JP5908296B2 - Information terminal device, information terminal system, information terminal control method, and program - Google Patents

Description

  The present invention relates to an information terminal device, an information terminal system, an information terminal control method, and a program that can reproduce information such as moving image data that is encrypted and distributed.

  As a prior art, there is a digital right management (Digital Right Management: hereinafter referred to as “DRM”) system described in Patent Document 1. This DRM system is a system that operates on a user's computer in cooperation with a content server, a license server, and a black box server.

  When the user's computer obtains the encrypted digital content from the content server and plays it back with the rendering application, the rendering application calls the DRM system. The DRM system is equipped with a black box that performs encryption and decryption functions.

  FIG. 10 is a block diagram illustrating a configuration of a main part of the DRM system 90. The black box 93 is downloaded from the black box server 97 and updated regularly. The black box 93a is an old black box 93 before being updated, and the black box 93b is a new black box 93 after being updated. The DRM system 90 is controlled using a new black box 93b.

  The black box 93 includes a public / private key pair 95. The license server 96 encrypts the decryption key of the digital content and the license conditions with the public key of the black box 93, and transmits it as a license to the user's computer. The DRM system 90 stores the received license in the license store 92.

  When there is a digital content playback request, the license evaluation unit 91 causes the black box 93 to decrypt the decryption key and the license condition stored in the license store 92 with the secret key. Further, the license evaluation unit 91 causes the black box 93 to decrypt the encrypted digital content using the decrypted decryption key when the decrypted license condition permits the reproduction of the digital content. Then, the rendering application reproduces the decrypted digital content.

  Since the license store 92 stores the encrypted decryption key, the license store 92 is stored in a storage area accessible to general users. However, the license evaluation unit 91 and the black box 93 cannot be accessed by general users. It is stored in the storage area.

  Conventionally, in a service for distributing encrypted video over a network, each information terminal device that reproduces the video needs to store a decryption key in order to decrypt the encrypted video. is there. The decryption key needs to be stored in a protected storage area so that it is not used by an unintended program or taken out of the information terminal device.

  2. Description of the Related Art Conventionally, in a device that can reproduce a moving image or the like, a secure storage area is provided in the device, and a decryption key is stored in the secure storage area at the time of shipment. Such a secure storage area is protected by hardware, and cannot be used from an unintended program or taken out from the information terminal device.

Japanese translation of PCT publication No. 2003-522989

  Conventionally, when encrypting and distributing content such as video and music, in order to prevent leakage of encryption key information, write encryption key information in an area that cannot be rewritten except at the time of shipment. In general, it is impossible for a general user to access the information, and a method for securely storing key information is also required when such a moving image distribution is performed on a smartphone or the like.

  In a portable information terminal device such as a smartphone, an application program for an information terminal device (hereinafter also referred to as “application”) can be commonly executed by information terminal devices of each company, for example in Android (registered trademark). The movement to install the common platform represented in the hardware of each company is becoming active.

  In such a common platform, if a function that is uniquely installed by each company is used in an application, the application cannot be executed on a terminal that cannot use the function, and the purpose of application sharing cannot be achieved. Therefore, it is not desirable to implement a secure storage area by a method unique to each company in order to securely store the key information described above.

  In addition, such a function is not prepared in a common platform of each company, for example, a common platform such as Android. Therefore, the information terminal device according to the prior art cannot securely store the decryption key for decrypting the content such as the moving image that is encrypted and distributed.

  An object of the present invention is to provide an information terminal device, an information terminal system, an information terminal control method, and a program that can protect content such as moving images that are encrypted and distributed by using a decryption key for each application program. It is.

The present invention relates to an application received from an application distribution server device, which stores a plurality of applications for decrypting and reproducing encrypted content using a service key for decrypting the encrypted content A storage unit;
An application management unit that controls the execution of multiple applications stored in the application storage section,
A content receiving unit for receiving content encrypted for each application from a content distribution server device;
Wherein when requesting the service key distribution server device for distributing service key transmission of the service key, and transmits the service identification information for uniquely identifying the service that the application is compatible with the service key distribution server apparatus, the service A service key receiving unit that receives an encrypted service key from the key distribution server device ;
And a service key storage unit for storing a service key encrypted received by the service key receiving unit,
The service key needed to each application started by the application management unit decrypts the content that is the encrypted, read from the service key storage unit, read out the encrypted service key is the activated and a service key delivery section to pass to each application only contains,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key,
The content reproduction unit is an information terminal device that reproduces the content decrypted by the decryption unit .

In the present invention, the service key distributed by the service key distribution server device is encrypted,
Each application program includes a decryption unit including an application key uniquely generated for each application program in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content.
The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key,
The content playback unit plays back the content decrypted by the decryption unit.

In the present invention, the service key receiving unit includes client identification information for identifying its own information terminal device, and is included in the service key receiving unit when requesting the service key distribution server device to transmit a service key. Client identification information to be transmitted to the service key distribution server device,
The service key distribution server device authenticates the information terminal device including the service key receiving unit that has transmitted the client identification information based on the client identification information received from the service key receiving unit.

  Further, the present invention is characterized in that the service key distribution server device records the number of times a service key is issued for each client identification information transmitted from the service key receiving unit when a service key issuance request is made. .

Further, according to the present invention, the encrypted content reproduced by the application program is content distributed from a content distribution server device that distributes the encrypted content,
The service key distributed by the service key distribution server device is characterized in that a different value is generated each time a service key issuance request is made.

The present invention also distributes the encrypted content, and an application distribution server device for distributing a plurality of applications to be reproduced by decoding the service key for decrypting the content that is dark Goka, the service key and the service key distribution server apparatus, an information terminal system including a viable information terminal an application to be delivered from the application distribution server device,
The information terminal device
An application storage unit that stores a plurality of applications distributed from the application distribution server device ;
An application management unit that controls the execution of multiple applications stored in the application storage section,
A content receiving unit for receiving content encrypted for each application from a content distribution server device;
When requesting the transmission of the service key in the service key distribution server device transmits the service identification information for uniquely identifying the service that the application is compatible with the service key distribution server apparatus, the service key distribution server device and a service key reception unit for receiving a service key encrypted,
And a service key storage unit for storing a service key encrypted received by the service key receiving unit,
The service key needed to each application started by the application management unit decrypts the content that is the encrypted, read from the service key storage unit, read out the encrypted service key is the activated and a service key delivery section to pass to each application only contains,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key,
The content reproduction unit is an information terminal system for reproducing the content decrypted by the decryption unit .

The present invention also provides information terminal control executed by an information terminal device capable of executing a plurality of application programs for decrypting and reproducing encrypted content using a service key for decrypting the encrypted content. A method,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing the encrypted service key received in the service key reception step in a service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
A content terminal control method comprising: a playback step in which the content playback unit of each activated application plays back the content decrypted in the decryption step .

The present invention also provides a computer of an information terminal device including a computer capable of executing a plurality of application programs for decrypting and reproducing encrypted content using a service key for decrypting the encrypted content. ,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing the encrypted service key received in the service key reception step in a service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
A program for causing the content playback unit of each activated application to execute a playback step of playing back the content decrypted in the decryption step .

According to the present invention, the application storage unit is an application received from the application distribution server device , and decrypts the encrypted content using the service key for decrypting the encrypted content and reproduces it. Multiple applications to be stored are stored. Application management unit controls the execution of multiple applications stored in the application storage unit. The content receiving unit receives content encrypted for each application from the content distribution server device. Service key receiving unit, when requesting the transmission of the service key in the service key distribution server device for distributing the service key, service identification information the service key distribution server to uniquely identify the service the application is compatible The service key is transmitted to the apparatus and the encrypted service key is received from the service key distribution server apparatus . Service key storage unit stores the service key encrypted received by the service key receiving unit. The service key delivery unit, a service key needed to decrypt the content that the application started by the application management unit is the encrypted, read from the service key storage unit, are read out encrypted the service key was passed to each application, which is the start-up. Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt the encrypted service key, and a content reproduction unit that reproduces content. The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key, The content reproduction unit reproduces the content decrypted by the decryption unit .

