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What Devices Can I Enroll?

You can enroll using any of the devices below. We strongly encourage registering at least two devices, one of which is a phone.

Method of Authentication
Device Duo App 'Push' Duo Passcode Txt (SMS) Voice Callback Hardware Token
Smart phone X X X X  
Cell phone   X X X  
Land Line phone       X  
Tablet X X      
Token - U2F         X
Token - OATH   X     X
Token - Yubikey   X     X
Software - OATH   X      

* Enrollment requires contacting 4Help ( or 540-231-HELP/540-231-4357)

When you have WiFi or cellular connectivity, the Duo Mobile App asks you to approve or reject the login attempt. Touch the screen for “approve” and you are logged in.

The Duo Mobile App also works without connectivity (or at your choice). Touch the “key” symbol and receive a code generated by the app within your smart device. Type in the code and you are logged in.

Text messages provide you with a code to type into your login screen.

Voice callbacks ring your smart phone, cell phone, or landline phone. When you answer in a brief time, the automated voice asks you to press a key on the phone. That action completes your login.

Information Technology supports tokens. At this time, we recommend that you be familiar with the use of tokens, or have departmental support for tokens.

Whose device should I enroll?
Regardless of who owns the devices you register for your 2nd factor, you must have access to those device(s) whenever you log in. You may enroll a personal device or a university device. The Duo Mobile App for smartphones or tablets is very easy to use. Users should know that the information collected by Duo from the app pertains to the device itself, and is used only for the purpose of verifying a user’s identity. No other personal information is captured.

Text messages may be sent to either personally owned devices or to university owned cell phones.

To use only university-owned devices, consider a university landline phone or a departmentally purchased token.

Special cases

Lost device

Call 4help if you have lost a device. Like a compromised password, a lost device is a security risk. 4Help can “unenroll” that device for you.

Forgotten, lost, or damaged devices

Please enroll at least TWO (2) devices so that you have a backup. We recommend at least one phone to increase your options. If all your options are unusable, 4Help can help you through the situation.

International travel/remote area travel

Consider what devices you are likely to have during your travel.

  • Do you travel with a smartphone or tablet, even if you cannot use it for Internet or voice service while overseas? Remember you can use the “offline” feature of the Duo Mobile App that will work without WiFi or cellular connectivity, including during “airplane mode” or while using another computer.

  • Remember, too, that “2-factor authentication” does not necessarily require 2 devices. If you are using a smart phone or tablet as your Internet device, it can still run the Duo Mobile App as your second factor on that same smart phone or tablet.

  • Will you be at someone else’s landline? You can enroll that device and phone number as well.

  • If none of these options will work for you, consider a token. Contact 4Help for more information.
    ( or 540-231-HELP/540-231-4357)