This volume constitutes the refereed proceedings of two workshops: the International Cross-Domain Conference and Workshop on Availability, Reliability and Security, CD-ARES 2014, and the 4th International Workshop on Security and Cognitive Informatics for Homeland Defense, SeCIHD 2014, co-located with the International Conference on Availability, Reliability and Security, ARES 2014, held in Fribourg, Switzerland, in September 2014. The 23 revised full papers presented were carefully reviewed and selected from numerous submissions. The papers deal with knowledge management, software security, mobile and social computing, enterprise information systems, homeland security and information processing.