Single Sign-On (SSO) systems enable users to authenticate a single time when establishing a desktop session, after which the SSO system handles any further authentication behind the scenes. The user never sees the SSO at work - they just access every application for which they're authorized without authenticating again. This provides a more convenient system environment for users while also improving security - no more sticky notes on the monitors with a list of logins/password for applications.

The method of authentication used by applications can vary - Password, Challenge Response Questions, Biometric Tokens (Finger imaging, Voice Recognition, Facial Recognition, Iris and Retina Recognition), Physical Tokens, Smartcards, SecureID, or Digital Certificates. The SSO system may handle all these authentication methods, prompting the user for the required input or biometric during the initial logon or the first time the particular authentication method is required by an application.

The SSO concept is not new. SSO solutions emerged in 1996 with limited functionality far short of expectations. SSO products remain amongst a handful of vendors, all built upon a rigid framework requiring customer's to modify their operational workflow rather then adapt the solution to the environment.

The bigger challenges are related to authorization and the administration of user lists. Authorization tools enable organizations to control the resources each user has access to, based on set parameters within the organization. The authorization features give IT administrators the ability to enter data one time and have it applied to all applications. The SSO product can be configured to automatically enable certain users of a certain type to have access to specific applications of the organization. The same is true for revocation of access privileges. As a result, there are fewer errors and faster authorizations and revocations.

Another SSO necessity is auditing features. These are important for adhering to government security regulations but can also serve as a record of past performance, acting as a utilization tool for real-time management as well.