Starting today, we are beginning a phased rollout to allow Firefox Accounts users to opt into two-step authentication. If you enable this feature, then in addition to your password, an additional security code will be required to log in.We chose to implement this feature using the well-known authentication standard TOTP (Time-based One-Time Password). TOTP codes can be generated using a variety of authenticator applications. For example, Google Authenticator, Duo and Authy all support generating TOTP codes.Additionally, we added support for single-use recovery codes in the event you lose access to the TOTP application. It is recommend that you save your recovery codes in a safe spot since they can be used to bypass TOTP.<Ahref="https://support.mozilla.org/fr/kb/secure-firefox-account-two-step-authentication">https://support.mozilla.org/fr/kb/secure-firefox-account-two-step-authentication</A>