Now-a-days, most of the institution faces a huge problem related to security. Most of the institution uses the traditional way to provide authentication. That means most them are use passwords as an authentication mechanism. Now most of the users use same password in different accounts to avoid their work loads. But this is not a secure way. So many other mechanisms are designed for providing security such as two factor authentication. This paper discuss about a securing two factor authentication using mobile phones. Here, the authors use mobile phones for generating OTPs.