Abstract:
Disclosed herein is a copy component for copying a license describing a usage rule of the content between storage components that store the license in storages, the copy component comprising, a receiving section for receiving the license from the first storage component that stores the license in the first storage, an analyzing section for evaluating the license to allow or prohibit move of the license, and a transferring section for transferring the license to the second storage component that stores the license in the second storage if copy of the content is allowable.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a copy component, a program and a method thereof.  
         [0002]     Unlike analog content, digital content such as music content allows duplication a plurality of times without involving degradation of quality. For this reason, the recent rapid increase in the processing speed and storage capacity of the Internet and PCs (personal Computers) also increases the illegal distribution and exchange of content without permission by the copyright holders of the content.  
         [0003]     In an attempt to prevent these illegal activities, a copyright management system based on the DRM (Digital Rights Management) technology intended to restrict the distribution and use of content has been gaining popularity. As proposed by SDMI (Secure Digital Music Initiative) for example, it is a general practice for the above-mentioned system to restrict the use (reproduction and copy for example) of content on the basis of use conditions written in the license (rights information) to content.  
         [0004]     For example, Japanese Patent Laid-Open No. 2002-312211 (refer to patent document 1) discloses a copyright management system for restricting the use of content on the basis of a general license. The license to be used by this copyright management system has various content use conditions such as “time limit of use”, “time limit of download”, “permitted copy count”, “check-out count”, “CD-R recordable right”, “PD copyable right”, “right for moving to proprietary right”, and “specification logging right” for example (especially, refer to FIG. 8 of Patent Document 1). User devices such as a PC and a PD (Portable Device) evaluate these licenses by the incorporated copyright management block (a DMR module for example), thereby controlling the use of copyrighted content.  
         [0005]     However, the above-mentioned copyright management system presents problems that the copyright management block of this system for managing the use of content on the basis of the license thereof is individually designed and mounted in accordance with the use restriction capabilities of the system and the type of a user device for example, thereby almost lacking versatility and expandability. Consequently, it is difficult to transfer copyright-managed content between user devices having different installations of copyright management blocks similar restrictions of use are imposed.  
         [0006]     The primary role of each copyright management system is to enhance the legal portability of content in exchange for the restrictive use of content. However, with the above-mentioned related-art copyright management system, copyright-managed content may not be transferred with restriction between user devices if the installations of copyright management block thereof are different from one another, thereby limiting the enhancement of the portability of copyright-managed content. This drawback is an obstacle for the popularization of copyright management systems.  
         [0007]     The above-mentioned problems may be attributable to the method of designing the copyright management block and the license. That is, related-art copyright management blocks are not based on module configurations suitably adapted to various content use cases such as reproduction, copy, move, rent (or check-out), return (or check-in, and storage, thereby failing to execute full use of content between a plurality of user devices. In addition, as described above, the related-art license is written with various use conditions at the same that are not written in definite categories for the above-mentioned use cases, thereby presenting a problem of poor portability. Therefore, it is difficult for the copyright management block having a specific installation to suitably determine the use conditions for evaluating each of use cases from the license corresponding to another installation.  
       SUMMARY OF THE INVENTION  
       [0008]     Therefore, the present invention addresses the above-identified and other problems associated with related-art methods and apparatuses. In order to circumvent these problems, the present invention provides a copy component, a program, a method that may enhance the capabilities of controlling copying licenses between user devices having different installation of copyright control blocks.  
         [0009]     In carrying out the invention and according to one embodiment thereof, there may be provided a copy component for copying a license describing a usage rule of the content between storage components that store the license in storages. The above-mentioned copy component including a receiving section for receiving the license from the first storage component that stores the license in the first storage, an analyzing section for evaluating the license to allow or prohibit move of the license, and a transferring section for transferring the license to the second storage component that stores the license in the second storage if copy of the content is allowable.  
         [0010]     In the above-mentioned copy component, the receiving section receives, from the first storage component, a first message including the license, a first manipulation type defining a type of processing of the license between the first storage component and the copy component, and a first component attribute defining an attribute of the first storage component and the analyzing section analyzes the first message to allow or prohibit processing of the license on the basis of the first manipulation type and the first component attribute included in the first message. The above-mentioned copy component further includes a creating section for creating a second message including the license, a second manipulation type defining a type of processing of the license between the second storage component and the copy component, and a second component attribute defining an attribute of the second storage component if copy of the license is found allowable by the analyzing section.  
         [0011]     In the above-mentioned copy component, the manipulation type may be any one of transfer for transferring the license itself, show for transferring a copy of the license, and update for transferring the license to be updated.  
         [0012]     In the above-mentioned copy component, the analyzing section allows processing of the license if the manipulation type is show and prohibits processing of the license if the first manipulation type is one of transfer and update.  
         [0013]     In the above-mentioned copy component, the second manipulation type may be transfer.  
         [0014]     In the above-mentioned copy component, the analyzing section prohibits processing of license in the first message may be the component attribute in the first message received by the receiving section represents an attribute of a utilization component that utilizes the license.  
         [0015]     In the above-mentioned copy component, a copy status defining a copy status of the license may be described in the license, the creating section updates the copy status of the license if copy of the license is allowable, and the transferring section transfers the updated license including the updated copy status to the second storage component.  
         [0016]     In the above-mentioned copy component, a usage rule of the content may be described in the license for each license processing component that handles the license and the analyzing section evaluates a copy rule defined for the copy component in the license to allow or prohibit copy of the license.  
         [0017]     In the above-mentioned copy component, the copy rule is copy count limit or copy time limit.  
         [0018]     In the above-mentioned copy component, the receiving section receives a copy of the license stored in the first storage from the first storage component.  
         [0019]     In the above-mentioned copy component, the first storage component reads the license from the first storage and transfers the read license to the copy component without invalidating the license stored in the first storage.  
         [0020]     In the above-mentioned copy component, the receiving section receives, together with the license, a content key to decrypt content corresponding to the license from the first storage component and the transferring section transfers the license and the content key to the second storage component.  
         [0021]     In carrying out the invention and according to still another embodiment thereof, there may be provided a copy program for a copy component for copying a license describing a usage rule of the content between storage components that store the license in storages. The above-mentioned copy program including the steps of receiving the license from the first storage component that stores the license in the first storage, evaluating the license to allow or prohibit move of the license, and transferring the license to the second storage component that stores the license in the second storage if copy of the content is allowable.  
         [0022]     In carrying out the invention and according to another embodiment thereof, there may be provided a copy method for a copy component for copying a license describing a usage rule of the content between storage components that store the license in storages. The above-mentioned copy method including the steps of receiving the license from the first storage component that stores the license in the first storage, evaluating the license to allow or prohibit move of the license, and transferring the license to the second storage component that stores the license in the second storage if copy of the content is allowable.  
