The 3rd International Conference on Applied Cryptography and Network Security (ACNS 2005) was sponsored and organized by ICISA (the International Commu- cations and Information Security Association). It was held at Columbia University in New York, USA, June 7-10, 2005. This conference proceedings volume contains papers presented in the academic/research track. ACNS covers a large number of research areas that have been gaining importance in recent years due to the development of the Internet, wireless communication and the increased global exposure of computing resources. The papers in this volume are representative of the state of the art in security and cryptography research, worldwide. The Program Committee of the conference received a total of 158 submissions from all over the world, of which 35 submissions were selected for presentation at the a- demic track. In addition to this track, the conference also hosted a technical/ industrial/ short papers track whose presentations were also carefully selected from among the submissions. All submissions were reviewed by experts in the relevant areas.