RERUM will develop, evaluate, and trial an architectural framework for dependable, reliable, and secure networks of heterogeneous smart objects supporting innovative Smart City applications. The framework will be based on the concept of "security and privacy by design", addressing the most critical factors for the success of Smart City applications.The technical approach aims to enable tighter integration of Internet of Things (IoT) technology in the Smart City domain. The ultimate target is to provide innovative applications that will improve the citizens' quality of life. RERUM will design mechanisms to manage resources in an efficient and effective manner, ensuring confidentiality, authenticity, integrity, and availability of data gathered by IoT objects. The RERUM approach is scenario-independent, hence applicable to the entire gamut of future Smart City applications.To achieve these goals RERUM will:• analyse industrial and Smart City application requirements for steering the overall system design,• develop a new, technically innovative framework to interconnect a large number of heterogeneous software and hardware smart objects, using novel approaches, e.g. based on virtualization and cognitive radio,• increase the energy efficiency of IoT to provide sustainable infrastructures in the economic and ecologic sense,• model the trustworthiness of the IoT and enable secure and reliable exchange of trusted information,• enable secure bootstrapping and self-monitoring of networks to detect and mitigate security events,• perform proof-of-concept experiments and real-world trials in two Smart City environments to assess the project results with respect to technical feasibility and user acceptance, and• assess the portability and its "scenario-agnostic" characteristics by cross-evaluating the trials' results.To vertically address these aspects RERUM unites a consortium of complementary stakeholders covering all areas of the IoT-based Smart Cities paradigm.