Information security depends upon an understanding of the functionality of software systems. Customers and information can only be protected from attack if this functionality is guaranteed to be correct and safe. A scientific foundation of software engineering not only provides models enabling the capture of application domains and requirements, but also ensures an understanding of the structure and working of software systems, architectures and programs. This book presents contributions based on the lectures delivered at the 31st International Summer School: Software and Systems Safety: Specification and Verification held at Marktoberdorf, Germany, in August 2010, and provides an excellent overview of current research results with special emphasis on software information security. Leading international researchers and experts present their experience in the specification and verification of software systems, accompanied by corresponding tools and methods. Subjects addressed include: model-based testing, schemes and patterns of assumption/promise-based system specification, requirements models for critical systems, engineering evolving and self-adaptive systems, unifying models of data flow, model-based verification and analysis of real-time systems, and model checking. The book will be of interest to all those dealing with information systems for whom security is of paramount importance.