Strong authentication is an additional layer of security for your account. When enabled, you will automatically receive a security pin to your registered e-mail each time you attempt to log in. Until you receive and enter this pin, you will be unable to log in.
Enabling strong authentication is simple. Log in to your account and click 'My Account' at the top-right corner:
Scroll to the bottom of your account page to the My Security section. You will see the Strong Authentication option:
After checking the box, you will be required to enter your password again and select 'Activate'. An email will be sent with an initial code. Enter this into the box that appears and select 'Activate' again and strong authentication will be completely enabled on your account.