         [0023]     Other objects and aspects of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1  is a schematic diagram illustrating a specific example of license processing components and a combination thereof in a copyright management system practiced as an embodiment of the invention;  
         [0025]      FIG. 2  is a schematic diagram illustrating an overall configuration of the copyright management system practiced as the embodiment of the invention;  
         [0026]      FIG. 3  is a block diagram illustrating an exemplary hardware configuration of a personal computer according to the embodiment of the invention;  
         [0027]      FIG. 4  is a block diagram illustrating an exemplary hardware configuration of a portable device according to the embodiment of the invention;  
         [0028]      FIG. 5  is a block diagram illustrating a functional configuration of a copyright management block of a user device for example according to the embodiment of the invention;  
         [0029]      FIG. 6  is a block diagram illustrating an exemplary configuration in which licenses are transferred between license processing components according to the embodiment of the invention;  
         [0030]      FIG. 7  is a schematic diagram illustrating installations of license processing components configuring a copyright management block according to the embodiment of the invention;  
         [0031]      FIG. 8  is a block diagram illustrating correlation between basic data handled in the copyright management system according to the embodiment of the invention;  
         [0032]      FIG. 9  is a diagram illustrating a specific example of a description of a license according to the embodiment of the invention;  
         [0033]      FIG. 10  is a diagram illustrating another specific example of a description of the license according to the embodiment of the invention;  
         [0034]      FIG. 11  is a diagram illustrating a specific example of a description of rent source license according to the embodiment of the invention;  
         [0035]      FIG. 12  is a diagram illustrating a specific example of a description of a license for rent according to the embodiment of the invention;  
         [0036]      FIG. 13  is a schematic diagram illustrating an outline of message transmission between components according to the embodiment of the invention;  
         [0037]      FIGS. 14A, 14B , and  14 C are diagrams illustrating license transmission types between components according to the embodiment of the invention;  
         [0038]      FIG. 15  is a diagram illustrating a relationship between transmission type IDs and messages of one example of transmission type identification information according to the embodiment of the invention;  
         [0039]      FIG. 16  is a diagram illustrating a relationship between component IDs that are a specific example of component attribute information and messages according to the embodiment of the invention;  
         [0040]      FIG. 17  is a diagram illustrating message types and data configuration thereof according to the embodiment of the invention;  
         [0041]      FIG. 18  is a diagram illustrating transmission types that may be handled by license processing components according to the embodiment of the invention;  
         [0042]      FIG. 19  is a block diagram illustrating a functional configuration according to message transmission between a transmission source component and a transmission destination component according to the embodiment of the invention;  
         [0043]      FIG. 20  is a timing chart indicative of a license transmission method for transmitting licenses between the transmission source component and the transmission destination component according to the embodiment of the invention;  
         [0044]      FIG. 21  is a schematic diagram illustrating a specific example of transferring licenses between a plurality of license processing components according to the embodiment of the invention;  
         [0045]      FIG. 22  is a schematic diagram illustrating an outline of an ordinary content reproduction control method that does not involve updating of the license according to the embodiment of the invention;  
         [0046]      FIG. 23  is a timing chart indicative of a processing flow of the above-mentioned ordinary content reproduction control method that does not involve updating of the license according to the embodiment of the invention;  
         [0047]      FIG. 24  is a schematic diagram illustrating an outline of a content reproduction control method that involves updating of the license according to the embodiment of the invention;  
         [0048]      FIG. 25  is a timing chart indicative of a processing flow of the above-mentioned content reproduction control method that involves updating of the license according to the embodiment of the invention;  
         [0049]      FIG. 26  is a schematic diagram illustrating a license move method for moving licenses between two storage devices in the personal computer according to the embodiment of the invention;  
         [0050]      FIG. 27  is a schematic diagram illustrating an outline of a license move method for moving licenses between a plurality of devices according to the embodiment of the invention;  
         [0051]      FIG. 28  is a timing chart indicative of a processing flow of a license move method according to the above-mentioned embodiment of the invention;  
         [0052]      FIG. 29  is a schematic diagram illustrating a license copy method for copying licenses between two storage devices in the personal computer according to the embodiment of the invention;  
         [0053]      FIG. 30  is a timing chart indicative of a processing flow of a license copy method according to the embodiment of the invention;  
         [0054]      FIG. 31  is a schematic diagram illustrating an outline of a license rent-out method for renting out licenses between two storage means in the personal computer according to the above-mentioned embodiment of the invention;  
         [0055]      FIG. 32A  is a timing chart indicative of a processing flow of the license rent-out method according to the embodiment of the invention;  
         [0056]      FIG. 32B  is a timing chart continued from the timing chart shown in  FIG. 32A ;  
         [0057]      FIG. 33  is a schematic diagram illustrating an outline of a license return method for returning licenses between two storage devices in the personal computer according to the embodiment of the invention;  
         [0058]      FIG. 34A  is a timing chart indicative of a processing flow of the license return method according to the embodiment of the invention; and  
         [0059]      FIG. 34B  is a timing chart continued from the timing chart shown in  FIG. 34A . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0060]     The following describes, in detail, embodiments of the present invention with reference to accompanying drawings. It should be noted that components having substantially similar functional configurations are denoted by the same reference numerals herein and accompanying drawings for the purpose of brevity.  
       First Embodiment  
       [0061]     The following describes a copyright management system and components according to a first embodiment of the present invention.  
         [0000]     &lt;1. Outline of a Copyright Management Method&gt; 
         [0062]     First, the copyright management method used in the copyright management system according to the first embodiment will be described.  
         [0063]     The copyright management system according to the first embodiment of the invention manages the conditions and states of copyright-managed content (hereafter referred to simply as content) obtained by encrypting digital content such as video content and audio content among others. This copyright management system encrypts digital content with use conditions thereof specified by a copyright administrator and controls content use by means of a content encryption key used in the encryption and content use conditions and use status description, thereby executing copyright management. The basic data necessary for this copyright management includes: 
        (1) content;     (2) content encryption key (hereafter referred to simply as content key); and     (3) use conditions and use statuses description associated with the use of content and the transmission of basic data (hereafter referred to as a license).        
 
         [0067]     Content is a set of pieces of encrypted digital content (or copyright-managed content). This content becomes available when it is decrypted with the content key within a scope of the use condition described in the license. The content key becomes necessary when content is used and is managed as related with the license while keeping the key value confidential in each copyright management system. The license defines use conditions imposed on the use of content and the transmission of the above-mentioned three basic data and use statuses indicative of how content has been used up to the current time and is managed such that no forgery and alteration be practiced inside the copyright management system.  
