JP3381715B2 - Data storage device and data reproduction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data storage device for connecting a plurality of digital video equipments via a bus and transferring video data between the plurality of digital video equipments via the bus to store the data. The present invention relates to a data reproducing method, and particularly relates to protection of video data transferred via a bus.

[0002]

2. Description of the Related Art Satellite broadcasting in which a digital video signal is compressed and broadcast using a satellite, a digital VTR in which a video signal is compressed and recorded on a magnetic tape, and a digital video signal is compressed and recorded on an optical disk or a magneto-optical disk. Various AVs that handle digital video signals, such as recording / reproducing devices
Equipment is being developed. A bus has been proposed for exchanging data and commands with a common protocol between such various AV devices. By using such a bus, various AV devices can be easily connected, and operability can be improved by centralized management of controls such as one-touch dubbing.

A digital video signal is hardly deteriorated even if dubbing is repeated. From this, it is feared that the copyright will not be protected as the AV equipment handling such digital video signals becomes widespread.
Therefore, various methods for protecting video data have been conventionally proposed.

As one of methods for protecting video data, it has been proposed to include a flag indicating permission / prohibition of copying in data to be transmitted, for example. That is,
When transmitting copy-prohibited data, a copy-prohibition flag is set and the data is transmitted from the transmitting side. On the receiving side, the presence or absence of the flag is determined, and depending on the presence or absence of the flag,
Recording prohibition is controlled.

[0005]

However, the method using such a flag cannot sufficiently protect data in a system in which various AV devices as described above are connected by a bus. That is, even if the flag indicating the copy permission / prohibition is included, the video data is transferred as it is on the bus. It can be handled in the same way as transmitting a video signal with an analog signal line, so that video data can be recorded while displaying a video on the display, or video data can be recorded by multiple recording devices. No destination is specified for data on the bus. Therefore, all video devices connected to the bus are ready to take in the video data on the bus. Therefore, even if the video data including the copy prohibition flag is transferred onto the bus, the AV device that does not process the flag is in a defense state.

Therefore, an object of the present invention is to transfer a plurality of digital video devices via a bus when the plurality of digital video devices are connected via the bus and video data is transferred between the plurality of digital video devices via the bus. An object of the present invention is to provide a data storage device and a data reproduction method capable of sufficiently protecting video data.

[0007]

The present invention is supplied from a device corresponding to another MPEG compressed signal via a bus.
Recorded and reproduced MPEG compressed signal
Supports compressed signals to other MPEG compressed signals via the bus
A data storage device for transmitting to the device to the other MP
Authenticates whether or not the transfer of the MPEG compressed signal is permitted between the device supporting the EG compressed signal and the predetermined data.
And an encrypted MP supplied via the bus when it is determined that the transfer of the MPEG compressed signal is permitted as a result of the authentication.
Receiving means for starting reception of the EG compression signal, and
And descrambling means for releasing the cipher of the MPEG compressed signal is a data storage device characterized by comprising a recording means for recording an MPEG compressed signal encryption is released by descrambling means on a recording medium.

The present invention relates to an MPE recorded on a recording medium.
Reproduces the G compressed signal, a data storage apparatus for transmitting MPEG compressed signal reproduced through the bus to the machine <br/> device corresponding to another MPEG compressed signals, recorded on the recording medium MPEG Transfer of the MPEG compressed signal is permitted between the reproducing means for reproducing the compressed signal, the encrypting means for encrypting the MPEG compressed signal reproduced by the reproducing means, and the device corresponding to another MPEG compressed signal. Authentication means for performing authentication as to whether or not predetermined data is returned, and other predetermined authenticated if it is determined that transfer of the MPEG compressed signal is permitted as a result of the authentication .
The data reproducing apparatus is characterized in that the transfer of an encrypted MPEG compressed signal to a device is started depending on whether data is returned or not .

When a plurality of video equipments are connected via a bus and data is transmitted between the video equipments via the bus, commands are exchanged and key information is used to determine whether the transfer is permitted. To judge. Then, a command for decryption is sent to a specific partner type whose transfer is permitted, and then the data is encrypted and transmitted. This makes it possible to perform control such that data is transferred only to a specific partner who is permitted to transfer or only specific partner is allowed to receive the data. Therefore, the data transferred to the bus can be surely protected.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described.
The following order will be described with reference to the drawings. a. Overall system b. First embodiment b1. Example of device that transfers data from device to bus side b2. Example of device that transfers data from bus side to device side b3. Example of device that transfers data bidirectionally b4. Example of device for recording / reproducing data b5. System example c. Second embodiment c1. Example of device that transfers data from device to bus side c2. Example of device that transfers data from bus side to device side c3. Example of device that transfers data bidirectionally c4. Example of device for recording / reproducing data c5. System example

A. Overall System Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a video system to which the present invention can be applied. This video system uses a common bus to connect a plurality of AV devices.

In FIG. 1, 1 is a digital decoder box and 2 and 3 are digital VTRs. The digital decoder box 1 decodes a received signal of digital satellite broadcasting received by the parabolic antenna 6 and outputs an analog video signal. The video signal decoded by the digital decoder box 1 can be displayed on the television receiver 4 and, via the bus 5,
Can be transferred to other AV equipment. The television receiver 4
It receives ordinary analog television broadcasts. The digital VTRs 2 and 3 can record / reproduce digital video signals. These digital decoder box 1, digital VTR 2 and digital VTR 3 are connected to the bus 5.

Digital data is transferred to the bus 5, and a command for each device is transmitted. Data can be transferred between each device via this bus. That is, the video signal from the digital decoder box 1 is transferred to the digital VTR 2 or 3 via the bus 5.
The digital VTR 2 or 3 can record the video signal from the digital decoder box 1. Also, the reproduction signal from the digital VTR 2 or 3 is sent to the digital decoder box 1 via the bus 5,
This signal can be decoded by the digital decoder box 1 and displayed on the television receiver 4. Furthermore, the reproduction signal of the digital VTR 2 can be sent to the digital VTR 3 via the bus 5, and dubbing can be performed between the digital VTR 2 and the digital VTR 3.

In the above example, the television receiver 4 for receiving ordinary television broadcasts is used, and the digital decoder box 1 and the digital VTRs 2 and 3 are connected to the bus 5 to receive satellite broadcast reception signals. The system is configured so that it can be output, but of course, in addition to other AV
A system can be configured by connecting devices.

