JP2013150179A - Information processing apparatus, information storage device, information processing system, information processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve content usage control which limits hosts that are permitted content reproduction.SOLUTION: An information storage device such as a memory card stores encrypted content and a conversion title key generated by converting a title key serving as an encryption key, and generates a subkey to be applied to title key calculation from the conversion title key. The subkey is generated by applying a host ID that has been acquired from a server during recording of the content. When content is reproduced, a host ID serving as an identifier of a reproducer is acquired from the reproducer for decrypting the encrypted content. Then, a subkey is generated by applying the acquired host ID and output to the reproducer. Only a reproducer having a host ID the same as the host ID that has been applied to subkey generation in downloading successfully generates a correct title key based on the subkey, so as to enable the decryption and reproduction of content.

Description

  The present disclosure relates to an information processing device, an information storage device, an information processing system, an information processing method, and a program. In particular, the present invention relates to an information processing device, an information storage device, an information processing system, an information processing method, and a program that perform content usage control.

  For example, contents such as movies and music are sent to users via various media such as DVD (Digital Versatile Disc), Blu-ray Disc (registered trademark), flash memory, etc., networks such as the Internet, or broadcast waves. Provided. A user can play back content by using various information processing devices such as a PC, a portable terminal, a recording / playback device such as a BD player, and a television.

  However, many contents such as music data and image data provided to these users have copyrights, distribution rights, etc. held by their creators or distributors. Therefore, content providers often perform predetermined content usage restrictions when providing content to users.

  According to the digital recording device and the recording medium, for example, it is possible to repeat recording and reproduction without deteriorating images and sound, and illegal copy contents such as distribution of illegal copy contents via the Internet and distribution of so-called pirated discs. There is a problem that the use of is prevalent.

  As a specific configuration for preventing such unauthorized use of content, there is content encryption processing. The content provided to the user is encrypted, and the encryption key is set so that it can be acquired only by authorized users. These processes are described in, for example, Japanese Patent Application Laid-Open No. 2008-98765.

For example, the encryption key used for decrypting the encrypted data is recorded on the media owned by the user, for example, a memory card, together with the encrypted content when the encrypted content is purchased, for example, downloaded.
At the time of content playback, a playback device equipped with a memory card can read encrypted content and an encryption key from the memory card, decrypt the encrypted content using the encryption key, and play back the content.

However, as described above, when the encrypted content and the encryption key are recorded as one data set on a medium such as a memory card, the playback device (host) that can play back the content by mounting the memory card cannot be limited. .
That is, the encrypted content stored in a medium such as one memory card can be played back and used by an unspecified number of playback devices.

  That is, there is a problem that the content cannot be limited with respect to a media binding type content associated with one medium.

JP 2008-98765 A

  The present disclosure has been made in view of the above-described problems, for example, an information processing device that realizes content use control that can restrict a playback device that allows playback of content recorded on a medium such as a memory card, An object is to provide an information storage device, an information processing system, an information processing method, and a program.

The first aspect of the present disclosure is:
A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The data processing unit
The information processing apparatus or application that performs decryption of the encrypted content is executed by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. It is in the information storage device that executes the processing to be output.

  Furthermore, in one embodiment of the information storage device according to the present disclosure, the data processing unit receives a host ID from a server that performs content provision processing when recording encrypted content in the storage unit, and receives the received host ID. A subkey is generated by application, the generated subkey is transmitted to the server, and the converted title key generated by applying the subkey by the server is stored in the storage unit.

  Furthermore, in an embodiment of the information storage device according to the present disclosure, the host ID provided by the server is an identifier of an information processing device or application in which the information storage device is mounted during content provision processing, and reproduction of the provided content is performed. This is the identifier of the information processing apparatus or application to be allowed.

  Furthermore, in an embodiment of the information storage device of the present disclosure, the data processing unit is configured such that the certificate holding entity is a server based on type information recorded in a server certificate received from a server during authentication processing with the server. On the condition that the confirmation is made, the subkey generation process to which the receiving host ID is applied is executed.

  Furthermore, in one embodiment of the information storage device of the present disclosure, the converted title key is an exclusive OR operation result of the title key and the subkey.

  Furthermore, in an embodiment of the information storage device according to the present disclosure, the data processing unit generates the subkey by arithmetic processing or encryption processing using a unique key of the information storage device and the host ID.

  Furthermore, in an embodiment of the information storage device of the present disclosure, the data processing unit executes a subkey generation process using the hash value of the concatenated data of the unique key of the information storage device and the host ID as the subkey.

  Furthermore, in an embodiment of the information storage device according to the present disclosure, the data processing unit acquires the host ID from storage data of a host public key certificate that stores the public key of the host, and acquires the acquired host ID. Execute the applied subkey generation process.

  Furthermore, in an embodiment of the information storage device of the present disclosure, the storage unit is configured to store usage control information corresponding to the encrypted content, and the usage control information is included in the title key generation process. In this configuration, a sub key flag indicating whether or not a sub key is required is recorded.

Furthermore, the second aspect of the present disclosure is:
A data processing unit for performing decryption and reproduction processing of content by mounting media storing encrypted content encrypted by a title key,
The data processing unit
Obtaining usage control information corresponding to the content to be played from the media;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
When the sub key flag is a setting indicating that the sub key use is not necessary for the generation of the title key, the title key is acquired from the media;
The information processing apparatus performs decryption processing of the encrypted content by applying the generated or acquired title key.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data processing unit acquires from the medium when the subkey flag is a setting indicating that the subkey use is necessary for generating the title key. Title key generation processing is executed by exclusive OR operation of the converted title key and the subkey.

Furthermore, the third aspect of the present disclosure is:
A server that transmits content to an information storage device;
Receiving a host ID that is an identifier of a device or application that executes content reproduction processing from an information processing device equipped with the information storage device;
The received host ID is transmitted to the information storage device, the information storage device receives a subkey generated by applying the host ID, and the received subkey is applied to convert the title key that is the encryption key of the content The conversion title key is generated in the server, and the generated conversion title key is transmitted to the information storage device as stored data.

Furthermore, the fourth aspect of the present disclosure is:
An information storage device storing encrypted content and usage control information corresponding to the encrypted content;
An information processing system having an information processing apparatus that executes a reproduction process of the encrypted content,
The information processing apparatus includes:
Obtaining usage control information corresponding to the encrypted content to be reproduced from the information storage device;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary to generate the title key, a subkey acquisition request is output to the information storage device,
The information storage device includes:
Execute a subkey generation process using a host ID that is an identifier of the information processing apparatus, and output the generated subkey to the information processing apparatus;
The information processing apparatus includes:
Performing a title key generation process using a subkey obtained from the information storage device;
The information processing system executes decryption processing of the encrypted content by applying the generated title key.

Furthermore, the fifth aspect of the present disclosure is:
An information processing method executed in an information storage device,
The information storage device includes:
A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The data processing unit
The information processing apparatus or application that performs decryption of the encrypted content is executed by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. There is an information processing method for executing processing to be output.

Furthermore, the sixth aspect of the present disclosure is:
An information processing method for performing decryption and reproduction of content stored in a medium in an information processing device,
The information processing apparatus includes a data processing unit that loads a medium storing encrypted content encrypted by a title key and executes content decryption and reproduction processing;
The data processing unit
Obtaining usage control information corresponding to the content to be played from the media;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
When the sub key flag is a setting indicating that the sub key use is not necessary for the generation of the title key, the title key is acquired from the media;
The present invention is an information processing method for executing decryption processing of the encrypted content by applying a generated or acquired title key.

Furthermore, the seventh aspect of the present disclosure is:
An information processing method executed in a server that transmits content to an information storage device,
Receiving a host ID that is an identifier of a device or application that executes content reproduction processing from an information processing device equipped with the information storage device;
The received host ID is transmitted to the information storage device, the information storage device receives a subkey generated by applying the host ID, and the received subkey is applied to convert the title key that is the encryption key of the content In the information processing method, the conversion title key is generated and the generated conversion title key is transmitted as stored data in the information storage device.

Furthermore, an eighth aspect of the present disclosure is
A program for executing information processing in an information storage device;
The information storage device includes:
A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The program is stored in the data processing unit.
The information processing apparatus or application that performs decryption of the encrypted content by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. It is in the program that executes the processing to be output.

