Challenge Mode

Applications and devices that don't support the inline Duo Prompt or a secondary passcode field can use Challenge Mode. In this configuration, you'll see a text-based set of Duo authentication options returned to you after you submit your username and password. You will complete two-factor authentication by typing in your choice of the available options.

Login with Challenge Mode

Enter your username and password, and in response you'll receive the Duo challenge text response listing your available authentication methods:

Duo two-factor login for jdoe

Enter a passcode or select one of the following options:

1. Duo Push to XXX-XXX-1234
2. Phone call to XXX-XXX-1234
3. SMS passcodes to XXX-XXX-1234

Passcode or option (1-3)

In the text response area, type in the number that matches the option you want to use to log in. For example, to log in with Duo Push after receiving the above challenge prompt, enter 1, and then approve the Duo Push request you receive.

Instead of typing in the number that corresponds to the listed options, you may also enter a Duo factor option:

Type... To...
push Push a login request to your phone (if you have Duo Mobile installed and activated on your iOS or Android device). Review the request and tap Approve to log in.
phone Authenticate via phone callback.
sms Get a new batch of SMS passcodes. Your login attempt will fail — log in again with one of your new passcodes.
If you previously requested SMS passcodes, the challenge text gives you a hint like "next code starts with: 2".
passcode Log in using a passcode, either generated with Duo Mobile, sent via SMS, generated by your hardware token, or provided by an administrator. Examples: "123456" or "1456789".

You can add a number to the end of these factor names if you have more than one device registered. For example, push2 will send a login request to your second phone, phone3 will call your third phone, etc.

In some configurations, you may see a short version of the Duo challenge text response:

Choose a secondary factor from (`push1`, `phone1`, `sms1`) or enter passcode:

Respond to the short prompt in the same way as you would for the full prompt, by entering the name of the Duo factor you want to use, or a number that matches your chosen factor's position in the list.


Enroll with Challenge Mode

If you are a new Duo user and your organization's administrator allows you to self-enroll, the Duo challenge text response will provide an enrollment URL:

Please enroll at https://api-abcd1234.duosecurity.com/portal?code=a12b34cc67de89&akey=DABCD1234EFGH5678IJ90

Copy this URL into your browser to complete Duo enrollment.

After you complete Duo enrollment, log in again and you'll receive the challenge prompt showing your enrolled Duo authentication methods