That is, FIG. 2 shows another example of the video system. In this example, a television receiver 14 having a built-in digital video decoder is used. The digital satellite broadcast received by the parabolic antenna 16 is decoded by the decoder in the television receiver 14 and displayed on the television receiver 14. In addition to the digital VTR 12, this video system includes a digital video disc player 19 and an MPE.
A G decoder 17 and an analog VTR 18 are provided. The digital video disc player 19 is, for example, MPE.
The optical disc on which the video signal compressed by G is recorded is reproduced. The analog VTR 18 records / reproduces an analog video signal. Analog VTR
At 18, an MPEG decoder 17 is provided so that the digital video signal transferred via the bus 15 can be recorded. Television receiver 14 with built-in digital video decoder, digital video disk 19, MPEG
The decoder 17 is connected to the bus 15. This bus 15
Data can be transferred between each device via the.

B. First Embodiment As described above, the present invention is used to protect data transferred to a bus in a system in which a plurality of AV devices are connected to a common bus. According to the first embodiment of the present invention, a device to which transfer is permitted is designated in advance by a command, data is delivered only to a device to which transfer is permitted, and data is transferred to a device to which transfer is not permitted. So that each device has a switch,
It is designed to protect data. The AV device includes a device that transfers data from the device to the bus side,
There are devices that take data from the bus to the device side and devices that transfer data bidirectionally. Furthermore, there are devices that can record / reproduce data. The device that transfers data from the device to the bus side is, for example, a digital video disc player. A device that takes in data from the bus to the device side is, for example, an MPEG decoder or a television receiver with a built-in decoder. The device to which data is transferred bidirectionally is, for example, a digital decoder box. The device capable of recording / reproducing data is, for example, a digital VTR. The configuration of each of these devices will be described below.

B1. Example of a device that transfers data from the device to the bus side In a device that transfers data from the device to the bus side, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data. . When data is transferred to each device via the bus, first, a command is exchanged with each device in advance, and it is determined using the key information whether or not the transfer is permitted. Then, the switch is turned on only for the device for which the transfer is permitted, and the data is transferred.
For devices that are not allowed to transfer, the switch is turned off and data transfer is rejected.

FIG. 3 shows a digital video disc player as an example of such a device. Figure 3
In the optical disc 21, a video signal compressed by MPEG, for example, is optically recorded. The optical disk 21 is rotated by a spindle motor 22. The signal of the optical disk 21 is reproduced by the optical pickup 23, and this reproduced signal is supplied to the reproducing circuit 24.
The reproduction circuit 24 performs processing such as data demodulation and error correction. The output of the reproduction circuit 24 is supplied to the switch circuit 25. The switch circuit 25 is on / off controlled by the controller 27. The output of the switch circuit 25 is supplied to the I / O port 26. Further, the controller 27 exchanges commands with other devices via the I / O port 26. The controller 27 includes a key generator 2
Key information is given from 8.

In such a digital video disc player, when reproducing data is transferred to another AV device via the bus, first, commands are exchanged via the bus using the key information. This command uses the key information to specify the device for which transfer is permitted. Then, the switch circuit 25 is turned on only when the data is transferred to the device for which the transfer is permitted,
The data from the reproduction circuit 24 is transferred via the bus.
Otherwise, the switch 25 is turned off. This allows
It is possible to transfer the data only to the device to which the transfer is permitted and to refuse the transfer of the data to the device which is not permitted.

B2. Example of a device that transfers data from the bus side to the device side In a device that takes in data from the bus side to the device side, a switch circuit whose controller controls ON / OFF is provided on the digital data input side. To be
Then, when receiving data from each device via the bus, first, a command is exchanged with each device, and it is determined using the key information whether or not the transfer is permitted. Then, the switch circuit is turned on only for the device for which the transfer is permitted. For devices for which transfer is not permitted, the switch circuit is turned off and data transfer is rejected.

FIG. 4 shows an example of such a device as M
A PEG decoder is shown. In FIG. 4, I / O
The data from the port 31 is supplied to the switch circuit 32. The switch circuit 32 is controlled by the controller 36.
ON / OFF controlled. The output of the switch circuit 32 is MP
It is supplied to the EG decoding circuit 33. The MPEG decoding circuit 33 decodes the video data. MPEG
The output of the decoding circuit 33 is output from the output terminal 35 via the D / A converter 34. I / O port 31
The controller 36 exchanges commands with other devices via the. The controller 36 includes a key generator 37
Gives the key information.

When data is transferred to this MPEG decoder from another AV device via a bus, first, a command is exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. Then, the switch circuit 32 is turned on only for the data from the device for which the transfer is permitted,
Otherwise, the switch 32 is turned off. This allows
The data can be received only from the device to which the transfer is permitted, and the data from the device to which the data transfer is not permitted can be rejected.

FIG. 5 shows another example of such a device.
A television receiver with a built-in decoder is shown. In FIG. 5, an input terminal 41 is supplied with a reception signal of a normal television broadcast. The signal from the input terminal 41 is supplied to the tuner circuit 43. Tuner circuit 43
Then, the signal of the desired reception channel is extracted. The output of the tuner circuit 43 is supplied to the terminal 45A of the switch circuit 45.

A compressed digital video signal from the satellite is supplied to the input terminal 42. The signal from the input terminal 42 is supplied to the digital tuner circuit 44. A desired reception channel is selected by the digital tuner circuit 44. The output of the digital tuner circuit 44 is supplied to the terminal 45B of the switch circuit 45.

The data sent via the I / O port 46 is supplied to the switch circuit 47. The controller 48 controls ON / OFF of the switch circuit 47. The output of the switch circuit 47 is supplied to the terminal 45C of the switch circuit 45. Further, the controller 48 exchanges commands with other devices via the I / O port 46. The key information is provided to the controller 48 from the key generation unit 52.

When receiving a normal television broadcast, the switch circuit 45 is set to the terminal 45A side. When receiving a digital broadcast from a satellite, the switch circuit 45 is set to the terminal 45B side. I / O port 4
When displaying the data sent via 5, the switch circuit 45 is set to the terminal 45C side.

The output of the switch circuit 45 is supplied to the descrambler 49. The descrambler 49 descrambles the received signal when the received signal is scrambled. The output of the descrambler 49 is supplied to the MPEG decoder 50. The video signal is decoded by the MPEG decoder 50. When receiving a normal video signal, the MPEG decoder 50 is bypassed. The output of the MPEG decoder 50 is the signal processing circuit 5.
1 is supplied. The output of the signal processing circuit 51 is supplied to the CRT display 53.

In such a television receiver,
When data is transferred from another AV device via the bus, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. Then, the switch circuit 47 is turned on only for the data from the device for which the transfer is permitted, and the switch circuit 47 is turned off in other cases. Thereby, the data can be received only from the device to which the transfer is permitted, and the data from the device to which the transfer is not permitted can be rejected.

