JPH11306092A - Data processor and copy protect system applied to the processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide protection of digital contents flowing on a bus of a computer system and limit of the digital contents for each function module. SOLUTION: With regard to a CPU module 111, a tuner 113 for a satellite or digital TV, an MPEG 2 decoder 115, and a DVD-RAM drive 116, an interface part with a PCI bus 100 is provided with authentication processing parts (authenticators) 1111, 1131, 1151 and 1161 for performing equipment authentication, key exchange and the like. In this way, providing each function module with a authentication function for enciphering processing, it becomes possible to efficiently realize protection of digital contents flowing on the PCI bus 200 connecting between the function modules, and limit of the digital contents for each function module.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing apparatus such as a personal computer and a method for copy-protecting digital contents used in the apparatus, and more particularly to a data processing apparatus having an interface with an external bus such as an IEEE 1394 serial bus. The present invention relates to a copy protection method applied to an apparatus.

[0002]

2. Description of the Related Art In recent years, with the development of computer technology,
Digital video player, set-top box, T
Various types of multimedia-compatible electronic devices such as personal computers and personal computers have been developed.

An electronic device of this type is, for example, a DVD (Di
The digital content such as a movie and a digital satellite broadcast TV program stored in a digital versatile disk can be reproduced.

[0004] Digital contents are generally encoded using a moving picture high-efficiency encoding method called MPEG2.
It is sent to each home through a recording medium or a transmission medium. MP
The encoding by EG2 is based on the idea of variable rate encoding from the viewpoint of securing both the image quality and the recording time for the capacity. The data amount of the variable rate encoded data is
Depending on the image quality of the original image, the data amount increases as the scene moves more rapidly. Therefore, digital content
It is possible to provide each home with a high-quality image comparable to the original image.

[0005] In recent years, from the viewpoint of copyright protection of digital contents, the necessity of copy protection technology for preventing unauthorized copying has been called out, but an effective method has not been established. It is the current situation.

Therefore, CPTWG (Copy Prot)
action TechnicalWorking G
loop), IEEE 1394, a next-generation bus interface suitable for multimedia data transmission
The work of formulating a new copy protection method specification (hereinafter, referred to as IEEE 1394 copy protection technology) for a serial bus is in progress.

The IEEE 1394 serial bus is a next-generation bus interface for connecting digital video players, set-top boxes, TVs, personal computers, etc., and has two transfer modes, asynchronous sub-action and isochronous sub-action.
Supports types. The former is called an asynchronous transfer mode and is used when transferring general data that does not require real-time properties. The latter is a synchronous transfer mode in which a transfer band is guaranteed, and enables real-time transfer of digital contents represented by video data and audio data.

[0008] The IEEE 1394 copy protection technique uses a well-known encryption protocol such as a public key encryption scheme or a common key encryption scheme, and thereby uses the IEEE 1394 copy protection technique.
Digital contents exchanged between devices such as a digital video player, a set-top box, a TV, and a personal computer via a 1394 serial bus are encrypted so that unauthorized copying thereof can be prevented.

[0009]

However, since personal computers are originally open systems,
Encrypting the data flowing on the IEEE 1394 serial bus alone cannot provide sufficient protection against unauthorized copying. Hereinafter, this will be described specifically.

FIG. 15 shows an example of a configuration in which the IEEE 1394 copy protection technique is applied to a personal computer as it is. In FIG. 15, a personal computer (PC) 1 and a set-top box (ST
B) 2 and 3 of digital video camera (DVC) 3
1 shows a state in which two devices are connected via an IEEE 1394 serial bus 10.

[0011] These personal computers (PCs)
1, a set top box (STB) 2 and a digital video camera (DVC) 3
An encryption unit (Cipher) and a decryption unit (De-Ciphe)
r) or encryption / decryption with both encryption / decryption functions
It has a decoding unit (De- / Cipher).

That is, the digital video camera (DVC) 3 for transmitting digital contents to another device via the IEEE 1394 serial bus 10 is provided with an encryption unit (Cipher), and another digital video camera (DVC) 3 is provided via the IEEE 1394 serial bus 10. Personal computer (PC) 1 for transmitting and receiving digital contents to and from devices
The set / top box (STB) 2 is provided with an encryption / decryption unit (De- / Cipher).

[0013] Digital contents that require copy protection are encrypted by the device on the transmitting side and then transmitted to the IE.
The data is output onto the EE1394 serial bus 10, and the encrypted data is decrypted by the receiving device and decrypted. Thus, the IEEE 1394 serial bus 10
By encrypting the data flowing over it, IEEE1
Even if data flowing on the 394 serial bus 10 is illegally copied, it can be prevented from being reproduced normally.

In the personal computer (PC) 1, the encryption / decryption unit (De- / Cipher) includes:
As shown, a system bus such as a PCI bus 20 and an I
It is provided in a 1394 bridge 6 for bidirectional connection with the IEEE 1394 serial bus 10. This allows P
Since encrypted data does not flow on the CI bus 20 but only plaintext data flows as usual, an open bus architecture can be maintained.

[0015] From a digital video camera (DVC) 3 or a set-top box (STB) 2 to an IEEE 139
The encrypted data transmitted to the personal computer (PC) 1 via the 4 serial bus 10 is decrypted into plain text by the 1394 bridge 6 and then sent to the CPU 4 and the MPEG decoder 5 on the PCI bus 20. Similarly,
When transmitting digital video content from the CPU 4 or the MPEG decoder 5 to the set-top box (STB) 2, the plain text on the PCI bus 20 is encrypted by the 1394 bridge 6 and then sent out onto the IEEE 1394 serial bus 10.

