Patent Publication Number: US-8972301-B2

Title: Information processing device, data processing method, and program

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an information processing device, a data processing method, and a program, and more particularly, to an information processing device, a data processing method, and a program, which are configured to reproduce a content from various recording mediums such as a disk and a local memory unit. 
     2. Description of Related Art 
     DVD (Digital Versatile Disc), Blu-ray Disc (registered trademark), and the like are often used as recording mediums for various content such as music and movies. These information recording mediums having data recorded thereon include mediums (ROM type) not permitting the writing of new data thereto and mediums (R type, RE type, and the like) permitting the writing of data thereto. By using the data-writable information recording mediums, it is possible to copy or move content recorded in other mediums. For example, it is also possible to download and record content, for example, through a network or by the use of devices installed in public locations. 
     In addition to the DVD and the Blu-ray Disc (registered trademark), hard disks and flash memories are used as the recording mediums on which content is recorded. 
     Examples of a process type of recording content on a recording medium include the followings: 
     (a) a process of copying (or moving) content from a medium (for example, a ROM disk) having the content recorded thereon to another medium; 
     (b) a process of downloading and recording content from a server; and 
     (c) a process of recording content by the use of a terminal located in a public space such as a front of a store. 
     However, the copyright, the distribution right, and the like of various types of content such as music data and image data are possessed by the authors or sellers thereof. Therefore, when content is provided to users, predetermined usage restriction is generally taken, that is, the usage of the content is permitted to only a user having the regular right of usage and unauthorized copying is not permitted. 
     For example, AACS (Advanced Access Content System) is known as a standard for usage restriction of content. In the AACS standard, when a content is copied between the mediums like (a), this copy process is based on the premise that copy permission information should be acquired from a management server. That is, the copy process is permitted under predetermined management. This copy process is called managed copy (MC). 
     The content providing process of (b), that is, the download type content providing process, is called EST (Electric Sell Through). The content providing process of (c) using public terminals is called MoD (Manufacturing on Demand). The AACS standard requires these processes to be performed in accordance with a predetermined rule. 
     The following three processes will be described in brief with reference to  FIGS. 1 and 2 : 
     (a) Managed Copy (MC); 
     (b) EST (Electric Sell Through); and 
     (c) MoD (Manufacturing on Demand). 
     (a) Managed Copy (MC) 
     For example, as shown in (a) of  FIG. 1 , the managed copy (MC) is a process of allowing a user  1  to set an information recording medium (disk)  3  having a content recorded thereon to an information processing device  2  performing a data recording and reproducing process and copying the content read from the information recording medium (disk)  3  to, for example, a data-writable R/RE type disk such as an R type or RE type or a second information recording medium  4  such as a hard disk or a flash memory. 
     At the time of performing this content copying process, it is necessary that the data recording and reproducing device  2  accesses a management server  5  via a network  6  and obtains the permission to content copy from the management server  5 . 
     A configuration for performing the content copying process between plural mediums by the use of a single information processing device, that is, only one device, is shown in  FIG. 1 , but two devices of a device having a medium as a copy source attached thereto and another device having a medium as a copy destination attached thereto may be connected to each other with, for example, a USB cable or the like. 
     (b) EST (Electric Sell Through) 
     The process of downloading content from a server and recording the content on an information recording medium is called EST (Electric Sell Through). As shown in (b) of  FIG. 2 , the EST is a process of fitting a user&#39;s medium, for example, a data-writable R or RE type disk  12 , into an information processing device  13  such as a PC possessed by the user  11  and receiving and recording a content from a content server (EST server)  14  through a network  15 . 
     (c) MoD (Manufacturing on Demand) 
     The content providing process using a public terminal is called MoD (Manufacturing on Demand). As shown in (c) of  FIG. 2 , the MoD is performed when a user  21  intends to record content on a medium using a content server  24  as a terminal installed in public spaces such as convenience stores or stations. The MoD is a process of allowing the user  21  to set the user&#39;s data-writable medium such as an R or RE type disk  22  into the content server (MoD server)  24  as the terminal of a convenience store  23  and recording desired content on the disk  22  according to the operation by the user  21  such as selection of content. 
     The processes of (a) to (c) are described, for example, in JP-A-2008-98765. 
     In this way, users can record content on data-writable mediums and utilize (reproduce and the like) the recorded content. However, for example, when the content is to be protected by copyright, it is necessary to control the usage of content to prevent unauthorized usage. 
     As described above, the AACS (Advanced Access Content System) is known as a standard for the content copyright protection techniques. In the AACS standard, usage control information (usage rule) corresponding to content is defined and the content is used in accordance with the usage control information (usage rule). In addition, strict usage control is realized by dividing content into units, preparing encrypted content using unit keys corresponding to the units, and allowing only a specific user to acquire the unit keys. 
     When the disk having content recorded thereon is a medium such as a ROM type disk permitting only reproduction and not permitting the writing of new data, additional writing or editing of new content is not performed on the medium. Therefore, it is possible to provide users with the content-specific control information (usage rule) or unit keys corresponding to the content recorded on the medium in a state where the usage rule or unit keys are recorded on the medium. 
     However, in an example where content is recorded on a data-writable R or RE type medium such as a disk, a hard disk, and a flash memory and used, the content recorded on the medium is not fixed but can be subjected to the data updates such as the recording of new content or the deleting of recorded content. The usage rule or the unit keys need to be updated with content stored in the medium. 
     In this way, when a user records content on a medium, it is necessary to perform various complex processes such as recording various accessory data corresponding to the recorded content, as well as recording the content. 
     When it is intended to reproduce content, the information processing device reproduces the content stored in a disk or a local memory unit. At the time of reproducing content, various processes are performed by reading an encrypted content from the medium (the disk or the local memory unit) and acquiring data, for example, key information or various types of ID information, corresponding to the encrypted content. That is, it is necessary to perform a reproduction process such as a process of decoding the encrypted content and a process of authenticating the validity thereof in accordance with a predetermined sequence. At the time of reproducing the content corresponding to the mediums, the accessory information such as medium IDs is different depending on the mediums. Therefore, it is necessary to read the medium IDs depending on the content to be reproduced. In this way, when content is selectively reproduced from plural mediums, there is a problem in that the processes of the information processing device are complicated, thereby increasing the load. 
     SUMMARY OF THE INVENTION 
     It is desirable to provide an information processing device, a data processing method, and a program, which are configured to efficiently read necessary information in an information processing device selectively reproducing content from plural mediums. 
     According to a first embodiment of the invention, there is provided an information processing device including: a local memory unit storing data including first encrypted content; a memory storing data including key information to be used in a process of reproducing the first encrypted content; and a data processing unit selectively reproducing second encrypted content stored in a disk or the first encrypted content stored in the local memory unit. Here, the data processing unit reads a second medium ID from the disk when the content to be reproduced is stored in the disk and reads a first medium ID from the memory when the content to be reproduced is stored in the local memory unit. 
     In the information processing device according to the embodiment of the invention, the data processing unit may perform the medium ID reading process using an application programming interface (API) which defines a medium ID acquiring process sequence. 
     In the information processing device according to the embodiment of the invention, the process sequence defined by the API may include both a process of reading the medium ID from the disk and a process sequence of reading the medium ID from the memory and the process sequence may be selected and performed depending on whether the content to be reproduced is content stored in the disk or content stored in the local memory unit. 
