Single sign-on (SSO)is a session/user authentication process that permits a user to enter one name and password in order to access multiple applications. The process authenticates the user for all the applications they have been given rights to and eliminates further prompts when they switch applications during a particular session.
Single sign-on (SSO), is an authentication method that requires a user to only log on once, with a single user ID and password, to multiple applications, systems or Web sites. Prior to single sign-on, a user had to enter both a user ID and password, each usually different, every time they logged on to different applications or systems in the same session. This obviously can be time-consuming, especially in business environments, where time is money yet time is wasted because employees have to keep logging on each time they access a new system from their desktop.
SSO is usually implemented through a separate software authentication module that acts as a gateway to all the applications that require logging on. The module authenticates the user and then does all the heavy lifting -- managing access to the other applications. It acts as a master data store for all the required logon credentials.
An example of an SSO module is Microsoft's Passport, which allows a user to register once and then acts as a gateway to multiple Web sites, each of which normally requires its own logon. There are other commercial SSO modules available, such as Computer Associates' eTrust and there are other modules in Java and PAM for Linux.
