This book starts by exploring the popular HTTP, UPnP, CoAP, MQTT, and XMPP protocols. You will learn how protocols and patterns can put limitations on network topology and how they affect the direction of communication and the use of firewalls. Thing registries and delegation of trust are introduced as important tools to secure the life cycle of Things on the Internet. Once the fundamentals have been mastered, your focus will move to the Internet of Things architecture. A secure architecture is proposed that will take full advantage of the power of Internet of Things and at the same time protect end user integrity and private personal data without losing flexibility and interoperability.This book provides you with a practical overview of the existing protocols, communication patterns, architectures, and security issues important to Internet of Things.