Abstract: The present invention relates to a closed system having multiple electronic devices and to a method of communicating between electronic devices in a closed system. The method and system encode at least one output of a master device using an encoding code specific to the master device, transmit the encoded at least one output to a respective at least one slave device, and decode at each slave device the received encoded output of the master device using a decoding code that is symmetrical to the encoding code. More particularly, the system includes a master device and at least one slave device in communication with the master device. The master device comprises a master processor and an encoding module configured to encode at least one output of the master device using an encoding code specific to the master device. Each slave device comprises a slave processor and a decoding module configured to decode the output of the master device using a decoding code that is symmetrical to the encoding code.

Abstract: The described embodiments relate generally to data processing systems and methods for encoding and decoding of a subscription-based data service, such as a satellite or cable television service. These aspects are generally based on use of an encoding key by the service provider to encode the data prior to transmission and on a decoding key that is based on the encoding key and on a unique identifier of a particular target receiving device.