Therefore, the information terminal device can be protected using encrypted content such as the application your capital videos are distributed decryption key, for example, a service key. In the prior art, it is necessary to write the service key in the information terminal device in advance. However, in this information terminal device, since the service key is downloaded from the service key distribution server and stored, the service key is written in advance. also not out information terminal device, it is possible to reproduce the result content to the application.
In addition, since the service key distribution server device can encrypt and transmit the service key with a different application key for each application, the service key is not decrypted by an unintended application. One service key receiving unit can receive service keys of a plurality of applications.
Each application includes a decryption unit and a content reproduction unit. The decrypting unit includes an application key uniquely generated for each application in order to decrypt the encrypted service key. The content reproduction unit reproduces content. The decryption unit decrypts the service key delivered from the service key delivery unit with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key. The content playback unit plays back the content decrypted by the decryption unit.
Therefore, since the service key distribution server device can encrypt and transmit the service key with a different application key for each application, the service key is not decrypted by an unintended application. One service key receiving unit can receive service keys of a plurality of applications.

  According to the present invention, the service key receiving unit includes client identification information for identifying its own information terminal device. When requesting the service key distribution server device to transmit a service key, the service key receiving unit Is transmitted to the service key distribution server device. Then, the service key distribution server device authenticates the information terminal device including the service key receiving unit that has transmitted the client identification information based on the client identification information received from the service key receiving unit. Therefore, since the service key distribution server device can identify the information terminal device by the client identification information, it can provide a service according to the model of the information terminal device.

  According to the present invention, the service key distribution server device records the number of times the service key has been issued for each client identification information transmitted from the service key receiving unit when issuing a service key request. Therefore, unauthorized terminals that frequently issue service key issuance requests can be identified, and such terminals are stored in the service key distribution server by taking measures such as stopping the issuance of service keys. It is possible to prevent the service key being used from being exhausted.

  According to the invention, the application receiving unit receives an application program from an application distribution server device that distributes the application program. The application storage unit stores the application program received by the application reception unit. The application program whose execution is controlled by the application management unit is an application program stored in the application storage unit.

  Therefore, the information terminal device can receive the application program and the service key from different server devices, and the service provider prepares the application program and the service key and distributes the application program and the service. It is only necessary to supply each to the server device that distributes the key. Therefore, it is possible to use a server device operated by another provider as a server for distributing the application program and the service key, and it is not necessary to operate it by itself.

  According to the present invention, the encrypted content reproduced by the application program is content distributed from a content distribution server device that distributes the encrypted content. The service key distributed by the service key distribution server device generates a different value each time a service key issuance request is made. Therefore, even if the content stored in the information terminal device is illegally copied to another information terminal device, the service key for decrypting the content is different, so the other information terminal device can decrypt the content. In other words, the information terminal device can prevent unauthorized use of the content.

  Therefore, even if the content stored in the information terminal device and the service key are illegally copied to the other information terminal device, the terminal individual information for decrypting the service key is different. Cannot be decrypted, and the information terminal device can prevent unauthorized use of the content.

According to the present invention, the encrypted content, and an application distribution server device for distributing a plurality of applications to be reproduced by decoding the service key for decrypting the content that is dark Goka, Service Key and the service key distribution server device for distributing is an information terminal system including a viable information terminal an application to be delivered from the application distribution server device.

The application storage unit stores a plurality of applications that are applications received from the application distribution server device and that decrypt the encrypted content using a service key for decrypting the encrypted content. . Application management unit controls the execution of multiple applications stored in the application storage unit. The content receiving unit receives content encrypted for each application from the content distribution server device. Service key receiving unit, when requesting the transmission of the service key in the service key distribution server device for distributing the service key, service identification information the service key distribution server to uniquely identify the service the application is compatible The service key is transmitted to the apparatus and the encrypted service key is received from the service key distribution server apparatus . Service key storage unit stores the service key encrypted received by the service key receiving unit. The service key delivery unit, a service key needed to decrypt the content that the application started by the application management unit is the encrypted, read from the service key storage unit, are read out encrypted the service key was passed to each application, which is the start-up. Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt the encrypted service key, and a content reproduction unit that reproduces content. The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key, The content reproduction unit reproduces the content decrypted by the decryption unit .

  Therefore, the information terminal system can protect contents such as moving images that are encrypted and distributed by using a decryption key, for example, a service key, for each application program. In the prior art, it is necessary to write the service key in the information terminal device in advance, but in this information terminal system, the service key is downloaded from the service key distribution server and stored in the information terminal device. Even in an information terminal device to which a service key is not written, content can be reproduced by an application program.

Further, according to the present invention, information executed by an information terminal device capable of executing a plurality of application programs for decrypting and reproducing the encrypted content with a service key for decrypting the encrypted content A terminal control method,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing the encrypted service key received in the service key reception step in a service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
The content playback unit of each activated application includes a playback step of playing back the content decrypted in the decryption step .

  Therefore, the information terminal control method can protect contents such as moving images that are encrypted and distributed by using a decryption key, for example, a service key, for each application program. In the prior art, it is necessary to write the service key in the information terminal device in advance, but in this information terminal control method, the service key is downloaded from the service key distribution server and stored in the information terminal device. Even an information terminal device to which a service key has not been written in advance can reproduce content by an application program.

According to the present invention, the content is encrypted, the information terminal apparatus including a plurality of applications capable of executing computer to reproduce and decode the service key for decrypting the content that is dark Goka On the computer,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing a plurality of encrypted service keys received in the service key reception step in the service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
The content reproduction unit of each activated application can be provided as a program for executing the reproduction step of reproducing the content decrypted in the decryption step .

It is a block diagram which shows the structure of the information terminal device 10 which is one Embodiment of this invention. It is a sequence diagram which shows the registration procedure of the content etc. by the service provider. 6 is a sequence diagram illustrating an installation procedure for an application 62 and the like in the terminal 10. FIG. FIG. 6 is a sequence diagram illustrating an application activation procedure in the terminal 10. It is a sequence diagram which shows the process sequence of first time reproduction | regeneration processing. It is a sequence diagram which shows the process sequence of a continuous reproduction process. It is a flowchart which shows the process sequence of an application starting process. It is a flowchart which shows the process sequence of first time reproduction | regeneration processing. It is a flowchart which shows the process sequence of a continuous reproduction process. It is a block diagram which shows the structure of the digital rights management system which is a prior art.

  FIG. 1 is a block diagram showing a configuration of an information terminal device 10 according to an embodiment of the present invention. The information terminal control method according to the present invention is executed by the information terminal device 10. An information terminal device (hereinafter referred to as “terminal”) 10 is included in the information terminal system 1. The information terminal system 1 includes a plurality of content servers 3, one application server 4, one service key distribution server 5, and at least one terminal 10.

  The terminal 10 is connected to the content server 3, the application server 4, and the service key distribution server 5 through an information communication network including a combination of the Internet, a local area network, and the like. The terminal 10 transmits / receives information to / from these servers via the information communication network.

  The service provider 2 is constituted by, for example, a server device or a user thereof. The service described here is a mechanism for distributing content data, such as video and music, to users who have paid a certain price via a network. The content is stored in the content server, and a portal site is prepared for the user who has registered as a user to select the content, and the content selected by the user on the portal site is viewed on the terminal. It is something that can be done. The user views the content by causing the terminal to execute a dedicated application for viewing the content.

  To be able to enjoy a certain service means that a plurality of contents provided in the service can be viewed. Generally, a terminal is provided with the service by one application. The system is configured to be able to view all the existing content. One service provider may provide a plurality of services, but this case is also treated as a different service service provider.

