Increasing security by using an additional independent factor for identity verification.

• The authentication service offers multi-factor authentication (MFA).
• Multi-factor authentication (MFA) enhances security by requiring an additional, independent factor to verify your identity.
• For TUaccount and TUvpn, the additional factor, in addition to the password, is a six-digit MFA code that is regenerated every 30 seconds. This method is called TOTP (time-based one-time password).

You can enable (or disable) multi-factor authentication (MFA) via the TU Login Portal:, opens an external URL in a new window  either by clicking “Enable now” in the blue banner under the heading, or by clicking the “Multi-factor authentication (MFA)” button at the bottom of the page.

As part of the activation process, you will receive a secret code that you must enter into an authenticator app in the form of a QR code or a string of characters. The authenticator app generates a new MFA code every 30 seconds. For this reason, the client and server clocks must be roughly synchronized. An internet connection is not required to generate an MFA code.

For TUaccount and TUvpn, the additional factor besides the password is a six-digit MFA code that is regenerated every 30 seconds. This method is called TOTP (time-based one-time password).