Furthermore, the ninth aspect of the present disclosure is
In an information processing device, a program for executing decryption and reproduction of content stored in a medium,
The information processing apparatus includes a data processing unit that loads a medium storing encrypted content encrypted by a title key and executes content decryption and reproduction processing;
The program is stored in the data processing unit.
Acquisition processing of usage control information corresponding to the content to be played from the media;
Execute the confirmation process of the setting of the sub key flag recorded in the acquired usage control information,
If the subkey flag is a setting indicating that the subkey use is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
If the subkey flag is a setting indicating that the use of a subkey is not necessary for the generation of the title key, a process of acquiring a title key from the medium is executed, and
A program for executing decryption processing of the encrypted content by applying a title key generated or acquired.

Furthermore, the tenth aspect of the present disclosure includes
A program that executes information processing in a server that transmits content to an information storage device,
A process of receiving a host ID which is an identifier of an apparatus or application for executing a content reproduction process from an information processing apparatus equipped with the information storage apparatus;
A process of transmitting the received host ID to the information storage device;
Processing in which the information storage device receives a subkey generated by applying a host ID, converts a title key that is an encryption key of the content by applying the subkey, and generates a converted title key;
A program for executing a process of transmitting the generated converted title key as stored data of the information storage device.

  Note that the program of the present disclosure is a program that can be provided by, for example, a storage medium or a communication medium provided in a computer-readable format to an information processing apparatus or a computer system that can execute various program codes. By providing such a program in a computer-readable format, processing corresponding to the program is realized on the information processing apparatus or the computer system.

  Other objects, features, and advantages of the present disclosure will become apparent from a more detailed description based on embodiments of the present disclosure described below and the accompanying drawings. In this specification, the system is a logical set configuration of a plurality of devices, and is not limited to one in which the devices of each configuration are in the same casing.

According to the configuration of an embodiment of the present disclosure, content usage control in which hosts that permit content reproduction are limited is realized.
Specifically, an information storage device such as a memory card stores a converted title key obtained by converting the encrypted content and a title key that is an encryption key, and generates a subkey to be applied to title key calculation from the converted title key. The sub key is generated by applying the host ID acquired from the server when recording the content. At the time of content playback, a host ID that is an identifier of the playback device is acquired from a playback device that decrypts the encrypted content, a subkey is generated by applying the acquired host ID, and is output to the playback device. Only a playback device having the same host ID as the host ID applied to the subkey generation at the time of download succeeds in generating a correct title key based on the subkey, and can decrypt and play back the content.
With these configurations, content usage control that limits hosts that permit content playback is realized.

It is a figure explaining the outline | summary of a content provision process and a utilization process. It is a figure explaining the utilization form of the content recorded on the memory card. It is a figure explaining the process between the information processing apparatus which performs content recording / reproducing, and the recording medium of content. It is a figure explaining the specific structural example of a memory card. It is a figure explaining the example of a data structure of usage control information (Usage Rule). FIG. 11 is a diagram for describing a configuration example of an information processing apparatus (host). It is a figure explaining the example of a data structure of a host public key certificate (Host Certificate). It is a figure explaining the data structural example of a server public key certificate (Server Certificate). It is a figure explaining the download recording process sequence of the content which limited the content reproduction | regeneration permission host. It is a figure which shows the flowchart explaining the subkey production | generation determination processing sequence performed in the download recording process of a content. It is a figure explaining the content download recording process sequence which does not limit a content reproduction permissible host. It is a figure explaining the reproduction | regeneration processing sequence of the content which limited the content reproduction | regeneration permission host. It is a figure explaining the reproduction | regeneration processing sequence of the content which limited the content reproduction | regeneration permission host. It is a figure explaining the reproduction | regeneration processing sequence of the content which does not limit a content reproduction | regeneration permission host. FIG. 25 is a diagram for describing an example hardware configuration of an information processing device. It is a figure explaining the example of hardware constitutions of information storage devices, such as a memory card.

The details of the information processing apparatus, information storage apparatus, information processing system, information processing method, and program of the present disclosure will be described below with reference to the drawings. The description will be made according to the following items.
1. 1. Overview of content provision processing and usage processing 2. Configuration example of information storage device 3. Data configuration example of usage control information 4. Configuration example of information processing apparatus (host) 5. Example of data structure of certificate (Certificate) 6. Content recording processing sequence for information storage device (media) 6-1. (A) Content provision and recording processing for limited information processing apparatus (host) capable of reproducing content 6-2. (B) Content provision and recording processing that does not limit the information processing apparatus (host) that can reproduce the content. 7. Usage sequence of content stored in information storage device (media) 8. Hardware configuration example of each device Summary of composition of this disclosure

[1. Overview of content provision processing and usage processing]
Hereinafter, the configuration of the present disclosure will be described with reference to the drawings.
First, the outline of the content providing process and the usage process will be described with reference to FIG.
In FIG. 1, from the left
(A) Content provider (b) Information processing device (content recording / playback device (host))
(C) Information storage device (content recording medium)
Examples of these are shown.

  (C) The information storage device (content recording medium) 30 is a medium on which a user records content and is used for content reproduction processing. Here, for example, a memory card 31 which is an information storage device provided with a flash memory is shown.

  A user records and uses various contents such as music and movies in an information storage device (content recording medium) 30 such as a memory card 31. These contents include contents that are subject to usage control, such as contents that are subject to copyright management.

  The content that is subject to usage control is, for example, content for which random copying or distribution of copy data is prohibited, content for which the usage period is limited, or the like. Note that when usage control content is recorded in the memory card 31, usage control information (Usage Rule) that records copy restriction information, usage period restriction information, and the like corresponding to the content is also provided and recorded.

  Further, the license management apparatus (LA) that manages the use of content is an identifier such as an identifier (ID) of an unauthorized device or an identifier of a public key certificate of the unauthorized device for an information processing device or an information storage device that is recognized as an unauthorized device. A revocation list (Revocation List) in which (ID) is registered is generated and provided to each device. In the revocation list, an electronic signature using a secret key of a license management apparatus (LA: License Authority) is set. The revocation list (Revocation List) is sequentially updated.

(A) A content provider is a provider of content such as music and movies. In FIG. 1, as an example, a broadcast station 11 and a content recording medium 13 such as a content server 12, a BD, or a DVD are shown as content providers.
The broadcast station 11 is, for example, a television station, and provides various broadcast contents on a terrestrial wave or a satellite wave to a user device [(b) information processing device (content recording / playback device (host))].
The content server 12 is a server that provides content such as music and movies via a network such as the Internet.
The content recording medium 13 is a medium on which content such as a movie is recorded in advance, such as a BD-ROM or a DVD-ROM.

For example, the user can attach the memory card 31 to the information processing apparatus 20 and record the content that the information processing apparatus 20 receives from the outside or plays back from the content recording medium 13 on the memory card 31.
In addition, the information processing apparatus 20 can read and reproduce content recorded on the memory card 31, for example.

  The information processing apparatus 20 includes a recording / reproduction device (CE device: Consumer Electronics device) 21 including a hard disk, a disk such as a DVD, or a BD, such as a DVD player. Further, there are a PC 22, a mobile terminal 23 such as a smartphone, a mobile phone, a mobile player, and a tablet terminal. These are all (c) information storage devices 30, for example, devices on which a memory card 31 can be mounted.

A usage form of the memory card 31 will be described with reference to FIG.
A memory card 31 that is one form of the information storage device 30 is a recording medium that can be attached to and detached from a content player such as a PC, for example, and can be freely removed from the device that has performed content recording and mounted on other user devices. Is possible.

That is, as shown in FIG.
(1) Recording process (2) Reproduction process These processes are executed.
Some devices execute only one of recording and reproduction.
Moreover, it is not essential that the recording and playback processing devices are the same, and the user can freely select and use the recording device and the playback device.

In many cases, the usage control content recorded on the memory card 31 is recorded as encrypted content, and the content playback devices such as the recording / playback device 21, the PC 22, and the portable terminal 23 follow a predetermined sequence. After executing the decryption process, the content is reproduced.
In addition, reproduction processing and the like are performed in a usage-permitted mode recorded in usage control information (Usage Rule) set corresponding to the content.
(B) The content recording / playback apparatus (host) stores a program (host application) for executing content use and content decryption processing in accordance with usage control information (Usage Rule). Execute according to the program (host application).

Also,
An information processing apparatus 20 for executing content recording / playback;
An information storage device 30 for storing content;
Each of these devices stores a revocation list (Revocation List) that is a list in which identifiers (IDs) of unauthorized devices are recorded in the storage unit.
When the information processing apparatus 20 such as the PC 22 mounts the information storage device 30 such as the memory card 31 and records the content in the information storage device 30 or when reproducing the content recorded in the information storage device 30 As the pre-processing, as shown in FIG.
(Processing A) Mutual authentication processing between the information processing device 20 and the information storage device 30,
(Process B) Revocation list synchronization process between the information processing device 20 and the information storage device 30;
These processes are executed.

