viii As we look for such a strategy, technological development races on with new technologies that make our efforts and existing technologies on which they are based obsolete in shorter and shorter periods. For example, when I started to write the first edition in 1996, computer networking and associated computer network security were not big, the Internet and associated d- coms were yet to become commercialized and associated with big money, and mass global computer network attacks like "e;Malissa"e;, "e;Love Boy"e;, and Distributed Denial of Services (DDOS) were unknown. All these illustrate the speed at which the computing environment is changing and demonstrate a need for continuous review of the computer s- ence education in both content and pedagogy. So the focus in this edition is to address those changes. In this edition, I have made major changes in some of the chapters, reorganized others, and added new ones to bring the book update with current issues.