Patent ID: 7529375
Filing Date: 2009-05-05
Classification: H04N

Abstract:
1. A method of processing data encrypted according to an encryption method specific to a first domain such that the data cannot be decrypted without using a first secret specific to said first domain, said data being received in a presentation device connected to a network belonging to a second domain, the method comprising: (a) transmitting at least a portion of said encrypted data to a processing device connected to the network; (b) receiving, in said presentation device, processed data from said processing device, at least one element of said processed data being used by said presentation device to decrypt said received data using a second secret specific to said second domain, said second secret being contained in the presentation device, said second secret specific to said second domain being different from said first secret specific to said first domain; wherein the data received in the presentation device are encrypted using a first symmetric key, said first symmetric key being received with said data in a form encrypted using the first secret; step (a) comprises transmitting to the processing device the first symmetric key encrypted using the first secret; and step (b) comprises receiving from the processing device: (c) decrypting, using the second secret, the second encrypted symmetric key; (d) decrypting, using the second symmetric key, the first encrypted symmetric key; and (e) decrypting the data received by said presentation device using the first symmetric key.