As described above, if the encryption / decryption function is provided in the 1394 bridge 6, the open architecture of the PCI bus 20 can be maintained as it is.
The I-bus 20 stores the decrypted data (Plain
Content flows, and copying becomes easy.

In the personal computer shown in FIG. 15 in which the 1394 bridge 6 is provided with an encryption / decryption function, the type of content that can be handled by each functional module constituting the personal computer (only once) It is difficult to perform control such as limiting copying permitted, copying prohibited, and copying free.
For example, an MPEG2 decoder needs to be able to handle all types of content (copy once, copy impossible, copy free), whereas DVD-
It is necessary that a storage device such as a RAM or an HDD can handle only copy-enabled content and copy-free content only once. But,
When Plain Contents flows into the PCI bus 20, it is practically difficult to limit the content that can be handled by each functional module. This is because such content restriction is usually performed by authentication processing between devices. That is, when an encryption / decryption function is provided in the 1394 bridge 6, the personal computer is also treated as one device on the IEEE 1394 serial bus. For this reason, it is possible to limit the types of content that can be handled by the personal computer by performing authentication processing between the personal computer and another device on the IEEE 1394 serial bus. Types cannot be restricted.

In DVD video and the like, digital content is often realized as a stream including a plurality of different types of content. In this case, the type of the content to be reproduced is dynamically switched. However, if the authentication is performed again each time the type of content is switched, there is a problem that the content cannot be processed in real time.

The present invention has been made in view of the above-mentioned circumstances, and has been made in consideration of the protection of digital content flowing on a bus in a data processing device such as a personal computer, and the protection of digital content in units of functional modules constituting the data processing device. It is an object of the present invention to provide a data processing device capable of efficiently performing digital content copy protection and a copy protection method applied to the data processing device.

[0020]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an interface with an external bus to which an external device having an authentication function for encrypting and exchanging copy-protected data can be connected. A data processing device having an internal bus, a plurality of functional modules respectively coupled to the internal bus, for transmitting or receiving copy-protected data via the internal bus, and provided for each of the functional modules; An authentication unit for performing an authentication process for encrypting and exchanging the copy-protected data between the functional module or the external device that transmits and receives the data to be protected, and the data processing apparatus; The authentication process is performed for each of the functional modules.

In this data processing apparatus, an authentication means is provided in an interface section of each of a plurality of functional modules for handling copy-protected data such as digital contents, and is provided between functional modules or between a functional module and an external device. Authentication processing is performed individually. Therefore, on the internal bus to which these function modules are connected, the key for decryption and the digital contents are transferred while being encrypted,
It is possible to prevent illegal copying of digital contents. In addition, since authentication processing is performed for each functional module, it is possible to efficiently limit the types of digital content that can be handled by each functional module (copy once, copy impossible, copy free). Becomes

Further, external bus interface means for transparently connecting between an external bus connectable to an external device having an encryption / decryption function for copy-protected data and a bus in the data processing apparatus are further provided. The provision makes it possible to use the same authentication and encryption protocol both between the function modules and between the external device and the function module. That is, when viewed from each functional module or application program in the data processing device,
The function modules in the data processing device and the external devices can be handled in the same manner without distinction.

The types of data to be copy-protected include data that can be copied only once and data that cannot be copied. Each of the functional modules includes a type of data that can be processed by the functional module. Identification information for defining is assigned, and the authentication unit determines that the transmission destination functional module performs the transmission based on the type of data to be transmitted and the identification information (system ID) of the transmission destination functional module. It is preferable to determine whether or not the module is a functional module that can handle target data.

The use of the system ID makes it possible to easily manage the types of digital contents that can be handled in units of functional modules. Further, it is preferable to change the decryption key necessary for decrypting the encrypted data for each type of data to be transmitted (copying is allowed only once and copying is not allowed). Thereby, for example, by notifying only each key corresponding to the content that can be handled to each functional module at the time of authentication processing, even if the encrypted content is broadcast-transferred to a plurality of functional modules, the content can be handled. It is possible to limit the decoding so that only the functional module can perform the decoding.

When transmitting a stream composed of a plurality of different types of data, the authentication means includes:
Performs authentication processing for the number of types of content that can be handled by the destination functional module, and performs decryption corresponding to the number of types of data that can be processed by the destination functional module among the types of data constituting the stream. Preferably, a key is notified to the destination functional module. In this way, by previously passing the decryption key for each type of content to the function module on the receiving side, it is possible to decrypt in real time even if the type of content is dynamically changed. In this case, data type information indicating the type of data is embedded in the stream, and the decryption unit may dynamically change the decryption key used for the decryption processing based on the data type information. .

According to the present invention, there is provided a data processing apparatus for transmitting data to a receiving apparatus so as to prevent illegal copying of digital content flowing on an internal bus. An authentication unit for authenticating whether or not data processing is permitted; and, if authenticated by the authentication unit, what kind of digital content is to be subjected to copy protection to which the receiving device is permitted to process. And a key for transmitting, to the receiving device, an decryption key corresponding to each type of digital content to which the receiving device is permitted to process based on the determination result of the determining device. Transmitting means, and a transmitting means for transmitting digital content which can be decrypted by the receiving device using the decryption key. Characterized by comprising and.

In this data processing device, it is authenticated whether or not processing of data to be copy protected is permitted with the receiving device. If the data processing device is authenticated, the receiving device is permitted to perform processing. It is determined what kind of digital content the copy-protected data is, and based on the result of the determination, the receiving apparatus performs encryption corresponding to the type of digital content for which processing is permitted. Only the release key is transmitted to the receiving device. Then, digital content that can be decrypted by the receiving device using the decryption key is transmitted to the receiving device.

