This book constitutes the refereed proceedings of the 25th IFIP TC 11 International Information Security Conference, SEC 2010, held as a part of the 21th World Computer Congress, WCC 2010, in Brisbane, Australia, in September 2010. The 27 revised full papers presented were carefully reviewed and selected from 102 submissions. The papers are organized in topical sections on security management, security management and governance, network security and authentication, intrusion detection, trust management, and models, software security and assurance, panel, access control and privacy, and privacy.