The 11th Australasian Conference on Information Security and Privacy (ACISP 2006) was held in Melbourne, 3–5 July, 2006. The conference was sponsored by Deakin University, the Research Network for a Secure Australia, and was organized in cooperation with the University of Wollongong. The conference brought together researchers,practitioners and a wide range of other users from academia, industries and government organizations. The program included 35 papers covering important aspects of information security technologies. The papers were selected from 133 submissions through a two-stage anonymous review process. Each paper received at least three reviews by members of the Program Committee, and was then scrutinized by the whole committee during a two-week discussion. There were 19 papers eligible for the “best student paper” award. The award was given to Yang Cui from the U- versity of Tokyo for the paper “Tag-KEM from Set Partial Domain One-Way Permutations. ” In addition to the regular papers the program also included three invited talks. Bart Preneel gave an invited talk entitled “Electronic Identity Cards: Threats and Opportunities. ” Mike Burmester’s talk was “Towards Provable - curity for Ubiquitous Applications. ” The details of the third talk had not been ?nalized at the time of publication of these proceedings. We wish to thank all the authors of submitted papers for providing the c- tent for the conference;their high-quality submissions madethe task of selecting a program very di?cult.