This book presents the most interesting talks given at ISSE 2015 - the forum for the interdisciplinary discussion of how to adequately secure electronic business processes. The topics include: �         Encrypted Communication �         Trust Services, eID and Cloud Security �         Industrial Security and Internet of Things �         Cybersecurity, Cybercrime, Critical Infrastructures �         BYOD and Mobile Security �         Regulation and Policies �         Biometric Applications Adequate information security is one of the basic requirements of all electronic business processes. It is crucial for effective solutions that the possibilities offered by security technology can be integrated with the commercial requirements of the applications. The reader may expect state-of-the-art: best papers of the Conference ISSE 2015. Content �         Encrypted Communication �         Trust Services, eID, Cloud Security and Management �         Industrial Security and Internet of Things �         BYOD, Mobile Security and Applications �         Cybersecurity, Cybercrime, Critical Infrastructures       �   Security Management �         Regulations and Policies Target Groups �         Chief Information Security Officers �         Developers of Electronic Business Processes �         IT Managers �          IT Security Experts �         Researchers Editors Norbert Pohlmann: Professor for Information Security and Director of the Institute for Internet Security at the Westphalian University of Applied Sciences Gelsenkirchen. Additionally he is chairman of TeleTrusT - IT Security Association Germany. Helmut Reimer: Senior Consultant, TeleTrusT - IT Security Association Germany Wolfgang Schneider: Senior Adviser, Fraunhofer Institute SIT.