This book offers complete coverage of all aspects of computer security, including users, software, devices, operating systems, networks, law, and ethics. Reflecting rapidly evolving attacks, countermeasures, and computing environments, it introduces up-to-the-minute best practices for authenticating users, preventing malicious code execution, using encryption, protecting privacy, implementing firewalls, detecting intrusions, and more. Cryptography is critical to computer security; it is an essential tool that students and professionals must know, appreciate and understand. But as with most tools, the user does not need to be a maker: using a screwdriver successfully is entirely separate from knowing how to forge the metal from which it is made. This edition will separate the use of cryptography from its underlying mathematical principles. It will introduce cryptography early in the book to provide a solid background on types of algorithms, appropriate uses of these different types, and advanced concepts such as digital signatures and cryptographic hash codes. It will also address how cryptography can fail. However, it will cover these topics without revealing the internals of cryptography; closer to the end of the book it will delve into the internals of specific algorithms. In this way, readers who want to know the details can study those (and can even read the later chapter early, out of the normal sequence), but it will not unnecessarily burden readers who, like most users, will never get closer to cryptography than an encrypt() function. One strength of SiC4 has been its sidebars. Readers enjoy the brief examples of real life exploits. Fortunately, the news is full of stories of security failures, and it is important to connect these actual events to the strong pedagogy of the book. ACS, which was organized around attacks of different types, include many timely incident stories that we can pull into SiC5. Cloud computing and mobile code and computing are not covered extensively in SiC4. Cloud computing appears as a six page interlude in ACS, but in the few years since ACS was written, the use of cloud computing has expanded, as well as the security ramifications. We intend to devote an entire chapter to cloud computing. Similarly, mobile code and mobile computing have grown. These topics appeared briefly in SiC4 and ACS, but we plan to expand mobile computing into its own chapter, as well. The topic progression of SiC4 largely followed its predecessor editions, back to the first edition (1988). In 1988 networking was certainly neither as important nor pervasive as it has become. Trying to defer all coverage of network topics until Chapter 7, its position in SiC4 delays important content significantly and, perhaps more importantly, makes for a long and broad network security chapter. In 1988 readers had less direct contact with a network than now, and these readers had limited experience using a network prior to reading the book. Obviously readers in 2014 come with vastly more network exposure. This exposure is an asset: Readers now can appreciate a network-delivered attack even before they study network security. SiC5 will take advantage of readers' familiarity with networks, and present attacks delivered by a network-assisted attacker based on the primary source of vulnerability -- software, operating system, protocol, user error -- and not defer these topics to the networks chapter just because a network was involved in the attack. Finally, privacy has been an important topic in the book in early editions, and its importance and coverage have grown as well. The authors will again expand the coverage of privacy, expanding on topics such as web tracking and social networking. These additions cannot come without some pruning. Previously hot topics, such as trusted operating systems and multilevel databases, are being pared down. The authors will also reconsider topics such as economics and management which, although interesting and important, appeal to a relatively small target audience. - Publisher.