     In the information processing device according to the embodiment of the invention, the data processing unit may perform a content reproducing process accompanied with a process of decoding the content stored in the local memory unit by selectively using key information, which is stored in the memory, corresponding to the content stored in the local memory unit when the content to be reproduced is stored in the local memory unit. 
     In the information processing device according to the embodiment of the invention, the data processing unit may acquire a unit key by decoding a unit key file storing a unit key, which is used to decode the encrypted content stored in the local memory unit, using key data stored in the memory and may decode the encrypted content using the acquired unit key. 
     In the information processing device according to the embodiment of the invention, the data processing unit may acquire a first key by processing a key block stored in the local memory unit using device-specific key data stored in the memory, may acquire a second key by decoding a key file storing a key, which is used to decode the encrypted content, using the acquired first key, and may decode the encrypted content using the acquired second key. 
     According to a second embodiment of the invention, there is provided a data processing method carried out in an information processing device, including the steps of: allowing a data processing unit to selectively reproduce the encrypted content stored in a disk or a local memory unit; and allowing the data processing unit to read a medium ID from the disk when the content to be reproduced is stored in the disk and to read a medium ID from the memory when the content to be reproduced is stored in the local memory unit. 
     According to a third embodiment of the invention, there is provided a program allowing an information processing device to perform data processing, including: allowing a data processing unit to selectively reproduce the encrypted content stored in a disk or a local memory unit; and allowing the data processing unit to read a medium ID from the disk when the content to be reproduced is stored in the disk and to read a medium ID from the memory when the content to be reproduced is stored in the local memory unit. 
     The program according to the embodiment of the invention is a computer program which can be provided to a general-purpose computer system executing various program codes by a recording medium or a communication medium in a computer-readable manner. By providing the program in the computer-readable manner, processes corresponding to the program are carried out by the computer system. 
     Other advantages, features, and effects of the invention will become apparent by the following detailed description based on specific embodiments of the invention or the accompanying drawings. A system referred to in this specification means a logical set of plural devices and is not limited to a configuration in which the devices are disposed in the same chassis. 
     According to the embodiments of the invention, in an information processing device selectively reproducing content from plural mediums, a medium ID is read using the API. When the content to be reproduced is stored in a disk, the medium ID is read from the disk. When the content to be reproduced is stored in a local memory unit, the medium ID is read from the memory. The API includes the overall sequence of the process of reading the medium ID from the disk and the process of reading the medium ID from the memory and a process sequence is selected and performed depending on whether the content to be reproduced is stored in the disk or the local memory unit. According to this configuration, it is possible to read different medium IDs using one API, thereby reducing the processing load of the information processing device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of MC (managed copy) which is a process of copying content between information recording mediums and is performed under predetermined control. 
         FIG. 2  is a diagram illustrating EST which is a process of downloading content from a server and MoD which is a process of providing content using a public terminal. 
         FIG. 3  is a diagram illustrating a specific process example of the MC (managed copy) which is a process of copying content between information recording mediums and is performed under predetermined control. 
         FIG. 4  is a diagram illustrating process examples of the content downloading process and the inter-medium content copying process. 
         FIG. 5  is a diagram illustrating a directory configuration example of a local memory unit of an information processing device. 
         FIG. 6  is a sequence diagram illustrating an example of a process sequence of the content downloading process. 
         FIG. 7  is a sequence diagram illustrating an example of a process sequence of the inter-medium content copying process. 
         FIG. 8  shows diagrams illustrating flowcharts of the process sequence of the inter-medium content copying process. 
         FIG. 9  is a diagram illustrating a specific process sequence and a process configuration of the inter-medium content copying process. 
         FIG. 10  is a diagram illustrating details of data movement and recording processes performed in the inter-medium content copying process. 
         FIG. 11  is a diagram illustrating details of data movement and recording processes performed in the inter-medium content copying process. 
         FIG. 12  is a diagram illustrating a process example of a process, which is performed by the information processing device, of reproducing content stored in a local memory unit. 
         FIG. 13  is a diagram illustrating a process example of the process, which is performed by the information processing device, of reproducing content stored in a local memory unit. 
         FIG. 14  is a flowchart illustrating a medium ID reading sequence in the content reproducing process performed by the information processing device. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, an information processing device, a data processing method, and a program according to an embodiment of the invention will be described in detail with reference to the drawings. 
     First, a process example of the managed copy (MC) performed by an information processing device according to an embodiment of the invention will be described with reference to  FIG. 3 . As described above, the managed copy (MC) is a process of copying content to another medium on the condition that copy permission information is received from a management server. 
     In  FIG. 3 , a disk  110  having content recorded thereon, an information processing device  120  reading the content from the disk  110  and recording the read content to a data-writable second recording medium  150 , a data-writable second recording medium  150  which is the copy destination of the content, and a management server  140  providing permission information for the content copying process or management data are shown from the left side. 
     The disk  110  is, for example, a ROM disk, and is a disk  110  such as Blu-ray Disc (registered trademark). 
     The data-writable second recording medium  150  as the copy destination of the content is a recording medium such as a hard disk, a R/RE disk, and a flash memory. 
     The information processing device  120  is constructed, for example, by a PC, a recording and reproducing device, or the like and has a function of reading data from the disk  110  and writing the read data to the second recording medium  150 . 
     As shown in the drawing, a BD-J application  111  which is a Java (registered trademark) application program, a managed-copy management file (MCMF)  112 , management data  113 , and an encrypted content  114  are recorded in the disk  110 . 
     The BD-J application  111  is a program which is executed by the information processing device  120  at the time of performing a managed copy (MC) process and is used to perform, for example, a process of communication with the management server  140 . The BD-J application  111  may be constructed by a single application program or a combination of plural BD-J applications performing specific processes. 
     For example, the plural BD-J applications can include a BD-J application making a communication with a server and a BD-J application performing a charging process. At the time of copying content, the plural BD-J applications are executed by the information processing device  120 . 
     The managed-copy management file (MCMF)  112  is a file used to perform a content copying process and is an XML-described data file including the following information: 
     (a) a content ID which is an identifier (ID) uniquely representing content recorded in the information recording medium (disk  110 ); 
     (b) URI (URL) which is information for accessing a management server giving permission to copy at the time of copying content and generating a token by a binding process, for example, information for accessing the management server  140 ; and 
     (c) directory name and file name which are information on names of a directory and a file in which data for permitting a copy process is recorded. 
     The management data  113  is management data defined by an AACS (Advanced Access Content System) which is a standard management system for content copyright protecting techniques and includes a CPS unit key file including keys (unit keys) used to decode the encrypted content  114 , usage control information, a content certificate (CC) representing the validity of the content, and an MKB (Media Key Block) which is an encryption key block including key information (medium key) for acquiring the CPS unit keys. 
     The encrypted content  114  is an encrypted content according to, for example, the AACS standard. For example, the encrypted content includes an AV (Audio Visual) stream of moving image content such as HD (High Definition) movie content which is high-definition moving image data, music data, a game program, an image file, voice data, or text data. 
     The encrypted content  114  is configured to control usage by, for example, content management units (CPS units) and is an encrypted content to which different unit keys (CPS unit keys) are applied by the content management units (CPS units). Different keys (CPS unit keys) are assigned to the units, respectively, are encrypted, and are stored. 
