We once took a tour of a well-known brewery in St. Louis, Missouri. We mention this not just because we enjoyed it, but because the tour, like this book, was divided into three parts. In the first part of our tour we were informed about the issues of beer?the difficulties of producing good flavor and the importance of good ingredients. In the second part we walked the factory floor and looked at the machinery, the tanks, and pipes involved in the production process. Finally, we met the real thing as we were given the opportunity to drink the product.
In a similar way the three parts of this book address the theory, implementations, and reality concerning Wi-Fi security. If you are not interested in the mechanics, you can skip the finer details. Likewise, you may be comfortable with the theory and want to focus on how it is put into practice. Either way, you do not have to read the book from cover to cover to realize its benefits.
Part I examines the security problem in general. Initially we look at the general principles on which security is built and then specifically at why Wi-Fi and other wireless LAN technologies are vulnerable to attack. We discuss where attacks might come from and the types of people who might carry them out. Finally we look at the types of tools that attackers use to break into systems. This section of the book is not highly technical, but it should help you understand how vulnerable a Wi-Fi system can be.
In Part II we head to the factory floor to look at the machinery that can protect you. In the overview of how Wi-Fi systems work, we do not discuss such issues as how to install the software drivers or how to plug in the USB connector. Instead, we go right into the IEEE 802.11 protocol to look at the messages being transmitted between systems. It is at this level that the attack tools work, and it is only at this level that you can get an understanding of how the security defenses work. The original IEEE 802.11 standard did provide a security method called "WEP." Many people relied on WEP for protection and were alarmed to discover that it was not effective. Part II includes a chapter that details how WEP works and why it was broken. Look here for a useful lesson in understanding security.
The remainder of Part II describes the security technologies that are being introduced to provide real protection. There are many pieces to the picture, and successive chapters deal with the solutions from the lowest layers up. You may have seen jargon words and acronyms used in relation to Wi-Fi security. You will find them explained here.
Part III moves to real implementation issues. We look at the special requirement of public access networks such as hotspot zones. We review attacks that have been performed against Wi-Fi systems and analyze how they worked. We let you sit in the attacker's seat and, if you wish, try out some of the attack tools yourself. This is a good way to test whether you can break into your own system. Finally, we look at an open source implementation of wireless LAN security. We do not provide step-by-step guides to installing particular brands of equipment. When you understand how all the pieces fit together, you will be much better positioned to understand and successfully follow the installation instructions that come with the products you purchase.