This book comprehensively addresses the issues currently faced in wireless networks and systems. Special attention is paid to wireless specific issues, such as tradeoffs between security and power consumption, adaptively changing security protocols in response to the radio channel. Wireless infrastructure networks (e.g., GSM and 3G Cellular), wireless ad hoc and sensor networks, and hybrid wireless networks are used as examples and case studies throughout the book for wireless security. The book is divided into three parts: Wireless Security Techniques; Security for Emerging Wireless Networks and Systems; and The Future.