Wireless Communication, Sensing, and REM: A Security Perspective
IEEE Open Journal of the Communications Society
The diverse requirements of next-generation communication systems necessitate awareness, flexibility, and intelligence as essential building blocks of future wireless networks. The awareness can be obtained from the radio signals in the environment using wireless sensing and radio environment mapping (REM) methods. This is, however, accompanied by threats such as eavesdropping, manipulation, and disruption posed by malicious attackers. To this end, this work analyzes the wireless sensing and
... io environment awareness mechanisms, highlighting their vulnerabilities and provides solutions for mitigating them. As an example, the different threats to REM and its consequences in a vehicular communication scenario are described. Furthermore, the use of REM for securing communications is discussed and future directions regarding sensing/REM security are highlighted. INDEX TERMS 5G, 6G, cryptography, joint radar and communication (JRC), physical layer security, radio environment mapping (REM), REM security, sensing security, vehicle-to-everything (V2X) communication, wireless sensing, WLAN sensing. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ VOLUME 2, 2021 287 • To the best of authors' knowledge, this is the first work that provides a comprehensive analysis of different components, processes, and methods of wireless sensing and REM from a security point of view. Furthermore, a distinction is made between the security perspectives of communication and sensing. • Taking inspiration from wireless communication security literature, the attacks on wireless sensing/REM are defined, and their consequences are highlighted. • Solutions for the highlighted (security) weaknesses are then provided from diverse domains such as wireless communications, military radars, machine learning, and crowdsourcing. • To enable easier understanding of the threats to sensing/REM and their consequences, vehicle-toeverything (V2X) communication is presented as a case study. This use case is chosen since it relies on both communication and sensing for its proper operation. • The concept of REM-assisted cognitive wireless security is proposed and presented, supported by yet another case study illustrating its applicability in V2X scenario. • The various challenges and roadblocks in realizing secure wireless sensing and REM are pointed out. Moreover, the guidelines for addressing these challenges are provided. C. STRUCTURE OF THIS ARTICLE As illustrated in Fig. 2 , the structure of this article is as follows. Preliminary concepts related to wireless security are covered in Section II. Section III describes the different aspects of radio environment awareness including architecture, standardization activities, sensing methods and processes. Sections IV, V, and VI discuss the exploratory, manipulation, disruption attacks with solutions, respectively. A case study to highlight the need for a secure REM in the context of V2X communication is described in Section VII. Section VIII presents the concept of sensing/REM-assisted cognitive security for wireless networks, while Section IX highlights the challenges in realizing a secure communication, sensing, and REM framework. Section X provides our concluding remarks. II. SECURITY PRELIMINARIES Here, preliminary information related to communication and sensing security is presented. This includes possible 288 VOLUME 2, 2021 FIGURE 2. Structure/outline of this article. motivations of the different attacks, the requirements of communication and/or sensing from a security perspective, definitions of different security threats, overview of possible solutions, and the corresponding performance metrics. A. ATTACK MOTIVATIONS AND SECURITY REQUIREMENTS As explained earlier, our surroundings contain a myriad of radio signals. These signals can be leveraged to extract information about the environment itself and the users/devices within. As such, a malicious node might have the following motivations when attacking a (communication and/or sensing) wireless network: • Confidentiality Violation: The malicious node tries to intercept either the communication or characteristics of the legitimate nodes. In the context of sensing, this information may include a user's location, mobility pattern, social trends, etc. • Degradation: The malicious node attempts to impair the communication link and/or sensing capabilities of the legitimate parties. • Exploitation: The malicious node tries to exploit the communication and/or sensing for its own benefit. This may include learning and then manipulating the legitimate communication (or sensing) to acquire resources for itself. Corresponding to the aforementioned intentions of the malicious attackers, the network strives to guarantee that its nodes and users are protected. This includes ensuring no illegitimate access to the information/transmission is allowed, the data shared between legitimate nodes is accurate, and there is no disruption of the services offered by the network  .