Knowledge Base Frequently Asked Questions Universal 2nd Factor (U2F) What is U2F? What is a FIDO U2F-enabled key and how do I get one? How many services can the U2F-certified YubiKeys be associated with? What is the difference between a FIDO U2F Security Key and YubiKey? How do I tell what type of key my Special Edition Octocat Key is? What happens if I lose my Security Key? Can I use the U2F YubiKey I have for Gmail and Google Apps with other apps? Where else can I use my FIDO U2F Security Keys/YubiKeys? What browsers support U2F? Why do I need a Security Key when I already have SMS and Google Authenticator as a second-factor? Is the touch button on the the Security Key biometrics? Why doesn’t the YubiKey Personalization Tool recognize my Security Key? What is the security benefit of using a device with NFC, such as YubiKey NEO for Android devices? Where can I use my YubiKey NEO on an NFC-capable mobile device to authenticate? Does my YubiKey NEO support U2F over NFC? Can I update my current YubiKey NEO for U2F? How can I activate U2F on my YubiKey NEO or NEO-N? How can I set up my Linux system for use with U2F? What are the core benefits of hardware-backed keys compared to software-based authenticators? Why aren’t built-in authenticators in computers and mobile devices better than Security Keys? Can I use my Security Key to enable strong two-factor authentication for my enterprise? Can I use my Security Key with multiple Gmail Accounts? Where can I find more information on administering Dropbox Business? How can my Dropbox users combine their personal accounts with our business accounts? How do I enforce two-step verification for my team members in Dropbox?