The proliferation of commercial and non-commercial activities over different networked systems has brought security concerns on an unprecedented scale. Every new network technology brings along another wave of attacks exploiting new ways to comprise the confidentiality, integrity, authenticity, or availability of services and data. To protect these network assets, communication endpoints as well as every layer of the communication stack needs to be secured. Current trends from stationary to mobile devices, local to cloud storage, native to web apps, centralized to distributed processing, pre-configured to ad hoc set up, narrowband to broadband, homogenous to heterogeneous networks, special-purpose to consumer devices and closed to open platforms force us to re-design and sometimes completely rethink existing security mechanisms. At the same time novel security solutions must meet the special needs and constraints of these new communication technologies. The main purpose of this workshop is to promote further research interests and activities on Network Security. This workshop aims to increase the synergy between academic and industrial researchers working in this area. We are interested in experimental, systems-related, and work-in-progress papers in all aspects of Network Security.