         [0068]     Also, the copyright management system that uses the above-mentioned three basic data is required to satisfy the following three requirements: 
        (1) security of the content key (the content key shall not be broken);     (2) license confidentiality (the license shall not be altered); and     (3) secured relationship of three basic data (the relationship of content, content key, and license shall not be changed).        
 
         [0072]     In order to build a copyright management system capable of coping with various installations corresponding to user device types, content types, and use restriction types while satisfying the above-mentioned requirements, the copyright management system according to the present embodiment regards copyright management functions as a set of a plurality of basic functions and divides a copyright management block (actually software for copyright management) that executes copyright management in each user device into a plurality of modules of the above-mentioned basic functions. Next, the copyright management system transfers the three basic data between these modules that process the received basic data for the execution of the copyright management of content.  
         [0073]     This modularization will be described in detail below. First, the use restriction functions of the copyright management block are all listed to be divided into the following two factions: 
        (a) functions associated with the permanent storage of licenses; and     (b) functions associated with temporary use of licenses.        
 
         [0076]     Further, in these two major classifications, the use restriction functions are divided by the use case of content on the basis of the viewpoint of users of content and the copyright management block is modularized (into license processing components) for each divided use restriction function.  
         [0077]     Consequently, combining one or more license processing components belonging to (a) and (b) above may realize the content use restriction of each use case. Also, each license is written with parameters associated with use restriction functions by dividing the parameters by each license processing component. The license thus written is transferred in a portable manner between the above-mentioned license processing components of user devices arranged in a network. As a result, the location where content use restriction is practiced may be distributed over a plurality of user devices interconnected by a network.  
         [0078]     As described above, the copyright management system according to the first embodiment of the invention divides the copyright management block (or the software for copyright management) into a plurality of license processing components (or basic functional modules) by the license processing unit corresponding to the use case of content and distributably arrange these components. By combining these components on a network, the portability of content inside a network may be achieved.  
         [0079]     The following describes the above-mentioned license processing components and an exemplary combination thereof with reference to  FIG. 1 .  FIG. 1  schematically shows license processing components of the copyright management system according to the present embodiment and an exemplary combination of these components.  
         [0080]     As shown in  FIG. 1 , license processing components  11 ,  12 ,  21  and  22  for executing copyright management are divided into a storage component (or a storage module)  1  for executing the above-mentioned function (a) and a use component (or a utilization module)  2  for executing the above-mentioned function (b).  
         [0081]     The storage component  1  is a license processing component having a license permanent storage function, securely storing a license  305  and a content key  302  in a storage device. The storage component  1  includes a storage component  11  for a hard disk drive (hereafter referred to as a HDD) and a storage component  12  for a removable storage media such as a semiconductor memory, for example. The storage component  11  for HDD securely stores the license  305  and the content key  302  into a HDD  111  incorporated in a user device. The storage component  12  for removable storage media securely stores the license  305  and the content key  302  into a removable storage medium  40  loaded on a user device. Thus, the storage component  1  is arranged for each of a plurality of storage devices having different storage media.  
         [0082]     The storage component  1  thus configured reads the license  305  and the content key  302  from the storage device corresponding to the storage component  1  itself and transmits the license  305  and content key  302  to the use component  2 . Also, the storage component  1  writes to the license  305  and the content key  302  to the corresponding storage device.  
         [0083]     On the other hand, the use component  2  is a license processing component having a license temporary use function that evaluates the license  305  received from the storage component  1  to control the use of content and the transmission of the license  305  and the content key  302 . This use component  2  includes a reproduction component  21  for controlling content reproduction by evaluating the license  305  received from the storage component  1  and a move component  22  for control move of the license  305  by evaluating the license  305  received from the storage component  1 .  
         [0084]     Thus, the use component  2  only temporarily uses the license  305  and so on received from the storage component  1  at the time of content use and therefore cannot permanently store the license  305  and so on (in a storage device for example).  
         [0085]     As described above, dividing the basic functions for the copyright management block into a plurality of storage components  1  and a plurality of use components  2  allows the transfer of the license  305  and so on between these components, thereby controlling the use of content.  
         [0086]     For example, in the control of content reproduction, the storage component  11  reads the license  305  and the content key  302  corresponding to the content subject to reproduction from the HDD  111  and transmits these license  305  and content key  302  to the reproduction component  21  as shown in  FIG. 1 . The reproduction component  21  evaluates the reproduction condition written to the license  305  and determines whether the content subject to reproduction is reproducible or not. If the content is found reproducible, the reproduction component  21  decrypts the content with content key L and makes a reproduction application program to be described later execute the reproduction of the content.  
         [0087]     In the control of moving a license corresponding to the content to be moved between user devices, the storage component  11  reads the license  305  and the content key  302  corresponding to the content subject move is read from the HDD  111  and transmits the license  305  and the content key  302  to the move component  22  as shown in  FIG. 1 . The move component  22  evaluates the move condition written to the received license  305  to determine whether this license and the content key  302  are movable. If they are found movable, the move component  22  transmits the license and the content key  302  to the storage component  12 . The storage component  12  stores the received license and content key  302  into the removable storage medium  40 . When the license  305  and so on have thus been moved, the above-mentioned content subject to move is also moved from the HDD  11  to the removable storage medium  40  by a move application program to be described later. Consequently, another user device connected with the removable storage medium  40  can reproduce the content subject to move on the basis of the license  305  moved as described above. Thus, controlling the move of the license  305  and the content key  302  eventually can control the move of content.  
         [0088]     Thus, a copyright management method in the copyright management system according to the present embodiment of the invention has been outlined. Installing the copyright management block (or the copyright management software) in accordance with each individual user device and content type on the basis of such a copyright management method enhance the portability of content by transferring various types of content between user devices interconnected by a network for example. The following describes, in detail, each of the components of the above-mentioned copyright management system and operations of these components.  
         [0000]     &lt;2. System Configuration&gt; 
         [0089]     The following describes an entire configuration of a copyright management system  100  according to the first embodiment of the invention with reference to  FIG. 2 .  FIG. 2  is a diagram schematically showing an entire configuration of the copyright management system  100 .  
         [0090]     As shown in  FIG. 2 , the copyright management system  100  has a plurality of user devices  10   a ,  10   b , and so on (hereafter generically referred to as a user device  10 ), a distribution server  20 , a network  30  (including a home network  30   a  and a local line  30   b ) for interconnecting these devices, and the removable storage medium  40  for transferring data such as content and licenses between these devices, for example.  
