A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends

This paper examines the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient defense mechanisms for improving the wireless network security. We first summarize the security requirements of wireless networks, including their authenticity, confidentiality, integrity and availability issues. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provide a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term evolution (LTE) systems. Then, we discuss the state-of-the-art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. We also introduce the family of various jamming attacks and their counter-measures, including the constant jammer, intermittent jammer, reactive jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, some technical challenges which remain unresolved at the time of writing are summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201

Multifunction Radios and Interference Suppression for Enhanced Reliability and Security of Wireless Systems

Wireless connectivity, with its relative ease of over-the-air information sharing, is a key technological enabler that facilitates many of the essential applications, such as satellite navigation, cellular communication, and media broadcasting, that are nowadays taken for granted. However, that relative ease of over-the-air communications has significant drawbacks too. On one hand, the broadcast nature of wireless communications means that one receiver can receive the superposition of multiple transmitted signals. But on the other hand, it means that multiple receivers can receive the same transmitted signal. The former leads to congestion and concerns about reliability because of the limited nature of the electromagnetic spectrum and the vulnerability to interference. The latter means that wirelessly transmitted information is inherently insecure. This thesis aims to provide insights and means for improving physical layer reliability and security of wireless communications by, in a sense, combining the two aspects above through simultaneous and same frequency transmit and receive operation. This is so as to ultimately increase the safety of environments where wireless devices function or where malicious wirelessly operated devices (e.g., remote-controlled drones) potentially raise safety concerns. Specifically, two closely related research directions are pursued. Firstly, taking advantage of in-band full-duplex (IBFD) radio technology to benefit the reliability and security of wireless communications in the form of multifunction IBFD radios. Secondly, extending the self-interference cancellation (SIC) capabilities of IBFD radios to multiradio platforms to take advantage of these same concepts on a wider scale. Within the first research direction, a theoretical analysis framework is developed and then used to comprehensively study the benefits and drawbacks of simultaneously combining signals detection and jamming on the same frequency within a single platform. Also, a practical prototype capable of such operation is implemented and its performance analyzed based on actual measurements. The theoretical and experimental analysis altogether give a concrete understanding of the quantitative benefits of simultaneous same-frequency operations over carrying out the operations in an alternating manner. Simultaneously detecting and jamming signals specifically is shown to somewhat increase the effective range of a smart jammer compared to intermittent detection and jamming, increasing its reliability. Within the second research direction, two interference mitigation methods are proposed that extend the SIC capabilities from single platform IBFD radios to those not physically connected. Such separation brings additional challenges in modeling the interference compared to the SIC problem, which the proposed methods address. These methods then allow multiple radios to intentionally generate and use interference for controlling access to the electromagnetic spectrum. Practical measurement results demonstrate that this effectively allows the use of cooperative jamming to prevent unauthorized nodes from processing any signals of interest, while authorized nodes can use interference mitigation to still access the same signals. This in turn provides security at the physical layer of wireless communications

Satellite-Based Communications Security: A Survey of Threats, Solutions, and Research Challenges

Satellite-based Communication systems are gaining renewed momentum in Industry and Academia, thanks to innovative services introduced by leading tech companies and the promising impact they can deliver towards the global connectivity objective tackled by early 6G initiatives. On the one hand, the emergence of new manufacturing processes and radio technologies promises to reduce service costs while guaranteeing outstanding communication latency, available bandwidth, flexibility, and coverage range. On the other hand, cybersecurity techniques and solutions applied in SATCOM links should be updated to reflect the substantial advancements in attacker capabilities characterizing the last two decades. However, business urgency and opportunities are leading operators towards challenging system trade-offs, resulting in an increased attack surface and a general relaxation of the available security services. In this paper, we tackle the cited problems and present a comprehensive survey on the link-layer security threats, solutions, and challenges faced when deploying and operating SATCOM systems.Specifically, we classify the literature on security for SATCOM systems into two main branches, i.e., physical-layer security and cryptography schemes.Then, we further identify specific research domains for each of the identified branches, focusing on dedicated security issues, including, e.g., physical-layer confidentiality, anti-jamming schemes, anti-spoofing strategies, and quantum-based key distribution schemes. For each of the above domains, we highlight the most essential techniques, peculiarities, advantages, disadvantages, lessons learned, and future directions.Finally, we also identify emerging research topics whose additional investigation by Academia and Industry could further attract researchers and investors, ultimately unleashing the full potential behind ubiquitous satellite communications.Comment: 72 page

Implementation and Analysis of Spectral Subtraction and Signal Separation in Deterministic Wide-Band Anti-Jamming Scenarios

With the increasing volume of wireless traffic that military operations require, the likelihood of transmissions interfering with each other is steadily growing to the point that new techniques need to be employed. Furthermore, to combat remotely operated improvised explosive devices, many ground convoys transmit high-power broadband jamming signals, which block both hostile as well as friendly communications. These wide-band jamming fields pose a serious technical challenge to existing anti-jamming solutions that are currently employed by the Navy and Marine Corps. This thesis examines the feasibility of removing such deterministic jammers from the spectral environment, enabling friendly communications. Anti-jamming solutions in self-jamming environments are rarely considered in the literature, principally due to the non-traditional nature of such jamming techniques. As a result, a combination of approaches are examined which include: Antenna Subset Selection, Spectral Subtraction, and Source Separation. These are combined to reduce environmental interference for reliable transmissions. Specific operational conditions are considered and evaluated, primarily to define the limitations and utility of such a system. A final prototype was constructed using a collection of USRP software defined radios, providing solid conclusions of the overall system performance

Electronic warfare self-protection of battlefield helicopters : a holistic view

The dissertation seeks to increase understanding of electronic warfare (EW) self-protection (EWSP) of battlefield helicopters by taking a holistic (systems) view on EWSP. It also evaluates the methodologies used in the research and their suitability as descriptive tools in communication between various EWSP stakeholders. The interpretation of the term "holistic view" is a central theme to the dissertation. The research methodology is bottom-up – which is necessary since no previous work exists that could guide the study – and progresses from analysis to synthesis. Initially several methods are evaluated for presenting findings on EWSP, including high-level system simulation such as Forrester system dynamics (FSD). The analysis is conducted by a comprehensive literature review on EW and other areas that are believed to be of importance to the holistic view. Combat scenarios, intelligence, EW support, validation, training, and delays have major influence on the effectiveness of the EWSP suite; while the initial procurement decision on the EWSP suite sets limits to what can be achieved later. The need for a vast support structure for EWSP means that countries with limited intelligence and other resources become dependent on allies for support; that is, the question of EWSP effectiveness becomes political. The synthesis shows that a holistic view on EWSP of battlefield helicopters cannot be bounded in the temporal or hierarchical (organizational) senses. FSD is found to be helpful as a quality assurance tool, but refinements are needed if FSD is to be useful as a general discussion tool. The area of survivability is found to be the best match for the holistic view – for an EWSP suprasystem. A global survivability paradigm is defined as the ultimate holistic view on EWSP. It is suggested that future research should be top-down and aiming at promoting the global survivability paradigm. The survivability paradigm would give EWSP a natural framework in which its merits can be assessed objectively.reviewe