Foreword from the Program Chairs These proceedings contain the papers selected for presentation at the 10th - ropean Symposium on Research in Computer Security (ESORICS), held S- tember 12 14, 2005 in Milan, Italy. In response to the call for papers 159 papers were submitted to the conf- ence. These paperswere evaluated on the basis of their signi?cance, novelty, and technical quality. Each paper was reviewed by at least three members of the program committee. The program committee meeting was held electronically, holding intensive discussion over a period of two weeks. Of the papers subm- ted, 27 were selected for presentation at the conference, giving an acceptance rate of about 16%. The conference program also includes an invited talk by Barbara Simons. There is a long list of people who volunteered their time and energy to put together the symposiom and who deserve acknowledgment. Thanks to all the members of the program committee, and the external reviewers, for all their hard work in evaluating and discussing papers. We are also very grateful to all those people whose work ensured a smooth organizational process: Pierangela Samarati, who served as General Chair, Claudio Ardagna, who served as P- licity Chair, Dieter Gollmann who served as Publication Chair and collated this volume, and Emilia Rosti and Olga Scotti for helping with local arrangements. Last, but certainly not least, our thanks go to all the authors who submitted papers and all the attendees. We hope you ?nd the program stimulating."

This book constitutes the thoroughly refereed post-proceedings of the Second International Workshop on Privacy Enhancing Technologies, PET 2002, held in San Francisco, CA, USA, in April 2002. The 17 revised full papers presented were carefully selected during two rounds of reviewing and improvement. Among the topics addressed are Internet security, private authentication, information theoretic anonymity, anonymity measuring, enterprise privacy practices, service architectures for privacy, intersection attacks, online trust negotiation, random data perturbation, Website fingerprinting, Web user privacy, TCP timestamps, private information retrieval, and unobservable Web surfing.