Av data transmission apparatus and av data transmission method

An AV data transmission apparatus which has two or more output channels and transmits encrypted AV data to AV data reception apparatuses each of which corresponds to one of said output channels, said AV data transmission apparatus comprising:

• an encryption unit configured to encrypt AV data using an encryption key;
• an AV data transmission unit configured to transmit the encrypted AV data to the AV data reception apparatuses through each of said output channels;
• an encryption key switching unit configured to select at least one of said output channels, and to switch an encryption key generation scheme to another encryption key generation scheme to generate another encryption key used for encrypting the AV data to be transmitted through said selected output channel;
• an output suspension unit configured to select at least one of said output channels, and to suspend output of the encrypted AV data transmitted through said selected output channel;
• and
• a control unit configured to cause (i) said output suspension unit (i-a) to select, from among said output channels, an output channel for which the encryption key generation scheme is to be switched to another encryption key generation scheme, and (i-b) to suspend the output, through said selected output channel, of the AV data which has been encrypted using the encryption key, and then to cause (ii) said encryption key switching unit (ii-a) to select said output channel selected by said output suspension unit, and (ii-b) to switch the encryption key generation scheme to another encryption key generation scheme to generate another encryption key to encrypt the AV data for said selected output channel.