[TYPO3] BE strong/better authentication method

[stefano]

Hi,

I'm looking  for authenticating users to the backend, like CAPTCHA, strong 
authentication or others.

The target is to find a better authentication method that will not use 
simple user/password.

I'm sure that typo3 will allow some of theses methodes, but I was not able 
to find a reference explaining how to implement this.

Best regards

Stefano