The mutual authentication process is executed in accordance with, for example, an ECDH (Elliptic Curve Diffie-Hellman) encryption method which is a public key encryption algorithm.
In this mutual authentication process, a process using a key set of a public key and a secret key held by the information processing apparatus 20 and the information storage apparatus 30 is executed.
Also, whether or not the public key certificate is mutually provided between the devices, and the other device or key or the ID of the public key certificate is recorded in the revocation list (Revocation List) which is the registration list of unauthorized devices Processing to verify whether or not. For example, when the ID of the counterpart device is recorded in the revocation list, it is determined that the counterpart device is an unauthorized device. In this case, subsequent processing, for example, content reproduction and recording processing may be stopped.

  The revocation synchronization process performs a version comparison between the revocation list (Revocation List) held by the information processing device 20 and the revocation list (Revocation List) held by the information storage device 30 to obtain a newer version of the revocation list. This is a process of selecting an application list (Revocation List) and replacing the old revocation list (Revocation List) of each device with a new one. This processing is called revocation list synchronization processing or update processing.

  The revocation synchronization process (update process) is performed not only between the information storage device 30 and the information processing device 20, but also between the information storage device 30 and the content server 12 that is the content provider, or with the information processing device 20, for example. It is also executed between content servers.

[2. Configuration example of information storage device]
Next, a configuration example of an information storage device such as a memory card 31 used as a content recording medium will be described.
A specific configuration example of the memory card 31 is shown in FIG.

  The memory card 31 is attached to, for example, an information processing apparatus (host) 20 that records and reproduces content, and is accessed from the information processing apparatus 20 or a server connected via the information processing apparatus 20 to read data. And writing is done.

As shown in FIG.
A controller (data processing unit) 110, a storage unit 120, and a communication IF 140 are included.
For example, communication with an information processing apparatus (host) or the like is performed via the communication IF 140.

The controller (data processing unit) 110 includes a CPU 111 having a program execution function, a RAM 112, and the like. The RAM 112 is used as a recording area for data processing programs executed by the CPU, various parameters, controller-specific ID information, key information, and the like.
The storage unit 120 is basically divided into a general-purpose area (user data area) 121 where free access is allowed and a protected area (secure area) 122 where free access is not allowed.

The general-purpose area (user data area) 121 includes
For example, content 131 provided by a content server or the like, and usage control information 132 that records usage permission information such as copy control information corresponding to the content are recorded. In many cases, the content is content encrypted by a title key.
The usage control information is set corresponding to the content, and is often provided together with the content. For example, when content is downloaded from a server and recorded, a usage control information file corresponding to the downloaded content is also downloaded and recorded.

Various types of secret information are recorded in the protection area (secure area) 122.
For example, an encryption key (title key) or the like applied to content decryption. The example shown in FIG. 4 shows a storage example of the following data.
Title key 133,
Revocation list 134,
Media secret key 135,
Media public key certificate 136,
License management device public key 137,

The title key 133 is an encryption key applied to encryption / decryption processing of content recorded in the general-purpose area 121.
The title key stored in the protected area (secure area) 122 is stored as a converted title key that has been subjected to predetermined data conversion. Specifically, for example, it is stored as exclusive OR (XOR) result data with a subkey generated by applying a unique key of the media, a hash value of content-related usage control information, or other information.

  When decrypting the content, the conversion title key stored in the protected area (secure area) 122 is acquired, a predetermined operation is performed to calculate the title key, and the decryption process is performed using the calculated title key To do.

  The revocation list 134 is an unauthorized device, specifically, an apparatus identifier (ID) such as an information processing device such as a recording / playback device determined as an unauthorized device, an information storage device such as a memory card, or the like. It is the list which registered the identifier (ID) of the public key certificate (Certificate) stored in the unauthorized device. A revocation list 134 is a list that is issued and sequentially updated by the license management apparatus, and is configured such that the signature of the license management apparatus is set and tampering verification is possible.

  The media private key 135 and the media public key certificate 136 are a certificate (Certificate) that stores a private key corresponding to the memory card 31 according to the public key cryptosystem and a public key.

The license management device public key 137 is, for example, the public key of the license management device that is the issuer of the revocation list 134, the media private key 135, and the media public key certificate.
For example, it is used in the verification process of the signature set in the revocation list 134 and the verification process of the signature set in the public key certificate.

[3. About data structure example of usage control information]
FIG. 5 shows a data configuration example of the usage control information 132.
As described above, the usage control information 132 records usage permission information such as copy control information corresponding to the content. Specifically, for example, as shown in FIG.
Header information (Header),
Subkey flag (SubKey Flag),
Copy control information (CCI: Copy Control Information),
Usage period control information (Period)
Usage period control information (before)
Usage period control information (After)
Movement control information (Move OK / NG)
For example, such information is recorded.

  In the header information (Header), identification information indicating usage control information, an identifier of the corresponding content, and the like are recorded.

The sub key flag (SubKey Flag) is a flag indicating whether or not a sub key is required when generating a title key which is an encryption key applied to content encryption and decryption processing. For example, the following setting flags are recorded.
Flag = 0: The subkey is not used for generating the title key.
Flag = 1: A subkey is used to generate a title key.

The copy control information is information regarding whether or not copying of content is permitted, and information on the number of times of copying when permitted.
The usage period control information is date and time information that allows the use of content. It is recorded as information such as a certain period (Period), a certain date and time (Before), and a certain date and time (After).
The movement control information (Move OK / NG) is information indicating whether or not the content is allowed to move (Move) to an external device.

  For example, these pieces of information are recorded in a usage control information file corresponding to the content. For example, when a user device such as a playback device uses content such as content playback, the control information recorded in the usage control information corresponding to the content is used. Processing to be used is executed.

[4. Configuration example of information processing device (host)]
Next, a configuration example of an information processing apparatus (host) that reproduces content recorded in an information storage device such as a memory card or records content in the information storage device will be described.

FIG. 6 is a diagram illustrating a configuration example of the information processing apparatus (host) 20.
As shown in FIG.
A data processing unit 210, a storage unit 220, and a communication IF 240 are included.
For example, communication with an information storage device or a server is performed via the communication IF 140.

  The data processing unit 210 includes a CPU 211 having a program execution function, a RAM 212, and the like. The RAM 22 is used as a recording area for data processing programs executed by the CPU, various parameters, unique ID information, and the like.

For example, the following data is recorded in the storage unit 220 as shown in the figure.
Host secret key 221,
Host public key certificate 222,
License management device public key 223,
Revocation list 224,

  The host secret key 221 and the host public key certificate 222 are a certificate (Certificate) storing a secret key corresponding to the host according to the public key cryptosystem and the public key.

The license management device public key 223 is, for example, the public key of the license management device that is the issuer of the revocation list, the host secret key, and the host public key certificate.
For example, it is used in the verification process of a signature set in the revocation list and the verification process of the signature set in the public key certificate.

The revocation list 224 is an unauthorized device, specifically, an information processing device such as a recording / reproducing device determined to be an unauthorized device, a device identifier (ID) such as an information storage device such as a memory card, or the like. It is the list which registered the identifier (ID) of the public key certificate (Certificate) stored in the unauthorized device.
The revocation list (Revocation List) 224 is a list that is issued and sequentially updated by the license management apparatus, and is configured such that the signature of the license management apparatus is set and tampering verification is possible.

[5. About data structure example of certificate (Certificate)]
FIG. 7 shows a data configuration example of the host public key certificate (Host Certificate) 222.
As shown in FIG. 7, the following data is recorded in the host public key certificate (Host Certificate) 222.
(A) Header information (Header)
(B) Host ID
(C) Type
(D) Host public key (Host Public Key)
(E) Signature (signature of public key certificate issuing entity (= license management device))

(A) In the header information (Header), a public key certificate and further data configuration information are recorded.
(B) The host ID (Host ID) is an identifier of the host, that is, in the case of the example shown in FIG. 6, the identifier of the information processing apparatus 20 is recorded. As described above, the host may be an application such as a content recording / playback apparatus or a playback program, and a unique host public key certificate is set for these devices or applications. It is set as an identifier corresponding to the device or application.

