You can authenticate by phone call to a cell phone or landline, via the Duo Mobile app on a smartphone or tablet, or by SMS text message. You may also authenticate via a Yubikey hard token purchased from the ITS Site License office. Please review UH Hard Tokens for more details on Yubikey hard tokens. For more details on the different authentication methods, please review the article, UH Login Multi-Factor Authentication (MFA) - Which authentication method should I use?.