According to the present invention, there is provided a data processing apparatus for receiving and processing data transmitted from a transmitting apparatus so as to prevent unauthorized copying of digital contents flowing on an internal bus. An authentication unit that authenticates whether processing of the data to be protected is permitted; and, if authenticated by the authentication unit, indicates a type of copy-protected digital content to which the data processing device is permitted to perform processing. A type information transmitting unit that transmits information to the transmitting device; an encryption decryption key corresponding to each type of copy-protected digital content to which the data processing device is permitted to perform processing based on the type information; Digital content that can be decrypted by the data processing device using a decryption key, Receiving from the serial transmission apparatus, characterized by comprising a decoding means for decoding the digital content.

In this data processing apparatus, it is authenticated whether or not processing of data to be copy protected is permitted with the transmitting apparatus. If the processing is authenticated, the copy processing which is permitted to receive data is performed. Information indicating the type of digital content to be protected is transmitted to the transmitting device. Then, based on the type information, a decryption key corresponding to each type of digital content for which the receiving process is permitted is received from the transmitting device, and then the receiving device uses the decryption key to encrypt the digital content. Digital content that can be released is received from the transmitting device. Then, the digital content is decrypted using the decryption key.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system configuration of a personal computer (hereinafter, referred to as a PC) according to an embodiment of the present invention. This PC11 is IEEE
Communication with external consumer electronics, such as a set-top box (STB) 12, a digital video camera or DV camcorder (DVC) 13, and a digital video cassette recorder (D-VCR) 14, as shown, via a 1394 serial bus 200 It is configured to be possible.

The set-top box (STB) 12, digital video camera (DVC) 13, and digital video cassette recorder (D-VCR) 14 interface with the IEEE 1394 serial bus 200 to support IEEE 1394 copy protection technology. An authentication processing unit (Authenticator) 12 for performing device authentication, key exchange, etc.
1, 131, 141. Set-top box (STB) 12 and digital video cassette recorder (D-VCR) 1 for transmitting and receiving digital contents
For No. 4, encryption / decryption units (De- / Cipher) 122 and 142 having both encryption and decryption functions are provided. The digital video camera (DVC) 13 that only transmits digital contents is provided with only an encryption unit (Cipher) 132.

PC 11, set-top box (ST
B) 12, a digital video camera (DVC) 13, and a digital video cassette recorder (D-VCR) 14
Digital contents exchanged between them are transferred on the IEEE 1394 serial bus 200 in an encrypted state.

The PC 11 is connected to the PCI bus 1 as shown in FIG.
00 and a plurality of functional modules connected thereto. Among these functional modules, functional modules for handling digital contents, that is, a CPU module 111, a tuner 113 for satellite or digital TV, an MPEG2 decoder 115, a DVD-R
As for the AM drive 116, an authentication processing unit (Authenticator) 111 for performing device authentication and key exchange is provided in an interface unit with the PCI bus 100.
1, 1131, 1151, 1161 are provided.
Each of these authentication processing units (Authenticator) 1
Basically, the functions of 111, 1131, 1151, and 1161 are basically the same as the set-top box (STB) 12 and the digital video camera (DVC) 1 which are 1394 devices.
3, and a digital video cassette recorder (D-VC
R) It is the same as that of 14, and performs authentication and key exchange necessary for encrypting and transmitting digital contents.

The CPU module 111, the tuner 113, and the interface section of the MPEG2 decoder 115 are further provided with an encrypted content (en
A decryption unit (De-ciphe) that performs decryption processing for decrypting encrypted content (Decrypted content).
r) or an encryption unit (Cipher). Whether to have an encryption unit, a decryption unit, or both depends on the function of each functional module. Here, for the tuner 113, the encryption unit (C
ipher) 1132 is provided, and the CPU module 1
11 and the MPEG2 decoder 115 are provided with decoding units (De-cipher) 1112 and 1152.

The CPU module 111 includes a microprocessor, a memory controller, a PCI bus bridge, and the like. The authentication unit 1111 and the decryption unit 1112 can be incorporated as a part of the PCI bus bridge, for example. Also, the CPU module 111
Authentication unit 1111, decryption unit 1112, MPEG2
The decoder unit 1113 may be realized by software.

The DVD-RAM drive 116 is a PC 11
And is connected to the PCI bus 100 via an IDE interface or an ATAPI interface or the like. DVD-RAM
The drive 116 has only an authentication processing unit 1161, and includes a decryption unit (De-cipher) and an encryption unit (Ciphe).
r) is not provided. DVD-RAM1 with the encrypted digital contents encrypted
16 for recording.

The PC 11 further includes a PCI bus 100
And a IEEE1394 serial bus 200 are provided with a 1394 bridge 117 for bidirectional connection. 13
The 94 bridge 117 is not provided with any of an authentication processing unit, an encryption unit, and a decryption unit, and the encrypted digital content is kept in the PCI bus 100 in an encrypted state.
From the IEEE 1394 serial bus 200 to the IEEE 1394 serial bus
EE1394 serial bus 200 to PCI bus 100
Is forwarded to Thus, the 1394 bridge 117
Connects transparently between the function module in the PC 11 and the 1394 device.

Here, the IEEE 1394 serial bus 2
A description will be given of a processing procedure when digital content transferred from the DVC 13 above is decoded by the CPU module 111 by software.

First, the DVC 13 and the CPU module 11
1 and performs device authentication with each other to confirm that they are valid devices having a copy protection function. This device authentication uses a well-known method such as a random challenge and response method, a method using a one-way function, a method using a time-varying key that changes every time using random numbers, or a combination of these methods. Can be realized.

