Date Added: Dec 2009
Nowadays, user authentication is one of the important topics in information security. Strong text-based password schemes could provide with certain degree of security. However, the fact that strong passwords are difficult to memorize often leads their owners to write them down on papers or even save them in a computer file. Graphical authentication has been proposed as a possible alternative solution to text-based authentication, motivated particularly by the fact that humans can remember images better than text. In recent years, many networks, computer systems and Internet based environments try used graphical authentication technique for their user's authentication. All of graphical passwords have two different aspects which are usability and security.