User Dynamics in Graphical Authentication Systems

In this paper, a graphical authentication system is presented which is based on a matching scheme. The user is required to match up thumbnail graphical images that belong to a variety of categories – in an order based approach. The number of images in the selection panel was varied to determine how this effects memorability. In addition, timing information was included as a means of enhancing the security level of the system. That is, the user’s mouse clicks were timed and used as part of the authentication process. This is one of the few studies that employ a proper biometric facility, namely mouse dynamics, into a graphical authentication system. Lastly, this study employees the use of the 2-D version of Fitts’ law, the Accot-Zhai streering law, which is used to examine the effect of image size on usability. The results from this study indicate that the combination of biometrics (mouse timing information) into a graphical authentication scheme produces FAR/FRR values that approach textual based authentication schemes.