What's New in the Third Edition

    In the three years since the second edition of this book was published, the field has seen continued innovations and improvements. In this new edition, I try to capture these changes while maintaining a broad and comprehensive coverage of the entire field. To begin this process of revision, the second edition was extensively reviewed by a number of profressors who tech the subject. In addition, a number of professionals working in the field reviewed individual chapters. The result is that, in many places, the narrative has been clarified and tightened, and illustrations have been improved. Also, a large number of new "field-tested" problems have been added.

    Beyond these refinedments to improve pedagogy and user friendliness, there have been major substantive changes throughout the book. Highlights includes:

- Stream ciphers : Stream ciphers are used in number of network security protocols and applications.
   The third edition covers this area and descripble the most widely used such algorithm, RC4
- Public Key Infrastructure (PKI): This important topic is trated in this new edition.
- Distributed denial of service (DDos) attacks: DDoS attacks have assummed increasing significance in
   recent years.
- Common Criteria for Information Technology Security Evaluation: The Common Criteria have become
   the international framework for expressing security requirements and evaluating products and
   implementations.

Part One Cryptography
Part Two Network Security Applications
Part Three System Security
Appendices
Appendix A Some Aspects of Number Theory
Appendix B Projects for Teaching Network Security