         [0091]     Each user device  10  is an information processing apparatus of one of various types for using content and one configurational example of the license processing apparatus according to one embodiment of the present invention.  FIG. 2  shows a note-type or desktop-type personal computer (hereafter referred to as a PC)  10   a , a portable device (hereafter referred to as a PC)  10   b  that is a portable content reproducing device, a home server  10   c , a television receiver  10   d , a recording/reproducing device  10   e  such as CD, HD or DVD recorder/player, a stationary audio player  10   f , a car audio player  10   g , and a mobile phone  10   h , as one example of the user device  10 . However, the present embodiment is not limited to this configuration; for example, a computer of any type, a PDA (Personal Digital Assistant) or another portable terminal, a digital video camera, a home game machine, a home information appliance, and other various devices may be used.  
         [0092]     The user device  10  thus configured has content use functions (for example, content reproduction, storage, move, combination, division, conversion, copy, rent, and return functions), a content use control function based on license, a content management function (for example, search and delete of content, license, content key and so on based on content ID) and a content creation function based on ripping and self recording, for example.  
         [0093]     Of the user devices  10 , the devices having a capability of communication through the network  30  (for example, the PC  10   a , the home server  10   c , and so on) are communicably connectable with the distribution server  20 . These user devices  10  are capable of downloading the software for content distribution service and the software for copyright management from the distribution server  20  and installing the downloaded software in themselves, for example. Consequently, each user device  10  may receive the distribution of encrypted content, an encrypted license, and encrypted content key from the distribution server  20  and store these received data into a storage device such as a storage unit or the removable storage medium  40 .  
         [0094]     In addition, each user device  10  may newly create content by means of self recording (including audio and video recording) or ripping and store the created content in a storage unit or the removable storage medium  40 , for example. “Self recording” herein denotes recording, as digital data, an image signal or an audio signal for example shot or picked up by an imaging device or a sound pickup device of the user device  10  itself. “Ripping” herein denotes extracting digital content (audio or image for example) from a music CD, a video DVD, or a software CD-ROM for example, converting the extracted data into a computer-readable file format, and storing the converted data into a storage unit or the removable storage medium  40 .  
         [0095]     Further, each user device  10  is capable of using content in a scope of use conditions (for example, reproduction condition and move condition) written to the license of this content. In order to execute such content use restriction, each user device  10  has a copyright management block (or a copyright management module) for evaluating the license of content to control the processing of the content and the license thereof. This copyright management block may be configured by installing the copyright management software in the user device  10  such as the PC  10   a  in an ex post manner or pre-installing in the user device  10  such as the PC  10   a , the PD  10   b , the television receiver  10   d , the recording/reproducing apparatus  10   e , the stationary audio player  10   f , or the car audio device  10   g.    
         [0096]     Each user device  10  evaluates the use conditions and the use statuses of the content written to the license thereof by the above-mentioned copyright management block to determine whether the use conditions are satisfied. If the use conditions are found satisfied, the user device  10  permits the use (reproduction, copy, and so on) of the content and the processing of the license (storage, copy, and move). For example, if the reproduction of the content is permitted, the user device  10  is able to obtain a key for decrypting the encrypted content key, decrypt the encrypted content key by the obtained key, and decrypt the encrypted content by the decrypted content key, thereby reproducing the decrypted content.  
         [0097]     Further, each user device  10  is capable of transferring (move, copy, rent, and return) of content and licenses with other user devices  10  via the network  30 , home network  30   a , the local line  30   b , or the removable storage medium  40 . However, the transfer of content and licenses between user devices  10  requires that the copyright management block evaluate the move condition for example written to the license to permit the move for example of the content and the license thereof.  
         [0098]     The distribution server  20  is made up of a computer having server capabilities and arranged on a content distribution service provider. This distribution server  20  is a server for providing content distribution services for example and, upon a distribution request from the user device  10 , distributes the requested content to that user device  10  via the network  30 .  
         [0099]     For example, in the distribution of music content, the distribution server  20  is configured as an EMD server that provides electronic music distribution (EMD) services. In this case, the distribution server  20  compresses the music content subject to processing by a data compression algorithm such as ATRAC3 (Advanced Transform Acoustic Coding) or MP3 (MPEG Audio Layer-3) for example, encrypts the compressed music content by an encryption algorithm such as DES (Data Encription Standard), and distributes the encrypted music data to the user device  10 . Also, the distribution server  20  distributes the license written with use conditions of that encrypted music content and an encrypted content key for decrypting the encrypted music content to the user device  10 , along with the encrypted music content.  
         [0100]     In addition, the distribution server  20  may also be configured as a server that provides created content use services for managing the use of the content created by the user device  10  by ripping or self recording for example. In this case, the distribution server  20  distributes the license written with use conditions of the created content and content key for decrypting the content to the user device  10 . Consequently, the user device  10  becomes ready for using (reproducing or copying for example) the content created by itself by ripping for example on the basis of the license and the content key obtained from the distribution server  20 .  
         [0101]     It should be noted that, in the example shown in  FIG. 2 , content, a license thereof, and a content key for example are provided by the distribution from a service provider by the distribution server  20  through the network  30  to the user device  10 , however the present embodiment is not restricted to this configuration. For example, content, a license thereof, and a content key for example may be provided to the user device  10  via the removable storage medium  40  such as DVD, CD, MD, or semiconductor memory.  
         [0102]     The network  30  is a communication network for communicably interconnect the user device  10  and the distribution server  20 . The network  30  is based on public line networks such as the Internet, a telephone line network, or a satellite communication network or a dedicated line network such as WAN, LAN or IP-VPN for example, in a wired or wireless manner.  
         [0103]     Further, the network  30  includes a private network such as the home network  30   a  and the local line  30   b . From the viewpoint of copyright management, the private network is a network for interconnecting a plurality of user devices  10  that commonly has content within a scope of private use. Specific examples of such a private network include the home network  30   a  which is LAN for interconnecting a plurality of user devices  10  for use within a house whole of limited users and a LAN for interconnecting a plurality of user devices  10  for use in a small-sized, limited group (offices or friends).  
         [0104]     For example, the home network  30   a  installed in a user&#39;s home shown in  FIG. 2  interconnects the PC  10   a , the home server  10   c , the television receiver  10   d , the recording/reproducing device  10   e , and the stationary audio player  10   f . The home server  10   c  has hub, router, and gateway capabilities to manage the communication between the user device  10  in the user&#39;s home and the outside.  
         [0105]     The local line  30   b  is a cable for interconnecting a plurality of user devices  10  and is made up of a USB (Universal Serial Bus) cable, a SCSI (Small Computer System Interface) cable, an IEEE 1394 cable, or a mini plug. Connecting the PD  10   b  and the PC  10   a  through the local line  30   b  allows the communication of various kinds of data like content between the PD  10   b  and the PC  10   a . It should be noted that the user devices  10  may be interconnected in a wireless manner.  
