Key Dropbox

Late last year, Google also added support for the U2F method for its services, though this was limited to the Chrome browser.

U2F keys

Starting today Dropbox will now support Universal 2nd Factor (U2F) security keys as a valid 2-factor authentication method. This is done to add a greater variety authentication protocols into its system. Google already uses U2F security keys. U2F are physical objects like a key chain that you put into your USB drive. The key is based on an open standard from the FIDO Alliance. Although Dropbox is just adding U2F, they have had other authentication methods in place for a while. So if you do not own a U2F device you are not out of luck. You can use two-step verification through text message or an authenticator app such as  Duo.

Considering that nothing is uncrackable from the federal government to your LastPass. Using an extra form of security such as U2F should not be deemed excessive. Considering some people store some very sensitive material on Dropbox. Dropbox has provided documentation on how to enable U2F through its help center.