diversity order of N-1 can be achieved for an N relay nodes network. Secondly, the artificial noise (AN) aided secure transmission strategy for a multiple-input single-output multiple-Eve (MISOME) system with a secure user (Bob) and a normal user (NU) is investigated. The power allocations among Bob, NU and AN, as well as the wiretap code rates, are jointly optimized to maximize the effective secrecy throughput (EST), under the average throughput constraint of NU. An alternative optimization algorithm with guaranteed convergence is proposed to obtain the optimal parameters. It is shown that the EST increases with the transmitting power and the number of transmit antennas, and decreases with the throughput constraint of NU, and the EST can be improved through injecting AN and concurrent transmission of Bob and NU. Thirdly, physical layer security in a multi-antenna small-cell network is investigated, where the multi-antenna base stations (BSs), cellular users, and Eves are all randomly distributed according to independent Poisson point processes. Stochastic geometry is applied to analyze the connection and secrecy outage probabilities and the average achievable secrecy rate. The impact of different parameters, including power allocation, BS and Eve density, and the adaptive eavesdropping or jamming on the secrecy performance is analyzed. It is shown that the average secrecy rate is a quasi-concave function of the power allocation factor and monotonically decreases with the ratio of the Eve-BS density. Finally, we study the physical layer security in a large-scale heterogeneous network consisting of both sub-6 GHz massive multi-input multi-output (MIMO) macro cells and millimeter wave (mmWave) small cells. By considering pilot spoofing attacks from the Eves, the coverage and secrecy probabilities are derived using stochastic geometry and the conditions under which the millimeter wave tier outperforms the sub-6 GHz counterpart are discussed in terms of both coverage and secrecy.It is shown that the mmWave small cell can provide better coverage performance in the high transmission code-rate region, and the secrecy performance of the mmWave system outperforms the sub-6 GHz counterpart in the low redundant rate region, which reveals the advantage of using mmWave for secure communication.
Physical layer security (PLS) has grown in popularity as it guarantees secure and reliable communication between wireless devices without restricting the ability of data analysts to eavesdrop. PLS benefits from the randomization property of the wireless channel, which improves immunity and protects against many dangers of information breaches from eavesdroppers. MIMO and Massive MIMO, which use numerous antennas at the transmitter and receiver ends, are fundamental technologies for improving efficiency in 5G and future network systems. The PLS still requires a significant amount of work before it can be employed in practical systems. The interception of eavesdroppers can be made difficult by adding artificial noise. This paper focuses on the physical layer security considering maximal ratio combining, and artificial noise with beamforming techniques to further enhance the secrecy rate. The proposed work demonstrates that the use of transmitter beamforming with artificial noise can significantly improve the degree of confidentiality of information being transmitted between a transmitter and an intended receiver while making it more difficult for eavesdroppers to intercept. The simulation results in terms of bit error rate show that the proposed method has a significant impact on the error rate performance of the eavesdropper.
Due to the dramatic increase in high data rate services and in order to meet the demands of the fifth-generation (5G) networks, researchers from both academia and industry are exploring advanced transmission techniques, new network architectures and new frequency spectrum such as the visible light and the millimeter wave (mmWave) spectra. Visible light communication (VLC) particularly is an emerging technology that has been introduced as a promising solution for 5G and beyond, owing to the large unexploited spectrum, which translates to significantly high data rates. Although VLC systems are more immune against interference and less susceptible to security vulnerabilities since light does not penetrate through walls, security issues arise naturally in VLC channels due to their open and broadcasting nature, compared to fiber-optic systems. In addition, since VLC is considered to be an enabling technology for 5G, and security is one of the 5G fundamental requirements, security issues should be carefully addressed and resolved in the VLC context. On the other hand, due to the success of physical layer security (PLS) in improving the security of radio-frequency (RF) wireless networks, extending such PLS techniques to VLC systems has been of great interest. Only two survey papers on security in VLC have been published in the literature. However, a comparative and unified survey on PLS for VLC from information theoretic and signal processing point of views is still missing. This paper covers almost all aspects of PLS for VLC, including different channel models, input distributions, network configurations, precoding/signaling strategies, and secrecy capacity and information rates. Furthermore, we propose a number of timely and open research directions for PLS-VLC systems, including the application of measurement-based indoor and outdoor channel models, incorporating user mobility and device orientation into the channel model, and combining VLC and RF systems to realize the potential of such technologies.