The Seventh International Conference on Information and Communications - curity, ICICS2005, washeldinBeijing, China,10-13December2005. TheICICS conference series is an established forum for exchanging new research ideas and development results in the areas of information security and applied crypt- raphy. The ?rst event began here in Beijing in 1997. Since then the conference series has been interleaving its venues in China and the rest of the world: ICICS 1997 in Beijing, China; ICICS 1999 in Sydney, Australia; ICICS 2001 in Xi'an, China; ICICS 2002 in Singapore; ICICS 2003 in Hohhot City, China; and ICICS 2004 in Malaga, Spain. The conference proceedings of the past events have - ways been published by Springer in the Lecture Notes in Computer Science series, with volume numbers, respectively: LNCS 1334, LNCS 1726, LNCS 2229, LNCS 2513, LNCS 2836, and LNCS 3269. ICICS 2005 was sponsored by the Chinese Academy of Sciences (CAS); the Beijing Natural Science Foundation of China under Grant No. 4052016; the National Natural Science Foundation of China under Grants No. 60083007 and No. 60573042;the NationalGrandFundamentalResearch973ProgramofChina under Grant No. G1999035802, and Hewlett-Packard Laboratories, China. The conference was organized and hosted by the Engineering Research Center for Information Security Technology of the Chinese Academy of Sciences (ERCIST, CAS) in co-operation with the International Communications and Information Security Association (ICISA). The aim of the ICICS conference series has been to o?er the attendees the opportunity to discuss the latest developments in theoretical and practical - pects of information and communications security.

The 2003 Information Security Conference was the sixth in a series that started with the InformationSecurity Workshopin 1997.A distinct feature of this series is the wide coverage of topics with the aim of encouraging interaction between researchers in di?erent aspects of information security. This trend continued in the program of this year s conference. There were 133 paper submissions to ISC 2003. From these submissions the 31papersintheseproceedingswereselectedbytheprogramcommittee, covering a wide range of technical areas. These papers are supplemented by two invited papers;athirdinvitedtalkwaspresentedattheconferencebutisnotrepresented by a written paper. We would like to extend our sincere thanks to all the authors that submitted papers to ISC 2003, and we hope that those whose papers were declined will be able to ?nd an alternative forum for their work. We are also very grateful to the three eminent invited speakers at the conference: Paul van Oorschot (Carleton University, Canada), Ueli Maurer (ETH Zur ] ich, Switzerland), and Andy Clark (Inforenz Limited, UK). We were fortunate to have an energetic team of experts who took onthe task of the program committee. Their names may be found overleaf, and we thank them warmly for their considerable e?orts. This team was helped by an even larger number of individuals who reviewed papers in their particular areas of expertise. A list of these names is also provided, which we hope is complete."