Improved Wireless Security through Physical Layer Protocol Manipulation and Radio Frequency Fingerprinting

Wireless networks are particularly vulnerable to spoofing and route poisoning attacks due to the contested transmission medium. Traditional bit-layer defenses including encryption keys and MAC address control lists are vulnerable to extraction and identity spoofing, respectively. This dissertation explores three novel strategies to leverage the wireless physical layer to improve security in low-rate wireless personal area networks. The first, physical layer protocol manipulation, identifies true transceiver design within remote devices through analysis of replies in response to packets transmitted with modified physical layer headers. Results herein demonstrate a methodology that correctly differentiates among six IEEE 802.15.4 transceiver classes with greater than 99% accuracy, regardless of claimed bit-layer identity. The second strategy, radio frequency fingerprinting, accurately identifies the true source of every wireless transmission in a network, even among devices of the same design and manufacturer. Results suggest that even low-cost signal collection receivers can achieve greater than 90% authentication accuracy within a defense system based on radio frequency fingerprinting. The third strategy, based on received signal strength quantification, can be leveraged to rapidly locate suspicious transmission sources and to perform physical security audits of critical networks. Results herein reduce mean absolute percentage error of a widely-utilized distance estimation model 20% by examining signal strength measurements from real-world networks in a military hospital and a civilian hospital

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