KR20060106250A - System for receiving or transmitting video contents and information security module used in the same - Google Patents

Abstract

Disclosed are a system for transmitting and receiving image data and a security module used for the same. The encryption key provided from the service provider is provided in the form of a video signal. The user computer receives the frame key provided in the form of an image signal, and the image signal compressed by the receiving codec is decompressed. Since the encryption key is provided in the form of an image signal, the frame key may be transmitted to the image output terminal even if the compression is decompressed by the reception codec file. Therefore, the encrypted image is decrypted at the image output end, and the security of the image content is maintained.

Description

System for Receiving Or Transmitting Video Contents And Information Security Module Used In the Same}

1 is a block diagram illustrating a system for transmitting and receiving image content according to the prior art.

2 is a block diagram illustrating a decompression operation of a compressed image of a computer system according to the related art.

3 is a block diagram illustrating an image signal authentication operation between a computer system and a display device according to the related art.

4A, 4B, 4C, and 4D are block diagrams illustrating a video signal transmission and reception system and a security module according to a first embodiment of the present invention, and a data format diagram of a video signal.

5 is a block diagram illustrating a video signal transmission and reception system according to a second embodiment of the present invention.

6 is a block diagram showing a video signal transmission and reception system according to a third embodiment of the present invention.

7 is a block diagram showing another video signal transmission and reception system according to a third embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

400, 500, 600, 700: Service Provider

430, 530, 630, 730: your computer

443, 553, 643, 755: trans codec

480: frame key decoder 482: content key decoder

484: private key generator 486: video decoder

The present invention relates to a security module and a system for transmitting / receiving video information using the security module, and more particularly, to a transmission / reception system for transmitting a key used for encrypting video content and decrypting the encrypted video content. It relates to the security module used.

In a typical video content delivery system, a service provider compresses video content, transmits the compressed video content to a computer system, and the computer system decompresses the compressed video content by using a built-in codec to generate the original video. Provide content to the display device.

The codec is a device used to decompress a compressed digital signal or to compress an original signal. The codec also refers to a method of compressing or decompressing a moving image or a still image. Computers usually come with codecs in the form of files.

1 is a block diagram illustrating a system for transmitting and receiving image content according to the prior art.

Referring to FIG. 1, an image content transmission / reception system includes a service provider 100, a computer system 120, and a display device 140.

The service provider 100 may produce image content and transmit the produced image content to the user's computer system 120. The service provider 100 compresses the image content or scrambles the image content to provide it to the computer system 120. Joint Picture Expert Group (JPEG) is a method of compressing or decompressing still images, and Moving Picture Expert Group (MPEG) is a method of compressing or decompressing moving images.

An encryption technique is used to scramble video content. Usually, encryption technology is divided into symmetric cryptography and asymmetric cryptography.

The symmetric encryption method refers to an encryption method in which an encryption key and a decryption key are identical, and the asymmetric encryption method refers to an encryption method in which an encryption key and a decryption key are different.

The user's computer system 120 decompresses the received video signal and decrypts the encrypted video to reproduce the original video. The release or decoding of the video signal is performed through a codec stored in the computer system 120. The reproduced image is supplied to the display device 140, and the display device 140 displays a predetermined image.

2 is a block diagram illustrating a release operation of a compressed image of a computer system according to the related art.

Referring to FIG. 2, the compressed video signal from the service provider is stored in the auxiliary memory device 200. The auxiliary memory device 200 may include a hard disk. The central processing unit (CPU) 210 activates the codec stored in the form of a file in the auxiliary memory device 200. The compressed video signal is released by the activated codec. In other words, the compressed video signal is reproduced by the codec. The reproduced video signal is input to the main memory device 230, and the main memory device 230 supplies the reproduced video signal to the graphic unit.

3 is a block diagram illustrating an image signal authentication operation between a computer system and a display device according to the related art.

Referring to FIG. 3, the reproduced video signal output from the main memory device 310 is input to the graphic card 331 of the graphic unit 330. The graphic card 331 processes the reproduced video signal and outputs the reproduced video signal to the high-bandwidth digital protection (HDCP) transmitting device 333, or the reproduced video signal bypasses the HDCP transmitting device 333. Do it. In addition, the HDCP transmitter 333 receives an HDCP recognition signal from the CPU. The HDCP recognition signal has information on whether a compressed video signal received from a service provider requires authentication. Therefore, when the HDCP recognition signal requires authentication, the HDCP transmitter 333 is activated. If the HDCP recognition signal does not require authentication, the HDCP transmitter 333 is deactivated, and the reproduced video signal output from the graphics card 331 bypasses the HDCP transmitter 335 to the DVI transmission port 335. Is delivered to.

