University of California, Riverside

Central Authentication Service


History of CAS

Developed at Yale University, the Common Authentication Service (CAS) provides the ability to access multiple protected web applications in a single authenticated session.

The CAS provides a safe way to provide authentication services to untrusted third parties. Web applications which are programmed to take advantage of the CAS never see authentication credentials, only (the CAS server) sees this information (remember, only give your authentication credentials to

The user may allow the CAS to set a session cookie when they initially authenticate; this cookie is called a ‘ticket granting’ cookie, or TGC. On subsequent attempts to access protected resources, the TGC is used to verify that the user has authenticated during the current session. Since the TGC is a session cookie, the user will also be logged out when their web browser exits.

If the user doesn't allow the ticket granting cookie to be set, they lose all SSO functionality: each time they access a protected resource, they will be prompted for their authentication credentials. Other than this loss of SSO functionality, no ill effects will result.

More Information 

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Central Authentication Service
Computing & Communications Bldg.

Tel: (951) 827-4741
Fax: (951) 827-4541