The system ID is used to authenticate whether or not the communication partner device can handle what kind of content. This system I
D is embedded in the circuit or firmware of each functional module in the 1394 device and the PC 11, so that it can be copied only once, cannot be copied,
It is determined whether the device can handle all types of copy-free digital contents, or can only copy once or handle only copy-free digital contents.

In this authentication process, the CPU module 11
1 exchanges a key with the DVC 13 to generate a key for decrypting the encrypted content. Since the authentication unit is located in the CPU module 111, the key itself or the information for generating the key is stored in the encrypted state.
DVC via the 94 bus 200 and the PCI bus 100
13 to the CPU module 111.

The DVC 13 encrypts the digital content and sends it to the CPU module 111. The encrypted content remains encrypted and remains on the 1394 bus 200.
And the CPU module 11 via the PCI bus 100
1 and the decoding unit (De-c
The ipher) 1112 decrypts the content using the key obtained by the authentication. When the authentication unit and the decryption unit of the CPU module 111 are realized by software, it is needless to say that the software must not be falsified or an algorithm must not be understood.

The decrypted contents are stored in a software MPEG2 decoder (De
coder 1113), and then directly connects the main memory 112 and the VGA controller 114 to the AG.
P (Accelerated Graphics Por)
The data is sent to the VGA controller 114 via t) and reproduced.

As described above, the authentication processing unit and the encryption or decryption unit are provided in the interface unit of each of the plurality of function modules that handle digital contents, and copy protection is performed between the function modules or between the function module and the 1394 device. When the digital contents of the IEEE 1394 bus are transferred, the authentication processing and the encryption / decryption processing of the digital contents are performed between the devices, so that the IEEE 1394 bus 200 and the PCI bus 10
In either case, the key for decryption and the digital content are transferred while being encrypted, so that unauthorized copying of the digital content can be prevented.

Since the authentication process can be performed for each functional module in the PC 11, the types of digital contents (copy once, copy impossible, copy free) that can be handled in function module units can be efficiently performed. It is possible to restrict well.

FIG. 2 shows the relationship between software and hardware in the system shown in FIG. In FIG. 2, software is above the dashed line and hardware is below. Blocks with thick frames, which are hierarchically arranged in the vertical direction, are hardware modules such as functional modules in the PC 11 or 1394 devices.

The Authenticator handler is:
In response to a request from an application program such as digital content reproduction software, control for authentication processing and key exchange with necessary hardware devices is performed. As described above, the 1394 bridge 117 is a PC
Since each functional module in the PC 11 is transparently connected to the 1394 device, one functional module in the PC 11 is connected to the 1394 device.
By implementing the same authentication and encryption / decryption protocols as the 394 device, as shown by the dotted line, the application program can equalize each functional module in the PC 11 and the 1394 device without distinguishing them. Can be handled.

FIG. 3 shows an example of an authentication process and a key exchange procedure used in the present embodiment. The device that sends the content is the source device
ce, the receiving device is Sink Device
It is.

The sink device firstly uses a random challenge key (N
a) and passes the random challenge key (Na) along with the authentication request to the Source Device.
Then, the sink device creates Ar from Na using the determined function.

Source Device is a random challenge key (Nb) that changes every time using a random number.
And generate it as a response to the authentication request.
Return to kDevice. And Source Dev
ice creates Br from Nb using the determined function.

Thereafter, the Source Device is:
Send the message (Bv) to Sink Device.
This message (Bv) is created from the public key and Na and Br.

The sink device sends a message (Av) to the source device. The message (Av) is created from the public key and Nb and Ar.

The source device checks whether the Av is correct, and if it is correct, determines that the other party is a valid device and generates an authentication key (Ak). Similarly, Sink
Device also checks whether Bv is correct, and if correct, determines that the other party is a valid device and creates an authentication key (Ak).

After that, the Source Device is
Control key (eKx) encrypted with authentication key (Ak)
To Sink Device. Sink Devi
ce decrypts the encrypted control key (eKx) with the authentication key (Ak) to create a control key (Kx).

Note that the procedure of the authentication process in FIG. 3 is merely an example, and if it is possible to verify that each device is a correct device, as described above, the normal random challenge & Response methods and other well-known methods can be used.

Next, a description will be given of a method of restricting the content that can be handled for each device when the type of digital content to be transferred (copy once, copy impossible, copy free) is switched in real time.

A device capable of transmitting copy-impossible and copy-once content only once separately has two types of control keys (a key for decrypting a content decryption key) for copy prohibition and copy-once only. Prepare and change the number of control keys passed to it according to the capabilities of the receiving device. If the receiving device can handle both contents (copying not possible and copying only once), authentication is performed twice and both control keys are obtained in advance. It is natural for the transmitting device to change the key according to the type of content, but by preparing both keys in advance on the receiving side through the authentication process, it is possible to flexibly switch the content type dynamically. Can be handled.

Hereinafter, an example of a specific procedure of the authentication processing will be described with reference to a flowchart of FIG. First, the following processing is performed for each device on the receiving side that is a transmission destination of digital content. First, a system ID is obtained from the receiving device. And the system ID
It is determined whether the receiving-side device can handle the uncopyable content based on the information (step S1).
01). If the receiving device is a device that can handle the uncopyable content, the transmitting device transmits a control key (eKcontrol # 1) for the uncopyable content to the receiving device, and the receiving device disables the copy. The control key for content (eKcontrol # 1) is received (step S102). A control key for uncopyable content is not transmitted to a device that cannot handle uncopyable content.