     Two data processing units are set in the information processing device  120 . 
     The first data processing unit is a BD-JVM (BD-J virtual machine)  121 . The BD-JVM  121  is set as a virtual machine which is a virtual hardware environment for executing the BD-J application  111  recorded in the disk  110 . 
     The second data processing unit is an AACS layer  122 . The AACS layer  122  is set as a data processing unit for performing a data process according to the AACS standard, such as a process of acquiring an ID recorded in the disk  110 , treatment of information with high security, and data transformation in a content copying process. 
     In this way, when a process of copying content recorded in the disk  110  to another medium is performed, the BD-JVM  121  as an execution area of the BD-J application  111  recorded in the disk  110  and the AACS layer  122  as an execution area of a program for performing the processes according to the AACS standard are established to transmit and receive process requests and process results therebetween. 
     In order to transmit and receive process requests and process results between the BD-J application and the AACS layer, an API (Application Programming Interface) is used. The API is a set of functions for performing various processes necessary for the content copying process. The API is recorded in the BD-J application  111  or other areas which can be read by the information processing device  120 . A specific example of the API will be described in detail later. 
     The information processing device  120  executes the BD-J application  111  in the BD-JVM  121 , communicates with the management server  140 , and performs the process of acquiring the copy permission information  132  and the like. 
     When the content  114  stored in the disk  110  is copied to a second recording medium  150 , it is necessary to transform the content or the usage control information (usage rule) depending on the medium as a copy destination. This process is performed in the program executing area (AACS layer  122 ) for performing the processes according to the AACS standard. 
     The BD-J application  111  is a program for executing processes necessary for the content copying process and is executed in the BD-JVM  121  of the information processing device  120 . The following processes are performed as the processes employing the BD-J application: 
     (a) a server accessing process using the URI of a managed-copy management file (MCMF); 
     (b) a process of acquiring a permitted process list from a server; 
     (c) a process of transmitting the user&#39;s process selection information to the server; 
     (d) a payment process; 
     (e) a process of acquiring copy permission information from the server, a check process, a process of outputting the copy permission information to a recording controller; 
     (f) a process of monitoring the content copying process, which is performed by the recording controller; and 
     (g) a process of monitoring a process of writing data downloaded from the server, which is performed by the recording controller. 
     As described above, the BD-J application  111  may be constructed by a single application program, but may also be constructed by a combination of plural BD-J applications performing specific processes. For example, the processes of (a) to (g) may be performed by plural BD-J applications. 
     The process of the BD-J application will be described now with reference to  FIG. 3 . The BD-J application is started in the BD-JVM  121  established in the information processing device  120 , in step S 101  shown in  FIG. 3 . 
     At the time of performing the process, a guide picture as a user interface such as a menu provided from the BD-J application is displayed on the display of the information processing device  120 . A series of processes for performing the content copying process (managed copy) is started by a user&#39;s instruction. 
     The BD-J application first accesses the management server  140  using the server URI included in the managed-copy management file (MCMF)  112  in accordance with the user&#39;s instruction. At this time, a content ID corresponding to the content to be copied is transmitted to the management server  140 . 
     In step S 102 , the management server  140  generates a permitted process list which is list data of processes permitted for the content and transmits the generated permitted process list to the information processing device  120 , on the basis of the content ID received from the information processing device  120 . For example, the permitted process list is a list including information on whether the copying of the content is permitted and information on the fee of the copy process. 
     The information processing device  120  receives the permitted process list  123  from the management server  140  and displays the permitted process list on the display in step S 103  so as to allow a user to select a process to be performed. 
     When the user selects a process to be performed, the information processing device  120  performs a payment process by transmitting payment data  131  to the management server  140 . For example, the user inputs the data necessary for the payment such as a credit card number to the payment picture and transmits the payment data. Then, in step S 104 , the management server  140  permits the process and transmits the copy permission information to the information processing device  120 . 
     The information processing device  120  sends the copy permission information  124  received from the management server  140  to the AACS layer  122 . The AACS layer  122  performs the process of step S 105  and the processes subsequent thereto. The AACS layer  122  performs a process of transforming the management data  113  read from the disk  110  into management data based on the medium type of the second recording medium  150  such as a hard disk, an R/RE disk, and a flash memory as a copy destination. For example, a process of adding an encryption key (unit key) corresponding to the copied content or a process of transforming the usage control information, the content certificate, and the like to data corresponding to the copied content. The information necessary for transforming the data is included in the copy permission information  124 . The transformed management data  151  is recorded in the second recording medium  150 . 
     In step S 106 , the information processing device  120  reads the encrypted content  114  recorded in the disk  110  and outputs content copy data having been subjected to a data transformation such as a format transformation. In this way, the copied data of the content recorded in the disk  110  is recorded as the encrypted content  152  in the second recording medium  150 . The management data  151  recorded in the second recording medium  150  includes the usage control information, the content certificate, the MKB, the CPS unit key file, and the token corresponding to the content recorded in the second recording medium  150 . 
     At the time of performing the content copying process, the information processing device  120  and the management server  140  may perform a process of confirming the medium identifier (serial number) of the second recording medium  150  and a process of signing the medium identifier with a secret key of the management server  140  to generate a token. This token may be included in the management data. The management data including the token and the like is indicated by the management data  141  in the management server  140  in  FIG. 3 . The management data (CP data)  151  recorded in the second recording medium  150  may include the token information. 
     This content copying process has been roughly described with reference to  FIG. 3 . As described above, the content copying process is performed using the BD-J application and the program executed in the AACS layer. Therefore, the necessary information needs to be transmitted and received between the BD-J application and the program executed in the AACS layer. The API which defines various processes is employed in this process. 
     Plural process examples, which are performed by the information processing device according to the embodiment of the invention, using a server, will be described now with reference to  FIG. 4 . The following two processes are shown in  FIG. 4 : 
     Process Example 1: a process of allowing the information processing device (user device)  210  to download content A from the server  220  and to store the downloaded content in the local memory unit  213 ; and 
     Process Example 2: a process of copying content B stored in the disk  212  to the local memory unit  213 . 
     Process Example 1 corresponds to the content downloading process corresponding to the EST (Electric Sell Through) described with reference to (b) of  FIG. 2 . 
     Process Example 2 corresponds to the MC (Managed Copy) described with reference to  FIG. 1  and is a process of acquiring copy permission information from the server  220  and copying content between mediums. 
     Process Example 1 will be roughly described now. 
     The ROM disk  212  having content such as a movie recorded thereon is first mounted on the information processing device  210 . A program  251  recorded in the ROM disk  212  is then executed by the data processing unit  211  to perform a download process of acquiring content A from the server  220 . The program  251  is a BD-J application program which is a Java (registered trademark) program corresponding to the BD standard, when the ROM disk  212  is the Blu-ray Disc (registered trademark). 
     The data processing unit  211  transmits a content download request to the server  220  in accordance with the program  251 . The server  220  provides content A to the information processing device  210  in response to the request. The data processing unit  211  of the information processing device  210  stores content A downloaded from the server  220  in a local memory unit  213  in the device, for example, the local memory unit  213  constituted by a hard disk or the like. 
     At the time of downloading the content from the server  220 , the following process may be performed concurrently. That is, the information processing device  210  transmits the ID (device binding ID) of the information processing device or a random number (binding nonce) to the server  220 . The server signs the data with a secret key of the server to generate server authentication information (token) and provides the server authentication information to the information processing device  210 . 
