Encryption transmission system

• US 20030145336A1
• Filed: 12/02/2002
• Published: 07/31/2003
• Est. Priority Date: 12/18/2000
• Status: Active Grant

• Current Assignee: General Video, LLC (Ideahub, Inc.)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Suzuki, Hidekazu, Tatebayashi, Makoto, Nishio, Toshiro, Matsuzaki, Natsume
• Granted Patent: US 7,359,511 B2
• Time in Patent Office: Days
• US Class Current: 725/136
• CPC Class Codes: G09G 1/167 Details of the interface to the display terminal specific for a CRT details suitable for both CRT and flat panel G09G5/006, specific for a flat panel G09G3/2096
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/4143 embedded in a Personal Computer [PC]
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 7/083 with signal insertion during the vertical and the horizontal blanking interval , e.g. MAC data signals
• CPC Class Codes: H04N 7/167 Systems rendering the television signal unintelligible and subsequently intelligible

Abstract

A video signal and an audio signal are time division multiplexed, encrypted, and transmitted. A transmission side time-compresses the audio signal, multiplexes, encrypts, and transmits the time-compressed audio signal in a blanking period of the video signal. Control is performed using an audio signal data enable signal ADE, and a audio signal/video signal switch signal.

Claims

1. A transmission system comprising:

a transmission device and a reception device,

the transmission device transmitting digital video information while providing one or more blanking intervals during transmission of the digital video information, and the reception device receiving the digital video information,

wherein the transmission device transmits digital audio information during the one or more blanking intervals, and the reception device receives the digital audio information during the one or more blanking intervals.

2. A transmission system comprising:

a video transmission device and a video display device,

the video transmission device encrypting and transmitting frame information that includes digital video information while providing one or more blanking intervals during the frame information, and the video display device receiving and decrypting the encrypted frame information, extracting the digital video information from the decrypted frame information, and displaying the extracted video information,

wherein in the one or more blanking intervals the video transmission device multiplexes digital audio information with the frame information, encrypts the multiplexed frame information with which the digital audio information has been multiplexed, and transmits the encrypted frame information, and

the video display device receives the encrypted frame information, decrypts the received encrypted frame information to generate frame information, extracts the digital audio information from the one or more blanking intervals provided in the generated frame information, and converts the extracted digital audio information to an audio signal.

3. A video transmission device that transmits and encrypts frame information that includes digital video information, while providing one or more blanking intervals during the digital video information, the video transmission device, comprising:

multiplex means for multiplexing digital audio information with the frame information during the one or more blanking intervals;

encryption means for encrypting the frame information with which the digital audio information has been multiplexed; and

transmission means for transmitting the encrypted frame information.

4. The video transmission device of claim 3

wherein the frame information includes, after a vertical blanking interval, a predetermined number of pieces of line video information after each of which a horizontal blanking interval is provided,

the digital audio information is composed of a plurality of pieces of line audio information, and

the multiplex means multiplexes the pieces of line audio information during the vertical blanking interval and/or the horizontal blanking intervals.

5. The video transmission device of claim 4,

wherein the encryption means includes:

a frame key generation unit for generating a frame key that corresponds to the frame information, to be used as an encryption key; and

a frame encryption unit for encrypting, using the frame key generated corresponding to the frame information, the digital audio information and the digital video information included in the frame information.

6. The video transmission device of claim 5

wherein the frame encryption unit includes:

a line encryption sub-unit for encrypting, using the frame key, one of the pieces of line audio information and one of the pieces of line video information included in the frame information;

a key updating sub-unit for updating the frame key; and

a repeat control sub-unit for controlling, until encryption of all of the pieces of line audio information and all of the pieces of line video information has finished, so that the line encryption sub-unit encrypts a next piece of line audio information and a next piece of line video information using the updated frame key, and controlling so that the key updating means updates the updated frame key again.

7. The video transmission device of claim 5,

wherein the frame encryption unit uses a same encryption method in encrypting the digital audio information and the digital video information.

8. The video transmission device of claim 7

wherein the line encryption sub-unit sets an initial value for audio, encrypts the line audio information using the set an initial value for audio, then sets an initial value for video to have a same value as the initial value for audio, and encrypts the line video information using the set initial value for video.