When the HDCP recognition signal requires an authentication task, the HDCP transmitter 335 performs an authentication task through communication with the HDCP receiver 353 included in the display apparatus 350.

If the HDCP recognition signal does not require authentication, the reproduced video signal bypasses the HDCP transmission device 333 and is transmitted to the display device 350 through the DVI transmission port 335. The reproduced video signal transmitted to the display device 350 is applied to the DVI receiving port 351, and bypasses the HDCP receiving device 353 and is transmitted to the display panel 355.

The above-described authentication technology using HDCP is already proposed by Intel, and is currently being applied to computers and display devices.

That is, the authentication operation for the display apparatus 350 is performed through communication between the HDCP transmitting apparatus 333 and the HDCP receiving apparatus 353. That is, the HDCP transmitting device 333 requests a response that does not violate the HDCP protocol from the HDCP receiving device 353, and starts transmitting the video signal when a response corresponding to the HDCP protocol is received from the HDCP receiving device 353. . If a response is received from the HDCP receiving device 353 that violates the HDCP protocol, the zeroing signal is not transmitted.

Authentication methods and protocols using the above-described HDCP technology are disclosed in the HDCP Specification Revision 1.1 published at http://digital-cp.com.

The limitation of the above-described HDCP technology is that it does not secure complete security in the digital right management (DRM) area. In other words, the compressed or scrambled video content is maintained only between the service provider and the codec program activated by the CPU, and its security is ensured. In addition, HDCP technology can be secured only between the DVI transmit port of the graphics card and the DVI receive port of the display device.

Therefore, the security of the information between the graphics card and the graphics card in which the compression is decompressed and the scrambled state is not substantially protected.

A first object of the present invention for solving the above problems is to provide a video signal transmission and reception system for transmitting and receiving encrypted content from the service provider to the display device.

In addition, a second object of the present invention is to provide a security module used to achieve the first object.

According to the present invention for achieving the first object, scrambled raw video data to generate scrambled video data, encrypts the scrambled key used for scrambled into a frame key in the form of a video signal, the scrambled video data and the frame key A service provider for compressing the compressed signal to generate a compressed scramble signal; A user computer for receiving the compressed scramble signal, transmitting the frame key to an image output terminal regardless of a decompression operation, and generating a reproduced video signal using the scramble key decoded from the frame key at the image output terminal; And a display device for receiving and displaying the reproduced video signal.

In addition, the first object of the present invention is to scramble the raw video data to generate scrambled video data, to encrypt the scrambled key used for scrambled into a frame key in the form of a video signal, the scrambled video data and the frame key A service provider for compressing to generate a compressed scrambled signal; A user computer for receiving the compressed scramble signal, decompressing the compressed scramble signal to generate a reproduced scramble signal, and transmitting the frame key to an image output terminal regardless of the decompression operation; And a display device for receiving the playback scrambled signal, decoding the frame key to generate the scrambled key, and converting and displaying the scrambled video data into a playback video signal using the scrambled key. It can also be achieved through the provision of a system.

In addition, the present invention for achieving the second object, a frame key decoder having a form of a video signal, for decoding the transmitted frame key to the content key in the form of a bit string despite the decompression operation of the central processing unit; A private key generator for generating an independent private key for each user computer; A content key decoder for decoding the content key into the scrambled key using the private key; And an image decoder for converting the scrambled image data encrypted with the raw image data into the reproduced image using the scrambled key.

According to the present invention, the image content encrypted by the service provider and the key value used to decrypt the encrypted image content are transmitted to the image output terminal despite the decompression operation at the user computer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First embodiment

4A to 4D are block diagrams illustrating a video signal transmission and reception system and a security module according to a first embodiment of the present invention, and a data format diagram of a video signal.

4A is a block diagram illustrating a video signal transmission and reception system according to the present embodiment.

Referring to FIG. 4A, a video signal transceiving system includes a service provider 400, a user computer 430, and a display device 450.

The service provider 400 encrypts the raw image data to generate a scrambled signal. The scrambled signal may have a compressed form before being transmitted to the user computer 430. Hereinafter, the image content provided from the service provider 400 according to the present invention is referred to as a compressed scramble signal.

The scrambled signal is composed of compressed scrambled image data, a frame key provided in the form of an image signal, and information on image data provided in a header portion.

The user computer 430 has an auxiliary memory 431, a central processing unit (CPU) 433, a main memory device 437, and a graphics unit 440.

The auxiliary memory device 431 receives the compressed scramble signal from the service provider 400 and stores it.

