User authentication for mobile device through image selection

To provide adequate authentication to users is a constant problem, especially with mobile devices such as personal digital assistants (PDAs). However, these devices are also being used extensively by government agencies, hospitals and military and in businesses so there is a security risk not only because they contain sensitive information but they may also present means to access information on wireless networks. So user authentication is a main question for the security of mobile devices that may be caught by unauthorized individual. However traditional alphanumeric passwords do not provide high security level to mobile devices as they are more vulnerable to brute force and dictionary attacks. To overcome this problem visual authentication techniques were introduced. In this research paper we are going to analyze several visual techniques for authentication of mobile device users. And in the end we will describe our own technique which uses an alphanumeric string with pictures as passwords.