A system and method is disclosed for restricting a remote control interface port of a set-top box configured to broadcast multimedia programs over a provider network. A change schedule that changes communication parameters may restrict the remote control interface port. The operating frequency or the code set used to transmit data and commands may be changed at random or at predefined intervals. The set-top box, the remote control, or an external network device may initiate the change schedule. Encryption of communications between the set-top box and the remote control unit may also be performed to protect the set-top box from unauthorized access.