         [0106]     For example, in the user home shown in  FIG. 2 , PC  10   a  and the PD  10   b  are interconnected by the local line  30   b . In the user&#39;s villa, the PC  10   a  and the stationary audio player  10   f  are interconnected by the local line  30   b . In the car, the car audio device  10   g  and the PD  10   b  are interconnected by the local line  30   b.    
         [0107]     The removable storage medium  40  is a storage device capable of storing various kinds of data including content, licenses, and content keys and is made up of any one of optical disks  3  such as DVD-R, DVD-RW, DVD-RAM, CD-R, CD-RW, and magneto-optical disk, magnetic disks such as flexible disk and hard disk drive, and various types of semiconductor memories. It should be noted that the removable storage medium  40  may be a storage medium having a copyright management capability for restricting the use of content by means of an encryption key for example.  
         [0108]     The user devices  10  may mutually transfer content, licenses, and content keys via the removable storage medium  40  without use of the network  30 . Also, the removable storage medium  40  may be loaded on a content vending terminal (not shown) installed at the vendor to store the purchased content and license into the removable storage medium  40 . Consequently, the purchased content and so on may be provided to the user device  10  by means of the removable storage medium  40 .  
         [0109]     With the copyright management system  100  thus configured, the copyright management block having the above-mentioned component or modular configuration on a license processing basis (or on a content use restriction function basis) is installed on each user device  10  in accordance with the type and so on of each user device  10 . Therefore, the copyright management system  100  is advantageous in that the user is able to transfer content, licenses and content keys between the user&#39;s user devices  10  comparatively freely, thereby using the content in various forms.  
         [0110]     To be more specific, content, licenses, and content keys (hereafter referred to as “content and so on”) may be freely moved, copied, rented, and returned (hereafter generically referred to as “move” unless otherwise specified) between the user devices  10  installed with the copyright management blocks of different configurations. A communication route that is used for this processing are the network  30 , the home network  30   a , and the local line  30   b . For example, in the user&#39;s home, content and so on may be moved between a plurality of user devices  10  connected to the home network  30   a  regardless of device type. Also, the content and so on stored in the PC  10   a  may be moved to the PD  10   b  through the local line  30   b . In addition, the content and so on stored in the PC  10   a  in the user&#39;s home may be moved to the user PC  10   a  in the remote user&#39;s villa or the car audio device  10   g  in the car through the network  30 . Besides, content and so on may be moved, via the removable storage medium  40 , between user devices  10  capable of reading and writing the removable storage medium  40 . For example, the content and so on downloaded from the distribution server  20  by the mobile phone  10   h  may be recorded to the removable storage medium  40  for the provision to the PC  10   a  in the user&#39;s home.  
         [0111]     Further, content may be remotely controlled for use between user devices  10  that are physically separated from each other. For example, the content stored in one user device  10  (for example, the home server  10   c  of the home network  30   a ) may be referenced for use, from other user devices  10  (namely, the PC  10   a , the PD  10   b , and the television receiver  10   c , and so on connected to the home network  30   a ). Still further, the content and so on stored in the PC  10   a  may be reproduced and sounded by the stationary audio player  10   f  connected to the same home network  30   a . Yet further, the content and so on stored in the PC  10   a  and the home server  10   c  in the user&#39;s home may be reproduced and sounded by the PC  10   a  in the user&#39;s villa or the car audio device  10   g  in the car by remotely controlling the PC  10   a  in the user&#39;s villa or the car audio device  10   g  in the car.  
         [0112]     Thus, the copyright management system practiced according to the first embodiment of the invention, while guaranteeing the copyright management capabilities for restricting the use of content, may enhance the portability of content between various types of user devices  10 , thereby enhancing user convenience and the degree of freedom of content use.  
         [0000]     &lt;3. Hardware Configuration of User Device&gt; 
         [0113]     The following described an exemplary hardware configuration of the user device  10  according to the present embodiment. In what follows, exemplary hardware configurations of the PC  10   a  and the PD  10   b  will be described as a typical example of the user device  10 . It should be noted that the PC  10   a  and the PD  10   b  that are user devices  10  are configured as embodiments of the license processing apparatus of the present invention.  
         [0114]     First, a hardware configuration of the PC  10   a  according to the present embodiment will be described with reference to  FIG. 3 .  FIG. 3  is a block diagram approximately showing an exemplary hardware configuration of the PC  10   a  according to the present embodiment.  
         [0115]     As shown in  FIG. 3 , the PC  10   a  has a CPU (Central Processing Unit)  101 , a ROM (Read Only Memory)  102 , a RAM (Random Access Memory)  103 , a host bus  104 , a bridge  105 , an external bus  106 , an interface  107 , an input unit  108 , an output unit  110 , a storage unit (HDD)  111 , a drive  112 , a connection port  114 , and a communication unit  115 .  
         [0116]     The CPU  101  functions as an arithmetic processing unit and a control unit and operates as instructed by programs stored in the ROM  102  or the HDD  111 , thereby controlling components of the PC  10   a . To be more specific, the CPU  101  executes the processing of content encryption and decryption, the processing of generating and verifying digital signatures (such as MAC (Message Authentication Code)) for preventing data alteration and verifying data, the processing of authentication and session key sharing at the time of inputting/outputting content and so on to be executed with other connected user devices  10 , the processing of controlling the inputting/outputting of content, licenses, and content keys, and the processing of copyright management such as license evaluation, for example.  
         [0117]     The ROM  102  stores programs for use by the CPU  101  and computation parameters, for example. The ROM  102  is also available as a storage device for storing content, licenses, and content keys, for example. The RAM  103  temporarily stores programs for use at the execution by the CPU  101  and parameters that change from time to time during that execution. The CPU  101 , the ROM  102  and the RAM  103  are interconnected through the host bus  104  based on a CPU bus for example.  
         [0118]     The host bus  104  is connected to the external bus  106  such as PCI (Peripheral Component Interconnect/Interface) through the bridge  105 .  
         [0119]     The input unit  108  is based on operator devices such as mouse, keyboard, touch panel, buttons, switches, and levers for example and an input control circuit for generating input signals and supplies them to the CPU  101 . The user of the PC  10   a  operates the input unit  108  to enter various kinds of data into the PC  10   a  and give instructions thereto for necessary processing operations.  
         [0120]     The output unit  110  is made up of a display device such as a CRT (Cathode Ray Tube) display, a LCD (Liquid Crystal Display), and/or indicators such as lumps and an audio output device such as a speaker, for example. The output unit  110  outputs the reproduced content for example. To be more specific, the display device displays the reproduced video content in text or in image in a moving picture or a still picture. The audio output device sounds audio content.  
