I stumbled upon this news article on BBC,

• RSA splits passwords in two to foil hackers' attacks

tl;dr - a (randomized) password is split in half and is stored across two separate servers, to foil hackers that gained access to either server upon a security breach.

Now the main question is, how would this kind of system would be made... codespeaking, for PHP which I commonly develop on my web applications, the database password is normally stored in a configuration file, i.e. config.php with the username and password, in that case it is understandable that the passwords can be stolen if the security was compromised.

However when splitting and sending the other half to the other server, how would this go on when making a communication to the other server (keeping in mind with PHP) since the other server password would be stored in a configuration file, wouldn't it? In terms of security is to keep the other server password away from the main one, just exactly how would the main server communicate, without exposing any other password, apart from the first server.

This certainly makes me think...