B3. Examples of devices that transfer data bidirectionally In devices that transfer data bidirectionally, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data, and the input side of digital data is also provided. In addition, a switch circuit whose on / off is controlled by the controller is provided. When data is transferred to each device via the bus, first, a command is exchanged with each device in advance, and it is determined using the key information whether or not the transfer is permitted. Then, the switch circuit on the output side is turned on only for the device for which the transfer is permitted, and the switch is turned off for the device for which the transfer is not permitted, so that the data transfer is rejected. Further, when receiving data from each device via the bus, a command is exchanged with each device in advance, and it is determined whether the transfer is permitted or not by using the key information. The switch circuit on the input side is turned on only for the device for which the transfer is permitted, and the switch circuit on the input side is turned off for the device for which the transfer is not permitted, and the data transfer is rejected.

FIG. 6 shows a digital video box as an example of such a device. In FIG.
A compressed digital video signal from a satellite is supplied to the input terminal 61. The signal from the input terminal 61 is supplied to the digital tuner circuit 62. A desired reception channel is selected by the digital tuner circuit 62. The output of the digital tuner circuit 62 is supplied to the descrambler 63. The descrambler 63 descrambles the received signal when the received signal is scrambled. The output of the descrambler 63 is the switch circuit 64.
And to the terminal 65A of the switch circuit 65. On / off of the switch circuit 64 is controlled by the controller 67. The output of the switch circuit 64 is supplied to the I / O port 66.

The data sent via the I / O port 66 is supplied to the switch circuit 68. On / off of the switch circuit 68 is controlled by the controller 67. The output of the switch circuit 68 is supplied to the terminal 65B of the switch circuit 65. Further, the controller 67 exchanges commands with other devices via the I / O port 66. Key information is given to the controller 67 from the key generation unit 69.

The switch circuit 65 is switched between displaying the received signal on the television receiver and displaying the transmitted data on the television receiver. When the received signal is displayed on the television receiver, the switch circuit 65 is set on the terminal 65A side. When an image based on the data sent via the bus is displayed on the television receiver, the switch circuit 65 is set on the terminal 65B side.

The output of the switch circuit 65 is supplied to the MPEG decoding circuit 70. MPEG decoding circuit 70
At, the video signal is decoded. The output of the MPEG decoding circuit 70 is supplied to the D / A converter 71. D
The output of the / A converter 71 is output from the output terminal 72.

This digital video box is used when a received signal is decoded and displayed on a television receiver. Furthermore, this digital video box is used when sending received data to other devices via the bus, and it also receives and decodes data from other devices sent via the bus to receive a television image. Used when supplying to the machine.

When data from the digital video box is transferred to another AV device via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. Then, the data from the descrambler 63 is transferred via the bus. At this time, the switch circuit 64 is turned on only when the data is transferred to the device for which the transfer is permitted, and the switch circuit 64 is turned off otherwise. As a result, the data can be transferred only to the device to which the transfer is permitted, and the data transfer to the device to which the transfer is not permitted can be rejected.

When the digital video box receives data from another AV device via the bus, the switch circuit 65 is set to the terminal 65B side. Then, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. Then, the switch circuit 68 is turned on only for the data from the device for which the transfer is permitted, and the switch 68 is turned off in other cases. As a result, the data can be received only from the device to which the transfer is permitted.

B4. Examples of devices that record / reproduce data In a device that records / reproduces data, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data, and an input side of digital data is provided on the output side. A switch circuit whose on / off is controlled by the controller is provided. Then, a card key is attached to identify whether the device is permitted to transfer.

When data is transferred to each device via the bus at the time of reproduction, first, a command is exchanged with each device in advance, and the key information is used to determine whether or not the transfer is permitted. Then, the switch on the output side is turned on to send data only to the device to which the transfer is permitted, and the switch is turned off to the device to which the transfer is not permitted so that the data is not transferred. In addition, when receiving data from each device via the bus at the time of recording, commands are exchanged with each device in advance and the key information is used to determine whether the transfer is permitted,
The switch on the input side is turned on only for the device for which the transfer is permitted, and the switch on the input side is turned off for the device for which the transfer is not permitted, and the data transfer is rejected.

FIG. 7 shows a digital VTR as an example of such a device. In FIG. 7, when recording the data transferred via the bus, I /
The data transferred via the O port 81 is supplied to the switch circuit 82. The output of the switch circuit 82 is supplied to the recording / reproducing circuit 83. This data is recorded by the recording / reproducing circuit 83. At the time of reproduction, the data reproduced from the recording / reproducing circuit 83 is supplied to the switch circuit 84. The output of the switch circuit 84 is the I / O port 81.
Is supplied to. In addition, commands are exchanged with the controller 85 via the I / O port 81 with other devices.
A card key 86 is detachably attached to the card attachment terminal 87. From this card key 86 to the controller 85
Is given the key information.

When data is recorded on the digital VTR from another AV device sent via the bus, first, commands are exchanged via the bus using the key information of the card key 86. This command identifies the device for which transfer is permitted. If the transfer is permitted, the switch circuit 82 is turned on,
Otherwise, the switch 82 is turned off. This allows
Data can only be recorded if the transfer is allowed.

When the reproduced data from the digital VTR is transferred to another AV device via the bus, first, commands are exchanged via the bus using the key information of the card key 86. This command identifies the device for which transfer is permitted. Then, the reproduction data from the recording / reproducing circuit 83 is transferred via the bus. At this time, the switch circuit 84 is turned on only when the data is transferred to the device for which the transfer is permitted, and the switch 84 is turned off otherwise. As a result, the reproduction data can be transferred only to the device to which the transfer is permitted, and the transfer of the data to the device to which the transfer is not permitted can be rejected.

B5. System Example The following describes how data is protected by using each device configured as described above. Figure 8
Is a system that includes the digital decoder box 101, the digital VTRs 102 and 103, and the television receiver 104, as shown in FIG. 1, using the AV equipment configured as described above. The digital decoder box 101 is constructed as shown in FIG. 6, and the digital VTRs 102 and 103 are constructed as shown in FIG. Digital decoder box 1
01, digital VTRs 102 and 103 are connected to the bus 10
5 are commonly connected.

Commands and data are transferred onto the bus 105. The command is transferred by designating a destination so that predetermined processing can be performed for each video device.
The data is transmitted without specifying the destination.

