Patent ID: 8311220
Filing Date: 2012-11-13
Classification: H04L,H04N

Abstract:
1. An AV data transmission apparatus including two or more output channels and transmitting encrypted AV data to a plurality of AV data reception apparatuses, each AV reception apparatus of the plurality of AV reception apparatuses corresponding to one output channel of said two or more output channels, said AV data transmission apparatus comprising: an encryption device encrypting AV data using an encryption key; an AV data transmission device transmitting the encrypted AV data to the plurality of AV data reception apparatuses through each output channel of said two or more output channels; an encryption key switching device selecting at least one output channel of said two or more output channels, and switching an encryption key used for encrypting the AV data to be transmitted through said selected at least one output channel; an output suspension device selecting, when a first AV data reception apparatus, of the plurality of AV reception apparatuses, which cannot decrypt encrypted AV data encrypted using a first encryption key switched to by said encryption key switching device is present, a first output channel, of said two or more output channels, corresponding to the first AV data reception apparatus, and suspending an output of the encrypted AV data transmitted through said selected first output channel; and a control device causing (i) said output suspension device to suspend the output of the encrypted AV data transmitted through said selected first output channel, and (ii) said encryption key switching device to switch the first encryption key, used for encrypting the AV data for which the output through said first output channel is suspended, to a second encryption key and then to transmit AV data encrypted using the second encryption key through at least said first output channel of said two or more output channels.