         [0121]     The HDD  111  is a data storage device configured as one example of a storage device of the PC  10   a  according to the present embodiment of the invention. The HDD  111  stores programs (the above-mentioned copyright management software for example) to be executed by the CPU  101  and various kinds of data. The HDD  111  also stores various kinds of data such as content, licenses, and content keys, for example.  
         [0122]     The drive  112  is a storage media reader/writer arranged internal or external to the PC  10   a . The drive  112  records and/or reproduces various kinds of data such as content, licenses, and content keys for example on removable storage medium  40  such as magnetic disk (including HD), optical disk (including CD and DVD), magneto-optical disk (including MO), or a semiconductor memory loaded on the PC  10   a.    
         [0123]     To be more specific, the drive  112  reads data from the removable storage medium  40  and supplies the data to the RAM  103  via the interface  107 , the external bus  106 , the bridge  105 , and the host bus  104 . The CPU  101  stores the supplied data to the ROM  102  or the HDD  111  as required. On the other hand, the drive  112  receives data from the ROM  102  or the HDD  111 , newly generated data, and data received from an external device and writes the data to the removable storage medium  40 .  
         [0124]     The connection port  114  connects the PC  10   a  with external peripheral devices such as other user devices  10  for example and has connection terminals such as USB and IEEE 1394 for example. The connection port  114  is connected to the CPU  101  and so on via the interface  107 , external bus  106 , the bridge  105 , and the host bus  104 . By this connection port  114 , the PC  10   a  is connected to the PD  10   b  and so on via the local line  30   b  for the communication of various kinds of data.  
         [0125]     The communication unit  115  is a communication interface made up of a communication device for the connection to the network  30  (including the home network  30   a ), for example. The communication unit  115  transmits and receives various kinds of data such as content, a source ID list L, a group certificate G, and control signals with external devices such as other user devices  10  and distribution server  20 .  
         [0126]     The following describes a hardware configuration of the PD  10   b  according to the first embodiment of the invention with reference to  FIG. 4 .  FIG. 4  is a block diagram approximately showing an exemplary hardware configuration of the PD  10   b.    
         [0127]     As shown in  FIG. 4 , the PD  10   b  has a control unit  201 , a flash memory  202 , a ram  203 , a bus  206 , an input unit  208 , a display unit  210 , a HDD  211 , a drive  212 , a decoder  213 , a communication unit  215 , an audio output circuit  216 , a remote controller  218 , and a headphone  219 .  
         [0128]     The control unit  201  operates as instructed by programs stored in the flash memory  202  or the HDD  211  for example, controlling components of the PD  10   b . The flash memory  202  stores programs specifying operations of the control unit  201  and various kinds of data, for example. The ROM  102  may also be available as a storage device for storing content, licenses, and content keys, for example. The RAM  203  is made up of an SDRAM (Synchronous DRAM) and temporarily stores various kinds of data associated with the processing by the control unit  201 .  
         [0129]     The bus  206  is a data line interconnecting the control unit  201 , the flash memory  202 , the RAM  203 , the input unit  208 , the display unit  210 , the HDD  211 , the drive  212 , the decoder  213 , the communication unit  215 , and the audio output circuit  216 , and the remote controller  218 .  
         [0130]     The input unit  208  and the remote controller  218  are each made up of an operator device based on a touch panel, button keys, levers, and dials and an input control circuit for generating input signals as specified by the user and supplying them to the control unit  201 . The user of the user device  10  operates the input unit  208  or the remote controller  218  to be described later to enter various kinds of data into the user device  10  and gives instructions thereto.  
         [0131]     The display unit  210  is made up of an LCD panel and an LCD control circuit, for example. The display unit  210  displays various kinds of information in text or image as controlled by the control unit  201 .  
         [0132]     The HDD  211  is a data storage device configured as one example of a storage device of the PD  10   b  according to the present embodiment of the invention. The HDD  211  is based on a hard disk drive (HDD) having a storage capacity of several tens of GB for example and stores content, licenses, content keys, programs to be executed by the control unit  201 , and various kinds of data. The PD  10   b  having the HDD  211  thus configured is configured as a content recording/reproducing device capable of recording and reproducing content. Consequently, not only the content provided from the PC  10   a  via the removable storage medium  40  but also the content received from the PC  10   a  and so on via the local line  30   b  may be stored in the HDD  211  for reproduction. However, the present embodiment is not restricted to this configuration. For example, the PD  10   b  may be configured as a content reproduction-only device without having the HDD  211 . In this case, the PD  10   a  may only reproduce content read from the removable storage medium  40  for example (not recordable).  
         [0133]     The drive  212  is a recording media reader/writer and incorporated in the PC  10   a . The drive  212  records and/or reproduces various kinds of data such as content, licenses, and content keys with the removable storage medium  40  loaded on the PD  10   b . The decoder  213  decodes the encrypted content, executes surround processing on the decoded content, and converts the processed content into PCM data, for example.  
         [0134]     The communication unit  215  is made up of a USB controller and a USB terminal for example and transmits and receives various kinds of data such as content, licenses, content keys, and control signals with the user device  10  such as the PC  10   a  connected by the local line  30   b  such as a USB cable for example.  
         [0135]     The audio output circuit  216  amplifies the analog audio data obtained by decoding the encrypted content by the decoder  213  and D/A converted by the control unit  201  and outputs the amplified analog audio data to the remote controller  218 . The analog audio data is then outputted from the remote controller  218  to the headphone  219  to be sounded from a speaker (not shown) incorporated in the headphone  219 .  
         [0136]     Thus, the exemplary hardware configurations of the PC  10   a  and the PD  10   b  that are examples of the user device  10  have been described with reference to  FIGS. 3 and 4 . However, the user device  10  that uses content is not restricted in configuration to the above-mentioned examples of the PC  10   a  and the PD  10   b . For example, the PC  10   a  an the PD  10   b  may also be configured by any of the home server  10   c , the television receiver  10   d , the recording/reproducing device  10   e , the stationary audio player  10   f , the car audio device  10   g , and the mobile phone  10   h  as shown in  FIG. 2  or any of other electronic devices and information processing devices. Therefore, the user device  10  may have a hardware configuration unique to itself and execute processing in accordance with the unique hardware configuration.  
         [0137]     However, the user device  10  that is a license processing apparatus for processing licenses for controlling the use of content has the above-mentioned copyright management block (or the copyright management module). To be more specific, the user device  10  has a storage device for storing a copyright management program and a processor for processing this program, evaluates the use conditions of each license to determine whether the content may be used on itself, and, if the content is found usable, executes the use of the content.  
