Due to the vulnerability caused by poor password selection it is very important to have a secure authentication and authorization infrastructure for Web based applications. In the current scenario it is very difficult to remember different passwords for different Web based applications. We propose centralized password based multiuser and multi-application single sign-on (SSO) framework for such applications. Unlike traditional single sign-on architectures we are using identity based encryption system (IBES) instead of public key infrastructure (PKI). Our proposed design provides better security for the users and the system is efficient. This framework is deployed as a Web service and can be deployed on a Web server.