Advances in communication and networking technologies are rapidly making ubiquitous and cognitive network connectivity a reality. Wireless networks are indispensable for supporting such access anywhere and anytime. Security in wireless networks is gaining more and more attention. On the one hand, due to its ``open air'' nature, the wireless environment imposes greater challenges on ensuring network security than in wired networks. Because of the broadcast nature of the wireless medium, the communication can be easily eavesdropped or intercepted. The wireless devices can be compromised and modified to behave maliciously or selfishly. These vulnerabilities in wireless networks would undermine the authenticity, confidentiality, integrity, and availability if they are not carefully addressed. On the other hand, other than these vulnerabilities, the inherent and unique characteristics of the wireless medium or devices can be exploited to enhance the network security. These challenges and unique advantages presented in wireless networks have motivated numerous research on their security and performance issues.

The objective of this project is to exploit physical and cross-layer characteristics to enhance network security, especially wireless network security.

We consider the unique characteristics of wireless devices and channels as advantages to enhance and supplement existing network security mechanisms.

We take advantage of emerging technologies, such as Multiple-Input Multiple-Output (MIMO) and Software Defined Radio (SDR), from new angles to improve network security.

We take advantage of unique characteristics (e.g. mobility) of emerging networks to enhance security.

We are particularly interested in developing practical protocols and validating our ideas in real systems, scenarios and environments.

A holistic cross-layer security design is desirable for securing emerging wireless networks, such as cognitive radio networks (CRNs), mobile ad hoc networks (MANETS), etc.