     When the downloaded content is used by the information processing device  210 , the server authentication information (token) is verified to confirm that the acquired server authentication information (token) is valid. Only when this confirmation is made, the decoding and reproducing of the downloaded content is permitted. By this setting, the usage of the downloaded content is permitted to only a specific device (information processing device). 
     Process Example 2 shown in  FIG. 4  will be described now. This process is a process of copying content B stored in the disk  212  to the local memory unit  213 . Content B is content stored in the ROM disk  212  and is content to be subjected to usage control. Therefore, at the time of performing the copy process, it is necessary to acquire the copy permission information from the server  220 . 
     The program for performing this serial copy process is a program (for example, BD-J application)  252  stored, for example, in the ROM disk  212 . The program  252  is different from the program  251  recorded in the ROM disk  212  in Process Example 1 shown in  FIG. 4 . The program  251  is a program for performing the content downloading process and the program  252  is a program for performing the content copying process. The different programs may be stored in the ROM disk  212 . 
     At the time of performing the copy process on the condition that the copy permission information is acquired from the server  220 , that is, the managed copy (MC) process, the data processing unit  211  of the information processing device  210  reads and executes the program (BD-J)  252  from the ROM disk  212 . The data processing unit  211  performs a series of processes such as a process of reading a medium ID recorded in the ROM disk  212 , a process of transmitting the medium ID to the server  220 , and a process of acquiring the copy permission information from the server  220  in accordance with the program  252 . After these processes are performed, the process of copying the content recorded in the ROM disk  212  to the local memory unit  213  is performed. 
     In this way, various content such as the content downloaded from the server and the copied content from the ROM disk, that is, the content copied in the managed copy (MC) process performed under the control of the server by acquiring the copy permission information from the server, is recorded in the local memory unit  213 . 
       FIG. 5  shows a configuration of a directory of the local memory unit in which various content is recorded. As shown in  FIG. 5 , a copied content (MC content) directory  281  for storing content copied from other mediums by the managed copy or the management data and a downloaded content (EST content) directory  282  for storing the content acquired in the download process from the server or its management data are established, for example, in the local memory unit  213  constituted by a hard disk. 
     The copied content and the downloaded content are divided into the units of titles and are stored in the directories  281  and  282 . By this division and setting in the units of titles, data can be selected and copied at the time of performing the copy process on another medium. 
     However, it is not preferable that the process of reproducing the content recorded in the local memory unit can only be performed using the data recorded in the local memory unit. It is preferable that it should be necessary to use data recorded in an internal memory of the information processing device other than the local memory unit. This is because the data recorded in the local memory unit such as a hard disk can be copied to another medium and non-permitted usage of the content could be encouraged when the content can be reproduced using only the copied data. 
     An example of data stored in the local memory unit and the memory in the information processing device will be described with reference to  FIG. 6  and the subsequent drawings. Plural examples of data storage will be described now in two patterns of (A) an example of data storage where the content downloaded from the server is stored in the local memory unit (see  FIGS. 6 to 8 ) and (B) an example of data storage where the content copied from another medium is stored in the local memory unit (see  FIGS. 9 to 11 ). 
     The data processing unit of the information processing device performs a process of recording the encrypted content downloaded from the server or the encrypted content copied from the medium in the local memory unit. The data processing unit makes a data communication with the server, which is performed along with the recording process, or performs a key block process such as the MKB. The data processing unit performs a content reproducing process accompanied with the process of decoding the encrypted content or the process of confirming the validity by using the data stored in the local memory unit and the data stored in the secure memory at the time of performing a process of reproducing the encrypted content recorded in the local memory unit. 
     The example (A) of data storage where the content downloaded from the server is stored in the local memory unit will be first described with reference to  FIGS. 6 to 8 . 
       FIG. 6  shows a server  310  providing download content and an information processing device  320  having a local memory unit  350  storing the download content. The information processing device  320  further includes a secure memory  360  as an internal memory. The secure memory  360  is a memory in which the reading or the changing of the stored data is permitted in only a predetermined sequence. 
     In the example shown in  FIG. 6 , a device key set  361 , a device binding ID  362 , and a binding nonce  363  are stored in the secure memory  360 . 
     The device key set  361  is a key set established to correspond to the information processing device  320  as a device. That is, the device key set is a key set specific to an information processing device as a device or set of plural information processing devices. This device key set  361  is used to generate a decoding key at the time of decoding the encrypted content  353  stored in the local memory unit  350 . This device key set  361  needs to be managed in a secrecy required system. 
     The device binding ID  362  is an identifier specific to the information processing device as a device or a set of plural information processing devices. The binding nonce  363  is random number information and is generated and stored in the secure memory  360  by the information processing device  320 , for example, at the time of downloading the content from the server  310 . 
     The device binding ID  362  and the binding nonce  363  are data that must be transmitted to the server in order to acquire the server authentication information (token)  356  from the server  310  at the time of downloading the content from the server  310 . The device binding ID  362  and the binding nonce  363  need to be managed in a system with anti-falsification (Integrity required). 
     In this example, three pieces of data of the device key set  361 , the device binding ID  362 , and the binding nonce  363  are stored in the secure memory  360  other than the local memory unit  350 . The device key set  361  or the device binding ID  362  may be stored at the time of manufacturing the information processing device  320 , or may be acquired and stored from a server or a medium providing the data. When the data is acquired from the server or the medium, it is necessary to have high security to prevent leakage. 
     When requesting the downloading of content from the server  310 , the information processing device  320  transmits the device binding ID  362  and the binding nonce  363  stored in the secure memory  360  to the server  310 . 
     The server  310  generates the server authentication information (token) by signing the data with the secret key and transmits the server authentication information to the information processing device  320 . The information processing device  320  stores the server authentication information (token) in the local memory unit  350 . The server authentication information (token)  356  in the local memory unit  350  is shown in  FIG. 6 . 
     As shown in the drawing, the server  310  transmits a CPS unit key file  311 , a CPS unit usage control information file  312 , an encrypted content  313 , an MKB  314 , and a content certificate  315  to the information processing device  320  at the time of downloading the content. 
     The CPS unit key file  311  is a file storing key used to decode the CPS units of the encrypted content  313  or a key used to generate the keys. 
     The CPS unit usage control information file  312  is a file storing usage control information of the CPS units of the encrypted content  313 . 
     The encrypted content  313  is an entity of the content to be reproduced and is divided into units (CPS units) as a usage unit. 
     The MKB  314  is data including key information used to generate a decoding key of the encrypted content  313 . 
     The content certificate  315  is used to confirm the validity of the encrypted content  313 . The information processing device  320  confirms the validity of the encrypted content  313  using the content certificate  315  at the time of reproducing the encrypted content  313 . By this process, the reproduction of the content is permitted on condition that the validity of the encrypted content  313  is confirmed. 
     The information processing device  320  stores the data transmitted from the server  310  in the local memory unit  350 . That is, the following data is stored in the local memory unit  350  shown in  FIG. 6 : a CPS unit key file  351 , a CPS unit usage control information file  352 , an encrypted content  353 , an MKB  354 , and a content certificate  355 . The server authentication information (token)  356  is recorded in addition to these data. 
