It has been realised for nearly thirty years (Young, J. R., Hammon, R. W., Method and apparatus for verifying an individual's identity, Patent Number 4,805,222, U.S. Patent and Trademark Office, Washington D.C., 1989) that the way in which a person uses a keyboard may be used to identify that person. Since that realisation, advances in technology mean that the processing and matching of keyboard use, that is, Keystroke Dynamics, may be applied outside of the laboratory for purposes beyond the theoretical and experimental. We are now in the position where Keystroke Dynamics is already in use to support password authentication and is considered to be a biometric as useful and unique as fingerprints or iris scans.
Further interesting research on analysis of keystroke characteristics derived from free-form text has been done by DANIELE GUNETTI and CLAUDIA PICARDI University of Torino and others have made it possible to move away from analysing many users typing the same words to allowing analysis of user typing their own words. This might allow continuous monitoring of a user's pattern of keyboard use to make sure that nobody has "slipped into the chair" and is using a computer session illegally.