This book constitutes the thoroughly refereed post-conference proceedings of the 4th International Conference on Information Security and Cryptology, Inscrypt 2009, held in Beijing, China, in December 2009. The 22 revised full papers and 10 short papers presented were carefully reviewed and selected from 147 submissions. The papers are organized in topical sections on cryptanalysis; signature and signcryption; key exchange; private computations; cipher design and analysis; public key cryptography; network and system security; hardware security; and web security.
The 5th China International Conference on Information Security and Cryptology (Inscrypt 2009) was co-organized by the State Key Laboratory of Information Security and by the Chinese Association for Cryptologic Research in cooperation with the International Association for Cryptologic Research (IACR). The conference was held in Beijing, China, in the middle of December, and was further sponsored by the Institute of Software, the Graduate University of the Chinese Academy of Sciences and the National Natural Science Foundations of China. The conference is a leading annual international event in the area of cryptography and information security taking place in China. The scientific program of the conference covered all areas of current research in the field, with sessions on central areas of cryptographic research and on many important areas of information security. The conference continues to get the support of the entire international community, reflecting on the fact that the research areas covered by Inscrypt are important to modern computing, where increased security, trust, safety and reliability are required.