     At the time of reproducing the encrypted content  353 , the process including the process of confirming the validity of the encrypted content  353  and the process of decoding the encrypted content is performed using all the data stored in the local memory unit and the device key set  361  stored in the secure memory  360 . 
     In this example, the data stored in the secure memory  360  includes the following data: a device key set  361  used to generate a key for decoding the encrypted content; and a device binding ID  362  and a binding nonce  363  used to acquire authentication information from the server, which are stored in the secure memory. 
     Another example of data where the content downloaded from the server is stored in the local memory unit and the device key set is not necessary will be described now with reference to  FIG. 7 . 
     In  FIG. 7 , similarly to  FIG. 6 , a server  310  providing download content and an information processing device  320  including a local memory unit  350  storing the download content and a secure memory  360  are shown. 
     In the example shown in  FIG. 7 , a volume-unique key  367  and content management data (AACS data)  368  are stored in the secure memory  360 . These data are provided from the server  310 . That is, in the example shown in  FIG. 6 , the information processing device  320  needs to store the device key set  361  and the device binding ID  362  in the secure memory  360  in advance, but the storage of the data is not required in the example shown in  FIG. 7 . The information processing device  320  can receive the volume-unique key  367  and the content management data (AACS data)  368  from the server  310  and store the received data in the secure memory  360 , at the time of downloading the content from the server  310 . 
     Specific data of the volume-unique key  367  and the content management data (AACS data)  368  will be described with reference to  FIG. 8 . 
     The volume-unique key is set as a unique key in the title unit of the downloaded content or the copied content. This key is key information used to decode the encrypted content of the corresponding title. The volume-unique key is also encrypted and is decoded for use. 
     In (a) in  FIG. 8 , an example of data in which the volume-unique key is correlated with the title number is shown. The correlated data is stored in the secure memory  360 . At the time of reproducing the content, the title is designated, the content correlated with the designated title is selected, and the volume-unique key is selectively used depending on the title. 
     When the download content is acquired from the server, a disk storing one type of content is fitted into the information processing device and the download process is performed, for example, using a program read from the disk. The volume-unique key or the volume ID is a volume-unique key or a volume ID set to correspond to the content title of the disk. When content is copied from the disk and recorded in the local memory unit, the volume-unique key or the volume ID corresponding to the content title of the disk storing the content is recorded as storage data of the secure memory. In (a) in  FIG. 8 , an example where volume-unique keys corresponding to the titles of various disks are registered is shown. 
     In an setting example of title numbers, the copy content (MC content) is set when the first bit is 0, the download content (EST content) is set when the first beat is 1, and the directory names or sub-directory names of the local memory unit storing the content are set in the second bit and the subsequent bits. The correspondence between the title numbers and the content becomes clear by this setting. 
     As shown in (b) in  FIG. 8 , the content management data (AACS data)  368  includes data corresponding a title number, a volume ID, a PMSN (Prerecorded Media Serial Number), and an anti-falsification code. 
     The title number is a title of the download content or the copy content. 
     The volume ID is an identifier of a title unit. 
     The PMSN (Prerecorded Media Serial Number) is an ID specific to the medium (disk) and is an ID set in the ROM disk storing the content. The PMSN corresponds to the ID of the ROM disk used to download the content or the ID of the ROM disk as a copy source when the content is copied. 
     The anti-falsification code is data for verifying the falsification of the title number, the volume ID, and the PMSN. 
     In this process example, the volume-unique key  367  and the content management data (AACS data)  368  are stored in the secure memory  360  shown in  FIG. 7 . The volume-unique key  367  needs to be managed in a system requiring secrecy. The content management data (AACS data)  368  needs to be managed in a system with anti-falsification (Integrity required). 
     The volume-unique key  367  and the content management data (AACS data)  368  are both data used to reproduce the encrypted content  353  stored in the local memory unit  350 . These data include data necessary for generating a key used to decode the encrypted content  353  or for performing the validity confirming process. When the data included in the content management data (AACS data)  368  is used, it should be necessarily confirmed that no falsification is made therein using falsified verifying data. The data can be used after the absence of falsification is confirmed. 
     When the information processing device  320  requests the download content from the server  310 , the server  310  transmits, as data to be stored in the local memory unit  350  of the information processing device  320 , the CPS unit key file  311 , the CPS unit usage control information file  312 , and the encrypted content  313 , as shown in the drawing. 
     The server  310  transmits the volume-unique key  317  and the content management data (AACS data)  318  as data to be stored in the secure memory  360  of the information processing device  320 . 
     The CPS unit key file  311  is a file storing key used to decode the CPS units of the encrypted content  313  or a key used to generate the keys. 
     The CPS unit usage control information file  312  is a file storing usage control information of the CPS units of the encrypted content  313 . 
     The encrypted content  313  is an entity of the content to be reproduced and is divided into units (CPS units) as a usage unit. 
     In this process example, the MKB and the content certificate stored in the local memory unit in the process example having been described with reference to  FIG. 6  are not included in the data provided from the server. In this example, the data need not be stored in the local memory unit. 
     The information processing device  320  stores the data transmitted from the server  310  in the local memory unit  350  or the secure memory  360 . That is, the following data are stored in the local memory unit  350  shown in  FIG. 7 : a CPS unit key file  351 , a CPS unit usage control information file  352 , and an encrypted content  353 . A volume-unique key  367  and a content management data (AACS data)  368  are stored in the secure memory  360 . 
     At the time of reproducing the encrypted content  353 , processes using all the data stored in the local memory unit and the data stored in the secure memory are performed. 
     In the process example shown in  FIG. 7 , the data necessary for the process of reproducing the encrypted content  353  acquired by download is provided from the server  310 . In the configuration having been described with reference to  FIG. 6 , only a specific information processing device storing the device key set in advance can use the download content. However, in the configuration shown in  FIG. 7 , any device can use the download content, not just the device having the specific data. 
     (B) The example of data storage where the content copied from another medium is stored in the local memory unit will be described now with reference to  FIGS. 9 to 11 . 
     In  FIG. 9 , a disk  410  storing an encrypted content  417  to be copied and an information processing device  420  including a local memory unit  450  in which the encrypted content  417  of the disk  410  is copied and stored are shown. The information processing device  420  includes a secure memory  460  as an internal memory. 
     In the example shown in  FIG. 9 , content management data (AACS data)  461 , a device key set  462 , and a volume-unique key  463  are stored in the secure memory  460 . 
     The content management data (AACS data)  461  is the same content management data as described with reference to  FIG. 8 . As shown in (b) in  FIG. 8 , the title number, the volume ID, the PMSN (Prerecorded Media Serial Number), and the anti-falsification code are set therein as corresponding data. 
     As the content management data (AACS data)  461 , the volume ID  411  and the medium ID (PMSN)  412  stored in the disk  410  storing the encrypted content  417  to be copied are read and stored in the secure memory  460  by the information processing device  420 . 
     The device key set  462  is recorded in the information processing device  420  in advance. Alternatively, the device key set may be acquired from a server or a medium providing the device key set. However, when the device key set is acquired from the server or the medium, it is necessary to secure the security thereof and to prevent the leakage thereof. 
     The volume-unique key  463  is generated by a data process using the medium key acquired from the volume ID  411  stored in the disk  410  and the MKB  414  stored in the disk  410 . As shown in the drawing, the information processing device  420  performs the MKB process in step S 201  to generate the volume-unique key  463  and stores the generated volume-unique key in the secure memory  460 . 