The CPU 433 activates the reception codec file 435 stored in the auxiliary memory device 431, and decompresses the compressed scramble signal using the reception codec 435. The released scrambled signal has scrambled image data and a frame key. That is, even if the compression is released by the reception codec 435 according to the information provided in the header unit, only the compressed state of the scrambled video data is released. In addition, the frame key provided in the form of an image signal is not deleted by the reception codec 435 even if the compression is released. That is, the reception codec 435 determines the frame key as a part of the video signal and decompresses it. Thus, the scrambled signal released by the receiving codec 435 is provided to the main memory device 437 in an encrypted state.

The main memory device 437 stores the playback scramble signal released through the reception codec 435. The playback scrambled signal is composed of playback scrambled video data and a playback frame key. The reproduction scramble signal is input to the graphic unit 440.

The graphics unit 440 is composed of a graphics card 441, a trans codec 43, and an I / O port 445.

Depending on the embodiment, the trans codec 443 may be incorporated in a graphics card.

The playback scrambled signal processed by the graphics card 441 is decrypted by the trans codec 443 which is a security module, and the display device 450 is converted into a signal suitable for displaying an image. The trans codec 443 decrypts the playback frame key to decrypt the encrypted scrambled video data. That is, the playback frame key in the form of a video signal is decoded into a content key in the form of a bit stream, and the content key is converted into a scrambled key according to the private key. To generate the scrambled key, the trans codec 443 generates a private key using a private key generator. The scrambled key generated using the private key is used to decode the scrambled video data to generate a reproduced video.

In order to perform the above-described operation, the trans codec 443, which is a security module, is preferably a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) in which a predetermined algorithm is physically implemented.

The reproduced image decoded by the trans codec 443 is transmitted to the display apparatus 450 through the I / O port 445 of the graphic unit 440.

The I / O port 451 of the display device 450 receives the reproduced image and supplies it to the display panel 453, which is displayed to the user.

According to the above-described video signal transmission and reception system, video content is transmitted in an encrypted state from a service provider to an I / O port of a user's computer. That is, the scrambled video is not decoded even if the compression is released by the receiving codec. The scrambled key is required to decrypt the scrambled video, but the scrambled key is transmitted to the trans codec in an encrypted state. The transmission of the scrambled key from the receiving codec to the trans codec is because the scrambled key is encrypted and transmitted in the form of a video signal. That is, since the scramble key is transmitted as the frame key in the form of an image frame, it is treated as an image signal by the receiving codec and transmitted to the trans codec.

4B is a block diagram illustrating the formation of a compressed scramble signal on the service provider side according to the present embodiment.

Referring to FIG. 4B, raw image data is scrambled by the scrambler 466 using a scrambled key.

As a method of scrambled raw image data, a technique of adding or subtracting a predetermined value to an entire image of one frame may be used. In this case, the displayed image may have a specific color blurring on the entire screen. That is, the white balance of the image is biased to a specific color.

In addition, as a method of scrambled raw image data, a technique of dividing an image of one frame into a plurality of sectors and adding or subtracting gradation data irregularly for each divided sector may be used. In this case, the displayed image is displayed in a form in which a plurality of divided image signals in one frame are white balanced with different colors.

In addition, every successive frame may be scrambled irregularly. That is, data added to or subtracted from an image of one frame or divided sectors within a frame may be set differently for each frame.

The above scramble operation is performed to suit the scramble key.

The scrambled key is encrypted with the content key by the content key encryption unit 460 by the public key. The content key takes the form of a bit stream. When the content key encrypted with the scrambled key is directly input to the user's computer and decrypted by the receiving codec, the content key is placed in the header of the data format and therefore does not appear in the output of the receiving codec. That is, a problem arises in that a key for decrypting the scrambled image data encrypted from the reception cortex is lost.

Therefore, the content key is converted into a frame key by the frame key encryptor 462. The frame key has the form of an image signal. That is, the frame key takes the form of image data of red, green, and blue.

The frame key and scrambled video data are compressed by the transmission codec 464, converted into a compressed scrambled signal, and transmitted to the user computer.

4C is a data format diagram of a compressed scrambled signal according to the present embodiment.

Referring to FIG. 4C, the compressed scramble signal has a header, a compressed frame key, and compressed scrambled image data.

The header contains information on the transmitted image data. The compressed scrambled video data is obtained by scrambled raw video data by the scrambled key. In addition, in the scrambled key format illustrated in FIG. 4C, as described in FIG. 4B, one frame is divided into a plurality of sectors, and a scramble operation in which gradation values are randomly added or subtracted from the divided sectors is performed. It is shown.