  The service provider 2 creates content and an application program that reproduces the content (hereinafter also simply referred to as “application”). The content includes moving image content and audio content. FIG. 1 shows a service provider 2a and a service provider 2b. Hereinafter, when it is not necessary to distinguish between the individual service providers 2a and 2b, they are collectively referred to as the service provider 2. Further, the contents server 3 and the like are collectively referred to by omitting alphabetic subscripts when it is not necessary to distinguish them individually.

  Each content is provided with content identification information for uniquely identifying each content. Each application is given application identification information for uniquely identifying each application.

  The service provider 2 is connected to the content server 3, the application server 4, and the service key distribution server 5 through an information communication network. The service provider 2 transmits / receives information to / from these servers via the information communication network. The content server 3, the application server 4, and the service key distribution server 5 can transmit and receive information to and from each other via the information communication network.

  The service provider 2 generates a plurality of sets for the service encryption key for encrypting the content and the service key for decrypting the content encrypted with the service encryption key. The service key includes service encryption key identification information for identifying the corresponding service encryption key. The generated service key is encrypted with an application key uniquely generated for each application. Then, the service provider 2 includes an application key uniquely generated for the application in the generated application.

  The service provider 2 associates the generated content with a service encryption key for encrypting the content, transmits it to the content server 3 provided for each service provider 2, and stores it in each content server 3 Let The content server 3 can identify the content by the content identification information that can uniquely identify the content.

  The service provider 2 creates an application, transmits it to the application server 4, and stores it in the application server 4. The application key is embedded in the application by an obfuscation method as described later. That is, the application key is analyzed so that the application key cannot be extracted. Further, the service provider 2 associates the service key (encrypted) so that it can be decrypted with the application key, and transmits it to the service key distribution server 5 in association with the service key identification information. Remember me.

  The content server 3 that is a content distribution server device is a server device that distributes content to the terminal 10. A content server 3 is provided for each service provider 2. That is, each content server 3 is associated with each service provider 2 on a one-to-one basis. FIG. 1 shows a content server 3a corresponding to the service provider 2a and a content server 3b corresponding to the service provider 2b.

  When there is a content transmission request from the terminal 10, the content server 3 transmits the content corresponding to the content identification information included in the content transmission request to the terminal 10 that has requested the content transmission. At the time of content transmission request, service key identification information included in the service key is also transmitted to the content server 3, and the content is encrypted with the service encryption key corresponding to the service key identification information, and then the terminal 10 Send to.

  The application server 4 that is an application distribution server device is a server device that distributes an application and a service key management application to the terminal 10. The application distributed by the application server 4 is an application for enjoying a service provided from each service provider 2. The application server 4 distributes the application requested for distribution from the terminal 10 to the terminal 10 that transmitted the distribution request. The application distributed to the terminal 10 is activated and executed on the distributed terminal 10.

  The service key management application distributed by the application server 4 can be executed in common by all terminals 10, but includes a client authentication key generated by the service provider 2. The client authentication key is embedded in the service key management application using an obfuscation method as described later. That is, the client authentication key cannot be extracted even if the service key management application distributed to the terminal 10 is analyzed.

  The service provider 2 registers the client authentication key embedded when creating the service key management application in the service key distribution server 5 in advance. The service key management application distributed to the terminal 10 is activated and executed on the distributed terminal 10.

  An encryption method for encrypting content using a service encryption key, and an encryption method for encrypting a service key so that it can be decrypted with an application key are a common key encryption method (secret key encryption method). Also called). Specifically, for example, a DES (Data Encryption Standard) system or an AES (Advanced Encryption Standard) system is used. As an encryption method other than the DES method or the AES method, a method such as triple DES, SNOW 2.0, RC4 (Rivest Cipher 4), Serpent, or Blowfish may be used.

  When an application key is included in an application or a client authentication key is included in a service key management application, it is obfuscated and embedded. Obfuscation is, for example, by analyzing the binary code of the application by decomposing the character string that makes up the application key and separating the code representing the decomposed character string into the program code. Is to make it difficult to extract the application key.

  The service key distribution server 5 that is a service key distribution server apparatus is a server apparatus that distributes a service key to the terminal 10. The service key distributed by the service key distribution server 5 is a service key provided from each service provider 2 and is encrypted with an application key. For one service, a plurality of service keys are provided from the service provider 2, and the service key itself is associated with a service identifier for identifying a service in which the service key is used. Saved.

  When there is a service key issuance request from the terminal 10, the service key distribution server 5 generates a service key having a different value every time the issuance request is issued, and uses the client authentication key transmitted along with the issuance request to Certify. That is, if the received client authentication key matches the client authentication key embedded when the service provider 2 creates the service key management application, the client authentication key is authenticated as a valid service key management application.

  Further, when the terminal 10 is normally authenticated, the service key distribution server 5 uses one of the service keys associated with the service identification information transmitted together with the issuance request as the terminal 10 that has transmitted the issuance request. Deliver to. The service key distribution server 5 discards the service key once issued, and issues a service key with another value for the next issue request. As a result, all the terminals 10 always have different service keys in time series.

  The terminal 10 includes an application management unit 20, a secure storage unit 50, and a normal storage unit 60. The hardware configuration of the terminal 10 is, for example, a central processing unit (hereinafter referred to as “CPU”), as in the case of an information processing device such as a personal computer or a portable information terminal (for example, a smartphone or a tablet terminal) according to the related art. A storage device including a semiconductor memory, a display device such as a liquid crystal display, an audio output device such as a speaker, and an input device such as a touch panel and operation buttons are included. The CPU controls the display device and the input device by executing a program stored in the storage device. The CPU, storage device, display device, audio output device, and input device are based on the prior art and are not shown in FIG.

  The application management unit 20 is a function realized by the CPU executing a program stored in the storage device. The application management unit 20 functions as an operating system, for example, and controls the execution of the application. The application management unit 20 is also an application reception unit.

  Specifically, the application management unit 20 receives an application and a service key management application distributed from the application server 4 and stores the received application and service key management application in the application program storage unit 61.

  In addition, when the user makes an application activation request using the input device, the application management unit 20 reads out the requested application from the application program storage unit 61 and stores it in the storage device, and activates the application stored in the storage device. And let it run.

  When the application management unit 20 activates and executes the application, it is necessary to activate the service key management application for the operation of the application. If the service key management application is not activated, the service key management is performed. The application is read from the application program storage unit 61 and stored in the storage device, and the service key management application stored in the storage device is activated and executed. Whether or not the service key management application needs to be activated for the operation of the application is described as a process inside the application.

  The secure storage unit 50 and the normal storage unit 60 are included in the storage device of the terminal 10. The secure storage unit 50 that is a terminal individual information storage unit is a secure storage area, that is, a storage area that cannot be rewritten by a general user. The secure storage unit 50 is an area in which a vendor of the terminal 10 writes a value by a special method at the time of shipment, and a general user cannot rewrite information stored in the secure storage unit 50. The normal storage unit 60 is a storage area that can be rewritten by a general user, and the general user can rewrite information stored in the normal storage unit 60.

  The secure storage unit 50 includes a terminal individual information storage unit 51. The terminal individual information storage unit 51 stores terminal individual information that can uniquely identify the terminal 10 itself. The individual terminal information is, for example, either a media access control (Media Access Control: hereinafter referred to as “MAC”) address, an international mobile equipment identifier (hereinafter referred to as “IMEI”), or a combination thereof. However, the present invention is not limited to these, and other information may be used as long as it is identification information uniquely assigned to the terminal 10.

  The normal storage unit 60 includes an application program storage unit 61, an application data storage unit 63, and a service key storage unit 65. The application program storage unit 61 receives an application distributed from the application server 4 by the application management unit 20 and stores the received application. The application program storage unit 61 shown in FIG. 1 stores applications 62a and 62b and a service key management application 67.