     The content management data (AACS data)  461  stored in the secure memory  460  needs to be managed in a system with anti-falsification (Integrity required). Both the device key set  462  and the volume-unique key  463  need to be managed in a system requiring secrecy. 
     When the information processing device  420  copies the content from the disk  410 , the following data recorded in the disk  410  are read and recorded in the local memory unit  450  of the information processing device  420 : a content certificate  413 , a CPS unit key file  415 , a CPS unit usage control information file  416 , and an encrypted content  417 . 
     A content certificate  451 , a CPS unit key file  452 , a CPS unit usage control information file  453 , and an encrypted content  454  are stored in the local memory unit  450  shown in  FIG. 9 . 
     The information processing device  420  reads the volume ID  411  and the medium ID (PMSN)  412  from the disk  410 , generates the content management data (AACS data)  461  (see (b) in  FIG. 8 ) including the read data, and stores the generated content management data in the secure memory  460 . 
     In step S 201 , the information processing device  420  reads the MKB  414  from the disk  410  and acquires the medium key from the MKB  414  using the device key of the device key set  462  read from the secure memory  460 . The information processing device generates the volume-unique key  463  by a data process (encryption process) using the acquired medium key and the volume ID  411  read from the disk and stores the generated volume-unique key in the secure memory  460 . 
     At the time of reproducing the encrypted content  454  stored in the local memory unit  450 , the processes accompanied with the process of confirming the validity of the encrypted content  454  or the decoding process using the data stored in the local memory unit and the secure memory  460  are performed. 
     Similarly to  FIG. 9 ,  FIG. 10  shows the example of data storage (B) where the content copied from another medium is stored in the local memory unit. Similarly to  FIG. 9 , in  FIG. 10 , a disk  410  storing an encrypted content  417  to be copied and an information processing device  420  including a local memory unit  450  in which the encrypted content  417  of the disk  410  is copied and stored are shown. The information processing device  420  includes a secure memory  460  as an internal memory. 
     In the example shown in  FIG. 10 , a volume ID  465 , a medium ID (PMSN)  466 , and a device key set  462  are stored in the secure memory  460 . In the example described with reference to  FIG. 9 , the content management data (AACS data)  461  is stored. The content management data (AACS data)  461  is data including the volume ID and the medium ID (PMSN) as described with reference to (b) in  FIG. 8  and falsification verifying data or the like is added to the data. In the example shown in  FIG. 10 , such preparation of the data is not performed, but the volume ID  411  and the medium ID  412  recorded in the disk  410  are stored in the secure memory without any change. 
     The device key set  462  is recorded in the information processing device  420  in advance. Alternatively, the device key set may be acquired from a server or a medium providing the device key set. However, when the device key set is acquired from the server or the medium, it is necessary to secure the security thereof and to prevent the leakage thereof. 
     The volume ID  465  and the medium ID  466  stored in the secure memory  460  need to be managed in an system with anti-falsification (Integrity required). The device key set  462  needs to be managed in a system requiring secrecy. 
     When the information processing device  420  copies the content from the disk  410 , the following data recorded in the disk  410  are read and recorded in the local memory unit  450  of the information processing device  420 : a content certificate  413 , an MKB  414 , a CPS unit key file  415 , a CPS unit usage control information file  416 , and an encrypted content  417 . 
     A content certificate  451 , an MKB  455 , a CPS unit key file  452 , a CPS unit usage control information file  453 , and an encrypted content  454  are stored in the local memory unit  450  shown in  FIG. 10 . 
     The information processing device  420  reads the volume ID  411  and the medium ID (PMSN)  412  from the disk  410  and stores the read data in the secure memory  460 . 
     Unlike the example shown in  FIG. 9 , in the example shown in  FIG. 10 , the MKB  451  is stored in the local memory unit  450 . At the time of reproducing the encrypted content  454  stored in the local memory unit  450 , a process of acquiring the medium key using the device key included in the device key set  462  is performed on the MKB  455 . In addition, processes accompanied with the process of confirming the validity of the encrypted content  454  and the decoding process using the data stored in the local memory unit and the secure memory  460  are performed. 
     Similarly to  FIGS. 9 and 10 ,  FIG. 11  shows the example of data storage (B) where the content copied from another medium is stored in the local memory unit. In the example shown in  FIG. 11 , server authentication information (token) which is copy permission information is acquired from a server  500  and is stored in a local memory unit  550 . 
     In the example shown in  FIG. 11 , a device key set  561 , a device binding ID  562 , and a binding nonce  563  are stored in the secure memory  560 . 
     The device key set  561  is a key set established to correspond to the information processing device  520  as a device. That is, the device key set is a key set specific to an information processing device as a device or a set of plural information processing devices. This device key set  561  is used to generate a decoding key at the time of decoding the encrypted content  557  stored in the local memory unit  550 . This device key set  561  needs to be managed in a secrecy required system. 
     The device binding ID  562  is an identifier specific to the information processing device as a device or a set of plural information processing devices. The binding nonce  563  is random number information and is generated and stored in the secure memory  560  by the information processing device  520 , for example, at the time of acquiring the server authentication information (token) from the server  500 . The device binding ID  562  and the binding nonce  563  are data which should be transmitted to the server in order to acquire the server authentication information (token) from the server  500 . The device binding ID  562  and the binding nonce  563  need to be managed in a system with anti-falsification (Integrity required). 
     In this example, three pieces of data of the device key set  561 , the device binding ID  562 , and the binding nonce  563  are stored in the secure memory  560  other than the local memory unit  550 . The device key set  561  or the device binding ID  562  may be stored at the time of manufacturing the information processing device  520 , or may be acquired and stored from a server or a medium providing the data. When the data is acquired from the server or the medium, it is necessary to have high security to prevent leakage. 
     When copying the content from the disk  510  and storing the copied content in the local memory unit  550 , the information processing device  520  transmits the device binding ID  562  and the binding nonce  563  stored in the secure memory  560  to the server  500 . 
     In step S 221  shown in  FIG. 11 , the server  500  generates the server authentication information (token) by signing the data with the secret key of the server and transmits the server authentication information to the information processing device  520 . The information processing device  520  stores the server authentication information (token) in the local memory unit  550 . The server authentication information (token)  551  is shown in  FIG. 11 . 
     The server  500  provides a DL (download) content certificate  501 , which corresponds to the encrypted content  557  copied from the disk  510  and stored in the local memory unit  550 , to the information processing device  520  at the time of providing the server authentication information (token). The content certificate  501  includes data for confirming the validity of the encrypted content  557 . The information processing device  520  stores the data received from the server  500  in the local memory unit  550 . The server authentication information (token)  551  and the DL content certificate (CC)  552  are shown in the local memory unit  550  of  FIG. 11 . 
     The information processing device  520  performs the process of copying the content from the disk  510  after acquiring the data from the server  500 . When performing the process of copying the content from the disk  510 , the information processing device  520  reads the following data from the disk  510  and records the read data in the local memory unit  550  of the information processing device  520 : a content hash table  512 , an MKB  513 , a CPS unit key file  514 , a CPS unit usage control information file  515 , and an encrypted content  516 . 
     The data of a content hash table  553 , an MKB  554 , a CPS unit key file  555 , a CPS unit usage control information file  556 , and an encrypted content  557  are stored in the local memory unit  550  shown in  FIG. 11 . 