(C) The type (Type) is a certificate issued to the playback device or playback application that executes the content playback process, or issued to the server that provides the content. This is type information indicating the certificate owner of the certificate.
For example, the following setting type information is recorded.
Type = 0: Public key certificate (Certificate) of playback device or playback application
Type = 1: Server public key certificate (Certificate)

  The information processing apparatus (host) 20 shown in FIG. 6 is a reproduction apparatus. In the case of the host public key certificate 222 held by the information processing apparatus (host) 20, type = 0, that is, for the reproduction apparatus and the reproduction application. Type information indicating that the certificate has been issued.

(D) The host public key is the host's own public key.
For example, in the example shown in FIG.

(E) The signature is a signature set by a public key certificate issuing entity, for example, a private key of the license management apparatus. A signature set for the configuration data of the host public key certificate (Host Certificate),
Whether or not the host public key certificate (Host Certificate) has been tampered with can be verified by signature verification using the public key of the license management apparatus.
When using the data stored in the host public key certificate (Host Certificate), whether or not the host public key certificate (Host Certificate) has been tampered with is verified by signature verification using the public key of the license management device. The use process is performed on the condition that the determination is made.

As a reference, FIG. 8 shows a data configuration example of a server certificate (Server Certificate) held by a server that executes content providing processing.
As shown in FIG. 8, the following data is recorded in the server certificate (Server Certificate).
(A) Header information (Header)
(B) Server ID
(C) Type
(D) Server public key (Server Public Key)
(E) Signature (signature of public key certificate issuing entity (= license management device))

These stored data have the same data structure as the host certificate (Host Certificate) described above with reference to FIG.
However, the stored ID and key are data corresponding to the server, and the type includes type information indicating that the server is a server, that is, “type = 1: server public key certificate (Certificate).
The above type information is recorded.

For example, when data recording or reading is executed by connecting to an external device that performs data recording or data reading from an information storage device such as a memory card, the information storage device such as a memory card is connected The authentication process with the external device is executed.
In this authentication process, an information storage device such as a memory card receives a public key certificate from a connected external device. By confirming the type recorded in the received public key certificate, it is possible to determine whether the authentication processing partner is a server, or a playback device or a playback application.

[6. Content recording processing sequence for information storage device (media)]
Next, a content recording processing sequence for the information storage device (media) will be described.
The server selectively executes the following two different content provision and recording processes when content is provided and recorded on the information storage device (media).
(A) Content provision and recording processing limited to information processing apparatus (host) capable of reproducing content (B) Content provision and recording processing not limited to information processing apparatus (host) capable of reproducing content (B) Two types of content provision and recording processing are selectively executed.

  It should be noted that the information processing apparatus (host) capable of reproducing the provided content after performing the above-described process (A), that is, the content provision / recording process limited to the information processing apparatus (host) capable of reproducing the content. It is also possible to switch to content that does not limit the content. In this case, processing that omits the provision processing of the provided content is performed.

Hereinafter, each of the processes (A) and (B) will be described.
With reference to FIG. 9 and FIG. 10, (A) content provision / recording processing limited to an information processing apparatus (host) capable of reproducing content will be described.
Also, with reference to FIG. 11, (B) content provision and recording processing that does not limit the information processing apparatus (host) capable of reproducing content will be described.

[6-1. (A) Content provision and recording processing with limited information processing apparatus (host) capable of reproducing content]
First, content provision / recording processing limited to an information processing apparatus (host) capable of reproducing content will be described.

FIG. 9 is a diagram illustrating a processing sequence when recording content downloaded from a server in an information storage device such as a memory card.
In FIG. 9, from the left
(A) a server that executes content providing processing;
(B) Information processing device (host) with an information storage device (media) such as a memory card attached
(C) Information storage device (media) that is a recording destination of content
These are shown.

  An information processing device (host) is a playback device that can be loaded with an information storage device (media) such as a memory card and that can play back content recorded on the information storage device (media). This information processing apparatus (host) has the same configuration as the information processing apparatus 20 described above with reference to FIG. 6, for example, and stores a host public key certificate in the storage unit.

  The information storage device is, for example, the memory card 31 described with reference to FIG. 4, and includes a controller 110 that functions as a data processing unit that executes data processing, a storage unit 120, and the like.

The information processing device (host) is equipped with an information storage device (media) such as a memory card, and the data processing unit of the information processing device (host) and the information storage device (media) executes communication with the server. Then, the processing after step S101 shown in the figure is sequentially executed to execute the content download processing and recording processing.
Hereinafter, details of the processing after step S101 will be described.

(Step S101)
First, an information processing device (host) equipped with an information storage device (medium) such as a memory card serving as a download content recording medium transmits a host ID, which is an identifier of the own device, to the server. This host ID is the host ID recorded in the host public key certificate held by the information processing apparatus (host). As described above with reference to FIG. 7, the public key certificate records an identifier corresponding to the device or application that is the holding entity of the public key certificate. The information processing apparatus (host) acquires an identifier (host identifier) from its own public key certificate and transmits it to the server. The information processing apparatus (host) may be configured to transmit its own public key certificate to the server and acquire the host ID from the public key certificate received by the server.

(Step S102)
Next, the server transmits the content to the information storage device.
As a premise of this process, for example, a process in which a user operating the information processing apparatus accesses the server, displays a list of contents provided by the server on the display of the information processing apparatus, and the user selects download contents, etc. Is done.
The server transmits content according to the user's specification.
Note that the transmission content is an encrypted content encrypted with a title key corresponding to the content. The title key is an encryption key generated by the server as a content-compatible encryption key.

(Step S103)
In step S103, the encrypted content transmitted from the server is recorded in the general-purpose area (user data area) of the information storage device.
Note that the content cannot be reproduced or used only by acquiring the encrypted content. It is necessary to acquire a title key that is an encryption key corresponding to the encrypted content.

(Step S104)
In step S104, mutual authentication processing and session key (= bus key: Bk) exchange processing are executed between the server and the information storage device. This process is a mutual authentication process and a key exchange process in accordance with a public key cryptosystem, and performs both reliability confirmation and session key (= bus key: Bk) generation and sharing processes.

Specifically, each device verifies the signature of the other party's public key certificate, and further confirms that the device ID recorded in the public key certificate is not recorded in the revocation list.
If the signature verification fails or the device ID is registered in the revocation list, the subsequent processing is not executed. That is, content provision, recording processing, and the like are not executed.

(Steps S105 to S106)
In steps S105 to S106, a revocation list synchronization process is executed. That is, if the version of the revocation list stored in the information storage device is older than the version of the revocation list held by the server, a new revocation list is provided from the server to the information storage device and stored in the information storage device. The revocation list is updated by replacing the old revocation list with the new revocation list.

(Step S107)
Next, in step S107, the server transmits the host ID received from the information processing apparatus (host) in step S101 to the information storage device.
This host ID is the host ID received from the information processing device (host) in step S101, and the identifier (host) recorded in the public key certificate held by the information processing device (host) equipped with the information storage device. ID).

(Step S108)
In step S108, the information storage device executes a subkey generation determination process according to a predetermined subkey (Sub Key) generation determination sequence, and generates a subkey when it is determined that subkey generation is possible.

  The details of the sub key (SubKey) generation determination sequence in step S108 will be described with reference to the flowchart shown in FIG.

  First, in step S151, the data processing unit of the information storage device types from the public key certificate (Certificate) of the authentication partner currently communicating, that is, the server that performed the authentication process in the authentication process in step S104 shown in FIG. Get information.

Next, in step S152, it is determined whether or not the acquired type information is a value indicating that it is a server.
If the type information is type information indicating that it is a server, the process advances to step S153 to execute a subkey generation process.
On the other hand, if the type information is not type information indicating that the server is a server, the process ends without performing the subkey generation process.

In step S108 shown in FIG. 9, according to the flow shown in FIG. 10, a subkey generation determination is executed, and a subkey generation process or a generation stop process is performed.
If a sub key is generated in step S108, the processing from step S109 shown in FIG. 9 is performed.
If no subkey is generated in step S108, the processing after step S109 shown in FIG. 9 is not executed. In this case, for example, the information storage device outputs an error message to the information processing device and ends the process. In this case, the generation of the subkey is not executed, and as a result, the recording process of the title key for content decryption to the information storage device is not performed, so that the decryption and use of the content cannot be performed.

If the process proceeds to step S153 according to the flow shown in FIG. 10, a subkey generation process is performed. The sub key (SubKey) is generated according to the following formula, for example.
SubKey = Hash (Km || Host ID)
That is, a hash value of the concatenated data of the secret key (Km) of the information storage device and the host ID is calculated, and this calculated value is set as a sub key (SubKey).

  The above subkey generation processing example is an example, and the subkey may be data generated by applying the secret key (Km) of the information storage device and the host ID, for example, the secret key of the information storage device. The encrypted data of the host ID to which (Km) is applied may be set as a subkey.

