This book constitutes the refereed proceedings of the 11th International Conference on Information Security and Cryptology ICISC 2008 held in Seoul Korea during December 3-5 2008. The 26 revised full papers presented have gone through two rounds of reviewing and improvement and were carefully selected from 131 submissions. The papers are organized in topical sections on public key encryption key management and secret sharing privacy and digital rights digital signature and voting side channel attack hash and mac primitives and foundations as well as block and stream ciphers.