The ?rst SKLOIS Conference on Information Security and Cryptography(CISC 2005) was organized by the State Key Laboratory of Information Security of the Chinese Academy of Sciences. It was held in Beijing, China, December 15-17,2005andwassponsoredbytheInstituteofSoftware,theChineseAcademy of Sciences, the Graduate School of the Chinese Academy of Sciences and the National Science Foundation of China. The conference proceedings, represe- ing invited and contributed papers, are published in this volume of Springer’s Lecture Notes in Computer Science (LNCS) series. The area of research covered by CISC has been gaining importance in recent years, and a lot of fundamental, experimental and applied work has been done, advancing the state of the art. The program of CISC 2005 covered numerous ?elds of research within the general scope of the conference. The International Program Committee of the conference received a total of 196 submissions (from 21 countries). Thirty-three submissions were selected for presentation as regular papers and are part of this volume. In addition to this track, the conference also hosted a short-paper track of 32 presentations that were carefully selected as well. All submissions were reviewed by experts in the relevant areas and based on their ranking and strict selection criteria the papers were selected for the various tracks. We note that stricter criteria were applied to papers co-authored by program committee members. We further note that, obviously, no member took part in in?uencing the ranking of his or her own submissions.