  Password authentication is the most commonly used technique to authenticate
the user validity. However, due to its simplicity, it is vulnerable to pseudo
attacks. It can be enhanced using various biometric techniques such as thumb
impression, finger movement, eye movement etc. In this paper, we concentrate on
the most economic technique, based on the user habitual rhythm pattern i.e. not
what they type but how they type is the measure for authenticating the user. We
consider the latency between key events as the trajectory, and trajectory
clustering is used to obtain the hidden patterns of the user. Obtained pattern
can be considered as a cluster of measurements that can be used to
differentiate from other users. We evaluated the proposed technique on the data
obtained from the 100 users.
