In an effort to adopt a greater variety of strong authentication protocols into its system, Dropbox today announced via blog post that the company will now support Universal 2nd Factor (U2F) security keys as a valid 2-factor authentication method.
U2F security keys are physical objects that you place in a USB drive, which follows a open standard from the FIDO Alliance. In order to log in with this method, users must place their key into the USB when logging in to a site. If you want to access Dropbox with your key, the company says it is only currently supported through the Google Chrome browser.