There is a tremendous growth of wireless communication services over the last decade. The security concerns are becoming more serious with the growth of wireless networks. For providing a wide range of real-time and non-real-time applications, wireless networks with optimal security and performance are always desirable. In this book, we have focused on analysis and quantification of security-performance tradeoff in Wireless Local Area Networks (WLANs) and to propose solutions for optimal tradeoff suitable for wireless communication services.