When data is transferred between the AV devices, a process as shown in FIG. 9 is performed. That is, first, a command for determining whether or not the transfer is permitted is transmitted (step S1). Upon receiving the command, each device processes the command according to the key information of each device (step S2), and returns the data subjected to the predetermined process as an acknowledge. It is determined whether an acknowledge is received (step S3). When the acknowledge is received, the acknowledge, which is the data processed based on the key information for each device, is compared with the data processed based on the key information based on the device that issued the command (step S4). If the key information of each other is correct, both will match. If the key information of each other is incorrect, the two do not match. It is determined whether the two match (step S5). If they match, the data is permitted to be transferred to the AV device (step S6). If they do not match, the data is transferred to the AV device. Is rejected (step S7).

For example, as shown in FIG.
It is assumed that the TR 102 has no card key attached, and only the digital VTR 103 has the card key 86B attached. Then, the digital decoder box 10
It is assumed that data is transferred between 1 and the digital VTRs 102 and 103.

When a recording command is sent from the digital decoder box 101 side to the digital VTRs 102 and 103 to transfer the data from the digital decoder box 101 to the digital VTRs 102 and 103 for recording, the processing shown in FIGS. 10A and 10B is performed. Is done.

As shown in FIG. 10A, a recording command is given to the digital VTR 102 from the digital decoder box 101 side. When the recording command is transferred to the digital VTR 102, the digital VTR 102 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 101. Since no card key is attached to the digital VTR 102, the acknowledge returned from the digital VTR 102 to the digital decoder box 101 is not predetermined data. Therefore, after that, the data transfer is rejected.

As shown in FIG. 10B, a recording command is given from the digital decoder box 101 side to the digital VTR 103. When the command is transferred to the digital VTR 103, the digital VTR 103 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 101. Since the card key 86B is attached to the digital VTR 103, the acknowledge returned from the digital VTR 103 to the digital decoder box 101 becomes predetermined data. Therefore, thereafter, the data is transferred from the digital decoder box 101 to the digital VTR 103.

When a playback command is sent from the digital decoder box 101 side to the digital VTRs 102 and 103 to transfer the playback data from the digital VTRs 102 and 103 to the digital decoder box 101, the processing shown in FIGS. 11A and 11B is performed. Be seen.

As shown in FIG. 11A, a reproduction command is given to the digital VTR 102 from the digital decoder box 101 side. When the reproduction command is transferred to the digital VTR 102, the digital VTR 102 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 101. Since no card key is attached to the digital VTR 102, the acknowledge returned from the digital VTR 102 to the digital decoder box 101 is not predetermined data. Therefore, after that, the data transfer is rejected.

As shown in FIG. 11B, a reproduction command is given from the digital decoder box 101 side to the digital VTR 103. When the reproduction command is transferred to the digital VTR 103, the digital VTR 103 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 101. Since a card key is attached to the digital VTR 103, the acknowledge returned from the digital VTR 103 to the digital decoder box 101 becomes predetermined data. Therefore, thereafter, the digital VTR 103
The reproduced data from the digital decoder box 101
Transferred to.

When a data transmission command is sent from the digital VTRs 102 and 103 side to the digital decoder box 101 side to transfer the data from the digital decoder box 101 to the digital VTRs 102 and 103 for recording, as shown in FIGS. 12A and 12B. Processing is performed.

As shown in FIG. 12A, a digital VTR
From the 102 side to the digital decoder box 101 side,
A data transmission command is given. When a data transmission command is transferred to the digital decoder box 101,
The digital decoder box 101 forms an acknowledge based on the key information, and the digital VTR 102
Return to. Since no card key is attached to the digital VTR 102, the acknowledge returned from the digital VTR 102 to the digital decoder box 101 does not match the predetermined data on the digital VTR 102 side. Therefore, thereafter, the digital VTR 102 refuses to take in the data.

As shown in FIG. 12B, the digital VTR
From the 103 side to the digital decoder box 101 side,
A data transmission command is given. When a data transmission command is transferred to the digital decoder box 101,
The digital decoder box 101 forms an acknowledge based on the key information, and the digital VTR 103
Return to. The digital VTR 103 has a card key 86
Since B is attached, the acknowledge returned from the digital VTR 103 to the digital decoder box 101 matches the predetermined data on the digital VTR 103 side. Therefore, the digital decoder box 101
Data is transmitted to the digital VTR 102, and this data is recorded by the digital VTR 103.

When a data reception command is sent from the digital VTRs 102 and 103 to the digital decoder box 101 side to transfer the data from the digital VTRs 102 and 103 to the digital decode box 101, the processing shown in FIGS. 13A and 13B is performed. Be seen.

As shown in FIG. 13A, a digital VTR
From the 102 side to the digital decoder box 101 side,
A data reception command is given. When the data reception command is transferred to the digital decoder box 101,
The digital decoder box 101 forms an acknowledge based on the key information, and the digital VTR 102
Return to. Since no card key is attached to the digital VTR 102, the acknowledge returned from the digital VTR 102 to the digital decoder box 101 does not match the predetermined data on the digital VTR 102 side. Therefore, thereafter, the transfer of data from the digital VTR 103 is rejected.

As shown in FIG. 13B, the digital VTR
From the 103 side to the digital decoder box 101 side,
A data reception command is given. When the data reception command is transferred to the digital decoder box 101,
The digital decoder box 101 forms an acknowledge based on the key information, and the digital VTR 103
Return to. The digital VTR 103 has a card key 86
Since B is attached, the acknowledge returned from the digital VTR 103 to the digital decoder box 101 matches the predetermined data on the digital VTR 103 side. Therefore, thereafter, the data from the digital VTR 103 is transferred to the digital decoder box 101 and received by the digital decoder box 101.

As described above, in the first embodiment of the present invention, the command is exchanged based on the key information before transferring the data between the respective devices, and it is judged whether the transfer is permitted or not. It Then, the data is transferred only to the device for which the transfer is permitted. This makes it possible to protect the data.

C. Second Embodiment In the second embodiment of the present invention, a device to which transfer is permitted is designated in advance by a command, data is delivered only to the device to which transfer is permitted, and transfer is not permitted. Each device is provided with a switch so that the data is not transferred to the device, and the data is encrypted and transmitted to further protect the data.

C1. Example of a device that transfers data from the device to the bus side In a device that transfers data from the device to the bus side, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data. At the same time, an encryption circuit is provided. Then, when data is transferred to each device via the bus, first, a command is exchanged with each device in advance to determine whether the transfer is permitted. Then, the key for deciphering the encryption is given to the device to which the transfer is permitted.
The switch is turned on to the device to which the transfer is permitted, and the data is encrypted and sent. Since the key is given in advance to the device to which the transfer is permitted, the encrypted data can be decrypted. For devices that are not allowed to transfer, the switch is turned off and data transfer is rejected.