  The application 62a is an application generated by the service provider 2a, and the application 62b is an application generated by the service provider 2b. Each application 62 is provided with the above-described application identification information and stored in the application program storage unit 61, and each application 62 can be identified by the application identification information.

  The applications 62a and 62b and the service key management application 67 stored in the application program storage unit 61 are stored in the storage device, activated by the application management unit 20, and executed by the CPU.

  FIG. 1 shows applications 30a and 30b and a service key management application 40 executed by the CPU. The application 30a is the application 62a stored in the application program storage unit 61 is read out and stored in the storage device and executed. The application 30b is read out by the application 62b stored in the application program storage unit 61. In the service key management application 40, the service key management application 62c stored in the application program storage unit 61 is read out, stored in the storage device, and executed. It is what. The CPU can identify the application being executed based on the above-described application identification information.

  An application data storage unit 63 that is an application storage unit stores content data 64 received from the content server 3 by an application being executed. The content data 64 is data representing content. The application data storage unit 63 is provided for each installed application. The encrypted content, the content transmitted from the content server 3, and the content stored in the application data storage unit 63 are actually content data, but are hereinafter also simply referred to as content.

  FIG. 1 shows an application data storage unit 63a provided for the application 30a and an application data storage unit 63b provided for the application 30b. The application data storage unit 63a stores content data 64a received from the content server 3a by the application 30a. The application data storage unit 63b stores content data 64b received from the content server 3b by the application 30b.

  A service key storage unit 65 that is a service key storage unit stores a service key received from the service key distribution server 5 by a service key receiving unit 43 (to be described later) included in the service key management application 40. The service key storage unit 65 shown in FIG. 1 stores service keys 66a and 66b. The service key 66 a is a service key received by the service key receiving unit 43 from the service key distribution server 5 in response to a request from the application 30 a that has received a content reproduction request. The service key 66b is a service key received from the service key distribution server 5 by the service key receiving unit 43 in response to a request from the application 30b that has received a content reproduction request. The service key 66 is stored in the service key storage unit 65 in association with service identification information for uniquely identifying the service in which the service key is used.

  The application 30 includes a user interface unit (hereinafter referred to as “UI unit”) 31 and a license evaluation unit 32. The license evaluation unit 32 that is a decryption unit includes an application key 33. The application key 33 is an application key included in the application 62 received by the application management unit 20 from the application server 4. The license evaluation unit 32 decrypts the service key received from the service key reading unit 41 using the application key 33 included in the license evaluation unit 32, and the content data 64 read from the application data storage unit 63 using the decrypted service key. Is decrypted.

  The UI unit 31 which is a content reproduction unit reproduces content. Specifically, the UI unit 31 reproduces the content of the content data 64 decrypted by the license evaluation unit 32. If there is an image, the UI unit 31 displays the reproduced image on the display device, and if there is audio, The reproduced sound is output to the sound output device.

  The service key management application 40 includes a service key reading unit 41 and a service key receiving unit 43. The service key reading unit 41 serving as a service key delivery unit includes a terminal individual decryption unit 42. When the service key is requested from the license evaluation unit 32, the service key reading unit 41 requests the terminal individual decryption unit 42 to read the service key if the service key is already stored in the service key storage unit 65. . When the service key is requested from the license evaluation unit 32 and the service key is not yet stored in the service key storage unit 65, the service key reading unit 41 requests the service key reception unit 43 to acquire the service key. .

  When the service key reading unit 41 requests the service key reading unit 41 to read the service key, the terminal individual decoding unit 42 reads the service key 66 associated with the service identification information received together with the service key reading request from the service key storage unit 65, The read service key 66 is decrypted by the terminal individual information stored in the terminal individual information storage unit 51, and the decrypted service key is sent to the license evaluation unit 32.

  The service key receiving unit 43 includes a client authentication key 44 and a terminal individual encryption unit 45. The client authentication key 44 is a client authentication key embedded and distributed by the service provider 2 when creating the service key management application.

  When there is a service key acquisition request from the service key reading unit 41, the service key receiving unit 43 transmits service identification information received together with the service key acquisition request to the service key distribution server 5, and requests the service key to be issued. When the service key receiving unit 43 receives a service key associated with the transmitted service identification information from the service key distribution server 5, the terminal individual encryption unit 45 receives the service key received from the service key distribution server 5 as a terminal individual. Encryption is performed using terminal individual information stored in the information storage unit 51. Then, the terminal individual encryption unit 45 stores the service key encrypted by the terminal individual information in the service key storage unit 65 and notifies the service key reading unit 41 of the completion of service key acquisition. When the service key receiving unit 43 is informed of the completion of service key acquisition, the service key reading unit 41 requests the terminal individual decoding unit 42 to read the service key.

  FIG. 2 is a sequence diagram showing a procedure for registering content and the like by the service provider 2. In sequence S1, the service provider 2a uses a service key (plural) corresponding to a service encryption key used when encrypting the content created by the service provider 2a as service identification information of the service to which the content is distributed. Is transmitted to the service key distribution server 5 and registered. The service key is encrypted by the application key 33a of the application 62a created by the service provider 2a in order to reproduce the content created by the service provider 2a.

  In sequence S2, the service provider 2a transmits the application 62a created by the service provider 2a to the application server 4 and registers it. The application 62a includes an application key 33a. The inclusion includes, for example, that the application key 33a is embedded in the program code of the application 62a by the obfuscation method described above. The application 62a includes a service identifier of a service supported by the application. In sequence S3, the service provider 2a transmits the content data 64a representing the generated content to the content server 3a in association with the content identification information and registers it. The content identification information is a value that allows the content server 3a to uniquely identify the content, and is determined for each content by the service provider 2a. Content registration is performed for all content provided by the service.

  In sequence S4, the service provider 2a transmits the service key management application to the application server 4 and registers it. FIG. 2 shows a case where the service provider 2a is a service provider representing another service provider. The service key management application can be shared by a plurality of service providers, and is created and registered by a representative service provider. Other service providers do not create service key management applications, but only create and register applications. The representative service provider is not limited to the service provider 2a, and may be another service provider, for example, the service provider 2b.

  In sequence S5, the service provider 2a transmits the client authentication key included in the service key management application to the service key distribution server 5 for registration.

  In sequence S6, the service provider 2b uses the service key (plural) corresponding to the service encryption key used when encrypting the content created by the service provider 2b as the service identification information of the service to which the content is distributed. Is transmitted to the service key distribution server 5 and registered. The service key is encrypted by the application key 33b of the application 62b created by the service provider 2b in order to reproduce the content created by the service provider 2b.

  In sequence S7, the service provider 2b transmits the application 62b created by the service provider 2b to the application server 4 and registers it. The application 62b includes an application key 33b. Further, the application 62b includes service identification information of a service supported by the application. In sequence S8, the service provider 2b transmits the content data 64b representing the generated content to the content server 3b in association with the content identification information, registers it, and ends the registration procedure.

  FIG. 3 is a sequence diagram illustrating an installation procedure of the application 62 and the like in the terminal 10. When the user operates the input device to instruct the installation of the applications 62a and 62b, the terminal 10 proceeds to sequence S10. Further, when any application is installed, if the service key management application has not been installed yet, the terminal 10 proceeds to sequence S13. In addition, when the user operates the input device to instruct installation of the application 62b, the terminal 10 proceeds to sequence S16.

  The installation instruction is performed using an application management application preinstalled in the terminal 10. A list of applications that can be installed is displayed on the terminal 10 by connecting to the application server, and an installation instruction is issued for an application selected by the user. Since this is a conventional technique, details are omitted and not shown.

  Here, it is assumed that the user instructs installation of the application 62a and the application 62b.

  In sequence S10, the application management unit 20 of the terminal 10 requests the application 62a from the application server 4. In sequence S <b> 11, the application management unit 20 receives the application 62 a from the application server 4. In sequence S12, the application management unit 20 performs an installation process for storing the received application 62a in the application program storage unit 61.

