1. In a computer system, a method of performing authentication comprising: accessing spatial stroke data and pressure data captured by a digitizer of the computer system and representing a user-drawn signature wherein respective pressure data is associated with respective spatial stroke data, wherein a display screen of the computer system comprises the digitizer; storing the spatial stroke data and pressure data into a computer memory; comparing the spatial stroke data and pressure data of the user-drawn signature to stored spatial stroke data and pressure data of a reference signature for a match; generating an authentication signal upon a match of the spatial stroke data and pressure data and the stored spatial stroke data and pressure data; and provided the authentication signal is generated, allowing a user access to the computer system, otherwise prohibiting the user from accessing a portion of the computer system.