(Step S109)
In step S109, the information storage device encrypts the generated sub key (Sub Key) with the session key (Bk) and transmits it to the server. That is,
Enk (Bk, Sub Key)
The above encryption key data is transmitted to the server.

(Step S110)
Next, in step S110, the server generates a converted title key (XORed Title Key) that is conversion data of the title key to be stored in the information storage device (media) by applying the sub key (Sub Key).
Note that the encrypted content output to the information storage device in step S101 is encrypted with the title key generated by the server.
The server generates a converted title key by an arithmetic process in which a sub key is applied to the title key.
Specifically, a conversion title key (XORed Title Key) is generated according to the following formula.
XORed Title Key = (Title Key) (xor) (Sub Key)

Note that (A) (xor) (B) means an exclusive OR (XOR) operation of A and B.
That is, a converted title key for media storage is generated by an exclusive OR operation between the title key and the sub key.
In addition, for example, a hash value of usage control information (Usage Rule) may be set as exclusive OR (XOR) operation data.

(Step S111)
Next, in step S111, the server transmits the converted title key (XORed Title Key) generated in step S110 to the information storage device.

(Step S112)
Next, in step S112, the information storage device records the converted title key (XORed Title Key) received from the server in the protected area (secure area).

(Step S113)
Next, in step S113, the server transmits usage control information (Usage Rule) corresponding to the encrypted content transmitted in step S101 to the information storage device.
The usage control information (Usage Rule) is a data file having the data configuration described above with reference to FIG.
In this usage control information (Usage Rule), a sub key flag (SubKey Flag) indicating whether or not to use a sub key for generating a title key applied to content decryption is recorded.
The content transmitted in the sequence shown in FIG. 9 is content that is limited to the playback host, and the setting of the sub key flag records a flag indicating the setting for using the sub key for generating the title key.

(Step S114)
Next, in step S114, the information storage device records usage control information (Usage Rule) received from the server in the general-purpose area (user data area).
In this usage control information (Usage Rule), a sub key flag (SubKey Flag) indicating whether or not to use a sub key for generating a title key applied to content decryption is recorded.
The content transmitted in the sequence shown in FIG. 9 is content that has a limitation of the reproduction host, and the sub-key flag setting records a flag indicating the setting for using the sub-key for generating the title key.

According to the sequence shown in FIG. 9, the following data provided from the server is stored in the general-purpose area of the information storage device:
(1) encrypted content,
(2) Usage control information These data are recorded,
In the protected area of the information storage device, the following data provided by the server, that is,
(3) Conversion title key (XORed Title Key)
Is stored.

[6-2. (B) Content provision and recording processing without limiting information processing apparatus (host) capable of reproducing content]
Next, content provision and recording processing that does not limit an information processing apparatus (host) capable of reproducing content will be described.

FIG. 11 is a diagram illustrating a processing sequence when recording content downloaded from a server in an information storage device such as a memory card.
In FIG. 11, as in FIG. 9, from the left,
(A) a server that executes content providing processing;
(B) Information processing device (host) with an information storage device (media) such as a memory card attached
(C) Information storage device (media) that is a recording destination of content
These are shown.

  The information storage device is, for example, the memory card 31 described with reference to FIG. 4, and includes a controller 110 that functions as a data processing unit that executes data processing, a storage unit 120, and the like.

The information processing device (host) is equipped with an information storage device (media) such as a memory card, and the data processing unit of the information storage device (media) executes communication with the server via the information processing device (host). Then, the processing after step S201 shown in the figure is sequentially executed to execute the content download processing and recording processing.
Hereinafter, the details of the processing after step S201 will be described.

(Step S201)
First, the server transmits content to the information storage device.
As a premise of this process, for example, a process in which a user operating the information processing apparatus accesses the server, displays a list of contents provided by the server on the display of the information processing apparatus, and the user selects download contents, etc. Is done.
The server transmits content according to the user's specification.
Note that the transmission content is an encrypted content encrypted with a title key corresponding to the content. The title key is an encryption key generated by the server as a content-compatible encryption key.

(Step S202)
In step S202, the encrypted content transmitted from the server is recorded in the general-purpose area (user data area) of the information storage device.
Note that the content cannot be reproduced or used only by acquiring the encrypted content. It is necessary to acquire a title key that is an encryption key corresponding to the encrypted content.

  As described above, the processing of (A) described with reference to FIG. 9, that is, the content provision / recording processing limited to the information processing apparatus (host) capable of reproducing the content is performed, and then provided. It is also possible to switch the content of the information processing device (host) that can reproduce the content to a content that does not limit the content, and the processing of steps S201 to S202 is omitted for such an information storage device that has acquired the content. Only the processing after step S203 is performed.

(Step S203)
In step S203, mutual authentication processing and session key (= bus key: Bk) exchange processing are executed between the server and the information storage device. This process is a mutual authentication process and a key exchange process in accordance with a public key cryptosystem, and performs both reliability confirmation and session key (= bus key: Bk) generation and sharing processes.

Specifically, each device verifies the signature of the other party's public key certificate, and further confirms that the device ID recorded in the public key certificate is not recorded in the revocation list.
If the signature verification fails or the device ID is registered in the revocation list, the subsequent processing is not executed. That is, content provision, recording processing, and the like are not executed.

(Steps S204 to S205)
In steps S204 to S205, revocation list synchronization processing is executed. That is, if the version of the revocation list stored in the information storage device is older than the version of the revocation list held by the server, a new revocation list is provided from the server to the information storage device and stored in the information storage device. The revocation list is updated by replacing the old revocation list with the new revocation list.

(Step S206)
Next, in step S206, the server generates a title key to be stored in the information storage device (media), encrypts it with the session key (= bus key: Bk) generated in step S203, and transmits it to the information storage device.

(Step S207)
Next, in step S207, the information storage device decrypts the encrypted title key received from the server by applying the session key (= bus key: Bk) generated in step S203, and acquires and acquires the title key. The recorded title key is recorded in the protected area (secure area).

(Step S208)
Next, in step S208, the server transmits usage control information (Usage Rule) corresponding to the encrypted content transmitted in step S101 to the information storage device.
The usage control information (Usage Rule) is a data file having the data configuration described above with reference to FIG.
In this usage control information (Usage Rule), a sub key flag (SubKey Flag) indicating whether or not to use a sub key for generating a title key applied to content decryption is recorded.
The content transmitted in the sequence shown in FIG. 11 is content that is not limited by the playback host, and the sub-key flag is recorded with a flag indicating that the sub-key is not used for generating the title key.

(Step S209)
Next, in step S209, the information storage device records the usage control information (Usage Rule) received from the server in the general-purpose area (user data area).
In this usage control information (Usage Rule), a sub key flag (SubKey Flag) indicating whether or not to use a sub key for generating a title key applied to content decryption is recorded.
The content transmitted in the sequence shown in FIG. 11 is content that is not limited by the playback host, and the sub-key flag is set with a flag indicating that the sub-key is not used for generating the title key.

According to the sequence shown in FIG. 11, the general-purpose area of the information storage device has the following data provided from the server, that is,
(1) encrypted content,
(2) Usage control information These data are recorded,
In the protected area of the information storage device, the following data provided by the server, that is,
(3) The title key is stored.

[7. Usage sequence of content stored in information storage device (media)]
Next, a processing sequence in the case of reproducing the content recorded in the information storage device (medium) according to the sequence shown in FIG. 9 or FIG. 11 will be described with reference to FIGS.

As described with reference to FIGS. 9 to 11, the server selectively executes the following two different content provision and recording processes when content is provided and recorded on the information storage device (media). .
(A) Content provision and recording processing limited to information processing apparatus (host) capable of reproducing content (B) Content provision and recording processing not limited to information processing apparatus (host) capable of reproducing content (B) Two types of content provision and recording processing are selectively executed.

The content reproduction sequence shown in FIGS. 12 to 13 is a processing sequence in the case of reproducing the content limited to (A) the reproduction host described with reference to FIG.
The content playback sequence shown in FIG. 14 is a processing sequence in the case of playing back content that is not limited to the playback host (B) described with reference to FIG.
Hereinafter, each of these processes will be described sequentially.

[7-1. (A) Content playback processing with limited information processing device (host) capable of content playback]
First, with reference to FIG. 12 to FIG. 13, a content reproduction process in which information processing apparatuses (hosts) capable of reproducing content are limited will be described.
12 to 13,
(1) Information processing apparatus [host (Host = Player)] for executing content reproduction processing;
(2) Information storage device storing content [Media (Memory Card)]
These are shown.
Content playback is performed by sequentially executing the processes in and after step S301 shown in FIGS. Hereinafter, processing of each step will be described.

