Patent ID: 7616763

Claim:
A method for verifying validity of a network key in a digital domestic network, communicating with at least a broadcasting device and at least one processing device, the broadcasting device having encrypted data to broadcast to the processing device, the method comprising: providing the encrypted data accessible by the processing device due to a network key unknown by the broadcasting device; transmitting by the broadcasting device a test key to the processing device, receiving from the processing device a cryptogram made up of the test key encrypted by the network key, and determining the validity of the network key by comparing the received cryptogram with at least one of a plurality of control cryptograms taken from a list of control data generated by a verification center for the test key, wherein the control cryptograms are in a black list containing cryptograms obtained by encrypting the test key with invalid network keys or in a white list containing the cryptograms obtained by encrypting the test key with valid network keys.