Continuous authentication by analysis of keyboard typing characteristics

This paper describes a simple, software based keyboard monitoring system for the IBM PC for the continuous analysis of the typing characteristics of the user for the purpose of continuous authentication. By exploiting the electrical characteristics of the PC keyboard interface together with modifications to the internal system timer, very accurate measurements can be made of keystroke interval and duration, including measurements of rollover. Rollover patterns, particularly when typing common diphthongs, can be highly characteristic of individual users and provide quite an accurate indication of the users identity.