The second International Conference on Applied Cryptography and Network Security (ACNS 2004) was sponsored and organized by ICISA (the International Communications and Information Security Association). It was held in Yellow Mountain, China, June 8 11, 2004. The conference proceedings, representing papers from the academic track, are published in this volume of the Lecture Notes in Computer Science (LNCS) of Springer-Verlag. The area of research that ACNS covers has been gaining importance in recent years due to the development of the Internet, which, in turn, implies global exposure of...