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IMSS  /  Services  /  Information Security  /  Duo MFA  /  Authentication Methods  /  YubiKey passcode

How to use YubiKey passcode

A YubiKey is a hardware device that can be used as a second-factor option with Duo.

Note: some YubiKey devices can function as a passcode generator as well as a Security Key. Others can only function as a security key. This document describes using a YubiKey as a passcode generator. Please also see "How to use YubiKey Security Key" and "What is the difference between YubiKey Passcode and YubiKey Security Key"?

How YubiKey passcode works

After you log in with your username and password, Duo prompts you to "Enter your passcode". Tap the button on your YubiKey device, and the passcode will be filled in automatically.

How to set up YubiKey passcode

In order to be used as a passcode generator with Duo at Caltech, a YubiKey must support OTP protocols and must be set up initially by the IMSS Help Desk. The Help Desk will configure the YubiKey and attach it to your account.

How to authenticate using YubiKey passcode

  1. Log in to a Duo-protected service using your username and password
  2. Duo will prompt you to "Enter your passcode". If you do not see the this prompt, Duo may have defaulted to a different authentication method. Click "Other options" and then "YubiKey passcode" to manually select this option. If you do not see "YubiKey passcode" in the list of options, you have not set up this method yet. Refer to the instructions above.
  3. Insert the YubiKey into a USB port in your computer if it is not connected already. Make sure the Duo "Enter your passcode" prompt is selected (click on the inside of the Passcode input box so that you see the blinking cursor), then tap the button on the top of the YubiKey device to trigger it to enter the passcode.
  4. Select "Verify" to proceed.