(Step S301)
First, a mutual authentication process and a session key (= bus key: Bk) exchange process are executed between the information processing apparatus that executes the content reproduction process and the information storage device that stores the content. This process is a mutual authentication process and a key exchange process in accordance with a public key cryptosystem, and performs both reliability confirmation and session key (= bus key: Bk) generation and sharing processes.

(Steps S302a and 302b)
When mutual authentication is established and it is confirmed that both devices are reliable devices, the information processing apparatus next converts the converted title key (in the protected area of the information storage device) in steps S302a and 302b ( XORed Title Key) is read out.
This converted title key (XORed Title Key) is the title key for media storage generated by the server in step S110 in the sequence diagram of FIG. 9 described above, and is an exclusive OR operation result of the title key and the sub key. . That is,
XORed Title Key = Title Key (xor) SubKey
It is.

In the data reading process from the protected area, a process for determining whether or not the information processing apparatus has an access right to the title key storage area of the protected area is executed. This determination process is performed by the information storage device with reference to the record information of the public key certificate (Host Certificate) received from the information processing device, for example.
In this determination process, only when it is determined that the information processing apparatus has an access right to the title key storage area of the protection area, the title key reading in steps S302a and 302b is executed.
If it is determined that the information processing apparatus does not have access rights to the title key storage area of the protected area, the title key reading in steps S302a and S302b is not executed. In this case, content reproduction is not executed.

(Steps S303a and 303b)
Next, in steps S303a and 303b, the information processing apparatus performs a process of reading usage control information (Usage Rule) stored in the general-purpose area of the information storage device.
Usage control information (Usage Rule) is information that stores the data described above with reference to FIG.

(Step S304)
Next, in step S304, the information processing apparatus confirms the subkey flag recorded in the acquired usage control information (Usage Rule). As described above with reference to FIG. 5, the subkey flag (SubKey Flag) indicates whether or not a subkey is required when generating a title key that is an encryption key applied to content encryption and decryption processing. It is a flag indicating that. For example, the following setting flags are recorded.
Flag = 0: The subkey is not used for generating the title key.
Flag = 1: A subkey is used to generate a title key.

The content playback sequence shown in FIG.
(A) Content reproduction processing that restricts information processing apparatuses (hosts) capable of reproducing content, and is set to use a sub key for generating a title key.
Accordingly, the sub key flag recorded in the usage control information (Usage Rule) is a flag (for example, flag = 1) indicating a setting for using the sub key for generating the title key.

(Step S305)
Next, in step S305, the information processing apparatus transmits a sub key (SubKey) acquisition request to the information storage apparatus.

(Step S306)
Next, in step S306, the information storage device generates a subkey (SubKey). The sub key (SubKey) is generated according to the following formula, for example.
SubKey = Hash (Km || Host ID)
That is, a hash value of the concatenated data of the secret key (Km) of the information storage device and the host ID is calculated, and this calculated value is set as a sub key (SubKey).
The host ID is acquired from the host certificate (Host Certificate) acquired from the information processing apparatus (host) during the authentication process in step S301.

  This subkey calculation is performed as the same process as the subkey calculation process of step S108 described above with reference to FIG.

As described above with reference to FIG. 9, the subkey generation processing example described above is an example, and the subkey is data generated by applying the secret key (Km) of the information storage device and the host ID. For example, the encrypted data of the host ID to which the secret key (Km) of the information storage device is applied may be set as the sub key.
However, the subkey generation process in step S108 in FIG. 9 and the subkey generation process in step S306 shown in FIG. 13 are executed in the same processing mode.

(Step S307)
When the generation of the sub key (SubKey) is executed in step S306, the information storage device encrypts the generated sub key with the session key (Bk) and transmits it to the information processing device (host) in step S307. That is,
Enc (Bk, SubKey)
The above encryption key data is transmitted to the information processing apparatus (host).

(Step S308)
Next, the information processing apparatus that has received the encryption key data Enc (Bk, SubKey) from the information storage device acquires a subkey (SubKey) by decrypting the encryption key data Enc (Bk, SubKey).
Further, the title key (Title Key) is calculated by executing a calculation process using the acquired subkey (SubKey) and the converted title key (XORed Title Key) read from the information storage device in Steps S302a and S302b.

The title key calculation process is executed according to the following equation.
Title Key = XORed Title Key (xor) SubKey
The title key is calculated according to the above formula.

  When the converted title key (XORed Title Key) is generated as an exclusive OR result of the sub key and the usage control information (Usage Rule) hash value, the usage control information (Usage Rule) hash value is further increased. Perform exclusive OR operation to calculate title key.

(Step S309)
Next, the information processing apparatus reads the encrypted content to be reproduced from the general-purpose area of the information storage device in step S309.

(Step S310)
Finally, the information processing apparatus performs a decryption process using the title key calculated in step S308 on the encrypted content read from the information storage device in step S309, and reproduces the content as the decryption result.

  As described above, in the process of reproducing the encrypted content stored in the information storage device, it is necessary to first obtain a subkey and generate a title key using the obtained subkey.

Here, a host identifier (Host ID) is used to generate the subkey.
That is, a subkey calculation process according to the following equation is performed.
SubKey = Hash (Km || Host ID)
That is, a hash value of the concatenated data of the secret key (Km) of the information storage device and the host ID is calculated, and this calculated value is set as a sub key (SubKey).
The host ID is acquired from the host certificate (Host Certificate) acquired from the information processing apparatus (host) during the authentication process in step S301.

If the subkey does not match the subkey generated in the content download process described with reference to FIG. 9, it is not possible to generate a correct title key to be applied to content decryption.
That is, at the time of content download, if the information processing apparatus (host) that provided the host ID to the server in step S101 shown in FIG. 9 does not match the information processing apparatus (host) shown in FIGS. A subkey for generating a key cannot be generated.

As a result, the information processing apparatus (host) that can execute the content reproduction process is limited to the information processing apparatus (host) that provided the host ID to the server in step S101 shown in FIG. Other information processing apparatuses (hosts) cannot perform content reproduction processing.
In this way, by following the processing sequence of the present disclosure, it is possible to limit information processing apparatuses (hosts) capable of reproducing content.

  The conditions that allow content reproduction, that is, the host that can generate the subkey that can generate the correct title key that can decrypt the encrypted content is only the host used for the content download process.

[7-2. (B) Content playback processing that does not limit information processing devices (hosts) capable of content playback]
Next, content reproduction processing that does not limit information processing apparatuses (hosts) capable of reproducing content will be described with reference to FIG.
In FIG.
(1) Information processing apparatus [host (Host = Player)] for executing content reproduction processing;
(2) Information storage device storing content [Media (Memory Card)]
These are shown.
Content playback is performed by sequentially executing the processing in step S401 and subsequent steps shown in FIG. Hereinafter, processing of each step will be described.

(Step S401)
First, a mutual authentication process and a session key (= bus key: Bk) exchange process are executed between the information processing apparatus that executes the content reproduction process and the information storage device that stores the content. This process is a mutual authentication process and a key exchange process in accordance with a public key cryptosystem, and performs both reliability confirmation and session key (= bus key: Bk) generation and sharing processes.

(Steps S402a and 402b)
When mutual authentication is established and it is confirmed that both devices are reliable devices, the information processing apparatus next performs the title key (Title) stored in the protection area of the information storage device in steps S402a and 402b. (Key) is read out.
The title key is a title key that is transmitted from the server to the information storage device in steps S206 to S207 in the sequence diagram of FIG. 11 described above and stored in the protection area of the information storage device.

In the data reading process from the protected area, a process for determining whether or not the information processing apparatus has an access right to the title key storage area of the protected area is executed. This determination process is performed by the information storage device with reference to the record information of the public key certificate (Host Certificate) received from the information processing device, for example.
In this determination process, only when it is determined that the information processing apparatus has an access right to the title key storage area of the protected area, the title key reading in steps S402a and 402b is executed.
If it is determined that the information processing apparatus does not have access rights to the title key storage area of the protection area, the title key reading in steps S402a and S402 is not executed. In this case, content reproduction is not executed.

(Steps S403a and 403b)
Next, in steps S403a and 403b, the information processing apparatus performs a process of reading usage control information (Usage Rule) stored in the general-purpose area of the information storage device.
Usage control information (Usage Rule) is information that stores the data described above with reference to FIG.

