Performance investigation of secure 802.11 wireless LANs : raising the security bar to which level?

2003 i Acknowledgments I would like to thank my supervisors, Dr John Vargo and Associate Professor Ray Hunt, who have provided me with invaluable answers to my questions and guidance in the preparation of this thesis. I would like to acknowledge all the support and encouragement given by my family and friends. Each of you have contributed in your own special way, and helped me during difficult times. I would like to express also my most sincere thanks to Peter Davison, for providing me with wireless technical support. I would also like to thank Dr. Paul Cragg for statistical guidance, Chris Harrow for Windows operating system management directions, and Chris Rodgers for experiment setup discussions. Government Communications Security Bureau for providing me the opportunity to perform this research. Abstract Wireless networks have gained popularity, providing users flexibility and mobility in accessing information. The IEEE 802.11 Wireless Local Area Network (WLAN) standard has become the dominant architecture in practice. Private WLANs are used by businesses and home users, while public WLANs have been established in areas expected to have high demand for bandwidth, such as cafes, airports, and hotels. Existing solutions for such WLAN access networks have been exposed to security vulnerabilities. Although researchers have proposed improved security for WLANs, very little work exists in the area of understanding the interaction between WLANs and their emerging and evolving security architectures with respect to the performance impacts of these security measures. The aim of this thesis is to quantify the impact on network performance resulting from the adoption of these security mechanisms. This study investigated the performance and security issues of IEEE 802.11 wireless networks using layered security models. The two models defined in the research were the IEEE 802.1X and Virtual Private Network (VPN). Our results showed that different security mechanisms degraded WLAN performance in different ways. Network performance degradation increased as the protection of the security mechanisms increased. Furthermore, the VPN model impacted the performance more than the 802.1X model. The performance degradation calculated was incorporated into constructing a wireless security policy template for wireless " security insurance " .