Answer:
Extended authentication
Explanation:
Xauth = Extended authentication
An extended authentication can cause security to be increased because it requires the user to enter a username and password. These details would then be authenticated at the internal database of the controller. This extension is an ipsec extension which would enable VPN users to enter a username and password. These details would be required of the user while trying to connect and they would be checked against the login details registered by such a user.