  After the installation process of the application 62a, when the service key management application has not been installed yet, the application management unit 20 proceeds to sequence S13. When the service key management application has already been installed, the application management unit 20 proceeds to sequence S16.

  In sequence S <b> 13, the application management unit 20 requests a service key management application from the application server 4. In sequence S <b> 14, the application management unit 20 receives a service key management application from the application server 4. In sequence S <b> 15, the application management unit 20 performs an installation process for storing the received service key management application in the application program storage unit 61.

  In sequence S16, the application management unit 20 requests the application 62b from the application server 4. In sequence S <b> 17, the application management unit 20 receives the application 62 b from the application server 4. In sequence S18, the application management unit 20 performs an installation process for storing the received application 62b in the application program storage unit 61, and ends the installation procedure.

  FIG. 4 is a sequence diagram showing an application activation procedure in the terminal 10. In sequence S <b> 30, the user performs an operation for requesting activation of the application 62 a using the input device of the terminal 10. Specifically, it is assumed that an application is activated by an operation in which the user selects an application to be activated on a screen on which a list of applications is displayed. Since this is a conventional technique, details are omitted and not shown.

  In sequence S31, the application management unit 20 reads the application 62a from the application program storage unit 61 and stores it in the storage device. In sequence S <b> 32, the application management unit 20 performs activation processing of the application 62 a stored in the storage device. The activated application 62a functions as the application 30a. The application 62a describes that the service key management application needs to be activated as the activation process, and the process proceeds to sequence S33.

  In sequence S33, the application management unit 20 reads the service key management application from the application program storage unit 61 and stores it in the storage device. In sequence S34, the application management unit 20 performs activation processing of the service key reception unit 43 of the service key management application stored in the storage device. In sequence S35, the application management unit 20 performs the activation process of the service key reading unit 41 of the service key management application.

  In sequence S36, the user performs an operation for requesting activation of the application 62b by the input device of the terminal 10. In sequence S37, the application management unit 20 reads the application 62b from the application program storage unit 61 and stores it in the storage device. In sequence S38, the application management unit 20 performs activation processing of the application 62b stored in the storage device. The activated application 62b functions as the application 30b. The application 62b describes that the activation of the service key management application is necessary as the activation process, but since the application 62b has already been activated, the application activation process is terminated without doing anything.

  FIG. 5 is a sequence diagram showing the processing procedure of the initial reproduction processing. The first playback process is a process when the content is played for the first time. In other words, the initial reproduction process is a content reproduction process that is executed when a reproduction request for encrypted content is instructed in a state where the service key has not yet been acquired.

  In sequence S40, the user operates the input device to request connection to the service. Specifically, for example, the user operates the input device and requests the UI unit 31a of the application 30a that has already been activated to connect to the portal site of the service. The portal site is a site that serves as a gateway to the service, and is a site that displays a guidance and a list of contents when using the service by connecting to a portal site server (not shown).

  In sequence S41, the UI unit 31a sends a test content reception request to the license evaluation unit 32a. The test content is content that is automatically reproduced such as a service logo received by the application 30a, and is content that is automatically reproduced when the use of the service is started. This is called “Welcome Video”.

  In sequence S42, the license evaluation unit 32a sends the service identification information included in the application 62a to the service key reading unit 41 and requests a service key. In sequence S43, since the service key associated with the requested service identifier is not stored in the service key storage unit 65, the service key reading unit 41 causes the service key receiving unit 43 to receive the service identification information requested for reproduction. To request reception of the service key and enter a wait state.

  In sequence S <b> 44, the service key receiving unit 43 acquires terminal individual information from the terminal individual information storage unit 51. In sequence S <b> 45, the service key receiving unit 43 requests client authentication from the service key distribution server 5. Specifically, the service key receiving unit 43 transmits the client authentication key 44 included in the service key receiving unit 43 to the service key distribution server 5 together with the service identification information passed from the application that requested the reproduction. Request client authentication and service key issuance. The service key distribution server 5 transmits terminal individual information in order to identify the terminal 10 that has issued the service key issue request.

  In sequence S46, the service key distribution server 5 performs client authentication processing. Specifically, the service key distribution server 5 determines whether or not the client authentication key 44 received from the service key receiving unit 43 matches the client authentication key included and distributed in the application 62a. The client authentication key is registered in advance in the service key distribution server 5 by the service provider 2 together with the service identifier. The service key distribution server 5 authenticates that the terminal 10 is a legitimate client when the client authentication key 44 received from the service key receiving unit 43 matches the client authentication key included in the application 62a. To do.

  In sequence S <b> 47, when the service key distribution server 5 authenticates that the terminal 10 that has transmitted the client authentication key 44 received from the service key receiving unit 43 is a valid client, the service key distribution server 5 uses the service identification information received together with the client authentication key 44. The associated service key is transmitted to the service key receiving unit 43.

  The service key to be transmitted here is one of a plurality of service keys registered in advance by the service provider 2, and the service key that has been transmitted once is discarded and not transmitted. As a result, a service key having a different value is transmitted every time an issue request is issued to all the terminals 10. At this time, the service key distribution server 5 stores the individual terminal information included in the service key issuance request together with the number of times the service key has been issued. This is for identifying an unauthorized terminal 10 that frequently issues service key issuance requests. Since the number of service keys stored in the service key distribution server 5 is limited, if a service key issuance request is frequently made by a malicious user or the like, the service keys are exhausted. This is because in such a case, the target terminal 10 is identified and countermeasures such as stopping the issuance of the service key are taken.

  In sequence S48, the service key receiving unit 43 reads and acquires the terminal individual information from the terminal individual information storage unit 51. In sequence S <b> 49, the service key receiving unit 43 encrypts the service key received from the service key distribution server 5 with the terminal individual information read from the terminal individual information storage unit 51. In sequence S50, the service key reception unit 43 stores the encrypted service key in the service key storage unit 65. In sequence S51, the service key receiving unit 43 notifies the service key reading unit 41 that the storage of the service key is completed, and the waiting state of the service key reading unit 41 is released.

  In sequence S52, the service key reading unit 41 reads the encrypted service key 66 from the service key storage unit 65. In sequence S <b> 53, the service key reading unit 41 reads and acquires the terminal individual information from the terminal individual information storage unit 51. In sequence S54, the service key reading unit 41 performs a first service key decryption process. Specifically, the service key reading unit 41 uses the terminal individual decryption unit 42 to decrypt the encrypted service key 66 with the terminal individual information. In sequence S55, the service key reading unit 41 sends the decrypted service key to the license evaluation unit 32a.

  In sequence S56, the license evaluation unit 32a performs a second service key decryption process. Specifically, the license evaluation unit 32a further decrypts the service key decrypted with the terminal individual information with the application key included in the license evaluation unit 32a. In sequence S57, the license evaluation unit 32a transmits the content identification information of the test content and the service key identification information included in the service key to the content server 3a, and requests transmission of the test content. It is assumed that the content identification information of the test content is embedded in the application 62 and stored in advance together with the content identification information in the content server 3a.

  In sequence S58, the content server 3a encrypts the test content corresponding to the received content identification information using the service encryption key corresponding to the received service key identification information, and transmits the encrypted content to the license evaluation unit 32a. The license evaluation unit 32a receives the test content transmitted from the content server 3a.

  In sequence S59, the license evaluation unit 32a performs content decryption processing for decrypting the received test content with the service key. Since the essence of the present invention is to securely distribute the service key used for content decryption processing to the application of the terminal 10, a specific method for content encryption and decryption may be arbitrary. In this embodiment, it is assumed that the Marlin IPTV-ES system, which is a conventional technique, is used. In the Marlin IPTV-ES system, in order to reduce the load of content encryption processing in the content server 3, the content data is previously encrypted with the license key, and only the license key is encrypted with the service encryption key, and the terminal 10 Send to. Since the license key has a shorter data length than the content data, the processing load can be reduced even if the encryption process is performed each time a content request is made from the terminal 10. In FIG. 5, these processes are omitted.