FIG. 14 shows an example of such a device.
A digital video disc player is shown. In FIG. 14, the optical disc 121 has, for example, MPEG.
The video signal compressed by is recorded optically. This optical disc 121 is rotated by a spindle motor 122. The signal of the optical disk 121 is reproduced by the optical pickup 123, and this reproduced signal is reproduced by the reproducing circuit 124.
Is supplied to. The reproduction circuit 124 performs processing such as data demodulation and error correction. The output of the reproduction circuit 124 is
It is supplied to the switch circuit 125. Switch circuit 125
Is on / off controlled by the controller 127. The output of the switch circuit 125 is supplied to the encryption circuit 129. The data to be transferred is encrypted by the encryption circuit 129. The output of the encryption circuit 129 is the I / O port 2
6 is supplied. Further, the command is transferred to the controller 27 via the I / O port 26. Controller 2
Key information is given to 7 from the key generation unit 28.

In such a digital video disc player, when reproducing data is transferred to another AV device via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. And
When transferring data to a device that is allowed to transfer, a key for decryption is passed. Then, the switch circuit 25 is turned on. Therefore, the data from the reproduction circuit 24 is encrypted by the encryption circuit 129 and transferred via the bus. Otherwise, the switch 25 is turned off. As a result, the data can be transferred only to the device to which the transfer is permitted, and the data transfer to the device not to be permitted can be refused. At the same time, since the data transferred to the bus is encrypted, the data transferred to the bus can be protected.

C2. Example of a device that transfers data from the bus side to the device side In a device that takes in data from the bus side to the device side, a switch circuit whose controller controls ON / OFF is provided on the digital data input side. And a decryption circuit is provided. When receiving data from each device via the bus, first, a command is exchanged with each device to determine whether or not the transfer is permitted. Then, if the transfer is permitted, the key for decryption is received. The switch circuit is turned on and data is input to the device to which the transfer is permitted. This data is encrypted, but the key for decrypting the encryption has been sent in advance, so the encryption can be decrypted. For devices for which transfer is not permitted, the switch circuit is turned off and data transfer is rejected.

FIG. 15 shows an example of such a device.
An MPEG decoder is shown. In FIG. 15, I
The data from the / O port 131 is sent to the switch circuit 132
Is supplied to. The switch circuit 132 is the controller 1
On / off control is performed by 36. Switch circuit 13
The output of 2 is supplied to the decryption circuit 138. The output of the decryption circuit 138 is supplied to the MPEG decoding circuit 133. The MPEG decoding circuit 133 decodes the video data. The output of the MPEG decoding circuit 133 is output to the output terminal 135 via the D / A converter 134.
Is output from. Commands are exchanged with the controller 136 via the I / O port 131. Key information is provided to the controller 136 from the key generation unit 137.

When data is transferred to this MPEG decoder from another AV device via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. If the transfer is permitted, the key for decryption is received, and the key for decryption is set in the decryption circuit 138. Then, the switch circuit 132 is turned on. As a result, the data sent via the bus is input. This data is encrypted, but the key is sent in advance so that the code can be decrypted. When the data transfer is not permitted, the switch 32 is turned off and the data transfer is rejected.

FIG. 16 shows an example of a television receiver having a built-in decoder. In FIG. 16, the input terminal 1
A reception signal of a normal television broadcast is supplied to 41. The signal from the input terminal 141 is supplied to the tuner circuit 14
3 is supplied. The tuner circuit 143 extracts a signal of a desired reception channel. The output of the tuner circuit 143 is supplied to the terminal 145A of the switch circuit 145.

A compressed digital video signal from the satellite is supplied to the input terminal 142. The signal from the input terminal 142 is supplied to the digital tuner circuit 144.
The digital tuner circuit 144 selects a desired reception channel. The output of the digital tuner circuit 144 is supplied to the terminal 145B of the switch circuit 145.

The data sent via the I / O port 146 is supplied to the switch circuit 147. On / off of the switch circuit 147 is controlled by the controller 148. The output of the switch circuit 147 is supplied to the encryption circuit 154. The controller 148 supplies the encryption circuit 154 with key information for decryption. The output of the decryption circuit 154 is supplied to the terminal 154C of the switch circuit 145. Also, I / O port 146
The command is transferred to the controller 148 via the. Key information is provided to the controller 148 from the key generation unit 152.

When receiving a normal television broadcast, the switch circuit 145 is set to the terminal 145A side. When receiving a digital broadcast from a satellite, the switch circuit 145 is set on the terminal 145B side. I /
When reproducing the data sent through the O port 145, the switch circuit 145 is set to the terminal 145C side.

The output of the switch circuit 145 is supplied to the descrambler 149. The descrambler 149 descrambles the received signal when the received signal is scrambled. The output of the descrambler 149 is M
It is supplied to the PEG decoder 150. The video signal is decoded by the MPEG decoder 150. Note that the MPEG decoder 150 is passed when receiving a normal video signal. The output of the MPEG decoder 150 is supplied to the signal processing circuit 151. Signal processing circuit 15
The output of 1 is supplied to the CRT display 153.

In such a television receiver,
When data is transferred from another AV device via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. If data transfer is allowed, the key for decryption is received. Then, in the case of the device for which the transfer is permitted, the switch circuit 47 is turned on and the data is sent. This data is encrypted, but the key is sent in advance so that the code can be decrypted. When the data transfer is not permitted, the switch 47 is turned off and the data transfer is rejected.

C3. Example of a device that transfers data bidirectionally In a device that transfers data bidirectionally, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data, and a data encryption circuit is provided. Is provided. Further, on the input side of the digital data, a switch circuit whose on / off is controlled by a controller is provided and a decryption circuit is provided.

When data is transferred to each device via the bus, first, a command is exchanged with each device in advance, and it is judged using the key information whether or not the transfer is permitted. If the transfer is allowed, the key for decryption is passed. Then, the encrypted data is sent. If the transfer is not allowed,
Data transfer is rejected.

When receiving data from each device via the bus, commands are exchanged with each device in advance,
The key information is used to determine if the transfer is allowed. A device for which transfer is permitted sends a key for decryption. Then, the switch circuit on the input side is turned on, and the data is encrypted and sent. This data is encrypted, but since the key information has been sent in advance, the code can be decrypted. Data transfer is rejected for devices for which transfer is not permitted.