     The content hash table is a table storing hash values of constituent data of the encrypted content. The content hash table is used to verify whether the content is valid content that was not falsified at the time of reproducing the content. 
     At the time of reproducing the encrypted content  557  stored in the local memory unit  550 , the process including the process of confirming the validity of the encrypted content  557  and the process of decoding the encrypted content is performed using all the data stored in the local memory unit and the device key set  561  stored in the secure memory  560 . 
     In this example, the data stored in the secure memory  560  includes the following data: 
     a device key set  561  used to generate a key for decoding the encrypted content; and 
     a device binding ID  562  and a binding nonce  563  used to acquire authentication information from the server, which are stored in the secure memory. 
     As described with reference to  FIGS. 6 to 11 , when the download content or the copy content is stored in the local memory unit of the information processing device, the data strongly requiring anti-leakage or anti-falsification measures is stored in the secure memory other than the local memory unit. By using this data storage configuration, it is possible to prevent the content from being used even when the data stored in the local memory unit is copied to leak to another medium, thereby preventing the non-permitted use of content. 
     Content Reproducing Process 
     A process of reproducing content stored in the local memory unit will be described now. As described with reference to  FIGS. 6 to 11 , the download content or the copy content from another medium is recorded in the local memory unit. The data stored in the secure memory as well as the data stored in the local memory unit is used to reproduce the content. Hereinafter, the content reproducing process in the local memory unit will be described with reference to  FIGS. 12  and  13 . 
     When reading the encrypted content stored in the local memory unit and performing the reproduction process, the data processing unit of the information processing device selectively reads the key information or the usage control information required to reproduce content from the local memory unit or the memory and performs the reproduction process. 
       FIG. 12  shows a process example of the content reproducing process when the server authentication information (token) is not stored in the local memory unit.  FIG. 13  shows a process example of the content reproducing process when the server authentication information (token) is stored in the local memory unit. 
     The process example of the content reproducing process when the server authentication information (token) is not stored in the local memory unit  650  will be first described with reference to  FIG. 12 . The same information processing device  620  as described with reference to  FIGS. 6 to 11  is used. The information processing device  620  includes a local memory unit  650  storing an encrypted content  654  acquired by the download process from a server or the copy process from another medium and a secure memory  660  storing key information and the like. 
     In the example shown in  FIG. 12 , a content certificate  651 , a CPS unit usage control information file  652 , a CPS unit key file  653 , and an encrypted content  654  are stored in the local memory unit  650 . Content management data (AACS)  661 , a device key set  662 , and a volume-unique key  663  are stored in the secure memory  660 . 
     This example of data storage has the same configuration as described with reference to  FIG. 9 . The content copying process is exemplified in  FIG. 9 , but the encrypted content  654  stored in the local memory unit  650  shown in  FIG. 12  is not limited to the copy content, but may be any of the copy content and the download content. 
     The process example described with reference to  FIG. 12  is an example of the content reproducing process when the server authentication information (token) is not stored in the local memory unit  650 . In this process example, the MKB is not stored in the local memory unit. As described with reference to  FIG. 9 , the volume-unique key  663  acquired by the MKB process is stored in the secure memory  660 . That is, the MKB process is performed in advance and the volume-unique key  663  as the result thereof is stored in the secure memory  660 . Therefore, the MKB process can be omitted in performing the reproduction process. 
     The data processing unit of the information processing device performs the processes of steps S 301  to S 303  shown in  FIG. 12  to reproduce the content. First, in step S 301 , the content certificate  651  and the CPS unit usage control information file  652  stored in the local memory unit  650  are verified. 
     The content certificate  651  and the CPS unit usage control information file  652  are signed with a secret key of the issuing server and the information processing device verifies the signature with a public key of the issuing server. Since the public key used to verify the signature is key data without secrecy, the public key is not stored in the secure memory  660 . The public key can be acquired from other memories accessible by the information processing device or via mediums or networks. 
     In step S 302 , the CPS unit keys are extracted from the CPS unit key file. This process is performed by a decoding process using the volume-unique key  663  stored in the secure memory. As described above, the volume-unique key  663  is acquired by the MKB process. 
     Specifically, as described with reference to  FIG. 9 , the medium key is acquired from the MKB using the device keys of the device key set and the volume-unique key is generated by the data process (encryption process) using the acquired medium key and the volume ID of the disk. In this example, since this process is performed in advance, this process can be omitted. 
     In step S 302 , the CPS unit key  671  is extracted from the CPS unit key file by performing a decoding process using the volume-unique key  663  stored in the secure memory and then the process of step S 303  is performed. 
     In step S 303 , the encrypted content  654  stored in the local memory unit  650  is decoded using the acquired CPS unit key  671  to generate and reproduce the content  672 . 
     This process example is an example of the content reproducing process when the server authentication information (token) is not stored in the local memory unit  650  and does not include any process using the server authentication information (token). 
     The example of the content reproducing process when the server authentication information (token) is stored in the local memory unit will be then described with reference to  FIG. 13 . 
     The information processing device  720  shown in  FIG. 13  includes a local memory unit  750  storing an encrypted content  756  acquired by the download process from a server or the copy process from another medium and a secure memory  760  storing key information and the like. 
     In the example shown in  FIG. 13 , a content certificate  751 , a CPS unit usage control information file  752 , server authentication information (token)  753 , MKB  754 , a CPS unit key file  755 , and an encrypted content  756  are stored in the local memory unit  750 . A device binding ID  762 , a binding nonce  763 , and a device key set  763  are stored in the secure memory  760 . 
     This example of data storage has the same configuration as described with reference to  FIG. 11 . The content copying process is exemplified in  FIG. 11 , but the encrypted content  756  stored in the local memory unit  750  shown in  FIG. 13  is not limited to the copy content, but may be any of the copy content and the download content. 
     The process example described with reference to  FIG. 13  is an example of the content reproducing process when the server authentication information (token) is stored in the local memory unit  750 . As described with reference to  FIGS. 6 and 11 , the server authentication information (token) is data received from the server at the time of downloading content from the server or copying content from a medium. The server authentication information (token) is data acquired by transmitting identification information (the device binding ID and the binding nonce) of the information processing device to a server and signing the data with a secret key of the server. 
     In this process example, the server authentication information (token)  753  is stored in the local memory unit  750  shown in the drawing. The MKB  754  is also stored in the local memory unit  750 . 
     In the configuration described with reference to  FIG. 12 , the MKB is not stored in the local memory unit and the volume-unique key acquired as the processing result of the MKB is stored in the secure memory. However, in the example shown in  FIG. 13 , the MKB  754  is stored in the local memory unit  750  and the volume-unique key is not stored in the secure memory  760 . Therefore, at the time of performing the reproduction process, the MKB  754  stored in the local memory unit  750  needs to be processed. 
     The data processing unit of the information processing device performs the processes of steps S 501  to S 505  shown in  FIG. 13  to reproduce the content. First, in step S 501 , the content certificate  751  and the CPS unit usage control information file  752  stored in the local memory unit  750  are verified. 
     In step S 502 , the server authentication information (token)  753  stored in the local memory unit  750  is verified. As described above, the server authentication information (token) is signed with the secret key of the server and the information processing device verifies the signature using the public key of the server. Since the public key used to verify the signature is key data without secrecy, the public key is not stored in the secure memory  760 . The public key can be acquired from other memories accessible to the information processing device or via mediums or networks. 
