Inferring Identity from User Behaviour

Biometrics using inherited characteristics are frequently used in security systems. An alternative metric is user behaviour. Examples of user behaviour are the set of web pages accessed over a number of Internet sessions, or, the set of television programmes viewed by an individual over a number of days. A mathematical framework is developed which enables simple and robust identification algorithms based on this kind of user behaviour to be presented. Experimental results are based on a database of 33 users' television viewing habits. The use of these algorithms to this domain is not intended as a real application, but rather as an illustration of the power of the techniques. Practical applications would include user authentication for fraud prevention and preference prediction on the Internet. The user discrimination performance using the TV viewing database is modest, an equal error rate of about 18%. However, it is reasonable to suppose that the discrimination given by this technique would be orthogonal to those of other biometrics and so could provide a useful improvement in performance in a system combining the two.