Next, based on the system ID, it is determined whether or not the receiving device can handle the content that can be copied only once (step S103). If the receiving device can handle the content that can be copied only once, the transmitting device transmits a control key (eKcontrol # 2) for the content that can be copied only once to the receiving device, The receiving device uses its control key (eKcontrol
ol # 2) (step S104). For devices that cannot handle content that can be copied only once, 1
The control key for the copy-only content is not transmitted once.

Each of these control keys (eKcont
The rolls # 1 and # 2) are obtained by encrypting a key for decrypting the encrypted content key as described above, and a time-varying key using a random number or the like can be used. The receiving-side device decrypts the eKcontrols # 1 and # 2 using the random number value transmitted / received in the authentication process or another key prepared in the device in advance, and obtains KK
Controls # 1 and # 2 are obtained.

In this way, a key corresponding to the function of each receiving device is passed to each receiving device. That is,
In the case of a device that can handle both contents that cannot be copied and that can be copied only once, both control keys are passed by authentication twice. In the case of a device that can handle only the content that can be copied only once, only the control key for the content that can be copied only once is passed.

When the authentication process with all the receiving devices is completed (step S105), the encrypted content key (eKcontent) and the encrypted content (Encrypted contents) are transmitted from the transmitting device to all the receiving devices. The broadcast is transmitted to the side device (steps S106 and S107). Encrypted content (Encrypted content)
In the header portion of nts), copy control information (CGMS) indicating one of copy unpossible, copy only once, and copy free is embedded.

Each device on the receiving side uses the copy control information (CGMS) as content identification information for dynamically changing a control key. In other words, each device on the receiving side determines the type of the content currently undergoing reception processing according to the copy control information (CGMS) included in the encrypted content, and determines the control key (Kcont) corresponding to the type of the content.
(roll). Then, by using the selected control key, the encrypted content key (eKcontent) is decrypted, and the encrypted content (Encrypted content) is decrypted.
ts) to decrypt the content key (Kc
Intent) is generated (step S108). For the device on the receiving side that has received the type of content that cannot be handled, the corresponding control key (Kcontro
Since there is no l), the content cannot be decrypted.

As described above, in the present embodiment, when transmitting a stream composed of a plurality of different types of contents, authentication processing is performed for the number of types of contents that can be handled by the receiving device, and Is performed, a decryption key corresponding to the number of types of content that can be processed by the receiving device among the types of content that constitutes is passed to the receiving device.

Here, it is assumed that, as shown in FIG. 5, for example, an encrypted sub-stream A composed of content that can be copied only once and an encrypted sub-stream B composed of content that cannot be copied are transmitted successively. .

As shown in FIG. 6, content identification information indicating the type of content is embedded in each header portion of each of the encrypted substreams A and B as information for instructing a change of a key to be used. ing. As described above, copy control information (CGMS) can be used as the content identification information.

A device (device # 1) that can handle both of an encrypted stream and a content that can be copied only once and a device that can handle only a content that can be copied only once or a content that can be copied only ( When transmitting to device # 2), device #
1, the decryption keys of both the encrypted substreams A and B are passed, and for the device # 2, only the decryption key of the encrypted substream B is passed.

Therefore, as shown in FIG. 7A, when the type of content is switched from the encrypted substream A to the encrypted substream B, the device # 1 responds accordingly. Is dynamically changed, correct decrypted data (plaintext) corresponding to each of the encrypted substreams A and B can be obtained.
On the other hand, as shown in FIG.
Does not have a key for decrypting the encrypted substream B, so that decrypted data (plaintext) corresponding to the encrypted substream A can be obtained. It cannot be decrypted.

Here, a control key according to the function of the device is passed to each receiving device. However, a content key corresponding to the function of the device may be prepared for each receiving device. Since it is essential, various methods can be used as a procedure for that depending on the authentication processing method to be used. The configuration in which the authentication unit and the encryption / decryption unit are provided for each functional module can be applied not only to a PC but also to various microcomputer application devices such as digital content recording / playback players.

Next, a method of recording contents in a storage device in the PC 11 of FIG. 1 will be described with reference to FIG. In general, a storage device used as an auxiliary storage device in a personal computer is not provided with an authentication function, so that it is not possible to record contents that require copy protection. Also, if an authentication function and a decryption function are provided, it is possible to record the contents on a storage device after decrypting the contents. However, in this case, the recorded contents (Plain Contents) are illegally changed. There is a risk of being used. In particular, in the case of a removable storage device using a portable recording medium,
The danger is high.

Therefore, in this embodiment, only an authentication processing unit (Authenticator) is provided in the storage device, the content is recorded on the recording medium while the content is encrypted, and the content key generated by the authentication is accessed by the system. Recording is performed in an area on a recording medium that cannot be used.

Hereinafter, the recording method will be specifically described by exemplifying a case where digital content that can be copied only once and that requires copy protection is received from the STB 12 and recorded on the DVD-RAM medium of the DVD-RAM drive 116. I do.

1. Authentication unit (Authenticator) for each of STB 12 and DVD-RAM drive 116
Authentication between the devices is performed using the devices 121 and 1161, and when the devices are confirmed to be valid devices, the control key (eKcontrol) encrypted and transmitted from the STB 12 is transmitted to the DVD-RAM drive 116. Decrypt the control key (Kco
ntrol).

2. The STB 12 sends the encrypted content key (ekcontent) to the DVD-RAM drive 116 together with the encrypted digital content.

3. The encrypted digital content contains copy control information (CGMS). 4. DVD-RAM drive 116 is Kcontrol
Then, a content key (Kcontent) is generated from eKcontent using CGMS. eKconte
nt is a time-varying key.

