Those without phones can use a security key for DUO. September 28, 2022 16:43 Updated A security key plugs into the USB port on your computer. When tapped or pressed it sends a signal back to Duo. Must have a U2F security key to complete the process. A supported USB security key. WebAuthn/FIDO2 security keys from Yubico or Feitian are good options. Go to https://guide.duo.com/security-keys for online instructions and requirements to enroll in Duo 2-factor authentication with a security key. Related articles How to add new phone to DUO mobile with the same phone number. I don't have a phone or access to a phone for DUO. Hardware tokens are available. Adding a new phone and number to DUO Duo Restore for Android Taking a college laptop off campus. Remote work or travel.