A secure OFDM data communication scheme is proposed for wireless or optical networks, where a 200Kbps data transmission integrated with 50Kbps physical-layer key distribution is demonstrated using non-orthogonal multiple access (NOMA).
Abstract With the exponential growth of wireless communication technologies, ensuring the confidentiality of transmitted data has become paramount. This paper introduces a cutting-edge encryption scheme utilizing Non-Orthogonal Multiple Access (NOMA) for secure key generation. It proposes a method that utilizes an identical secret key derived from channel randomness and distance to prevent eavesdropping in NOMA communication, thus enhancing the system's resistance against potential attacks. NOMA is employed to simultaneously serve multiple users at the same time and frequency resources by applying different power levels to each user. In the proposed encryption scheme, NOMA principles combine channel randomness and user-base station distance in a non-orthogonal manner. This approach allows the generation of identical encryption keys shared by multiple users, ensuring an efficient and robust security mechanism benefits increased spectral efficiency and an improved system. The non-orthogonal of the generated encryption key enhances the security level, as it becomes harder for eavesdroppers to intercept and decipher the key. Integrating NOMA in the key generation process introduces an additional layer of unpredictability, further bolstering security. Extensive simulations and analyses were conducted to assess the proposed NOMA-based dual key extraction performance. A qualitative comparison between sources and a new proposed direction shows the Secrecy rate, key secrecy capacity, and secrecy outage probability demonstrate its effectiveness in providing a high level of security while incurring minimal overhead on the communication system.
Driven by the ever-increasing requirements of ultrahigh spectral efficiency, ultralow latency, and massive connectivity, the forefront of wireless research calls for the design of advanced next-generation multiple access schemes to facilitate the provisioning of these stringent demands. This inspires the embrace of nonorthogonal multiple access (NOMA) in future wireless communication networks. Nevertheless, the support of massive access via NOMA leads to additional security threats due to the open nature of the air interface, the broadcast characteristic of radio propagation, and the intertwined relationship among paired NOMA users. To address this specific challenge, the superimposed transmission of NOMA can be explored as new opportunities for security-aware design; for example, multiuser interference inherent in NOMA can be constructively engineered to benefit communication secrecy and privacy. The purpose of this tutorial is to provide a comprehensive overview of the state-of-the-art physical layer security techniques that guarantee wireless security and privacy for NOMA networks, along with the opportunities, technical challenges, and future research trends.
Physical layer security is emerging as a promising means of ensuring secrecy in wireless communications. The key idea is to exploit the characteristics of wireless channels such as fading or noise to transmit a message from the source to the intended receiver while keeping this message confidential from eavesdroppers. Topics covered in Trusted Communications with Physical Layer Security for 5G and Beyond include secrecy metrics for physical layer security over fading channels; trusted wireless communications with spatial multiplexing; directional modulation enabled physical layer wireless security; secure waveform for 5G systems; confidential and energy efficient communications using physical layer security; secure data networks with channel uncertainty; antenna selection strategies for wiretap channels; physical layer security for massive MIMO systems, millimeter wave cellular networks, non-orthogonal multiple access, multiuser relay networks, cognitive radio networks, MIMOME-OFDM systems; wirelessly powered communication systems and D2D-enabled cellular networks; and security solutions and applications at the physical layer, including case studies of secret key generation and secrecy coding in communication nodes and terminals.
Non-orthogonal multiple access (NOMA) is emerging as a popular radio access technique to serve multiple users under the same resource block to improve spectral efficiency in 5G and 6G communication. But the resource sharing in NOMA causes concerns on data security. Since power domain NOMA exploits the difference in channel properties for bandwidth-efficient communication, it is feasible to ensure data confidentiality in NOMA communication through physical layer security techniques. In this work, we propose to ensure resistance against internal eavesdropping in NOMA communication through a secret key derived from channel randomness. A unique secret key is derived from the channel of each NOMA user; which is used to randomize the data of the respective user before superposition coding (SC) to prevent internal eavesdropping. The simulation results show that the proposed system provides very good security against internal eavesdropping in NOMA.
Abstract Internet of Things (IoT) technology has recently been adopted in different fields and applications. An IoT network allows for a large set of physical objects (or devices) with various technologies to work together and exchange a large amount of information. This, however, raises different security and privacy concerns, including the confidentiality of the exchanged data. Usually, data confidentiality is maintained in wireless networks utilizing data encryption using a pre‐shared secret key. Thus, protecting the key distribution process is essential to maintaining a secure network. However, due to the typically large size of IoT networks, conventional secret key distribution schemes are unsuitable and lead to resource inefficiency. Therefore, in this paper, an efficient key distribution scheme is proposed by using physical‐layer security concepts. Specifically, non‐orthogonal multiple access (NOMA) is utilized to distribute the key to multiple nodes in a resource‐efficient manner. Moreover, the instantaneous channel phase is also used to attain a secure distribution in which each node can obtain its own key only. The performance of the proposed scheme is analyzed in terms of the key error rate at both a legitimate node and an eavesdropper under different channel fading models, where closed form mathematical expressions are derived and verified via simulation results.
Non-orthogonal multiple access (NOMA) has been widely considered as a promising technology to enable high-efficient wireless transmissions in future 5G communication systems. In this chapter, we investigate single-input single-output (SISO) NOMA systems from the perspective of physical layer security. There into, two different SISO NOMA systems are studied in sequence so as to explore security issues in NOMA. First, we attempt the physical layer security technique in a SISO NOMA system which consists of a transmitter, multiple legitimate users and an eavesdropper who aims to wiretap the messages intended for all legitimate users. The objective is to maximise sum of secrecy rates subject to an individual quality of service constraint for each legitimate user, respectively. The investigations in this system will provide a preliminary analysis of the secure performance of SISO NOMA systems. Second, on the basis of the SISO NOMA system previously studied, a multi-antenna jammer is additionally equipped to enhance secure transmissions of the system. The joint optimisation of power allocation and beamforming design is considered. The efforts in this second system aim to propose an effective solution for realising secure transmissions for each legitimate user.