A Free Drawing Graphical Password Scheme

This paper presents a method for freely drawing a graphical password. The new method achieves better security than conventional textual passwords and other graphical password schemes. With this method it is also easier for a user to remember the password. The basic idea of the new method is to use a number of the user's representative sample drawings to predict the user's future drawing prediction interval. The predicted values are obtained by conducting the least squares method to the polynomial regression model. Based on the predicted values and deviation of the user's sample drawings, a prediction interval for the signature/picture is generated. This prediction interval is used as the password and, subsequently, if the signature/picture drawn by a user lies within the prediction interval, the user is authenticated into the application.