The Fourth International Workshop on Security (IWSEC 2009) was held at Toyama International
Conference Center Toyama Japan October 28-30 2009. The workshop was co-organized by CSEC a
special interest group on computer security of the IPSJ (Information Processing Society of
Japan) and ISEC a technical group on information security of IEICE (The Institute of
Electronics Information and Communication Engineers). The excellent Local Organizing Committee
was led by the IWSEC 2009 General Co-chairs Kazuo Takaragi and Hiroaki Kikuchi.
IWSEC2009received46papersubmissionsfromallovertheworld.Wewould like to thank all the authors
who submitted papers. Eachpaper was reviewedby at least three reviewers. In addition to the
Program Committee members many
externalreviewersjoinedthereviewprocessintheirparticularareasofexpertise. We were fortunate to
have this energetic team of experts and are grateful to all of them for their hard work. The
hard work includes very active discussion the discussion phase was almost as long as the
initial individual reviewing. The review and discussion were supported by a very nice Web-based
system iChair. We thank its developers. Following the review phases 13 papers were accepted
for publication in this volume of Advances in Information and Computer Security. Together with
the contributed papers the workshop featured an invited talk and a hash function panel both of
which were respectively given and chaired by eminent researcher Bart Preneel (Katholieke
Universiteit Leuven). An abstract of the talk titled TheFutureofCryptographicAlgorithms
isincludedinthisvolume.Wedeeply appreciate his contribution. Many people contributed to the
success of IWSEC 2009. We wish to - press our deep appreciation for their contribution to
information and computer security.
