While the attack systems have become more easy-to-use, sophisticated, and powerful, interest has greatly increased in the field of building more effective, intelligent, adaptive, active and high performance defense systems which are distributed and networked. The conference will cover research on all theoretical and practical aspects related to network and system security, such as authentication, access control, availability, integrity, privacy, confidentiality, dependability and sustainability of computer networks and systems. The aim of NSS is to provide a leading edge forum to foster interaction between researchers and developers with the network and system security communities, and to give attendees an opportunity to interact with experts in academia, industry, and governments. NSS 2015 is the next event in a series of highly successful events of Network and System Security. Previous editions were held in: Xi'an, China(2014), Madrid, Spain(2013); Wu Yi Shan, China (2012); Milan, Italy (2011); Melbourne, Australia; (2010); Gold Coast, Australia (2009); Shanghai, China (2008); and Dalian, China (2007).