(Step S404)
Next, in step S404, the information processing apparatus checks the subkey flag recorded in the acquired usage control information (Usage Rule). As described above with reference to FIG. 5, the subkey flag (SubKey Flag) indicates whether or not a subkey is required when generating a title key that is an encryption key applied to content encryption and decryption processing. It is a flag indicating that. For example, the following setting flags are recorded.
Flag = 0: The subkey is not used for generating the title key.
Flag = 1: A subkey is used to generate a title key.

The content playback sequence shown in FIG.
(B) Content playback processing that does not limit information processing apparatuses (hosts) that can play back content, and the setting is made so that a subkey is not used to generate a title key.
Therefore, the subkey flag recorded in the usage control information (Usage Rule) is a flag (for example, flag = 0) indicating a setting not to use the subkey for generating the title key.

(Step S405)
Next, in step S405, the information processing apparatus reads the encrypted content scheduled to be reproduced from the general-purpose area of the information storage device.

(Step S406)
Finally, the information processing apparatus executes a decryption process that applies the title key read from the protected area of the information storage device in step S402 to the encrypted content read from the information storage device in step S405, and outputs the decryption result. Playback of the content.

in this way,
(B) In content playback processing that does not limit information processing devices (hosts) that can play back content, it is not necessary to acquire a subkey, and content is obtained by decryption processing using a title key read from a protected area of the information storage device. Playback is possible.

Subkey generation to which the host ID is applied is unnecessary as shown in FIGS.
Accordingly, the host capable of content reproduction processing is not limited to the information processing apparatus (host) that provides the host ID to the server in step S101 shown in FIG. The content can be decrypted and reproduced in various information processing devices (hosts) equipped with the information storage device.
However, it is necessary that the host has an access right to the protection area of the information storage device storing the title key.

[8. About hardware configuration example of each device]
Finally, with reference to FIG. 15 and FIG. 16, a hardware configuration example of each apparatus that executes the above-described processing will be described.
FIG. 15 illustrates a hardware configuration example of an information processing apparatus applicable to an information processing apparatus that executes content recording on a medium or content reproduction from the medium, a content providing apparatus such as a content providing server, and a license management apparatus.

  A CPU (Central Processing Unit) 701 functions as a data processing unit that executes various processes according to a program stored in a ROM (Read Only Memory) 702 or a storage unit 708. For example, processing according to the above-described sequence is executed. A RAM (Random Access Memory) 703 stores programs executed by the CPU 701, data, and the like. The CPU 701, ROM 702, and RAM 703 are connected to each other via a bus 704.

  The CPU 701 is connected to an input / output interface 705 via a bus 704. The input / output interface 705 is connected to an input unit 706 including various switches, a keyboard, a mouse, and a microphone, and an output unit 707 including a display and a speaker. Yes. The CPU 701 executes various processes in response to commands input from the input unit 706 and outputs the processing results to the output unit 707, for example.

  The storage unit 708 connected to the input / output interface 705 includes, for example, a hard disk and stores programs executed by the CPU 701 and various data. A communication unit 709 communicates with an external device via a network such as the Internet or a local area network.

  A drive 710 connected to the input / output interface 705 drives a removable medium 711 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory such as a memory card, and records various data such as recorded contents and key information. To get. For example, using the acquired content and key data, the content is decrypted and played back according to the playback program executed by the CPU.

FIG. 16 illustrates a hardware configuration example of a memory card that is an information storage device.
A CPU (Central Processing Unit) 801 functions as a data processing unit that executes various processes according to a program stored in a ROM (Read Only Memory) 802 or a storage unit 807. For example, the communication processing with the server or host device described in each of the above-described embodiments, the processing such as writing and reading of the data in the storage unit 807, the access permission determination processing for each divided area of the protection area 811 of the storage unit 807, and the like. Run. A RAM (Random Access Memory) 803 appropriately stores programs executed by the CPU 801, data, and the like. These CPU 801, ROM 802, and RAM 803 are connected to each other by a bus 804.

  The CPU 801 is connected to an input / output interface 805 via a bus 804, and a communication unit 806 and a storage unit 807 are connected to the input / output interface 805.

  A communication unit 804 connected to the input / output interface 805 executes communication with, for example, a server or a host. The storage unit 807 is a data storage area, and includes a protection area 811 with access restrictions as described above and a general-purpose area 812 that allows free data recording and reading.

[9. Summary of composition of the present disclosure]
As described above, the embodiments of the present disclosure have been described in detail with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiments without departing from the gist of the present disclosure. In other words, the present invention has been disclosed in the form of exemplification, and should not be interpreted in a limited manner. In order to determine the gist of the present disclosure, the claims should be taken into consideration.

The technology disclosed in this specification can take the following configurations.
(1) a storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The data processing unit
The information processing apparatus or application that performs decryption of the encrypted content is executed by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. An information storage device that executes processing for output.

(2) When the encrypted content is recorded in the storage unit, the data processing unit receives the host ID from the server that performs the content providing process, and generates the subkey by applying the received host ID. The information storage device according to (1), wherein a subtitle is transmitted to the server, and a converted title key generated by applying the subkey by the server is stored in the storage unit.
(3) The host ID provided by the server is an identifier of an information processing device or application in which the information storage device is mounted during content provision processing, and is an identifier of an information processing device or application that allows reproduction of the provided content. The information storage device according to (2).
(4) On the condition that the data processing unit confirms that the certificate holding entity is the server based on the type information recorded in the server certificate received from the server during the authentication process with the server. The information storage device according to (2), wherein a subkey generation process to which the receiving host ID is applied is executed.

(5) The information storage device according to any one of (1) to (4), wherein the conversion title key is an exclusive OR operation result of the title key and the subkey.
(6) The information storage device according to any one of (1) to (5), wherein the data processing unit generates the subkey by arithmetic processing or encryption processing using a unique key of the information storage device and the host ID.
(7) The information according to any one of (1) to (6), wherein the data processing unit executes a subkey generation process using a hash value of the concatenated data of the unique key of the information storage device and the host ID as the subkey. Storage device.

(8) The data processing unit acquires the host ID from the stored data of the host public key certificate storing the public key of the host, and executes a subkey generation process using the acquired host ID. The information storage device according to any one of 1) to (7).
(9) The storage unit is configured to store usage control information corresponding to the encrypted content, and the usage control information includes a subkey indicating whether the subkey is required for the title key generation process. The information storage device according to any one of (1) to (8), wherein the flag is recorded.

(10) having a data processing unit for mounting the medium storing the encrypted content encrypted by the title key and executing the decryption and reproduction processing of the content;
The data processing unit
Obtaining usage control information corresponding to the content to be played from the media;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
When the sub key flag is a setting indicating that the sub key use is not necessary for the generation of the title key, the title key is acquired from the media;
An information processing apparatus that performs decryption processing of the encrypted content by applying a generated or acquired title key.

  (11) When the subkey flag is a setting indicating that the subkey is required to generate the title key, the data processing unit determines the exclusive logic between the converted title key and the subkey acquired from the medium. The information processing apparatus according to (10), wherein the title key generation process is executed by a sum operation.

(12) A server that transmits content to an information storage device,
Receiving a host ID that is an identifier of a device or application that executes content reproduction processing from an information processing device equipped with the information storage device;
The received host ID is transmitted to the information storage device, the information storage device receives a subkey generated by applying the host ID, and the received subkey is applied to convert the title key that is the encryption key of the content A server that executes a process of generating a converted title key and transmitting the generated converted title key as stored data of the information storage device.

(13) An encrypted content and an information storage device that stores usage control information corresponding to the encrypted content;
An information processing system having an information processing apparatus that executes a reproduction process of the encrypted content,
The information processing apparatus includes:
Obtaining usage control information corresponding to the encrypted content to be reproduced from the information storage device;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary to generate the title key, a subkey acquisition request is output to the information storage device,
The information storage device includes:
Execute a subkey generation process using a host ID that is an identifier of the information processing apparatus, and output the generated subkey to the information processing apparatus;
The information processing apparatus includes:
Performing a title key generation process using a subkey obtained from the information storage device;
An information processing system that executes decryption processing of the encrypted content by applying a generated title key.

  Furthermore, the configuration of the present disclosure includes a method of processing executed in the above-described apparatus and system, and a program for executing the processing.

  The series of processing described in the specification can be executed by hardware, software, or a combined configuration of both. When executing processing by software, the program recording the processing sequence is installed in a memory in a computer incorporated in dedicated hardware and executed, or the program is executed on a general-purpose computer capable of executing various processing. It can be installed and run. For example, the program can be recorded in advance on a recording medium. In addition to being installed on a computer from a recording medium, the program can be received via a network such as a LAN (Local Area Network) or the Internet and can be installed on a recording medium such as a built-in hard disk.

