Under the motto "comprehensible security in the networked world", KASTEL addresses challenges posed by the increasing interconnection of previously isolated systems. Of particular importance are the consequences of digitalization in critical infrastructures, for example, in the energy industry, in networked mobility, or in industrial production.

Within KASTEL Engineering Secure Systems, the research group cii focuses on the design of secure decentralized information systems. In the application context of networked mobility, we focus on implications for consumers emanating from different degrees of decentralization of information systems. Decentralization of information systems can increase data sovereignty for users in information systems, but requires also that users take on new tasks and roles when processing information. For example, users of decentralized information systems need to make efforts to operate their own data repositories. Moreover, the degree of decentralization of an information system is not a constant property but changes over time due to economic, political, social, and technical dynamics. These dynamics make it difficult to design decentralized information systems in such a way that they continue to meet user needs while allowing them to harness the benefits of decentralized information systems (e.g., increased data sovereignty). To better understand the design of decentralized information systems, the research group cii focuses in particular on the following research topics:

1. Dynamics influencing decentralization of information systems
2. Choosing appropriate degrees of decentralization to meet application-specific requirements of information systems
3. Implications of different degrees of decentralization for users of information systems