9. The video transmission device of claim 5 transmitting the encrypted frame information to a video display device,

wherein the encryption means uses a common calculation module in authentication of the video display device, in generating the frame key, and in encrypting the frame information.

10. The video transmission device of claim 4

wherein the multiplex means further generates (a) a video enable signal that shows transmission of the digital video information, in a period in which the digital video information is included in the frame information, and (b) an audio enable signal that shows transmission of the digital audio information, in the blanking intervals, and

the transmission means further transmits the generated video enable signal and the generated audio enable signal.

11. The video transmission device of claim 10

wherein the multiplex means generates the audio enable signal in the vertical blanking interval and/or the horizontal blanking intervals during which the digital audio information is multiplexed.

12. The video transmission device of claim 3

wherein the multiplex means generates the frame information using a multiplex control signal that identifies transmission of the digital audio information and the digital video information, and

the transmission means transmits the multiplex signal.

13. The video transmission device of claim 3

wherein the multiplex means generates frame information while providing a non-signal period between the digital audio information and the digital video information.

14. A video display device that receives the encrypted frame information from the video transmission device of claim 3, decrypts the received frame information, extracts the digital video information from the decrypted frame information, and displays the extracted digital video information, the video display device comprising:

reception means for receiving the encrypted frame information;

decryption means for decrypting the encrypted frame information;

extraction means for extracting the decrypted digital audio information from the blanking interval provided during the frame information, and extracting the digital video information from a period other than the one or more blanking intervals; and

output means for displaying the extracted digital video information, and converting the extracted digital audio information to audio.

15. The video display device of claim 14

wherein the digital audio information includes a plurality of pieces of line audio information,

wherein the frame information includes, after a vertical blanking interval, a predetermined number of pieces of line video information after each of which a horizontal blanking interval is provided,

the plurality of pieces of line audio information are multiplexed in the vertical blanking interval and/or the horizontal blanking intervals, and

the extraction means extracts the pieces of line audio information from the vertical blanking interval and/or the horizontal blanking intervals.

16. The video display device of claim 15

wherein the decryption means includes:

a frame key generation unit for generating a frame key that corresponds to the frame information, to be used as an decryption key; and

a frame decryption unit for decrypting, using the frame key generated corresponding to the frame information, the digital audio information and the digital video information included in the frame information.

17. The video display device of claim 16

wherein the frame decryption unit further includes:

a line decryption sub-unit for decrypting, using the frame key, one of the pieces of line audio information and one of the pieces of line video information included in the frame information;

a key updating sub-unit for updating the frame key; and

a repeat control sub-unit for controlling, until decryption of all of the pieces of line audio information and all of the pieces of line video information has finished, so that the line decryption sub-unit decrypts a next piece of line audio information and a next piece of line video information using the updated frame key, and controlling so that the key updating means updates the updated frame key again.

18. The video display device of claim 16

wherein the frame decryption sub-unit uses a same decryption method in decrypting the digital audio information and the digital video information.

19. The video display device of claim 18

wherein the line decryption sub-unit sets an initial value for audio, decrypts the line audio information using the set initial value for audio, then sets an initial value for video to have a same value as the initial value for audio, and decrypts the line video information using the set initial value for video.

20. The video display device of claim 16

wherein the decryption means uses a common calculation module in the authentication by the video display device, in generating the frame key, and in encrypting the frame information.

21. The video display device of claim 15

wherein the transmission means further receives the video enable signal that shows transmission of the digital audio information, and the audio enable signal that shows transmission of the digital audio information, and

the extraction means further extracts the digital video information in a period shown by the video enable signal, and extracts the digital audio information in a period shown by the audio enable signal.

22. The video display device of claim 14

wherein the reception means receives a multiplex control signal that identifies transmission of the digital audio information and the digital video information, and

the extraction means extracts the digital audio information and the digital video information using the multiplex control signal.

23. The video display device of claim 14

wherein the reception means receives encrypted frame information in which a non-signal period is provided between the digital audio information and the digital video information, and

the extraction means generates, using the non-signal period between the digital audio information and the digital video information, a multiplex control signal that identifies reception of the digital audio information and the digital video information, and extracts the digital audio information and the digital video information using the generated multiplex control signal.