Patent ID: 8732695

Claim:
A method of distributing software used to control a portable client device and supplemental display data operating under the control of the software and used to configure the display of the portable client device, the portable client device being connectable to a multi-cast network, the method comprising the steps of: providing a pre-recorded recording medium containing the software and a first decryption key, said software and first decryption key enabling the portable client device to connect to the multi-cast network; receiving from the multi-cast network, following connection thereto by the portable client device, said supplemental display data and a second decryption key, the second decryption key being re-transmitted by the multi-cast network periodically and used to decrypt the supplemental display data; storing, in a data storage device located in the portable client device that is separate from the pre-recorded recording medium, the supplemental display data; storing, in a volatile memory located in the portable client device, the second decryption key; graphically representing, on the portable client device, said supplemental display data using said software stored on the pre-recorded medium; and destroying at least one of the supplemental display data and the second decryption key in response to receiving at a predetermined time, from the multi-cast network, a signal which commands the portable client device to destroy at least one of the supplemental display data and the second decryption key or when the portable client device moves out of a range of the multi-cast network.