FIG. 17 shows a digital video box as an example of such a device. In FIG. 17, an input terminal 161 is supplied with a compressed digital video signal from a satellite. The signal from the input terminal 161 is
It is supplied to the digital tuner circuit 162. A desired reception channel is selected by the digital tuner circuit 162. The output of the digital tuner circuit 162 is supplied to the descrambler 163. Descrambler 163
Is to descramble the received signal if it is scrambled. The output of the descrambler 163 is supplied to the encryption circuit 173. Encryption circuit 17
The output of No. 3 is supplied to the switch circuit 164 and the terminal 165A of the switch circuit 165. On / off of the switch circuit 164 is controlled by the controller 167. The output of the switch circuit 164 is supplied to the I / O port 166.

The data sent via the I / O port 166 is supplied to the switch circuit 168. On / off of the switch circuit 168 is controlled by the controller 167. The output of the switch circuit 168 is supplied to the decryption circuit 174. The output of the decryption circuit 174 is supplied to the terminal 165B of the switch circuit 165. Also,
The command is transferred to the controller 167 via the I / O port 166. Key information is provided to the controller 167 from the key generation unit 169.

The switch circuit 165 is switched between displaying the received signal on the television receiver and displaying the transmitted data on the television receiver. When the received signal is displayed on the television receiver, the switch circuit 165 is set on the terminal 165A side. When an image based on the data sent via the bus is displayed on the television receiver, the switch circuit 165 is set on the terminal 165B side.

The output of the switch circuit 165 is supplied to the MPEG decoding circuit 170. MPEG decoding circuit 1
At 70, the video signal is decoded. The output of the MPEG decoding circuit 170 is supplied to the D / A converter 171. The output of the D / A converter 171 is the output terminal 172.
Is output from. The output of the output terminal 172 is supplied to the video input terminal of the television receiver.

This digital video box is used when a received signal is decoded and displayed on a television receiver. Furthermore, this digital video box is used when sending received data to other devices via the bus, and it also receives and decodes data from other devices sent via the bus to receive a television image. Used when supplying to the machine.

When data from the digital video box is transferred to another AV device via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. A key for decryption is handed to the device for which the transfer is permitted. Then, the switch circuit 64 is turned on, the data from the descrambler 63 is encrypted by the encryption circuit 173, and transferred via the bus. If the transfer is not permitted, the switch 64 is turned off. As a result, it is possible to reject the transfer of the data of the device for which the transfer is not permitted.

When the digital video box receives data from another AV device via the bus, the switch circuit 165 is set on the terminal 165B side. Then, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. A key for decryption is received for the data from the device permitted to be transferred. If the transfer is permitted, the switch circuit 16
8 is turned on and data is input. This data is encrypted, but the key for decryption is sent, so the encryption can be decrypted. If the transfer is not permitted, the switch 68 is turned off. As a result, it is possible to reject the transfer of data from a device for which transfer is not permitted.

C4. Examples of devices that record / reproduce data In a device that records / reproduces data, a switch circuit whose on / off is controlled by a controller is provided on the output side of digital data, and an input side of digital data is provided on the output side. A switch circuit whose on / off is controlled by the controller is provided. Then, a card key is attached to identify whether the device is permitted to transfer.

When data is transferred to each device via the bus at the time of reproduction, first, a command is exchanged with each device in advance and it is determined whether or not the transfer is permitted. If the transfer is allowed, the key for decryption is passed. Then, the switch on the output side is turned on, and the data is encrypted and sent. For devices that are not allowed to transfer, the output switch is turned off, and data transfer is rejected. Further, when receiving data from each device via the bus at the time of recording, a command is exchanged with each device in advance and it is determined whether or not the transfer is permitted. If the transfer is allowed,
A key for decryption is sent. When the transfer is permitted, the switch on the input side is turned on, and the encrypted data is input. This data is encrypted, but the key for decryption has been sent in advance, so the encryption can be decrypted. For devices for which transfer is not permitted, the input switch is turned off and data transfer is rejected.

FIG. 18 shows an example of such a device.
A digital VTR is shown. In FIG. 18, when recording the data transferred via the bus,
The data transferred via the I / O port 181 is supplied to the switch circuit 182. The output of the switch circuit 182 is supplied to the decryption circuit 188. The decryption circuit 188 is provided with a key for decryption from the controller 185. The output of the decryption circuit 188 is supplied to the recording / reproducing circuit 183. This data is recorded by the recording / reproducing circuit 183. At the time of reproduction, the data reproduced from the recording / reproducing circuit 183 is supplied to the encryption circuit 189. The output of the encryption circuit 189 is the switch circuit 1
84. The output of the switch circuit 184 is I / O
It is supplied to the port 181. In addition, I / O port 181
The command is transferred to the controller 185 via the. A card key 186 is detachably attached to the card attachment terminal 187. Key information is given to the controller 185 from the card key 186.

When data is recorded on the digital VTR from another AV device sent via the bus, first, commands are exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. If the transfer is permitted, a key for decryption is sent. When the transfer is permitted, the switch circuit 82 is turned on and the data is input. This data is encrypted, but if the transfer is allowed, the key can be sent to decrypt the encryption so that it can be decrypted.
If the transfer is not permitted, the switch 82 is turned off. As a result, the data can be recorded only when the transfer is permitted, and the data can be rejected when the transfer is not permitted.

When the reproduction data from the digital VTR is transferred to another AV device via the bus, first, a command is exchanged via the bus. This command uses the key information to specify the device for which transfer is permitted. For devices that are allowed to transfer,
The key for decryption is passed. Then, the switch circuit 84 is turned on, and the reproduced data from the recording / reproducing circuit 83 is encrypted and transferred via the bus. If the transfer is not permitted, the switch 84 is turned off.
As a result, the data transfer can be rejected to the device for which the transfer is not permitted.

C5. System Example The following describes how data is protected by using each device configured as described above. FIG. 19
Is a system that includes the digital decoder box 201, digital VTRs 202 and 203, and a television receiver 204, as shown in FIG. 1, using the AV equipment configured as described above. The digital decoder box 201 is constructed as shown in FIG. 17, and the digital VTRs 202 and 203 are constructed as shown in FIG. The digital decoder box 201 and the digital VTRs 202 and 203 are commonly connected to the bus 205.

Commands and data are transferred onto the bus 205. The command is transferred by designating a destination so that predetermined processing can be performed for each video device.
The data is transmitted without specifying the destination.

