Date Added: May 2013
Authentication is process of determining whether someone or something is, in fact who or what to be declared. For authentication mostly textual passwords are used. Passwords are the most commonly used method for identifying users in computer and communication systems. Typically, passwords are strings of letters and digits, i.e., they are alpha-numeric. Such passwords have the disadvantage of being hard to remember. Graphical passwords, which consist of some actions that the user performs on an image. Such passwords are easier to remember, but are vulnerable to shoulder surfing (which consists of simply watching a user login).