The key value performed for encryption for each scrambled sector becomes a frame key value represented by a video signal. That is, the compressed frame key has a plurality of divided sectors, each sector representing an encryption key value for a sector of the corresponding raw image data.

In addition, FIG. 4C illustrates a data format for one frame, and the data format for a plurality of frames is merely omitted for convenience of explanation and easy understanding. If the data format is for a plurality of frames, compressed frame keys may be arranged in succession, and scrambled image data representing each frame may be arranged in succession.

Further, according to the embodiment, the compressed framekey-compressed scrambled video signal-compressed framekey-compressed scrambled video signals may be arranged in succession. That is, a frame key and a scrambled video signal suitable for a frame may be repeatedly arranged in each frame.

4D is a block diagram illustrating a trans codec that is a security module according to the present embodiment.

Referring to FIG. 4D, the trans codec includes a frame key decoder 480, a content key decoder 482, a private key generator 484, and an image decoder 486.

The frame key decoder 480 receives the frame key. Since the frame key has a form of a video signal, the compression is released by the receiving codec. In addition, since the frame key has a form of an image signal, it cannot be used to decode scrambled image data. The frame key decoder 480 converts the frame key into a content key in the form of a digital bit. The content key is input to the content key decoder 482.

The content key decoder 482 decrypts the content key to generate a scrambled key. The private key is used to generate the scrambled key. The private key is generated by the private key generator 484. The private key generated by the private key generator 484 is provided independently for each user's computer. In addition, since the private key is not provided in software but is provided to the user's computer in the form of a semiconductor chip, the user cannot know information about his or her private key. However, when information on the semiconductor chip (for example, a product number, etc.) is input to a service provider, the service provider analyzes the information on the user's semiconductor chip, generates a public key suitable for the user's private key, and scrambles the key. Can be generated.

The private key is applied to the content key decoder 482. The content key decoder 482 decrypts the content key using a private key to generate a scrambled key. The generated scrambled key is applied to the image decoder 486.

The video decoder 486 receives scrambled video data decompressed by the reception codec, and generates a reproduced video using the scrambled key. The playback image is input to the display device through the I / O port.

Therefore, according to the present embodiment, the scrambled key is encrypted with a frame key in the form of a video signal and transmitted to the user's computer. Up to trans codecs can be transmitted. In addition, since the scrambled video signal is decoded using the scrambled key, the scrambled video signal is decoded in the transcotec of the graphic unit which is an output terminal of the user's computer. Thus, the security of the image content can be maintained up to the output of the computer. Therefore, even if the HDCP technology is not used, the security of the video content can be maintained, and the security of the video content from the receiving codec to the graphic unit can be secured.

In addition, the user computer according to the first embodiment of the present invention may be a personal portable terminal. That is, it may be a personal portable terminal used for Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), or Wireless Broadband Internet (WiBro) system. In this case, the display device may be a display panel provided in the personal portable terminal.

Second embodiment

5 is a block diagram illustrating a video signal transmission and reception system according to a second embodiment of the present invention.

The video signal transceiving system illustrated in FIG. 5 is the same as that of FIG. 4A of the first embodiment except that the trans codec 553, which is a security module, is provided in the display device 550. In addition, according to the embodiment, the trans codec 553 in the present embodiment is not provided in the display apparatus 550, but provided in a separate set-top box form connected between the computer 530 and the display apparatus 550. May be

Referring to FIG. 5, a video signal transceiving system includes a service provider 500, a user computer 530, and a display device 550.

The service provider 500 encrypts the raw image data to generate a scrambled signal. The scrambled signal may have a compressed form before being transmitted to the user computer 530.

The scrambled signal is composed of compressed scrambled image data, a frame key provided in the form of an image signal, and information on image data included in a header part.

The user computer has an auxiliary memory 531, a CPU 533, a main memory 537, and a graphics unit 540.

The auxiliary storage device 531 receives the compressed scramble signal from the service provider 500 and stores it.

The CPU 533 activates the reception codec file 535 stored in the auxiliary storage device 531, and decompresses the compressed scramble signal using the reception codec 535. The released scrambled signal has scrambled image data and a frame key. That is, even if the compression is released by the reception codec 535 according to the information provided in the header unit, only the compressed state of the scrambled video data is released. In addition, the frame key provided in the form of an image signal is not deleted by the reception codec 535 even if the compression is released. That is, the reception codec 535 determines the frame key as part of the video signal and decompresses it. Therefore, the scrambled signal released by the reception codec 535 is provided to the main memory device 537 in an encrypted state.

The main memory device 537 stores the playback scramble signal released through the reception codec 535. The playback scrambled signal is composed of playback scrambled video data and a playback frame key. The reproduction scramble signal is input to the graphic unit 540.

