The modern society depends on critical infrastructures and the services they provide, here referred to as critical societal services (CSS). They provide us with electricity, water, heat, and ways to travel, communicate, and trade. Traditionally, these vital systems have been kept isolated to avoid security threats and performance disturbances. However, a silent revolution is underway as more and more of them are becoming part of the Internet of Things (IoT), e.g., through smart grids, intelligent transportation systems, body sensor networks and intelligent habitats. There is a strong rationale for this transformation. For example, Internet-connected embedded systems can be upgraded and adapted to changing needs on demand, useful information can be immediately collected from remote geographic areas, and fault diagnosis and system restarts can be made more efficient and cost-effective by not having to send out technicians to remote place