5. Encrypted content encrypted with KContent (Encrypted Content)
s) is recorded as is on the media and the corresponding Kc
The content is recorded in a gap area between sectors as shown in FIG. 9, for example. Further, the content of the CGMS is changed from "copy once" to "copy no more" and is similarly recorded in the gap area. This gap area is an area that cannot be accessed from the system.

The control of these procedures is all performed by the CPU module 111. Next, FIG.
0, the encrypted content (EncryptedContent) recorded on the DVD-RAM medium.
The case of reproducing s) will be described.

1. DVD-RAM drive 116 and MP
Authentication is performed with the EG2 decoder 115. 2. Once they are verified as mutually valid devices,
Encrypted control key (eKcontrol)
Is sent from the DVD-RAM drive 116 to the MPEG2 decoder 115.

3. Out in the MPEG2 decoder 115
The eKcontrol is decrypted by the hentilator 1151, and a Kcontrol is created. 4. Encrypted Content (Encrypted Content)
ents) and the content key (ek
content) and CGMS are sent from the DVD-RAM drive 116 to the MPEG2 decoder 115.

5. Auth of the MPEG2 decoder 115
Kcontrol and CG at enticator 1151
Decrypt eKcontent from MS and Kcont
Generate ent.

6. De- in the MPEG2 decoder 115
Send Kcontent to Cipher1152. 7. De-Cipher 1152 uses the content key to encrypt the encrypted content (Encrypted Content).
nts), and decrypts the content Plain.
Generate Text.

8. The MPEG2 decoder 115 has a Play
VGA controller 11 after decoding nTxet
4 video input port and display it on the screen. As described above, the authenticator section for device authentication is provided in the bus interface section of the storage device, and the transmitted encrypted content is recorded as it is. It will be possible to record on a storage device. Further, by recording the transmitted content as it is, a decryption circuit for decrypting the content becomes unnecessary. Also, by writing the decrypted content decryption key to an area that cannot be read from the system, only a legitimate device can decrypt the storage contents of the storage device by authenticating with the storage device. It becomes possible.

Further, the digital contents thus encrypted are recorded in a normal area, and a key for decrypting the digital contents is recorded in an area which cannot be read from the system by using a computer-readable recording medium. Various titles may be distributed. This allows
The contents of the recording medium can be reproduced only by a legitimate device having the authentication and encryption / decryption functions, and illegal copying can be prevented.

Here, a DVD-RAM drive is exemplified as the storage device, but the present invention may be applied to a DVD-R drive, MO drive, HDD, and the like.
In addition, storage devices having such an authentication function are not only PCs but also DVD players and D-VCRs, for example.
And the like, such as a multifunction peripheral of the present invention, can be applied to various microcomputer application devices using a read / write storage device. It is needless to say that the present invention may be realized as an IEEE 1394 device.

Next, a data transfer restricting method for restricting devices that can handle the content by using the attribute (field, area) of the content to be transferred after being encrypted will be described.

That is, a method of restricting a device that can handle it based on copy control information of copying prohibited, copying only once, and copy free has been described so far. Is control in units of the entire stream composed of the same type of content. Therefore, it is difficult to perform detailed control such that only a part that meets a certain condition among the types of contents permitted to be handled can be handled.

Therefore, in the present data transfer restriction method, field information and region information indicating the contents of the content are embedded in the header portion of the stream data, and by using the field information and the region information, the type of data that can be handled ( In a stream composed of contents that cannot be copied, copied only once, or copied free), only a portion that meets conditions (field, area) specified in advance by a user or the like can be processed, and other portions can be processed. Parts cannot be processed.

FIG. 11 shows a system configuration for implementing the present data transfer restriction method. First, transfer control according to the field information added to the bucket header of the stream data will be described.

The term "field" as used herein means a classification required from social and educational aspects such as the presence / absence / degree of sexual depiction and the presence / absence / degree of violent depiction. The stream data is packetized at the time of passing through the network path, and this packet is composed of a header portion having data information and the data itself. Here, the header section may be a header defined by a network path or a header section included in data.

The data output system 301 comprises a storage device 302 for stream data and an interface unit 303 for outputting the same to the outside. Here, a data packet to be output to the network path is created. The "field" information is stored in the header of the packet as shown in FIG. The network may be wired or wireless. The IEEE 1394 serial bus 200 shown in FIG.
Or a PCI bus 100 or the like.

The data processing system 401 is in a device that receives stream data. For example, the PC 11 in FIG.
, The tuner 113 and the CPU module 11
1 or the MPEG2 decoder 115 corresponds to the data processing system 401. Further, the data processing system 401 may be not only a PC but also a 1394 device shown in the figure, and may be a satellite terminal or an Internet terminal.

The data processing system 401 performs processing for actually presenting data to the user, and includes an interface unit 402 for receiving data and a stream data processing unit 403 for processing. That is,
The "field" information is decoded at the timing of processing the data itself, not at the time of receiving the data, and is compared with a field defined by system attribute information set in advance by the user of the data processing system 401 or the like, and the data of the data is compared. Whether or not processing is possible is determined in data packet units.

The interface unit may be software only, hardware only, or a combination of both. In addition, the stream data includes not only “field” information, but instead or in addition to “field” information, a “region” for specifying a region where the corresponding content can be processed.
Information may be embedded. Here, the “region” is classified according to the intention of the creator or distributor of the stream data. Also in this case, the "region" information is decoded not at the time of receiving the data but at the timing of processing the data itself, and by comparing with the region specified by the system information of the data processing system 401, whether or not the data can be processed is determined. Determined in data packet units.

FIG. 13 shows how data processing is controlled based on stream attribute information such as “field” and “region” embedded in the packet header of the stream.

