Security and Protection in Information Processing Systems contains the papers selected for presentation at the 19th IFIP International Conference on Information Security (SEC2004), which was held in August 2004 as a co-located conference of the 18th IFIP World Computer Congress in Toulouse, France. The conference was sponsored by the International Federation for Information Processing (IFIP).This volume is essential reading for scholars, researchers, and practitioners interested in keeping pace with the ever-growing field of information security.