As Information Technology becomes a vital part of our everyday activities, ranging from personal use to government and defense applications, the need to develop high-assurance systems increases. Data and applications security and privacy are crucial elements in developing such systems. Research Directions in Data and Applications Security XVIII presents original unpublished research results, practical experiences, and innovative ideas in the field of data and applications security and privacy. Topics presented in this volume include:-Database theory; -Inference control;-Data protection techniques; -Distributed systems; -Access control models; -Security policy; -Design and management; -Privacy; -Network security. This book is the eighteenth volume in the series produced by the International Federation for Information Processing (IFIP) Working Group 11.3 on Data and Applications Security. It contains twenty-three papers and two invited talks that were presented at the Eighteenth Annual IFIP WG 11.3 Conference on Data and Applications Security, which was sponsored by IFIP and held in Sitges, Catalonia, Spain in July 2004.