         [0000]     &lt;4. Functional Configuration of the Copyright Management Block&gt; 
         [0138]     The following describes a functional configuration of a copyright management block (or the copyright management module)  3  of the user device  10  practiced as the first embodiment of the present invention with reference to  FIG. 5 .  FIG. 5  is a block diagram showing a functional configuration of the copyright management block  3  of the user device  10 .  
         [0139]     As shown in  FIG. 5 , the copyright management block  3  is connected to an application  4  for using content. The application  4  has a user interface function and a function of actually using content. To be more specific, as the user interface function, the application  4  accepts content use requests from user and displays various kinds of operator screens on a display device. As the content use function, the application  4  executes the reproduction of content or moves content between a plurality of the user devices  10  (for example, the PC  10   a  and the PD  10   b ) or different storage devices (for example, the HDD  111  and the removable storage medium  40 ) in the same user device  10 , for example. This use of content by the application  4  is controlled by the copyright management block  3 .  
         [0140]     The copyright management block  3  has a plurality of the above-mentioned license processing components and a component management block  5  for controlling these license processing components. Each license processing component is a module obtained in accordance with a processing unit (or each use restriction function) in which licenses are dynamically processed. Each license processing component has a function of processing (or evaluating, transmitting, etc.) of licenses and content keys for controlling the use (or reproduction, move, etc.) of content and a function of securely storing licenses and content keys in a storage device.  
         [0141]     In the copyright management block  3 , the information about license (licenses themselves and content keys) is securely transferred between the license processing components on the basis of the control by the component management block  5  to transmit the proper data to a proper license processing component, thereby controlling the use of content.  
         [0142]     Each of above-mentioned license processing components is divided into the storage component (or the storage module)  1  and the use component (or the utilization module)  2  as described above.  
         [0143]     First, the storage component  1  will be described in detail. The storage component  1  has a function of securely storing licenses and content keys in a storage device. To be more specific, the storage component  1  executes the processing of storing licenses and content keys in the HDD  111  or the removable storage medium  40  for example such that the correlation between these content keys, licenses and content be guaranteed (the above-mentioned requirement 3), while maintaining the secrecy of content keys (the above-mentioned required 1) and the security of licenses (the above-mentioned requirement 2) (this processing is referred to as bind processing). Further, the storage component  1  executes the processing of reading licenses and content keys from a storage device, rewriting licenses and content keys stored in a storage device, or deleting licenses and content keys from a storage device, in addition to the above-mentioned bind processing.  
         [0144]     Because its portion for storage device reading and writing depends on the installation environment, the storage component  1  is arranged for each of storage devices having different storage schemes. Hence, basically, one type of the storage component  1  corresponds to one type of storage device. To be more specific, the storage component  1  is arranged for each type and specification (for example, ordinary semiconductor memory, semiconductor memory with copyright management function, CD, and DVD) of the removable storage medium  40  and for each of HDDs (for example, the HDD  111  of the PC  10   a  and the HDD  211  of the PD  10   b ) of different types of user devices  10 .  
         [0145]     In the example shown in  FIG. 5 , a license &amp; content key storage block  6   a  based on a HDD corresponds to a storage component for HDD (bind  1 )  11  for storing licenses and content keys and a license &amp; content key storage block  6   b  based on the removable storage medium  40  corresponds to a storage component (bind  2 )  12  for removable media for storing licenses and content keys.  
         [0146]     The storage component  1  thus configured stores (or binds) licenses and content keys as securely related with a storage device such that the stored licenses and content keys be not altered or exposed to the third party. The following describes specific procedures for this secure storage method.  
         [0147]     For example, the storage component  1  may generate, separate from a normal storage area in which content and so on are stored, a confidential storage area, in a corresponding storage device, inaccessible by other than the storage component  1 , thereby storing licenses and content keys in the generated confidential storage area. Consequently, only the user authenticated by the copyright management block  3  may access the licenses and content keys stored in this confidential storage area, thereby guaranteeing the secrecy of content keys and the confidentiality of licenses. This approach is effective if the storage device concerned is an optical disk such as DVD.  
         [0148]     Also, the storage component  1  may encrypt licenses and content keys by a storage secret key (namely, a secret media key for preventing alteration) that can be handled only by the storage component and store the encrypted licenses and content keys in the corresponding storage device. Consequently, although the licenses and content keys in the storage device may be accessed, these licenses and content keys may not be used unless decrypted by the above-mentioned storage secret key, thereby guaranteeing the secrecy of content keys and the confidentiality of licenses. This approach is effective if the storage device is a semiconductor memory for example.  
         [0149]     The following describes the use component  2 . the use component  2  has a function of evaluating various use conditions (reproduction condition and move condition for example to be described later) written to each license by entering a license and a content key, and, if required, content, thereby controlling the use of content. Some types of the use component  2  may update licenses in accordance with how the use of content is controlled, outputting the updated license.  
         [0150]     Further, the use component  2  is connected to a content storage block  7  based on a HDD or the removable storage medium  40  for example and is capable of reading content from the content storage block  7  for processing. However, the use component  2  cannot obtain licenses and content keys directly from the license &amp; content key storage block  6 , so that the use component  2  must rely on the storage component  1  for obtaining licenses and content keys from the license &amp; content key storage block  6 . In other words, the use component  2  has no functions of reading, writing, and storing licenses and content keys with a storage device. Therefore, the use component  2  processes the licenses and content keys read by the storage component  1  from the license &amp; content key storage block  6  and transmitted to the use component  2  and transmits the processed licenses and content keys to the storage component  1  as required, making the storage component  1  write the processed licenses and content keys to the storage device.  
         [0151]     The use component  2  thus configured is arranged for at least each of content use cases (or operations). The following describes types of uses cases of content. The content use cases include “reproduction” in which content is outputted in the form of sound or video, “move” in which content is moved (master copy transfer) between user devices  10  or storage devices, “copy” in which content stored in a certain storage device is copied (copy transfer) to be stored in another storage device, “rent” in which content is rented between user devices  10  or storage devices, and “return” in which content rented between user devices  10  or storage devices is returned to the rent source, for example.  
         [0152]     It should be note that type “reproduction” includes normal-speed reproduction, normal-speed reverse reproduction, fast forward reproduction, rewind reproduction, fast forward, rewind, pause, and seek. The above-mentioned “rent” is equivalent to “check-out” of SDMI and the above-mentioned “return” is equivalent to “check-in” of SDMI.  
         [0153]     In order to control each use (or operation) of each component described above, the present embodiment has, as a specific example of the use component  2 , a reproduction (or play) component  21 , a move component  22 , a copy component  23 , a rent component  24 , and a return component  25 .  
