Information and Communication Security : Second International Conference ICICS99 Sydney Australia November 9 11 1999 Proceedings This book constitutes the refereed proceedings of the Second International Conference on Information and Communication Security ICICS99 held in Sydney Australia in November 1999. The 24 revised full papers presented were carefully reviewed and selected from a total of 62 submissions. The book is divided in topical sections on cryptanalysis language based approaches to security electronic commerce and secret sharing digital signatures security protocols applications cryptography and complexity and security functions