In FIG. 13, the data processing system 4
01 is composed of data packets A, B, C, and D, and "field" or "region" information is included as stream attribute information in the header of each data packet. Is shown.

The stream restriction function of the data processing system 401 processes only the “field” or “region” data (data A, data C) that is compatible with the data processing system 401, and processes other data (data B, data D). ) Are excluded from processing and discarded. The processing of the stream restriction function is executed according to the procedure shown in the flowchart of FIG. That is, first, the system attribute information set in the data processing system 401 is obtained and compared with the stream attribute information included in the packet header of the received stream (step S).
201 to S204). If they match, the stream (packet) is processed (step S20).
5) If they do not match, no processing is performed (step S20)
6).

Therefore, for example, when the stream restriction function of the data processing system 401 is added to the MPEG2 decoder 115 of FIG. 1, among the video contents (data A, B, C, D) transferred continuously, Only the data (data A, data C) matching the "field" or "region" set by the user is decoded and reproduced, and the other data (data B, data D) are not decoded and reproduced. That is, after the data A is reproduced, the reproduction period of the data B is blanking, and when the reproduction period of the data B ends, the data C is reproduced.

Therefore, by applying the system configuration of FIG. 11 to a content providing system for an unspecified majority, such as a satellite TV broadcast, only the scenes that match the conditions of each user are reproduced or recorded. This makes it possible to easily realize fine control such that only a part that meets a specific condition among the types of content permitted to be handled can be handled.

[0099]

As described above, according to the present invention,
By providing an authentication function for encryption processing in each functional module that constitutes a data processing device such as a personal computer, protection of digital content flowing on a bus connecting functional modules and digital content in functional module units Can be efficiently realized.

[Brief description of the drawings]

FIG. 1 is an exemplary block diagram showing the system configuration of a computer system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between software and hardware in the system of FIG. 1;

FIG. 3 is a diagram showing an example of device authentication and key exchange used in the system of FIG. 1;

FIG. 4 is an exemplary flowchart illustrating an example of a specific procedure of an authentication process used in the system of the embodiment.

FIG. 5 is an exemplary view showing an example of a stream configuration of digital content applied to the system of the embodiment.

FIG. 6 is an exemplary view showing a state where content identification information is added to a packet header of digital content applied to the system of the embodiment.

FIG. 7 is an exemplary view for explaining the principle of digital content restriction processing applied to the system of the embodiment.

FIG. 8 is an exemplary view for explaining an operation of recording content in a storage device provided in the system of the embodiment.

FIG. 9 is an exemplary view for explaining a key storage method in a storage device provided in the system of the embodiment.

FIG. 10 is an exemplary view for explaining an operation of reproducing content recorded in a storage device provided in the system of the embodiment.

FIG. 11 is an exemplary view for explaining the principle of a data transfer restriction method applied to the system according to the embodiment;

FIG. 12 is a diagram showing an example of the structure of stream data used in the data transfer restriction method of FIG. 11;

FIG. 13 is a diagram showing a data restriction processing operation according to the data transfer restriction method of FIG. 11;

FIG. 14 is a flowchart showing a processing procedure of the data transfer restriction method of FIG. 11;

FIG. 15 is a block diagram showing a system configuration of a computer system in which an encryption / decryption function is provided in a 1394 bridge.

[Explanation of symbols]

11 Personal computer (PC) 12 Set-top box (STB) 13 Digital video camera or DV camcorder (D
VC) 14 Digital video cassette recorder (D-VCR) 111 CPU module 112 Main memory 113 Thyrite or digital TV tuner 114 VGA controller 115 MPEG2 decoder 116 DVD-RAM drive 117 1394 bridge 121 Authentication unit (Authenticator) 122 ... Encryption / decryption unit (De- / Cipher) 131 ... Authentication unit (Authenticator) 132 ... Encryption unit (Cipher) 141 ... Authentication unit (Authenticator) 142 ... Encryption / decryption unit (De- / Cipher) 1111 ... Authentication unit (Authenticator) 1112 ... Decryption unit (De-cipher) 1131 ... Authentication unit (Authenticator) 1132 ... Encryption (Cipher) 1151 ... authentication unit (Authenticator) 1152 ... decoding unit (De-cipher) 1161 ... authentication unit (Authenticator)

Claims (16)

