Rolling code security for remote controls

Remote controls can be hacked. Especially the ones that use RF with out any encoding schemes can be hacked very easily. Key less entry for cars, garage doors etc are the ones which are more venerable to attack. Attackers use custom made handsets which mimic the frequency of the original handset to get the attack done. Rolling code security mechanisms are used to protect wireless remotes from such attacks.
The idea is to use a synchronized code. The transmitter and receiver agrees on a particular code for the next transmission. If only that matches in the next transmission will it be accepted. After every successful transmission the code is changed by either the transmitter or the receiver and is then synchronized. In this method no other handset can communicate with the receiver with out knowing the code. The only draw back of this system is that only one handset can be used.