Examines ways in which an individual's identity can be verified, different ways this information can be used, and technological advances in the process, and some issues concerning use of technology to identify people.

"The Science at the Edge" series focuses on developments and theories in science that are of widespread popular interest and give rise to controversy and public concern. Each book focuses on 'how science works' with applications and cutting edge examples, and features details of the development or discovery. They explain the underlying science and techniques, and review the issues and opinions involved (both scientific and non-scientific), all using a variety of examples and evidence. These revised editions include the latest developments in these fast-moving areas of science.