The graphics unit 540 is composed of a graphics card 541 and an I / O port 543. The graphics card 540 processes the playback scramble signal and sends it to the I / O port 543. The I / O port 543 of the user computer 530 supplies the playback scramble signal to the display device 550 to the display device 550.

The display device 550 has an I / O port 551, a trans codec 553, and a display panel 555.

The reproduction scramble signal received at the I / O port 551 of the display device 550 is decoded by the trans codec 553, and the display device 550 is converted into a signal suitable for displaying an image. The trans codec 553 decrypts the playback frame key to decrypt the encrypted scrambled video data. That is, the playback frame key in the form of a video signal is decoded into a content key in the form of a bit stream, and the content key is converted into a scrambled key according to the private key. To generate the scrambled key, the trans codec 553 generates a private key using a private key generator. The scrambled key generated using the private key is used to decode the scrambled video data to generate a reproduced video.

In order to perform the above-described operation, the trans codec 553 is preferably a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) in which a predetermined algorithm is physically implemented.

The reproduced video decoded by the trans codec 553 is transferred to the display panel 555, and the predetermined reproduced video is displayed.

According to the above-described video signal transmission and reception system, the video content from the service provider to the display device is transmitted in an encrypted state. That is, the scrambled video is not decoded even if the compression is released by the receiving codec. The scrambled key is required to decrypt the scrambled video, but the scrambled key is transmitted to the trans codec in an encrypted state. The transmission of the scrambled key from the receiving codec to the trans codec is because the scrambled key is encrypted and transmitted in the form of a video signal. That is, since the scrambled key is transmitted as the frame key in the form of an image frame, it is treated as an image signal by the receiving codec and transmitted to the trans codec.

In addition, the generation of the frame key and the formation of the scrambled image data on the service provider side are the same as in FIG. 4B of the first embodiment, and the data format of the compressed scramble signal is the same as in FIG. 4C of the first embodiment.

In addition, the structure and function of the trans codec which is a security module of this embodiment are the same as FIG. 4D of the said 1st embodiment.

Third embodiment

6 is a block diagram showing a video signal transmission and reception system according to a third embodiment of the present invention.

The video signal transceiving system illustrated in FIG. 6 is provided with the HDCP transmitting device 645 in the graphic unit 640 of the computer 630 and the HDCP receiving device 653 in the display device 650. Is the same as Fig. 4A of the first embodiment. In addition, according to the embodiment, the trans codec according to the present embodiment may not be provided inside the computer, but may be provided in the form of a separate set-top box connected between the computer and the display device.

Referring to FIG. 6, the video signal transceiving system includes a service provider 600, a user computer 630, and a display device 650.

The service provider 600 generates a scrambled signal by encrypting the raw image data. The scrambled signal may have a compressed form before being transmitted to the user computer 630.

The scrambled signal is composed of compressed scrambled image data, a frame key provided in the form of an image signal, and information on image data included in a header part.

The user computer has an auxiliary storage device 631, a CPU 633, a main memory device 637, and a graphics unit 640.

The auxiliary memory device 631 receives the compressed scramble signal from the service provider 600 and stores it.

The CPU 633 activates the reception codec file 635 stored in the auxiliary storage device 631, and decompresses the compressed scramble signal using the reception codec 635. The released scrambled signal has scrambled image data and a frame key. That is, even if the compression is released by the reception codec 635 according to the information provided in the header unit, only the compressed state of the scrambled video data is released. In addition, the frame key provided in the form of a video signal is not deleted by the reception codec 635 even if the compression is released. That is, the reception codec 635 determines the frame key as part of the video signal and decompresses it. Therefore, the scrambled signal released by the receiving codec is provided to the main memory 637 in an encrypted state.

The main memory 637 stores the playback scramble signal released through the reception codec 635. The reproduction scramble signal is composed of a reproduction scrambled video data and a reproduction frame key. The reproduction scramble signal is input to the graphic unit 640.

The graphics unit 640 is composed of a graphics card 641, a trans codec 643, an HDCP transmitter 645, and an I / O port 647. The graphics card 641 processes the reproduction scramble signal and transmits it to the trans codec 643.

The reproduction scramble signal is decrypted by the trans codec 643, which is a security module, and converted into a signal suitable for displaying an image by the display apparatus 650. The trans codec 643 decrypts the playback frame key to decrypt the encrypted scrambled video data. That is, the playback frame key in the form of a video signal is decoded into a content key in the form of a bit stream, and the content key is converted into a scrambled key according to the private key. To generate the scrambled key, the trans codec 643 generates a private key using a private key generator. The scrambled key generated using the private key is used to decode the scrambled video data to generate a reproduced video.

