Many services which we use today require us to login to ensure security and con?dentiality. As the number of services increase, it has become quite difficult to remember the username and password for each of them. In this system, user can access different services in which he can log in securely once and can access different services through a trusted authority. Sign-on mechanism is an integrated system setup that allows users to access application services by logging only once. It allows users to use the unitary token to access the service provider in distributed computer network. The user has to authorize himself to a trusted third party which will grant him the permission to access all the services by issuing encrypted key known as token. The user acquires this secret key to logon to various services provided by the service provider. This application can be used in desktop/ laptop or mobile phones.