Dr. William Stallings has authored 18 textbooks and over 70 books on computer security, computer networking, and computer architecture. With over 30 years’ experience in the field, he has worked as a technical contributor, technical manager, and an executive at several high-technology firms. Currently, he is an independent consultant whose clients have included computer and networking manufacturers and customers, software development firms, and leading-edge government research institutions. He has received the award for the best computer science textbook of the year thirteen times from the Text and Academic Authors Association. Dr. Stallings created and maintains the Computer Science Student Resource Site at ComputerScienceStudent.com. This site provides documents and links on a variety of subjects of general interest to computer science students and professionals. He is a member of the editorial board of Cryptologia, a scholarly journal devoted to all aspects of cryptology. He holds a Ph.D. from MIT in computer science and a B.S. from Notre Dame in electrical engineering.