In order to perform the above operation, the trans codec is preferably a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) in which a predetermined algorithm is physically implemented.

The reproduced video decoded by the trans codec 643 is applied to the HDCP transmitting device 645. The HDCP transmitter 645 receives an HDCP recognition signal from the CPU 633. When the HDCP recognition signal requires authentication of the display apparatus 650, an authentication operation is performed between the HDCP transmitting apparatus 645 and the HDCP receiving apparatus 653 of the display apparatus. As a result of the authentication operation, if it is determined that the display device is not the required display device, the HDCP transmitting device 645 does not supply the playback image to the display device 650. If the HDCP recognition signal does not require authentication of the display apparatus 650, the reproduced video decoded by the trans codec 643 is transmitted to the display apparatus 650 by bypassing the HDCP transmitting apparatus 645.

The display device 650 has an I / O port 651, an HDCP receiving device 653, and a display panel 655.

When the HDCP recognition signal requires authentication of the display apparatus 650, the HDCP receiving apparatus 653 performs an authentication operation together with the HDCP transmitting apparatus 645. In addition, when the HDCP recognition signal does not require authentication, the playback image received through the I / O port 651 is transmitted to the display panel 655 by bypassing the HDCP receiving device 653.

According to the above-described video signal transmission and reception system, the video content is transmitted in an encrypted state from the service provider 600 to the display device 650. That is, even if the compression is decompressed by the reception codec 635, the scrambled video is not decoded. The scrambled key is required to decrypt the scrambled video, but the scrambled key is transmitted to the trans codec 643 in an encrypted state. The transmission of the scrambled key from the reception codec 635 to the trans codec 643 is because the scrambled key is encrypted and transmitted in the form of a video signal. That is, since the scrambled key is transmitted as the frame key in the form of an image frame, it is treated as an image signal by the receiving codec and transmitted to the trans codec 643.

In addition, the generation of the frame key and the formation of the scrambled image data on the service provider side are the same as in FIG. 4B of the first embodiment, and the data format of the compressed scramble signal is the same as in FIG. 4C of the first embodiment. In addition, the structure and function of the trans codec of this embodiment are the same as that of Fig. 4D of the first embodiment.

Therefore, according to this embodiment, even if the HDCP technology is used as in the prior art, the trans codec can be used for the security of the video content. The HDCP technology mainly focuses on the authentication of the display device. In this embodiment, the encrypted video content is maintained at the output terminal or the display device of the computer. Therefore, the video signal transmission and reception system disclosed in this embodiment complements the HDCP technology and shows that it can be used in parallel with the HDCP technology.

7 is a block diagram showing another video signal transmission and reception system according to a third embodiment of the present invention.

The image signal transmission and reception system illustrated in FIG. 7 is the same as that of FIG. 6 except that the trans codec 755 is provided in the display apparatus 750. In addition, according to the embodiment, the trans codec according to the present embodiment may not be provided inside the computer, but may be provided in the form of a separate set-top box connected between the computer and the display device.

Referring to FIG. 7, a video signal transceiving system includes a service provider 700, a user computer 730, and a display device 750.

The service provider 700 encrypts the raw image data to generate a scrambled signal. The scrambled signal may have a compressed form before being transmitted to the user computer 730.

The scrambled signal is composed of compressed scrambled image data, a frame key provided in the form of an image signal, and information on image data included in a header part.

The user computer 730 has an auxiliary memory 731, a CPU 733, a main memory 737, and a graphics unit 740.

The auxiliary memory device 731 receives the compressed scramble signal from the service provider 700 and stores it.

The CPU 733 activates the reception codec file 735 stored in the auxiliary storage device 731, and decompresses the compressed scramble signal using the reception codec 735. The released scrambled signal has scrambled image data and a frame key. That is, even if the compression is released by the reception codec 735 according to the information provided in the header unit, only the compressed state of the scrambled video data is released. In addition, the frame key provided in the form of a video signal is not deleted by the reception codec 735 even if the compression is released. That is, the reception codec 735 determines the frame key as part of the video signal and decompresses it. Accordingly, the scrambled signal released by the reception codec 735 is provided to the main memory device 737 in an encrypted state.

The main memory device 737 stores the playback scramble signal released through the reception codec 735. The playback scrambled signal includes a playback scrambled video data and a playback frame key. The reproduction scramble signal is input to the graphic unit 740.

The graphics unit 740 is composed of a graphics card 741, an HDCP transmitter 743, and an I / O port 745. The graphics card 741 processes the playback scramble signal and transmits it to the HDCP transmitter 743.