  In sequence S60, the license evaluation unit 32a sends the decrypted test content to the UI unit 31a. In sequence S61, the UI unit 31a performs a reproduction process of the test content decrypted with the service key. As a result, a “welcome video” is presented to the user, and it is understood that the user can receive the service. In sequence S62, the UI unit 31a performs a portal site connection process and ends the initial reproduction procedure. Specifically, by connecting to a portal site server (not shown), a guidance when using the service and a list of contents are acquired and displayed on the terminal 10. The user can then select and view the content on the portal site.

  FIG. 6 is a sequence diagram illustrating a processing procedure of the continuous reproduction process. The continuous playback process is a process when the content is played back for the second time or later. That is, the continuous playback process is a content playback process that is executed when a playback request for encrypted content is instructed in a state where a service key has already been acquired. The continuous reproduction process shown in FIG. 6 is a portal site connection process.

  In sequence S70, the user operates the input device to request the UI unit 31a to reproduce the content. Specifically, the terminal 10 obtains and displays a content list by connecting to a portal site server (not shown), and the user operates the UI unit 31 to select one content from the content list. To do. The content list includes content identification information for identifying the content by the content server 3a as well as information such as the title and thumbnail of the content. In sequence S71, the UI unit 31a sends the content identification information of the content requested to be played by the user to the license evaluation unit 32a, and sends the reception request of the content requested to be played. In sequence S72, the license evaluation unit 32a sends the service identification information included in the application 62a to the service key reading unit 41, and issues a service key for decrypting the content requested to be played.

  In sequence S73, since the service key corresponding to the requested service identification information has already been acquired, the service key reading unit 41 is associated with the service identification information requested to be reproduced from the service key storage unit 65. The encrypted service key 66 is read out. In sequence S <b> 74, the service key reading unit 41 reads and acquires the terminal individual information from the terminal individual information storage unit 51. In sequence S75, the service key reading unit 41 performs a first service key decryption process. Specifically, the service key reading unit 41 uses the terminal individual decryption unit 42 to decrypt the encrypted service key 66 with the terminal individual information. In sequence S76, the service key reading unit 41 sends the decrypted service key to the license evaluation unit 32a.

  In sequence S77, the license evaluation unit 32a performs a second service key decryption process. Specifically, the license evaluation unit 32a further decrypts the service key received from the service key reading unit 41 with the application key included in the license evaluation unit 32a. In sequence S78, the license evaluation unit 32a requests the content data by transmitting the content identification information of the content requested to be played and the service key identification information included in the service key to the content server 3a.

  In sequence S79, the content server 3a encrypts the content data representing the content corresponding to the received content identification information using the service encryption key corresponding to the received service key identification information, and then the license evaluation unit The license evaluation unit 32a receives the content data transmitted from the content server 3a. In sequence S80, the license evaluation unit 32a stores and stores the received content data in the application data storage unit 63a. In sequence S81, the license evaluation unit 32a reads the content data from the application data storage unit 63a.

  In sequence S82, the license evaluation unit 32a performs content decryption processing for decrypting the read content data with the service key. As described above, it is assumed that the content encryption and decryption uses the Marlin IPTV-ES system.

  In sequence S83, the license evaluation unit 32a sends the decrypted content data to the UI unit 31a. In sequence S84, the UI unit 31a performs a reproduction process of the content represented by the content data received from the license evaluation unit 32a, and ends the continuous reproduction procedure.

  Note that sequences S80 to S84 may be executed simultaneously. That is, you may perform the streaming reproduction which reproduces | regenerates while receiving content data. Since the content data is stored in the application data storage unit 63a in sequence S80, if a reproduction request is made once and all content data has been stored, a content reception request is performed in sequence S71. It is also possible to proceed to sequence S81 immediately after the occurrence of the content and reproduce the content. In this case, the terminal 10 does not need to be connected to various servers via the network.

  2 to 5, communication between the terminal 10 and various servers is performed with encryption so that only the sender and the receiver can eavesdrop. Since the encrypted communication is performed using an existing technology such as HTTPS (Hypertext Transfer Protocol Security), details are omitted.

  FIG. 7 is a flowchart showing a processing procedure of application activation processing. When the user performs an operation for requesting activation of an application using the input device of the terminal 10, the terminal 10 proceeds to Step A1.

  In step A1, which is an activation step, the application management unit 20 activates the application requested to be activated by the input device. In step A2, when the started application requires a service key management application, the application requests the application management unit 20 to start the service key management application. If the activation of the service key management application is requested by the activated application, the application management unit 20 proceeds to step A3. If the activation of the service key management application is not requested by the activated application, the application management unit 20 ends the application activation process. .

  In step A3, the application management unit 20 determines whether or not the service key management application has not been started. The application management unit 20 proceeds to step A4 when the service key management application is not activated, and ends the application activation process when the service key management application is already activated.

  In step A <b> 4, the application management unit 20 performs activation processing of the service key reception unit 43. In step A5, the application management unit 20 performs the activation process of the service key reading unit 41 and ends the application activation process.

  FIG. 8 is a flowchart showing the processing procedure of the initial reproduction processing. If the user performs an operation for requesting the reproduction of the content using the input device of the terminal 10 in a state where the service key has not been acquired, the terminal 10 proceeds to Step B1.

  In step B1, the service key reading unit 41 determines whether or not the service key storage unit 65 stores a service key associated with the service identification information of the application that has made a reproduction request. When the service key storage unit 65 stores the service key associated with the service identification information requested to be played, the service key reading unit 41 proceeds to step B12, and the service key storage unit 65 When the service key associated with the service identification information is not stored in the service key storage unit 65, the process proceeds to step B2.

  In step B <b> 2, the service key receiving unit 43 requests client authentication from the service key distribution server 5. In step B3, which is a service key receiving step, the service key receiving unit 43 determines whether the client authentication has succeeded and the service key has been received. When the client authentication is successful and the service key can be received, the service key receiving unit 43 proceeds to Step B4. When the client authentication is not successful or the service key cannot be received, the service key receiving unit 43 proceeds to Step B13.

  In step B4, which is a service key storage step, the service key receiving unit 43 performs a service key encryption process on the service key received from the service key distribution server 5, and then stores and stores the service key in the service key storage unit 65. To do. The service key encryption process is a process of encrypting the service key received from the service key distribution server 5 with the terminal individual information stored in the terminal individual information storage unit 51.

  In step B5, which is a reading step and a service key delivery step, the service key reading unit 41 reads the encrypted service key 66 from the service key storage unit 65, performs the first service key decryption process, and then executes the license. It passes to the evaluation unit 32. The first service key decryption process is a process of decrypting the encrypted service key 66 read from the service key storage unit 65 with the terminal individual information stored in the terminal individual information storage unit 51.

  In step B6, the license evaluation unit 32 performs a second service key decryption process. The second service key decryption process is a process of decrypting the service key decrypted with the individual terminal information with the application key included in the license evaluation unit 32. In step B7, the license evaluation unit 32 requests the content server 3 to transmit test content.

  In step B8, the license evaluation unit 32 determines whether the test content has been received. The license evaluation unit 32 proceeds to step B9 when the test content can be received, and proceeds to step B13 when the test content cannot be received.

  In step B <b> 9, the license evaluation unit 32 performs decryption processing on the received test content, and then passes it to the UI unit 31. The decryption process is a process of decrypting the received test content with the service key decrypted with the application key in step B6. In step B10, the UI unit 31 performs reproduction processing of the content decrypted in step B9.

  In step B11, the UI unit 31 determines whether or not the test content has been successfully reproduced. The UI unit 31 proceeds to step B12 when the reproduction of the test content is successful, and proceeds to step B13 when the reproduction of the test content is not successful. In step B12, the UI unit 31 performs the portal site connection process and ends the initial reproduction process. In step B13, the UI unit 31 presents error information to the user and ends the initial reproduction process.

