Some Princeton applications use the Central Authentication Service (CAS), which requires Duo two-factor authentication.

Other applications use a Princeton-branded Microsoft sign-in page that supports two-factor authentication through Duo or the Microsoft Authenticator app.

Your Microsoft sign-in experience may vary depending on whether Microsoft Authenticator is set up as a sign-in method for your Princeton University Microsoft account.

Managing your Microsoft sign-in experience

If you’re using Authenticator for two-factor authentication, you can add Duo as a backup option. Sign in to your Microsoft account, select Add sign-in method, choose External MFA and follow the prompts. Even if you add Duo, Authenticator will remain your default sign-in method.

If Authenticator is your default and you want to switch to Duo, contact the IT Service Desk to reset your account.

The authentication experience for Microsoft sign-in

If you have not set up a two-factor authentication sign-in option, you'll be prompted to add one. Follow the instructions to Set Up Duo as your default authentication.

If you’ve only set up Duo for authentication, you will see the Duo prompt after you enter your netID@princeton.edu and password.

If Authenticator is set up, you'll be prompted to approve your sign-in using the Microsoft Authenticator app.

If you have Duo set up as a backup sign-in method, you can select the option I can’t use my Microsoft Authenticator app right now and select the option to Approve with Duo Two-Factor Authentication.