Over the past two decades, network technologies have been remarkably renovated and computer networks, particularly the Internet, have permeated into every facet of our daily lives. These changes also brought about new challenges, particularly in the area of security. Network security is essential to protect data integrity, con?d- tiality, access control, authentication, user privacy, and so on. All of these aspects are critical to provide fundamental network functionalities. This book covers a comprehensive array of topics in network security including secure metering, group key management, DDoS attacks, and many others. It can be used as a handy reference book for researchers, educators, graduate students, as well as professionals in the ?eld of network security. This book contains 11 r- ereed chapters from prominent researchers working in this area around the globe. Although these selected topics could not cover every aspect, they do represent the most fundamental and practical techniques. This book has been made possible by the great efforts and contributions of many people. First, we thank the authors of each chapter for contributing informative and insightful chapters. Then, we thank all reviewers for their invaluable comments and suggestions that improved the quality of this book. Finally, we thank the staff m- bers from Springer for publishing this work. Besides, we would like to dedicate this book to our families.