When data is transferred between the AV devices, a process as shown in FIG. 20 is performed. That is, first, a command for determining whether or not the transfer is permitted is transmitted (step S21). Upon receiving the command, each device processes the command according to the key information of each device (step S22), and returns the data subjected to the predetermined process as an acknowledgement. It is determined whether or not an acknowledge is received (step S23).
When the acknowledge is received, the acknowledge, which is the data processed based on the key information for each device, is compared with the data processed based on the key information based on the device that issued the command (step S24). If the key information of each other is correct, both will match. If the key information of each other is incorrect, the two do not match. It is determined whether the two match (step S25),
If they match, the transmission / reception of the encrypted data to be transferred to the AV device is permitted (step S26), and if they do not match, the data transfer to the AV device is rejected (step S27).

For example, in FIG. 19, the digital VTR 2
No card key is attached to 02, and digital V
It is assumed that the card key 186B is attached only to TR203. Then, the digital decoder box 201
And data transfer between the digital VTRs 202 and 203.

When a recording command is sent from the digital decoder box 201 side to the digital VTRs 202 and 203 side to transfer the data from the digital decoder box 201 to the digital VTRs 202 and 203 for recording, the processing as shown in FIGS. 21A and 21B is performed. Is done.

As shown in FIG. 21A, a recording command is given to the digital VTR 202 from the digital decoder box 201 side. When the recording command is transferred to the digital VTR 202, the digital VTR 202 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 201. Since no card key is attached to the digital VTR 202, the acknowledge returned from the digital VTR 202 to the digital decoder box 201 is not predetermined data. Therefore, after that, the data transfer is rejected.

As shown in FIG. 21B, a recording command is given from the digital decoder box 201 side to the digital VTR 203. When the command is transferred to the digital VTR 203, the digital VTR 203 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 201. Since the card key 186B is attached to the digital VTR 203, the acknowledge returned from the digital VTR 203 to the digital decoder box 201 becomes predetermined data. From this, it can be seen that the digital decoder box 201 is a device to which the digital VTR 203 is permitted to transfer. The digital decoder box 201 sends a key for decryption to the digital VTR 203 when it knows that the digital VTR 203 is a device permitted to transfer. Then, the digital decoder box 201 encrypts the data and transmits it. The encrypted data sent from the digital decoder box 201 is supplied to the digital VTR 203. This data is encrypted, but already
The key can be decrypted because the key for decryption is sent to the digital VTR 203. Digital VTR
The encryption of the data sent by the encryption decryption circuit 189B of 203 is decrypted, and this data is recorded in the digital VTR 203.

When a reproduction command is sent from the digital decoder box 201 side to the digital VTRs 202 and 203 side and the reproduction data from the digital VTRs 202 and 203 is transferred to the digital decoder box 201, the processing shown in FIGS. 22A and 22B is performed. Be seen.

As shown in FIG. 22A, a reproduction command is given to the digital VTR 202 from the digital decoder box 201 side. When the reproduction command is transferred to the digital VTR 202, the digital VTR 202 forms an acknowledge based on the key information, and returns this acknowledge to the digital decoder box 201. Since no card key is attached to the digital VTR 202, the acknowledge returned from the digital VTR 202 to the digital decoder box 201 is not predetermined data. Therefore, after that, the data transfer is rejected.

As shown in FIG. 22B, a reproduction command is given from the digital decoder box 201 side to the digital VTR 203. When the reproduction command is transferred to the digital VTR 203, the digital VTR 203 forms an acknowledge based on the key information and returns this acknowledge to the digital decoder box 201. Since the card key is attached to the digital VTR 203, the acknowledge returned from the digital VTR 203 to the digital decoder box 201 becomes predetermined data. As a result, the digital VTR 203
It can be seen that the digital decoder box 201 is a device whose transfer is permitted. Digital VTR 203
When the digital decoder box 201 finds that the transfer is permitted, it passes the key for decryption to the digital decoder box 201. Then, the reproduced data from the digital VTR 203 is encrypted and transferred to the digital decoder box 201. Although this data has been encrypted, since the key for decrypting the encryption has already been sent, the encryption can be decrypted by the digital decoder box 201.

When a data transmission command is sent from the digital VTRs 202 and 203 side to the digital decoder box 201 side to transfer the data from the digital decoder box 201 to the digital VTRs 202 and 203 for recording, as shown in FIGS. 23A and 23B. Processing is performed.

As shown in FIG. 23A, a digital VTR
From the 202 side to the digital decoder box 201 side,
A data transmission command is given. When the data transmission command is transferred to the digital decoder box 201,
The digital decoder box 201 forms an acknowledgment based on the key information and returns it to the digital VTR 202. Since a card key is not attached to the digital VTR 202, the acknowledge returned from the digital VTR 202 to the digital decoder box 201 is
It does not match the predetermined data on the digital VTR 202 side. Therefore, after that, the transfer of data to the digital VTR 202 is rejected.

As shown in FIG. 23B, the digital VTR
From the 203 side to the digital decoder box 201 side,
A data transmission command is given. When the data transmission command is transferred to the digital decoder box 201,
The digital decoder box 201 forms an acknowledge based on the key information, and the digital VTR 203
Return to. The digital VTR 203 has a card key 18
Since 6B is mounted, the acknowledge returned from the digital VTR 203 to the digital decoder box 201 matches the predetermined data on the digital VTR 203 side. This allows the digital decoder box 2
It can be seen that 01 is a device for which the digital VTR 203 is permitted. Digital decoder box 20
If it is found that the digital VTR 203 is a permitted device, the digital decoder box 20
1 passes the key for decryption to the digital VTR 203. Then, the encrypted data is transmitted from the digital decoder box 201. Although this data is encrypted, key information for decryption is sent to the digital VTR 103. Therefore, the digital VTR 103 can decrypt the encrypted data. This data is decrypted and recorded by the digital VTR 103.

When the data reception command is sent from the digital VTRs 202 and 203 side to the digital decoder box 201 side to transfer the data from the digital VTRs 202 and 203 to the digital decode box 201, the processing shown in FIGS. 24A and 24B is performed. Be seen.

As shown in FIG. 24A, the digital VTR
From the 202 side to the digital decoder box 201 side,
A data reception command is given. When the data reception command is transferred to the digital decoder box 201,
The digital decoder box 201 forms an acknowledge based on the key information, and the digital VTR 202
Return to. Since no card key is attached to the digital VTR 202, the acknowledge returned from the digital VTR 202 to the digital decoder box 201 does not match the predetermined data on the digital VTR 202 side. Therefore, thereafter, the transfer of data from the digital VTR 203 is rejected.