The HDCP transmitting apparatus 743 performs an authentication operation on the display apparatus 750 when the received image content requires authentication of the display apparatus 750. That is, the HDCP transmitter 743 receives the HDCP recognition signal from the CPU 733. When the HDCP recognition signal requires authentication of the display apparatus 750, an authentication operation is performed between the HDCP transmitting apparatus 743 and the HDCP receiving apparatus 753 of the display apparatus. If it is determined that the display device is not the required display device as a result of the authentication operation, the HDCP transmitting device 743 does not supply the reproduction scramble signal to the display device 750. When the HDCP recognition signal does not require authentication of the display apparatus 750, the reproduction scramble signal is transmitted to the display apparatus 750 by bypassing the HDCP transmitting apparatus 743.

The display device 750 has an I / O port 751, an HDCP receiving device 753, a trans codec 755, and a display panel 757.

When the HDCP recognition signal requires authentication of the display apparatus 750, the HDCP receiving apparatus 753 performs an authentication operation together with the HDCP transmitting apparatus 743. In addition, when the HDCP recognition signal does not require authentication, the reproduction scramble signal received through the I / O port 751 is transmitted to the trans codec 755 by bypassing the HDCP receiving device 753.

The input reproduction scrambled signal is decoded by the trans codec 755 and converted into a signal suitable for the display device 750 to display an image. The trans codec 755 decrypts the playback frame key to decrypt the encrypted scrambled video data. That is, the playback frame key in the form of a video signal is decoded into a content key in the form of a bit stream, and the content key is converted into a scrambled key according to the private key. To generate the scrambled key, the trans codec 755 generates a private key using a private key generator. The scrambled key generated using the private key is used to decode the scrambled video data to generate a reproduced video.

In order to perform the above-described operation, the trans codec 755 may be a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) in which a predetermined algorithm is physically implemented.

According to the above-described video signal transmission and reception system, the video content from the service provider to the display device is transmitted in an encrypted state. That is, even if the compression is decompressed by the reception codec 735, the scrambled video is not decoded. The scrambled key is required to decrypt the scrambled image, but the scrambled key is transmitted to the trans codec 755 in an encrypted state. The transmission of the scrambled key from the reception codec 725 to the trans codec 755 is because the scrambled key is encrypted and transmitted in the form of a video signal. That is, since the scramble key is transmitted as the frame key in the form of an image frame, the scramble key is treated as an image signal by the receiving codec 735 and transmitted to the trans codec 755.

In addition, the generation of the frame key and the formation of the scrambled image data on the service provider side are the same as in FIG. 4B of the first embodiment, and the data format of the compressed scramble signal is the same as in FIG. 4C of the first embodiment. In addition, the structure and function of the trans codec of this embodiment are the same as that of Fig. 4D of the first embodiment.

Therefore, according to this embodiment, even if the HDCP technology is used as in the prior art, the trans codec can be used for the security of the video content. The HDCP technology mainly focuses on the authentication of the display device. In this embodiment, the encrypted video content is maintained at the output terminal or the display device of the computer. Therefore, the video signal transmission and reception system disclosed in this embodiment complements the HDCP technology and shows that it can be used in parallel with the HDCP technology.

In addition, the user computer according to the third embodiment of the present invention may be a personal portable terminal. That is, it may be a personal portable terminal used for Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), or Wireless Broadband Internet (WiBro) system. In this case, the display device may be a display panel provided in the personal portable terminal.

According to the present invention as described above, the scramble key used to decrypt the encrypted video content is encrypted with a frame key having the form of video data and transmitted to the video output terminal. Therefore, even if the compression is released by the reception codec of the user's computer, the reception codec recognizes the frame key as an image signal and performs only the operation of decompressing the compression performed by the service provider. Accordingly, the frame key is transmitted to the image output terminal in a state in which the frame key is decompressed and converted into a scrambled key by a trans codec which is a security module included in the graphic unit or the display device. In addition, the video content encrypted by the trans codec, which is a security module, is decrypted by the scramble key, and the encrypted video content is decrypted. Therefore, the security of the image content from the central processing unit of the user computer to the image output stage can be made perfect.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (18)

