Multi-Factor Authentication

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Multi-factor Authentication (MFA) adds a second layer of security to your SDSUid account. By verifying your identity using a second factor (such as your mobile device or a key fob), MFA prevents anyone else from logging into your account, even if they know your password.

To help keep SDSU users and data safe, the campus utilizes Duo's MFA solution.

Getting Started


MFA Frequently Asked Questions


There are some common Duo MFA problems that seem to happen more frequently than any of us would like. We've put together this knowledge base to address the most common problems and some possible fixes. If your question is not listed below, please open a ticket.

Most Popular Cases

If you have a new phone with the same phone number, you will need to log into to SDSU Duo Portal to manage your Duo devices. Select Device Options and then Reactivate Duo Mobile.

Step-by-step instructions are provided here.

Since Duo Mobile is tied to a specific device's hardware security module (HSM), you will need to reinstall and reactivate Duo Mobile on the new phone by logging into the Duo Portal.

If you are having problems, please submit a ticket through SDSU ServiceNow.

You can also contact the Help Desk if you need immediate assistance.

If you set up a backup device, you can use the secondary device to authenticate with.

Duo Bypass Codes can be used to access resource protected by Duo when your device is unavailable. You may also need to use Bypass codes if your device is lost, stolen or replaced. Bypass codes should be placed in a secure location.

You will need to log into to SDSU Duo Portal to manage your Duo devices. Click Bypass Codes. Click Generate to create 10 new Bypass Codes. Any existing codes will no longer work. You must write down or print the Bypass Codes. They will only be displayed once and each code can only be used once.

If no other authentication method exists, please contact the Support Center. Note: Sending an email will resolve your issue faster than a phone call. The Support Center can verify you quickly through your email account. The Support Center can provide a temporary one-time passcode.

It is strongly recommended that you add an additional device to your MFA account to serve as a backup. This device could be a desk/landline, tablet, token or trusted family/friend phone number.

Yes. Duo Security's services are used in more than 100 countries. List of countries supported by Duo.

Please note that some countries and regions outside of North America and Europe have relatively unreliable telephony infrastructure. This can lead to inconsistent phone callback and SMS authentication experiences. In these circumstances, it is recommended using alternative authentication mechanisms such as Duo Push, generating passcodes in Duo Mobile, phone callback, or hardware tokens. Another consideration to keep in mind with these countries and regions is the high cost of telephony delivery.

For more information on using international phone numbers with Duo, please visit Duo's site.

Additional Help

If you still possess your previous authentication device, you will be able to manage your devices by logging into SDSU Duo Portal.

However, if you no longer have access to your previous authentication device, your new device will need to be added. Please contact the Help Desk if you need immediate assistance.

You can also submit a ticket using SDSU ServiceNow.

SIM cards with the same phone number.

If the Duo app is already installed on your phone and thew new SIM card uses the same phone number, Duo will work as normal.

SIM cards with a different phone number.

If you have the Duo app on your phone and change to a SIM card with a different phone number:

  1. Push notifications in the app — Changing SIM cards should not have any effect.
  2. Text (or call) notifications – You will need to register the phone number corresponding to the new SIM card, and then select which number to use when logging in.

For additional help, go to the Duo help guide.

Yes. You will not be able to receive PUSH notifications on your cell phone. However, if you touch the SDSU logo in the Duo app, it will give you a six-digit code to enter for authentication.

In addition, you can opt to use a Bypass Code that can be generated here.

User Support

For Faculty and Staff

  • Submit a Ticket - If you are having problems, please submit a ticket through SDSU ServiceNow.

For Students

Extra Resources