DUO Two-Factor Authentication


What is multi-factor authentication?

Multi-factor authentication protects against phishing, social engineering and password attacks by requiring multiple methods (or factors) to verify your identity. These factors usually include something you know, plus something you have.

What is Duo?

Duo is a third party multi-factor authentication tool that Caltech has licensed to improve security.

How much does it cost?

Duo is free to Caltech users. There is a cost if opting to use a YubiKey hardware token ($32-40 per key).

How can I start using Duo?

Submit a request to https://help.caltech.edu, request type IMSS > Information Security > Duo Request. Then visit our Get Started page.

I lost my YubiKey. Can I get another?

Yes, please contact Information Security to purchase another YubiKey for $32-40. Submit a request to https://help.caltech.edu, request type IMSS > Information Security > Duo Request.

Which services are Duo enabled?

Currently, these services are Duo enabled, with more planned:

  • AdvanceCaltech
  • Email
  • Remote Desktop
  • Central HPC

What if Duo is not compatible with my email client?

Microsoft Authenticator may be used in the case that Duo is not compatible with your email client. Currently, these do not work with Duo:

  • POP and IMAP
  • Android native app
  • Mac Mail (version 10.13 and below)
  • iOS 10.x and below

Are there accessibility limitations when using the Duo app or YubiKey?

There are some limitations, specifically when using a YubiKey. Please see the chart below for details.

2-Factor Method Email Accessibilty
Duo app Access email from work and home computers, and/or any smartphone or mobile device
Hardware Token (i.e. YubiKey) Hardware token must be attached to the computer that is accessing email (work or home); cannot access email via smartphone or mobile device (unless you are also using the mobile app)







Who can I contact with questions or concerns?

For any questions or concerns, please contact the Help Desk at https://help.caltech.edu (Request Type: IMSS > Email & Calendar > Duo Help) or x3500.

DUO Two-Factor Authentication