[Claims] 1. A data processing device having an interface with an external bus connectable to an external device having an authentication function for encrypting and exchanging copy-protected data, the internal bus being connected to the internal bus. A plurality of function modules for transmitting or receiving copy-protected data via the internal bus; and a destination functional module or the external device that is provided for each of the functional modules and that transmits and receives the copy-protected data. And an authentication unit for performing an authentication process for encrypting and exchanging the data to be copy-protected, and performing an authentication process for each functional module in the data processing device. Data processing device. 2. A function module on the transmission side for transmitting the data to be copy-protected via the internal bus is provided with an encrypting means for encrypting the data to be copy-protected, and is provided via the bus. The functional module on the receiving side that receives and processes the data to be copy protected is provided with decryption means for decrypting the encrypted data and decrypting the encrypted data. The data processing device according to claim 1, wherein 3. An external bus interface means for transparently connecting between the external bus and the internal bus, for exchanging copy-protected data between the external device and each of the functional modules. At this time, encrypted data is transferred on the external bus and the internal bus, and the same authentication and encryption protocol is used between the function modules and between the external device and the function module. 3. The data processing device according to claim 2, wherein: 4. The function module for handling data to be copy-protected includes at least one of a CPU module, a decoder for decoding digitally compressed and encoded data, and a storage device. The data processing device according to claim 1, wherein: 5. The type of data to be copy-protected includes data that can be copied only once and data that cannot be copied. Each of the functional modules includes data that can be handled by the functional module. Identification information for specifying a type is assigned, and the authentication unit is capable of handling the data to be transmitted by the reception-side functional module based on the identification information corresponding to the reception-side functional module. Determine whether the module is a module, and if the function module is capable of handling data to be transmitted, cause the receiving-side functional module to generate a decryption key necessary to decrypt the encrypted data. 2. A data processing apparatus according to claim 1, wherein the key exchange for the key is executed between the functional module on the receiving side. 6. A decryption key required for decrypting encrypted data is changed for each type of data to be transmitted, and when a stream composed of a plurality of different types of data is transmitted. In the authentication process, a number of decryption keys corresponding to the number of data types that can be processed by the receiving-side functional module among the types of data constituting the stream are generated on the receiving-side functional module. The data processing device according to claim 1, wherein 7. The data type information indicating the type of data is embedded in the stream, and the function module on the receiving side dynamically changes the decryption key to be used based on the data type information. The data processing device according to claim 6, wherein 8. The data processing device is a personal computer having a CPU module as the functional module, a decoder for decoding digital compression-encoded data, and a storage device, and the personal computer serves as the internal bus. PC
2. The data processing device according to claim 1, further comprising an I bus, and an IEEE 1394 serial bus as said external bus. 9. A data processing device having a bus and a plurality of function modules respectively coupled to the bus, wherein each of the plurality of function modules handling digital content to be copy protected is An authentication means for performing an authentication process for encrypting and transmitting the digital content with a functional module of a destination that transmits and receives digital content via a bus, and The types include content that can be copied only once and content that cannot be copied, and for each of the functional modules, the type of content that can be handled by the functional module is defined. For each functional module on the receiving side, that functional module handles the content to be transmitted The data processing apparatus characterized by determining a whether possible functional modules. 10. An internal bus, and a plurality of functional modules respectively coupled to the internal bus and transmitting or receiving data to be copy protected via the internal bus,
A copy protection method applied to a data processing apparatus including an external bus connectable to an external device having an encryption / decryption function for data to be protected and an external bus interface for connecting the internal bus. Wherein the external bus interface means transparently connects the external bus and the system bus, and transfers copy-protected data between the plurality of functional modules or between the functional modules and an external device. When performing the authentication process, the devices to be communicated perform an authentication process for confirming the validity of each other's function module. The transmission data is encrypted and transmitted to the destination device, and the encrypted data is transmitted to the receiving device. A copy protection method for both data flowing on the system bus and data flowing on the external bus. 11. A digital content copy protection method applied to a system including a bus and a plurality of devices connected to the bus, wherein the stream includes a plurality of different types of digital content. When transmitting the encrypted data to the receiving device, the transmitting device performs authentication processing for each of the receiving devices for the number of types of content that can be handled by the transmitting device before the transmission. Notify each receiving device of an decryption key corresponding to the number of data types that can be processed by the receiving device among the types of digital content that constitute the digital content. A copy protection method characterized by changing a decryption key to be used according to a type. 12. The stream has embedded therein type information indicating the type of digital content, and the receiving device, based on the data type information,
The copy protection method according to claim 11, wherein the decryption key used for the decryption processing is dynamically changed. 13. A data processing device for transmitting data to a receiving device so as to prevent unauthorized copying of digital content flowing on an internal bus, wherein processing of data to be copy protected between the receiving device and the receiving device is performed. Authentication means for authenticating whether or not permitted, When authenticated by the authentication means, data of the copy protection target that the receiving device is permitted to process,
Determining means for determining what kind of digital content the content is, and, based on the determination result of the determining means, the receiving apparatus sets an encryption decryption key corresponding to each type of digital content for which processing is permitted. A data processing apparatus comprising: a key transmitting unit that transmits to the receiving device; and a transmitting unit that transmits digital content that can be decrypted by the receiving device using the decryption key. 14. A copy protection method for properly transmitting data to a receiving device so as to prevent unauthorized copying of digital content flowing on an internal bus of a computer system, comprising: Authenticates whether or not the processing of the data to be protected is permitted.If authenticated, the type of digital content of the copy protected data to which the receiving apparatus is permitted to process is determined. Determining, based on the determination result, the receiving device transmits only the decryption keys corresponding to the types of digital contents to which the process is permitted to the receiving device, and using the decryption key A copy protection method, wherein the receiving device transmits digital content that can be decrypted. 15. A data processing device for receiving and processing data transmitted from a transmitting device so as to prevent unauthorized copying of digital content flowing on an internal bus, wherein data to be copy-protected with the transmitting device is provided. An authentication means for authenticating whether or not the processing of the data processing apparatus is permitted; and, if authenticated by the authentication means, transmitting the information indicating the type of copy-protected digital content to which the data processing apparatus is permitted to perform the processing. Type information transmitting means for transmitting to the device, an decryption key corresponding to each type of copy-protected digital content that the data processing device is permitted to process based on the type information, and a decryption key A digital content that can be decrypted by the data processing device using the And a decrypting means for decrypting the digital content. 16. A copy protection method for properly receiving and processing data from a transmission device side so as to prevent unauthorized copying of digital content flowing on an internal bus of a computer system, comprising: Authenticates whether or not processing of data to be copy protected is permitted, and if authenticated, transmits information indicating the type of digital content to be copy protected that is permitted to receive data to the transmitting device. Then, based on the type information, the decryption keys corresponding to the types of digital contents for which the reception process is permitted are received from the transmitting device, and the receiving device uses the decryption key to encrypt the received content. Receiving decryptable digital content from the transmitting device, encrypting the digital content; Copy protection method characterized by decoding using the divided key.