Dropbox is adding optional two step verification to all accounts over the next few days.
To use the new feature, and enhance your security, you’ll need to download the lastest Dropbox client from here. Currently 1.5.12.
Once downloaded, install the new Dropbox client.
Visit the URL below to try the new 2 step verification feature: http://www.dropbox.com/try_twofactor
Once you have signed in, select the Security tab, and then look for the Two-step verification link in Account sign in box, click change.
Confirm your password for your Dropbox account.
Select how you would like to receive your codes. In this example we’ll use SMS. The alternative is to use an app that supports Time-based One-Time password (TOTP) protocol, like Google Authenticator, or Amazon AWS MFA.
Click next and enter your mobile telephone number.
Make a note of the emergency backup code and click the button to Enable two-step verification.
Dropbox two-step verification is now enabled.
Additional help can be found on Dropbox’s website here.