Approaching wireless Internet security from the position of system architecture, this text describes the cryptographic and protocol-based tools for Internet security with a focus on understanding the system architecture of existing Internet security, and on developing architectural changes for new security services. Introducing the topics of security threats in wireless networks, security services for countering those threats, and the process of defining functional architecture for network systems, the author also discusses examples of wireless Internet security systems such as wireless network access control, local IP subnet configuration and address resolution, and location privacy. Each chapter describes the basic network architecture and protocols for the system under consideration, the security threats faced, a functional architecture, and the important Internet protocols that implement the architecture. This is an ideal resource for graduate students of electrical engineering and computer science, as well as for engineers and system architects in the wireless network industry.