AV DATA TRANSMISSION APPARATUS AND AV DATA TRANSMISSION METHOD

• US 20090257588A1
• Filed: 04/09/2009
• Published: 10/15/2009
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: AYAKI, Yasushi, Nishimura, Takuya, Fujiwara, Kazunari
• Granted Patent: US 8,311,220 B2
• Time in Patent Office: Days
• US Class Current: 380/212
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

An AV data transmission apparatus having two or more output channels, the apparatus comprising: an encryption unit which encrypts AV data using an encryption key; an AV data transmission unit which transmits the encryption key and the encrypted AV data to AV data reception apparatuses from each output channel; an encryption key switching unit which switches an encryption key generation scheme to another one for the encryption key transmitted through a selected output channel; an output suspension unit which suspends output of the encrypted AV data transmitted through a selected output channel; and a control unit which causes (i) the output suspension unit to select an output channel and suspend the output of the encrypted AV data through the selected output channel, and then causes (ii) the encryption key switching unit to select the same output channel and switch the encryption key generation scheme to another one for the output channel.

Claims

1. 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.

2. The AV data transmission apparatus according to claim 1,

wherein said control unit is configured to (i) cause said output suspension unit to suspend the output of the AV data, which has been encrypted using the encryption key, through said selected output channel for which the encryption key generation scheme is to be switched to another encryption key generation scheme, and then (ii) disconnect from one of the AV data reception apparatuses which corresponds to said selected output channel.

3. The AV data transmission apparatus according to claim 1, further comprising

a function verification unit configured to verify whether or not the AV data reception apparatuses have a detection function to detect that the encryption key generation scheme has been switched to another encryption key generation scheme,

wherein, when said function verification unit verifies that one of the AV data reception apparatuses has the detection function, said control unit is configured to cause said output suspension unit not to suspend the output of the encrypted AV data through one of said output channels which corresponds to the AV data reception apparatus having the detection function.

4. An AV data transmission method for transmitting, through two or more output channels, encrypted AV data to AV data reception apparatuses each of which corresponds to one of the output channels, said AV data transmission method comprising:

encrypting AV data using an encryption key;

transmitting the encrypted AV data to the AV data reception apparatuses through each of the output channels;

switching, by selecting at least one of the output channels, 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 the selected output channel;

suspending, by selecting at least one of the output channels, output of the encrypted AV data transmitted through the selected output channel; and

(i) causing, in said suspending, (i-a) selecting, from among the 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) suspending the output of the encrypted AV data through the selected output channel, and then (ii) causing, in said switching, (ii-a) selecting the output channel selected in said suspending, and (ii-b) switching the encryption key generation scheme to another encryption key generation scheme to generate another encryption key to encrypt the AV data for the selected output channel.