This book presents a wide range of modelling, analysis and assurance techniques that address computer network dependability, security and quality of service (QoS). In-depth coverage of technical material is supported with experimental data and numerical examples to illustrate why and how the technologies work, making the book useful as a text for graduate students. Since the next-generation of computer network systems and information infrastructure rely on the scientific and engineering approaches to provide security, QoS and ultimately system dependability, this book will benefit many people in academia and industry working to achieve this goal.