A service provider for generating scrambled image data by scrambled raw image data, encrypting the scrambled key used for scrambled into a frame key in the form of an image signal, and generating a compressed scrambled signal by compressing the scrambled image data and the frame key. ; A user computer for receiving the compressed scramble signal, transmitting the frame key to an image output terminal regardless of a decompression operation, and generating a reproduced video signal using the scramble key decoded from the frame key at the image output terminal; And And a display device for receiving and displaying the reproduced video signal. The method of claim 1, wherein the user computer, Auxiliary storage for storing the compressed scrambled signal transmitted from the service provider; A central processing unit for activating a receiving codec to decompress the compressed scrambled signal stored in the auxiliary storage device to generate a reproduced scrambled signal; A main memory device for storing the reproduction scramble signal from the central processing unit; And A graphic unit for receiving a playback scrambled signal stored in the main memory device, decoding a frame key in the form of the video signal to form a scrambled key, and converting the scrambled video data into a playback video using the scrambled key; Video signal transmission and reception system, characterized in that. The method of claim 2, wherein the graphic unit, A graphics card for receiving the reproduction scramble signal and performing image signal processing; A trans codec for decoding a frame key of the reproduction scramble signal to form a scramble key, and converting the scrambled image data into a reproduced image using the scramble key; And And an I / O port for supplying a playback image received from the trans codec to the display device. The method of claim 3, wherein the trans codec, A frame key decoder for decoding the frame key having a form of an image signal into a content key in the form of a bit string; A private key generator for generating an independent private key for each user computer; A content key decoder for decoding the content key into the scrambled key using the private key; And And a video decoder for converting the scrambled video data into the reproduced video using the scrambled key. The system of claim 4, wherein the trans codec is a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC) in which a predetermined algorithm is physically implemented. The method of claim 5, wherein the service provider, Encrypting the scrambled key with a content key through a public key, Generating the scrambled image data from the raw image data using the scrambled key, Converting the content key into the frame key in the form of a video signal, And compressing the frame key and the scrambled image data to generate a compressed scrambled signal. The method of claim 6, wherein the graphic unit, And an HDCP transmitting device for authenticating the display device. Scrambled raw video data to generate scrambled video data, encrypting the scrambled key used for scrambled into a frame key in the form of a video signal, and compressing the scrambled video data and the frame key to generate a compressed scrambled signal Service provider; A user computer for receiving the compressed scramble signal, decompressing the compressed scramble signal to generate a reproduced scramble signal, and transmitting the frame key to an image output terminal regardless of the decompression operation; And And a display device for receiving the reproduction scramble signal, decoding the frame key to generate the scramble key, and converting and displaying the scrambled image data into a reproduced video signal using the scramble key. . The method of claim 8, wherein the user computer, Auxiliary storage for storing the compressed scrambled signal transmitted from the service provider; A central processing unit for activating a receiving codec to decompress the compressed scrambled signal stored in the auxiliary storage device to generate a reproduced scrambled signal; A main memory device for storing the reproduction scramble signal from the central processing unit; And And a graphic unit configured to receive a reproduction scramble signal stored in the main memory device and perform image signal processing. The display device of claim 9, wherein the display device comprises: An I / O port for receiving a playback scramble signal from the graphics unit; A trans codec for decoding a frame key of the reproduction scramble signal received from the I / O port to form a scramble key, and converting the scrambled image data into a reproduced image using the scramble key; And And a display panel for receiving and displaying the reproduced image from the trans codec. The method of claim 10, wherein the trans codec, A frame key decoder for decoding the frame key having a form of an image signal into a content key in the form of a bit string; A private key generator for generating an independent private key for each user computer; A content key decoder for decoding the content key into the scrambled key using the private key; And And a video decoder for converting the scrambled video data into the reproduced video using the scrambled key. 12. The system of claim 11, wherein the trans codec is a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) in which a predetermined algorithm is physically implemented. The method of claim 12, wherein the service provider, Encrypting the scrambled key with a content key through a public key, Generating the scrambled image data from the raw image data using the scrambled key, Converting the content key into the frame key in the form of a video signal, And compressing the frame key and the scrambled image data to generate a compressed scrambled signal. The method of claim 13, The graphic unit has an HDCP transmission device for performing an authentication operation on the display device, The display device has a video signal transmission and reception system, characterized in that having an HDCP receiving device for performing communication for the authentication operation with the HDCP transmission device. A frame key decoder having a form of a video signal and decoding a frame key transmitted in the form of a bit string despite the decompression operation of the central processing unit; A private key generator for generating an independent private key for each user computer; A content key decoder for decoding the content key into the scrambled key using the private key; And And a video decoding unit for converting the scrambled video data encrypted with the raw video data into the playback video using the scrambled key. 16. The apparatus of claim 15, wherein the frame key has a form of image data of red, green, and blue, and is composed of a plurality of divided sectors, each of which corresponds to a plurality of divided sectors of the raw image data. And a gray level corresponding to an encryption value. The security module of claim 16, wherein the frame key has a different key value for each frame of the raw image data. 18. The security module of claim 17, wherein the trans codec is a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC) in which a predetermined algorithm is physically implemented.

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