This book originates from an international workshop on personal information held at the Isaac Newton Institute for Mathematical Sciences in Cambridge, UK, in June 1996. The workshop was organized under the joint sponsorship of the British Medical Association and the Isaac Newton Institute in the context of a six-month research program in computer security, cryptology, and coding theory. The revised workshop papers appearing in this volume reflect a lively interdisciplinary exchange of views and ideas between doctors, lawyers, privacy activists, and the computer security community. The volume gives a representative snapshot not merely of the state of the art of the medical computer security art in various countries, but of the complex interplay between human, political, and technical aspects.