  FIG. 9 is a flowchart showing the procedure of the continuous playback process. When the user performs an operation for requesting reproduction of content by using the input device of the terminal 10, the terminal 10 proceeds to Step C1.

  In step C <b> 1, the service key reading unit 41 determines whether or not the service key storage unit 65 stores a service key associated with service identification information held by an application that has made a reproduction request to the service key storage unit 65. To do. When the service key associated with the service identification information of the application that has made a reproduction request is stored, the service key reading unit 41 proceeds to step C2, and the service key storage unit 65 has the application that has made the reproduction request. When the service key associated with the service identification information is not stored, the process proceeds to step C11.

  In step C <b> 2, the license evaluation unit 32 determines whether or not content data representing the content requested to be played is stored in the application data storage unit 63. When the content data representing the content requested to be reproduced is stored in the application data storage unit 63, the license evaluation unit 32 proceeds to step C8, and the content data representing the content requested to be reproduced is not stored. Then go to step C3. In step C3, the license evaluation unit 32 makes a service key request to the service key reading unit 41.

  In step C4, which is a reading step and a service key delivery step, the service key reading unit 41 reads the service key from the service key storage unit 65, performs the first service key decryption process, and passes it to the license evaluation unit 32. That is, the service key reading unit 41 decrypts the encrypted service key 66 read from the service key storage unit 65 with the terminal individual information stored in the terminal individual information storage unit 51, and the license evaluation unit 32. To pass. In step C5, the license evaluation unit 32 performs a second service key decryption process. That is, the license evaluation unit 32 decrypts the service key decrypted with the terminal individual information with the application key included in the license evaluation unit 32.

  In step C6, the license evaluation unit 32 determines whether the content data has been received. The license evaluation unit 32 proceeds to step C7 when the content data can be received, and proceeds to step C12 when the content data cannot be received. In step C7, the license evaluation unit 32 stores the received content data in the application data storage unit 63.

  In step C8, the license evaluation unit 32 reads the content data from the application data storage unit 63, performs the content decryption process, and passes the content data to the UI unit 31. The content decryption process is a process for decrypting encrypted content data with a service key. In step C9, the UI unit 31 performs a reproduction process of the content represented by the content data decrypted in step C8. In step C10, the UI unit 31 determines whether or not the content has been successfully reproduced. The UI unit 31 ends the continuous reproduction process when the content reproduction is successful, and proceeds to step C12 when the content reproduction is not successful.

  In step C11, the terminal 10 performs an initial content reproduction process and proceeds to step C2. The initial content reproduction process is the process shown in FIG. In step C12, the UI unit 31 presents error information to the user and ends the continuous reproduction process.

  An information terminal device such as a smartphone according to the prior art can download and install an application serving as a client of a video distribution service from a distribution server (store) on the Internet.

  When the application is executed, the terminal 10 according to the present invention decrypts the service key, that is, the encrypted content from the service key distribution server 5 via the Internet using the secure existing communication method. The decryption key is downloaded, and the downloaded decryption key is stored in a storage area that can be commonly used by applications. However, the downloaded decryption key is distributed from the service key distribution server 5 in a state encrypted with the application key, and the application key is not disclosed and is installed only in the downloaded application.

  Therefore, even if the service key is acquired by the malicious application, the terminal 10 cannot use the service key, that is, the decryption key because the malicious application cannot decrypt the encrypted service key. I can't. As described above, since the terminal 10 can securely receive and store the decryption key, it is possible to mount an application that becomes a client of the moving image distribution service.

  In this way, the application management unit 20 controls the execution of a plurality of application programs that decrypt and reproduce the encrypted content using the service key for decrypting the encrypted content. The service key receiving unit 43 receives a service key from the service key distribution server 5 that issues and distributes a service key. The service key storage unit 65 stores the service key received by the service key receiving unit 43. The service key reading unit 41 reads a service key necessary for the application program started by the application management unit 20 to decrypt the encrypted content from the service key storage unit 65, and reads the read service key. To the activated application program.

  Therefore, the terminal 10 can protect content such as moving images that are encrypted and distributed by using a decryption key for each application program, for example, a service key having a different value for each of the aforementioned issuance requests. In the prior art, it is necessary to write the service key in the terminal 10 in advance. However, since the service key is downloaded from the service key distribution server and stored in the terminal 10, the service key is not written in advance. Even if the content is 10, the content can be reproduced by the application program.

  Further, the service key issued by the service key distribution server 5 is encrypted. Each application program includes a license evaluation unit 32 and a UI unit 31. The license evaluation unit 32 includes an application key uniquely generated for each application program in order to decrypt the encrypted service key. The UI unit 31 reproduces content. The license evaluation unit 32 decrypts the service key delivered from the service key reading unit 41 with the application key included in the license evaluation unit 32, and further decrypts the encrypted content with the decrypted service key. . Then, the UI unit 31 reproduces the content decrypted by the license evaluation unit 32.

  Accordingly, since the service key distribution server 5 can transmit the service key after encrypting it with a different application key for each application, the service key is not decrypted by an unintended application. One service key receiving unit 43 can receive service keys of a plurality of applications.

  Further, the service key receiving unit 43 includes a client authentication key for identifying the own terminal 10. When requesting the service key distribution server 5 to issue a service key, the service key receiving unit 43 receives the client authentication key included in the service key receiving unit 43. It transmits to the service key distribution server 5. Then, the service key distribution server 5 authenticates the terminal 10 including the service key receiving unit 43 that has transmitted the client authentication key, using the client authentication key received from the service key receiving unit 43. Therefore, since the service key distribution server 5 can identify the terminal 10 by the client authentication key, it can provide a service corresponding to the model of the terminal 10.

  Further, the application management unit 20 receives an application program from the application server 4 that distributes the application program. The application data storage unit 63 stores the application program received by the application management unit 20. The application program whose execution is controlled by the application management unit 20 is an application program stored in the application data storage unit 63.

  Therefore, the terminal 10 can receive the application program and the service key from different server devices. In Android, iOS, etc., a common server for distributing application programs is prepared as a platform. When a business operator who intends to provide a content distribution service is different from a business operator that operates these application servers, it is not desirable in terms of security to place a service key in the application server. However, according to the present invention, a standard mechanism prepared as a platform is used for distributing the application, and it becomes possible to distribute only the service key by another server, and it is necessary to operate the application server. Disappear.

  In addition, since one service key server can handle a plurality of services, if any service provider operates a service key distribution server, the other service provider prepares an application program and a service key. It is possible to implement a content distribution service simply by doing.

  Further, the encrypted content reproduced by the application program is content distributed from the content server 3 that distributes the encrypted content. The service key issued by the service key distribution server 5 is issued with a different value each time the service key is issued from the terminal 10 to the service key distribution server 5. Therefore, every time there is an issuance request from the terminal 10, the service key has a different value. Even if the content stored in the terminal 10 is illegally copied to another terminal 10, the service key for decrypting the content is different. The other terminal 10 cannot decrypt the content, and the terminal 10 can prevent the content from being used illegally.

  Further, the secure storage unit 50 stores terminal individual information that can uniquely identify the terminal 10 itself. The terminal individual encryption unit 45 encrypts the service key received by the service key reception unit 43 with the terminal individual information stored in the secure storage unit 50. The terminal individual decryption unit 42 decrypts the service key encrypted by the terminal individual information with the terminal individual information stored in the secure storage unit 50. The service key stored in the service key storage unit 65 is a service key encrypted by the terminal individual encryption unit 45. The service key transferred from the service key reading unit 41 to the activated application program is the terminal individual information stored in the secure storage unit 50 by the service key read from the service key storage unit 65 by the terminal individual decryption unit 42. Is the service key decrypted by.

