What does it do?

This extension is an authentication service for TYPO3 which extends the frontend and backend login process by strong two-factor authentication.

The two-factor authentication is provided by a TYPO3 users username and password combined with a OTP (one time password) which is generated by a YubiKey (a physical USB-key)

A YubiKey enabled user has to enter his username, password and a OTP to login to the TYPO3 backend and/or frontend.

More information about the YubiKey, Yubico and the YubiCloud OTP validation service can be found at http://www.yubico.com