  Note that the various processes described in the specification are not only executed in time series according to the description, but may be executed in parallel or individually according to the processing capability of the apparatus that executes the processes or as necessary. Further, in this specification, the system is a logical set configuration of a plurality of devices, and the devices of each configuration are not limited to being in the same casing.

As described above, according to the configuration of an embodiment of the present disclosure, content usage control in which hosts that permit content reproduction are limited is realized.
Specifically, an information storage device such as a memory card stores a converted title key obtained by converting the encrypted content and a title key that is an encryption key, and generates a subkey to be applied to title key calculation from the converted title key. The sub key is generated by applying the host ID acquired from the server when recording the content. At the time of content playback, a host ID that is an identifier of the playback device is acquired from a playback device that decrypts the encrypted content, a subkey is generated by applying the acquired host ID, and is output to the playback device. Only a playback device having the same host ID as the host ID applied to the subkey generation at the time of download succeeds in generating a correct title key based on the subkey, and can decrypt and play back the content.
With these configurations, content usage control that limits hosts that permit content playback is realized.

DESCRIPTION OF SYMBOLS 11 Broadcasting station 12 Content server 20 Information processing apparatus 21 Recording / playback dedicated device 22 PC
23 Mobile terminal 30 Information storage device 31 Memory card 110 Controller (data processing unit)
111 CPU
112 RAM
120 storage unit 121 general-purpose area (user data area)
122 Protection area (secure area)
131 Content 132 Usage Control Information 133 Title Key 134 Revocation List 135 Media Private Key 136 Media Public Key Certificate 137 License Management Device Public Key 140 Communication IF
210 Data processing unit 211 CPU
212 RAM
220 Storage Unit 221 Host Private Key 222 Host Public Key Certificate 223 License Management Device Public Key 224 Revocation List 240 Communication IF
701 CPU
702 ROM
703 RAM
704 Bus 705 Input / output interface 706 Input unit 707 Output unit 708 Storage unit 709 Communication unit 710 Drive 711 Removable media 801 CPU
802 ROM
803 RAM
804 Bus 805 I / O interface 806 Communication unit 807 Storage unit 811 Protection area 812 General-purpose area

Claims (19)

A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The data processing unit
The information processing apparatus or application that performs decryption of the encrypted content is executed by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. An information storage device that executes processing for output. The data processing unit
When recording encrypted content to the storage unit,
A conversion title key generated by receiving a host ID from a server that performs content providing processing, generating a subkey by applying the received host ID, transmitting the generated subkey to the server, and applying the subkey by the server The information storage device according to claim 1, wherein the information is stored in the storage unit.   3. The host ID provided by the server is an identifier of an information processing apparatus or application in which the information storage device is mounted during content provision processing, and is an identifier of an information processing apparatus or application that allows reproduction of the provided content. The information storage device described in 1. The data processing unit
Subkey generation using the received host ID on the condition that the certificate holding entity has been confirmed based on the type information recorded in the server certificate received from the server during the authentication process with the server The information storage device according to claim 2 which performs processing.   The information storage device according to claim 1, wherein the conversion title key is an exclusive OR operation result of the title key and the subkey. The data processing unit
The information storage device according to claim 1, wherein the subkey is generated by arithmetic processing or encryption processing using the unique key of the information storage device and the host ID. The data processing unit
The information storage device according to claim 1, wherein a subkey generation process is performed using the hash value of the concatenated data of the unique key of the information storage device and the host ID as the subkey. The data processing unit
The information storage device according to claim 1, wherein the host ID is acquired from storage data of a host public key certificate storing the host public key, and a subkey generation process is executed to which the acquired host ID is applied. The storage unit is configured to store usage control information corresponding to the encrypted content,
The information storage device according to claim 1, wherein the usage control information includes a subkey flag indicating whether or not the subkey is required for the title key generation process. A data processing unit for performing decryption and reproduction processing of content by mounting media storing encrypted content encrypted by a title key,
The data processing unit
Obtaining usage control information corresponding to the content to be played from the media;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
When the sub key flag is a setting indicating that the sub key use is not necessary for the generation of the title key, the title key is acquired from the media;
An information processing apparatus that performs decryption processing of the encrypted content by applying a generated or acquired title key. The data processing unit
If the subkey flag is set to indicate that the subkey must be used to generate the title key, a title key generation process is executed by an exclusive OR operation between the converted title key acquired from the media and the subkey. The information processing apparatus according to claim 10. A server that transmits content to an information storage device;
Receiving a host ID that is an identifier of a device or application that executes content reproduction processing from an information processing device equipped with the information storage device;
The received host ID is transmitted to the information storage device, the information storage device receives a subkey generated by applying the host ID, and the received subkey is applied to convert the title key that is the encryption key of the content A server that executes a process of generating a converted title key and transmitting the generated converted title key as stored data of the information storage device. An information storage device storing encrypted content and usage control information corresponding to the encrypted content;
An information processing system having an information processing apparatus that executes a reproduction process of the encrypted content,
The information processing apparatus includes:
Obtaining usage control information corresponding to the encrypted content to be reproduced from the information storage device;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary to generate the title key, a subkey acquisition request is output to the information storage device,
The information storage device includes:
Execute a subkey generation process using a host ID that is an identifier of the information processing apparatus, and output the generated subkey to the information processing apparatus;
The information processing apparatus includes:
Performing a title key generation process using a subkey obtained from the information storage device;
An information processing system that executes decryption processing of the encrypted content by applying a generated title key. An information processing method executed in an information storage device,
The information storage device includes:
A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The data processing unit
The information processing apparatus or application that performs decryption of the encrypted content is executed by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. An information processing method for executing a process for output. An information processing method for performing decryption and reproduction of content stored in a medium in an information processing device,
The information processing apparatus includes a data processing unit that loads a medium storing encrypted content encrypted by a title key and executes content decryption and reproduction processing;
The data processing unit
Obtaining usage control information corresponding to the content to be played from the media;
Check the setting of the subkey flag recorded in the obtained usage control information,
If the subkey flag is a setting indicating that the subkey usage is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
When the sub key flag is a setting indicating that the sub key use is not necessary for the generation of the title key, the title key is acquired from the media;
An information processing method for performing decryption processing of the encrypted content by applying a generated or acquired title key. An information processing method executed in a server that transmits content to an information storage device,
Receiving a host ID that is an identifier of a device or application that executes content reproduction processing from an information processing device equipped with the information storage device;
The received host ID is transmitted to the information storage device, the information storage device receives a subkey generated by applying the host ID, and the received subkey is applied to convert the title key that is the encryption key of the content An information processing method for generating a converted title key and transmitting the generated converted title key as stored data in the information storage device. A program for executing information processing in an information storage device;
The information storage device includes:
A storage unit that stores encrypted content and a converted title key obtained by converting a title key that is an encryption key applied to decryption of the encrypted content;
A data processing unit that generates a subkey to be applied to calculate a title key from the converted title key stored in the storage unit;
The program is stored in the data processing unit.
The information processing apparatus or application that performs decryption of the encrypted content by executing a subkey generation process using a host ID that is an identifier of a host that is an information processing apparatus or application that performs decryption of the encrypted content. A program that executes processing to be output. In an information processing device, a program for executing decryption and reproduction of content stored in a medium,
The information processing apparatus includes a data processing unit that loads a medium storing encrypted content encrypted by a title key and executes content decryption and reproduction processing;
The program is stored in the data processing unit.
Acquisition processing of usage control information corresponding to the content to be played from the media;
Execute the confirmation process of the setting of the sub key flag recorded in the acquired usage control information,
If the subkey flag is a setting indicating that the subkey use is necessary for the generation of the title key, the subkey is acquired from the media, and the title key generation process using the acquired subkey is executed.
If the subkey flag is a setting indicating that the use of a subkey is not necessary for the generation of the title key, a process of acquiring a title key from the medium is executed, and
A program for executing decryption processing of the encrypted content by applying a title key generated or acquired. A program that executes information processing in a server that transmits content to an information storage device,
A process of receiving a host ID which is an identifier of an apparatus or application for executing a content reproduction process from an information processing apparatus equipped with the information storage apparatus;
A process of transmitting the received host ID to the information storage device;
Processing in which the information storage device receives a subkey generated by applying a host ID, converts a title key that is an encryption key of the content by applying the subkey, and generates a converted title key;
A program for executing processing for transmitting the generated converted title key as stored data of the information storage device.