1. Karlsruhe Institute of Technology (KIT), Department of Economics and Management, Institute of Applied Informatics and Formal Description Methods (AIFB) Research Group Critical Information Infrastructures (cii) Kaiserstraße 89 Karlsruhe 76133 Germany
2. Darmstadt University of Technology (TU Darmstadt), Department of Law and Economics Chair of Information Systems and Electronic Services Hochschulstraße 1 Darmstadt 64289 Germany