As shown in FIG. 24B, the digital VTR
From the 203 side to the digital decoder box 201 side,
A data reception command is given. When the data reception command is transferred to the digital decoder box 201,
The digital decoder box 201 forms an acknowledge based on the key information, and the digital VTR 203
Return to. The digital VTR 203 has a card key 18
Since 6B is mounted, the acknowledge returned from the digital VTR 203 to the digital decoder box 201 matches the predetermined data on the digital VTR 203 side. From this, it can be seen that the digital VTR 203 is a device whose transfer is permitted by the digital decoder box 201. Digital VTR 203
Sends a key for decryption to the digital decoder box 201 when it knows that the digital decoder box 201 is a device permitted to transfer. Then, the encrypted data is sent from the digital VTR 203. Although this data is encrypted, a key for decryption is sent to the digital decoder box 201. Therefore, the encrypted data from the digital VTR 203 is transferred to the digital decoder box 201, and the digital decoder box 101
Be deciphered by.

As described above, in the second embodiment of the present invention, before transferring data between the devices, commands are exchanged based on the key information, and it is judged whether the transfer is permitted. It Then, a key for decryption is sent to a device permitted to transfer, and then data is encrypted and transferred. In this way, the data transmitted via the bus is encrypted, so that the data can be further protected.

[0104]

According to the present invention, it is possible to perform control such that the other party is specified and the data is transferred only to this particular other party, or only the particular other party is allowed to receive the data. Therefore, for example, a plurality of digital VTs may
When R is connected, control can be performed so that data can be recorded only by a specific digital VTR for which recording is permitted,
Ensures data protection.

[Brief description of drawings]

FIG. 1 is a perspective view used for explaining an example of a video system to which the present invention can be applied.

FIG. 2 is a perspective view used for explaining another example of a video system to which the present invention can be applied.

FIG. 3 is a block diagram used for describing the first embodiment of the present invention.

FIG. 4 is a block diagram used for describing the first embodiment of the present invention.

FIG. 5 is a block diagram used for explaining the first embodiment of the present invention.

FIG. 6 is a block diagram used for explaining the first embodiment of the present invention.

FIG. 7 is a block diagram used for explaining the first embodiment of the present invention.

FIG. 8 is a block diagram used for describing the first embodiment of the present invention.

FIG. 9 is a flowchart used to describe the first embodiment of the present invention.

FIG. 10 is a sequence chart showing a transfer procedure according to the first embodiment of this invention.

FIG. 11 is a sequence chart showing a transfer procedure according to the first embodiment of this invention.

FIG. 12 is a sequence chart showing a transfer procedure according to the first embodiment of this invention.

FIG. 13 is a sequence chart showing a transfer procedure according to the first embodiment of this invention.

FIG. 14 is a block diagram used for explaining a second embodiment of the present invention.

FIG. 15 is a block diagram used for explaining a second embodiment of the present invention.

FIG. 16 is a block diagram used to describe a second embodiment of the present invention.

FIG. 17 is a block diagram used for explaining a second embodiment of the present invention.

FIG. 18 is a block diagram used for explaining a second embodiment of the present invention.

FIG. 19 is a block diagram used to describe a second embodiment of the present invention.

FIG. 20 is a flowchart used for explaining the second embodiment of the present invention.

FIG. 21 is a sequence chart showing a transfer procedure according to the second embodiment of this invention.

FIG. 22 is a sequence chart showing a transfer procedure according to the second embodiment of this invention.

FIG. 23 is a sequence chart showing a transfer procedure according to the first embodiment of this invention.

FIG. 24 is a sequence chart showing a transfer procedure according to the second embodiment of this invention.

[Explanation of symbols]

1, 101, 201 Digital decoder box 2, 3, 102, 103, 202, 203 Digital VTR 5, 105, 205 Bus

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-132916 (JP, A) JP-A-1-246979 (JP, A) JP-A-4-180451 (JP, A) JP-A-7- 162832 (JP, A) JP 2000-217072 (JP, A) JP 6-261318 (JP, A) JP 58-85685 (JP, A) JP 64-16143 (JP, A) Table 5-501942 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 5/765 H04N 7/16

Claims (6)

(57) [Claims] 1. Pairing with other MPEG compressed signals via a bus
Records the MPEG compressed signal supplied from a device to respond, the MPEG compressed signal reproduced by a data storage apparatus for transmitting over the bus to the device corresponding to the other MPEG compressed signal, the other MPEG compression M between the device corresponding to the signal
Authenticate whether transfer of PEG compressed signal is allowed
Authenticating means that performs whether or not predetermined data is returned, and if the result of the above authentication indicates that the transfer of the MPEG compressed signal is permitted, the encrypted MPEG that is supplied via the bus. receiving means for starting a reception of the compressed signal, and descrambling means for releasing the cipher of the received MPEG compressed signal, and recording means for recording an MPEG compressed signal encryption is released by the descrambling means on a recording medium A data storage device comprising: 2. The deciphering means is the other MPEG
2. The data storage device according to claim 1, wherein the encryption of the transferred MPEG compressed signal is decrypted by using the encryption key information supplied from the device corresponding to the compressed signal via the bus. 3. A reproducing means for reproducing the MPEG compressed signal recorded on the recording medium, and a cryptographic means for encrypting MPEG compressed signal reproduced by said reproducing means, the result of the authentication, MPEG compressed signal If it is determined that the transfer is permitted, the encrypted MPEG compressed signal output from the above-mentioned encryption means is made compatible with other MPEG compressed signals.
2. The data storage device according to claim 1, wherein the data storage device transmits the data to a device that operates via the bus. 4. The encryption key information for releasing the encryption applied by the encryption means is transmitted to a device corresponding to the other MPEG compressed signal via the bus. Item 4. The data storage device according to item 3. With 5. Play MPEG compressed signal recorded on the recording medium, the MPEG compressed signal reproduced by a data storage device for transmitting to the device corresponding to another MPEG compressed signal via the bus, the Between the reproducing means for reproducing the MPEG compressed signal recorded on the recording medium, the encrypting means for encrypting the MPEG compressed signal reproduced by the reproducing means, and the device corresponding to the other MPEG compressed signal , M
Authenticate whether transfer of PEG compressed signal is allowed
An authenticating means that determines whether or not to send back predetermined data, and if the result of the above authentication indicates that the transfer of the MPEG compressed signal is permitted, the other predetermined data that has been authenticated is transmitted.
A data reproducing apparatus, wherein transfer of the encrypted MPEG compressed signal to the device via the bus is started depending on whether or not a data is returned . 6. The encryption key information for releasing the encryption applied by the encryption means is transmitted to a device corresponding to the other MPEG compressed signal via the bus. The described data reproducing device.