This book constitutes the refereed proceedings of the 4th International Conference on Information and Communication Security, ICICS 2002, held in Singapore in December 2002. The 41 revised full papers presented were carefully reviewed and selected from a total of 161 submissions. The papers are organized in topical sections on system security, crypto systems, security protocols, fingerprinting and watermarking, efficient implementation of algorithms, access control, and cryptanalysis and cryptographic techniques.