Asiacrypt, the annual conference of cryptology sponsored by IACR is now 11 years old. Asiacrypt 2005 was held during December 4-8, 2005, at Hotel Taj Coromandel,Chennai,India.This conferencewasorganizedby theInternational Association for Cryptologic Research (IACR) in cooperation with the Indian Institute of Technology (IIT), Chennai. Thisyearatotalof237papersweresubmittedtoAsiacrypt2005.Thesubm- sionscoveredallareasofcryptographicresearchrepresentingthecurrentstateof work in the crypto community worldwide. Each paper was blind reviewed by at least three members of the Program Committee and papers co-authored by the PC members were reviewed by at least six members. This ?rst phase of review by the PC members was followed by a detailed discussion on the papers. At the end of the reviewing process 37 papers were accepted and were presented at the conference. The proceedings contain the revised versionsof the accepted papers. In addition we were fortunate to have Prof. Andrew Yao and Prof. Bart Preneel as invited speakers.Based on a discussion and subsequent voting among the PC members, the Best Paper Award for this year's Asiacrypt was conferred to Pascal Paillier and Damien Vergnaud for the paper entitled "Discrete-Log-Based Signatures May Not Be Equivalent to Discrete Log." I would like to thank the following people. First, the General Chair, Prof.
