University of California, Riverside

Central Authentication Service


Frequently Asked Questions

What is CAS?

CAS stands for Central Authentication Service which was developed by Yale University. It was developed to provide a single authentication session to multiple web applications.

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How do I ensure security in the CAS environment?

Closing all of your web browsers after you have completed your work is the most secure way to log off all systems.

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What is Authorization?

The process whereby it is determined what applications a person is allowed to access. EACS is used for fine grained access control, and the UCR Enterprise Directory service is used for rough grained access control. Authentication precedes authorization.

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What is single sign-on?

A per-session process whereby a person authenticates once for access to multiple protected applications.

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What is the CAS login URL address?

Be sure the login address is when you log in.

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How do I log out of CAS?

The best way to log out of CAS is to exit the browsing application. For Windows users, close all open browser windows. For Mac users, the browsing application remains open until you quit the application from either the File menu or by right-clicking on the Dock icon. To verify the browser is closed on a Mac, check if there is no arrow or light under the application's icon in the Dock. If an arrow or light is displayed under the icon, the browser is still running. You can also log out of CAS by going to

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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