     In step S 503 , the volume-unique key  771  is acquired by processing the MKB stored in the local memory unit  750 . Specifically, the medium key is acquired from the MKB  753  using the device key of the device key set  763  stored in the secure memory  760  to generate the volume-unique key  771  by processing data (encryption process) using the acquired medium key and the volume ID of the disk. A volume ID included in the server authentication information (token)  753  is used as the volume ID. 
     In step S 504 , the CPS unit key is extracted from the CPS unit key file. This process is performed by a decoding process using the volume-unique key  771  acquired in step S 503 . 
     In step S 505 , the encrypted content  756  stored in the local memory unit  750  is decoded using the acquired CPS unit key  772  to generate and reproduce content  773 . 
     This process example is an example of the content reproducing process when the server authentication information (token)  753  is stored in the local memory unit  750 . Here, it is necessary to verify the server authentication information (token)  753 . 
     Medium ID (PMSN) Reading Process at the Time of Reproducing Content 
     The content stored in the local memory unit can be reproduced by the information processing device as described above with reference to  FIGS. 12 and 13 , but the content stored in the disk (ROM disk or the like) may also be reproduced. 
     That is, the data processing unit of the information processing device selectively reads and reproduces the encrypted content stored in the disk or the local memory unit. The data processing unit reads the encrypted content from the disk when the content to be reproduced is stored in the disk, reads the content from the local memory unit when the content to be reproduced is stored in the local memory unit, and then reproduces the read content. The key information or the usage control information required for reproducing the content is read and processed from the disk or the local memory unit or the memory. 
     The content reproducing process from the disk (ROM disk) or the local memory unit is performed by allowing the data processing unit of the information processing device to execute a reproduction program. For example, when the content reproducing process is performed to correspond to the BD format defined in the AACS standard, the CPS unit key is acquired and the encrypted content is decoded using the acquired CPS unit key. 
     Together with the content reproduction, the medium ID (PMSN) corresponding to the content to be reproduced may be read. For example, the content to be reproduced may be controlled on the basis of the confirmation of the medium ID or the medium ID may be transmitted to the server to acquire new service content. 
     However, when the content to be reproduced is stored in the disk, the medium ID to be acquired is recorded in a medium ID recording area of the disk. Specifically, in a BD-ROM disk, the medium ID is recorded in a BCA (Burst Cutting Area) and it is thus necessary to read the medium ID from the BCA. 
     On the other hand, when the content to be reproduced is stored in the local memory unit, the medium ID corresponding to the content to be reproduced is stored in the secure memory and it is thus necessary to read the medium ID from the secure memory. 
     In this way, the medium ID can be read in different ways depending on whether the content to be reproduced is stored in the disk or in the local memory unit. In the information processing device according to the embodiment of the invention, it is possible to read different medium ID depending on whether the content to be reproduced is stored in the disk or in the local memory unit. 
     The sequence of the medium ID reading process will be described with reference to the flowchart shown in  FIG. 14 . 
     The medium ID reading process is performed by the data processing unit of the information processing device using a BD-J application program different from the content reproducing program. As described above, the BD-J application program is executed in the BD-JVM (BD-J virtual machine). 
     The processes of the steps in the flowchart shown in FIG.  14  will be described now. In step S 701 , the reproduction of content is started. This content reproducing process is performed by the reproducing program. The content to be reproduced is designated by a user and it is determined at this time point whether the content to be reproduced is stored in the disk or in the local memory unit. 
     When the reading of the medium ID is required in performing the content reproducing process, the BD-J application program dedicated to the medium ID reading process is read and executed. The BD-J application program is stored in either the disk or the local memory unit. Alternatively, the BD-J application program may be stored in another memory in the information processing device. 
     In the BD-J application program, the API for performing the medium ID reading process is established. In step S 703 , the API [get PMSN] is performed. 
     The processes of steps S 704  to S 707  are based on the sequence defined in the API [get PMSN]. First, in step S 704 , it is determined whether the content to be reproduced is stored in the ROM disk. When it is determined that the content to be reproduced is stored in the ROM disk, the medium ID recorded in the BCA of the ROM disk is read in step S 705 . 
     On the other hand, when it is determined in step S 704  that the content to be reproduced is not stored in the ROM disk, the medium ID recorded in the secure memory is read in step S 706 . 
     Finally, in step S 707 , the result of the API, that is, one of the medium ID read from the BCA of the disk or the medium ID read from the secure memory is provided to the BD-J application program and the sequence is ended. 
     The BD-J application program uses the received medium ID, for example, for a process of employing the medium ID as the designation information of the content to be reproduced or a process of transmitting the medium ID to the server and receiving service content. 
     The data processing unit of the information processing device according to the embodiment of the invention performs the medium ID reading process using the API (Application Programming Interface) defining the sequence of the medium ID acquiring process. The sequence defined by the API includes both the process of reading the medium ID from the disk and the process of reading the medium ID from the memory and selectively performs the sequence depending on whether the content to be reproduced is stored in the disk or in the local memory unit. 
     Similarly to the case where the BD-J application program stored in the ROM disk is directly executed, when the data copied to the HDD by the managed copy process is reproduced or when the data copied to the HDD by the MoD/EST manner is reproduced, a player can perform the medium ID reading process, where the medium IDs are different depending on the position in which the content to be reproduced is recorded, using one API [get MediaID]. Accordingly, the process of changing the program depending on the position in which the content to be reproduced is recorded is not necessary and thus it is possible to guarantee the efficiency of the author making the BD-J. 
     The invention has been hitherto described with reference to specific embodiments. However, it is obvious to those skilled in the art that the embodiments can be modified in various forms without departing from the spirit and scope of the invention. That is, the invention has been described exemplarily but these should not be taken as definitive. The spirit and scope of the invention can be understood from the appended claims. 
     A series of processes described in this specification can be performed by hardware, software, or a combination thereof. When the processes are performed by software, a program including the process sequence can be installed in and executed by a memory of a computer assembled into exclusive hardware. Alternatively, the program can be installed in and executed by a general-purpose computer performing various processes. For example, the program can be recorded in a recording medium in advance. The program cannot only be installed in a computer from a recording medium but may be also received through a network such as a LAN (Local Area Network) and the Internet and installed in a recording medium such as a built-in hard disk. 
     The various processes described in this specification can be performed consecutively in the described order or may be performed in parallel or individually depending on the processing capability of the device performing the processes or as needed. The system in this specification is a logical set of plural devices and is not limited to a configuration in which the plural devices are disposed in the same chassis. 
     As described above, according to the embodiment of the invention, in the information processing device selectively reproducing content from plural mediums, a medium ID is read using the API. When the content to be reproduced is stored in a disk, the medium ID is read from the disk. When the content to be reproduced is stored in a local memory unit, the medium ID is read from a memory. The API includes the overall sequence of the process of reading the medium ID from the disk and the process of reading the medium ID from the memory and a process sequence is selected and performed depending on whether the content to be reproduced is stored in the disk or the local memory unit. According to this configuration, it is possible to read different medium IDs using one API, thereby reducing the processing load on the information processing device. 
     The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2008-209502 filed in the Japan Patent Office on Aug. 18, 2008, the entire contents of which is hereby incorporated by reference. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.