  Therefore, even if the content stored in the terminal 10 and the service key are illegally copied to the other terminal 10, the individual terminal information for decrypting the service key is different. Therefore, the other terminal 10 decrypts the content. The terminal 10 can prevent the content from being used illegally.

  Furthermore, the application server 4 that distributes a plurality of application programs that decrypt and reproduce the encrypted content with a service key for decrypting the encrypted content, and service key distribution that distributes the service key In reproducing the content in the information terminal system 1 including the server 5 and the terminal 10 that can execute the application program distributed from the application server 4, the terminal 10 includes an application management unit 20, a service key reception unit 43, A service key storage unit 65 and a service key reading unit 41 are included. The application management unit 20 controls execution of application programs distributed from the application server 4. The service key receiving unit 43 receives a service key from the service key distribution server 5. The service key storage unit 65 stores the service key received by the service key receiving unit 43. The service key reading unit 41 reads a service key necessary for the application program started by the application management unit 20 to decrypt the encrypted content from the service key storage unit 65, and reads the read service key. To the activated application program.

  Therefore, the information terminal system 1 can protect content such as moving images that are encrypted and distributed by using a decryption key, for example, a service key, for each application program. In the prior art, it is necessary to write the service key in the terminal 10 in advance. However, in the information terminal system 1, since the service key is downloaded from the service key distribution server and stored in the terminal 10, the service key is stored in advance. Even in the terminal 10 that does not write the content, the content can be reproduced by the application program.

  Further, when the terminal 10 capable of executing a plurality of application programs for decrypting and reproducing the encrypted content with a service key for decrypting the encrypted content executes the information terminal control method, In step B3, the service key is received from the service key distribution server 5 that distributes the service key. In step B4, the service key received in step B3 is stored in the service key storage unit 65. In step A1, an application program is activated. In step B5 and step C4, the service key necessary for the application program started in step A1 to decrypt the encrypted content is read from the service key storage unit 65. In step B5 and step C4, the read service key is transferred to the activated application program.

  Therefore, the information terminal control method can protect contents such as moving images that are encrypted and distributed by using a decryption key, for example, a service key, for each application program. In the prior art, the service key needs to be written in the terminal 10 in advance. However, in this information terminal control method, the service key is downloaded from the service key distribution server and stored in the terminal 10, so that the service key is stored in advance. Even in the terminal 10 to which no key is written, the content can be reproduced by the application program.

  Further, a service key is assigned to the computer of the terminal 10 including a computer capable of executing a plurality of application programs for decrypting and reproducing the encrypted content with the service key for decrypting the encrypted content. In step B3 for receiving the service key from the service key distribution server 5 to be distributed, step B4 for storing the service key received in step B3 in the service key storage unit 65, step A1 for starting the application program, and step A1 Steps B5 and C4 for reading the service key necessary for the started application program to decrypt the encrypted content from the service key storage unit 65, and the read service key for the started application program It can be provided as a program for executing the steps B5 and step C4 passing.

DESCRIPTION OF SYMBOLS 1 System 2 Service provider 3 Content server 4 Application server 5 Service key distribution server 10 Terminal 20 Application management part 30, 62 Application 31 UI part 32 License evaluation part 33 Application key 40 Service key management application 41 Service key reading part 42 Terminal individual Decryption unit 43 Service key reception unit 44 Client authentication key 45 Terminal individual encryption unit 50 Secure storage unit 51 Terminal individual information storage unit 60 Normal storage unit 61 Application program storage unit 63 Application data storage unit 64 Content data 65 Service key storage unit 66 Service key

Claims (7)

An application storage unit that stores a plurality of applications that are received from the application distribution server device and that are encrypted and decrypted with a service key for decrypting the encrypted content ;
An application management unit that controls the execution of multiple applications stored in the application storage section,
A content receiving unit for receiving content encrypted for each application from a content distribution server device;
Wherein when requesting the service key distribution server device for distributing service key transmission of the service key, and transmits the service identification information for uniquely identifying the service that the application is compatible with the service key distribution server apparatus, the service A service key receiving unit that receives an encrypted service key from the key distribution server device ;
And a service key storage unit for storing a service key encrypted received by the service key receiving unit,
The service key needed to each application started by the application management unit decrypts the content that is the encrypted, read from the service key storage unit, read out the encrypted service key is the activated and a service key delivery section to pass to each application only contains,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key,
The information terminal apparatus , wherein the content reproduction unit reproduces the content decrypted by the decryption unit. The service key receiving unit includes client identification information for identifying the self-information terminal device. When requesting the service key distribution server device to transmit a service key, the service key receiving unit includes the client identification information included in the service key receiving unit. Transmitted to the service key distribution server device,
Said service key distribution server apparatus, the client identification information received from the service key receiving unit, according to claim 1, characterized in that to authenticate the information terminal device including the service key receiving unit that transmitted the client identification information terminal equipment according to. It said service key distribution server apparatus, according to each client identification information transmitted from the service key receiving portion when the service key issuance request, to claim 2, characterized in that to record the number of times that issued the service key Information terminal equipment. The encrypted content played by the application program is content distributed from a content distribution server device that distributes encrypted content,
Service key the service key distribution server distributes the information terminal device according to any one of claims 1-3, characterized in that different values each time there is a request for issuing service keys are generated . The content that is encrypted, and the application distribution server device for distributing a plurality of applications to be reproduced by decoding the service key for decrypting the content that is dark Goka, the service key distribution server that distributes service key a device, an information terminal system including a viable information terminal an application to be delivered from the application distribution server device,
The information terminal device
An application storage unit that stores a plurality of applications distributed from the application distribution server device ;
An application management unit that controls the execution of multiple applications stored in the application storage section,
A content receiving unit for receiving content encrypted for each application from a content distribution server device;
When requesting the transmission of the service key in the service key distribution server device transmits the service identification information for uniquely identifying the service that the application is compatible with the service key distribution server apparatus, the service key distribution server device and a service key reception unit for receiving a service key encrypted,
And a service key storage unit for storing a service key encrypted received by the service key receiving unit,
The service key needed to each application started by the application management unit decrypts the content that is the encrypted, read from the service key storage unit, read out the encrypted service key is the activated and a service key delivery section to pass to each application only contains,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit decrypts the service key delivered from the service key delivery unit with an application key included in the decryption unit, and further decrypts encrypted content with the decrypted service key,
The content playback system plays back the content decrypted by the decryption unit . An information terminal control method executed by an information terminal device capable of executing a plurality of application programs for decrypting and reproducing encrypted content with a service key for decrypting the encrypted content,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing the encrypted service key received in the service key reception step in a service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
The information terminal control method characterized by including the reproduction | regeneration step which reproduces | regenerates the content decoded by the said decoding step in the content reproduction part of each said started application . The content that is encrypted, the computer of the information terminal device including a plurality of applications capable of executing computer to reproduce and decode the service key for decrypting the content that is dark Goka,
When requesting transmission of a service key to a service key distribution server device that distributes a service key , service identification information for uniquely identifying the service supported by the application is transmitted to the service key distribution server device, and the service key A service key receiving step of receiving an encrypted service key from the distribution server device ;
A service key storage step of storing the encrypted service key received in the service key reception step in a service key storage unit;
A startup step for starting the application program;
The service key needed to each application that was started with activation step decrypts the content that is the encrypted, and reading the read step from the service key storage unit,
And service key delivery steps of passing the read encrypted service key to each application that is the activation,
Each application executed by the application management unit includes a decryption unit including an application key uniquely generated for each application in order to decrypt an encrypted service key, and a content reproduction unit that reproduces content. ,
The decryption unit of each activated application decrypts the delivered service key with the application key included in the decryption unit, and further decrypts the encrypted content with the decrypted service key Steps,
A program for causing the content playback unit of each activated application to execute a playback step of playing back the content decrypted in the decryption step .

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