Computer technology evolves at a rate that challenges companies to maintain appropriate security for their enterprises. With the rapid growth in Internet and WWW facilities, database and information systems security remains a key topic in businesses and in the public sector, with implications for the whole of society. This study covers issues related to security and privacy of information in a wide range of applications, including: critical infrastructure protection; electronic commerce; information assurance; intrusion detection; workflow; policy modelling; multilevel security; role-based access control; data mining; data warehouses; temporal authorization models; and object-oriented databases. This book contains papers and panel discussions from the Thirteenth Annual Working Conference on Database Security, organized by the International Federation for Information Processing (IFIP) and held July 25-28, 1999, in Seattle, Washington, USA.