         [0154]     The reproduction component  21  evaluates reproduction conditions written to the license to control the reproduction of content. The reproduction component  21  is divided into two types depending on the reproduction control involving license update and the reproduction control not involving license update, details of which will be described later.  
         [0155]     In order to control the move of content, the move component  22  evaluates move conditions written to the license corresponding to this content, thereby controlling the move (or transfer of master copy) of the license and the content key between user devices  10  or storage devices. For example, if the move component  22  permits the move of a license and a content key between the storage devices of a move source and a move destination, the move of the content corresponding to that license is also permitted between these storage devices.  
         [0156]     In order to control the copy of the content, the copy component  23  evaluates copy conditions written to the license corresponding to this content, thereby controlling the copy (or transfer of copy) of the license and the content key between user devices  10  or storage devices. For example, if the copy component  23  permits the copy of a license and a content key between the storage devices of a copy source and a copy destination, the copy of the content corresponding to the license is also permitted between these storage devices.  
         [0157]     In order to control the rent of content, the rent component  24  evaluates rent conditions written to the license corresponding to this content, thereby controlling the rent of the license and the content key between user devices  10  or storage devices. For example, if the rent component  24  permits the rent of a license and a content key between the storage devices of a rent source and a rent destination, the rent of the content corresponding to the license is also permitted between these storage devices.  
         [0158]     In order to control the rent of content, the return component  25  evaluates return conditions written to the license corresponding to this content, thereby controlling the return of the license and the content key between user devices  10  or storage devices. For example, if the return component  25  permits the return of a license and a content key between the storage devices of a rent source and a rent destination, the return of the content corresponding to the license is also permitted between these storage devices.  
         [0159]     Thus, the five types of use component  2  have been described. It should be noted that the use component  2  for controlling the content use of the same type may be arranged in plural in accordance with portions dependent on installation environment. For example, two or more reproduction components  21  may be arranged for decoder types.  
         [0160]     The license processing components each composed of the above-mentioned storage component  1  and use component  2  controls the use of content by mutually transferring licenses and content keys as described above with reference to  FIG. 1 . For the transfer of licenses and content keys as described above, the license processing components pass messages to each other in accordance with a particular protocol. Each of these messages includes: 
        (1) a license;     (2) a content key;     (3) transmission type identification information indicative of a license transmission type (namely, the type of message); and     (4) component attribute information indicative of the attribute of the license processing component of the message transmission source.        
 
         [0165]     Of these messages, (3) and (4) are data for guaranteeing the proper transmission of a license and a content key to a proper license processing component, details of which will be described later.  
         [0166]     The following describes the component management block  5 . The component management block  5  has a function of executing the control of content use by using necessary license processing components in accordance with a content use request made by the application  4 . Basically, the component management block  5  uses one use of component  2  and one or more of storage components  1  for one content use request to control the requested use of content. The following describes basic operations of the component management block  5 .  
         [0167]     First, the component management block  5  determines license processing components to be used for content use control processing. To be more specific, upon reception of a content use request from the application  4 , the component management block  5  determines the use component  2  for the use control of the requested content and the storage component  1  for storing the license and the content key necessary for the use control of the content. Next, the component management block  5  transmits a load command to the determined storage component  1  and use component  2 , thereby loading (or starting up) these components.  
         [0168]     Next, the component management block  5  gives a command to the loaded storage component for the creation of a message according to the use of the content and obtains a message from the loaded storage component  1 . At this moment, in accordance with the content use, the component management block  5  may give a command for invalidating (or deleting) the license and content key stored in the storage component  1 . For example, in the case of the move of content, the component management block  5  gives a command to the storage component  1  to delete the license and content key stored therein and then transmit a message for transfer.  
         [0169]     Further, the component management block  5  transfers the message obtained from the storage component  1  to the use component  2 . After checking the received message for validity, the use component  2  evaluates use conditions written to the license to determine whether the content is usable or not. If the content is found usable, the component management block  5  gives a command to the application for the use of content. It should be noted that if the use component  2  is the move component  22  for example, the component management block  5  transmits a message to other storage components  1  to move also the corresponding licenses and content keys in accordance with the move of the content.  
         [0170]     Thus, the component management block  5  controls the requested content use by functioning the necessary two or more license processing components in accordance with a content use request to transfers licenses and the content keys between these license processing components.  
         [0171]     The following describes a specific example of content use control to be executed by transferring licenses between the license processing components according to the first embodiment of the invention, with reference to  FIG. 6 .  FIG. 6  shows an exemplary configuration in which licenses are transferred between license processing components according to the present embodiment.  
         [0172]     As shown in  FIG. 6 , it is assumed that three storage components  11 ,  12 , and  13 , one reproduction component  21 , and one move component  22  be in a connectable state. The connection route here is realized by a bus for example in the case of connection inside the same user device  10  or by the network  30 , the home network  30   a , or the local line  30   b  in the case of connection between different two or more user devices  10 .  
         [0173]     By use of a encryption technology and storage devices having confidential storage areas, the storage components  11 ,  12 , and  13  are capable of securely storing licenses in these storage devices. The storage component  1  reads a license from the storage device thereof, substantializes (or validates) the license so that it becomes interpretable by the use component  2 , and transmits the substantialized license to the use component  2 .  
         [0174]     For example, as shown in  FIG. 6 , the storage component  11  substantializes license A stored therein and transmits substantialized license A to the reproduction component  21 . The reproduction component  21  evaluates reproduction conditions written to license A received from the storage component  11  to control the reproduction of the content corresponding to license A.  
         [0175]     The storage component  12  substantializes license B stored therein and transmits substantialized license B to the move component  22 . The move component  22  evaluates move conditions written to received license B to determine whether license B may be moved and whether the content corresponding to license B may be moved. If license B and the content corresponding thereto are found movable, the storage component  12  transmits license B to the storage component  13 . The storage component  13  evaluates storage conditions written to received license B and, if license B is found storable, the storage component  13  secure stores (or binds) license B into the corresponding storage device. Further, upon reception of a command for transmission, the storage component  13  substantializes license B stored therein and transmits substantialized license B to the reproduction component  21 . The reproduction component  21  evaluates reproduction conditions written to the transmitted license B to control the reproduction of the content corresponding to license B.  
         [0176]     Thus, licenses are transferred between the storage component  11 , storage component  12  and storage component  13 , and between the use components such as the reproduction component  21  and move component  22  to control one case of content use. Namely, controlling the use of content requires that at least one storage component  1  and one use component  2  function in a cooperative manner.  
         [0177]     The following describes an exemplary installation of license processing components making up the copyright management block  3  according to the present embodiment, with reference to  FIG. 7 .  FIG. 7  shows an exemplary installation of license processing components making up the copyright management block  3 .  
         [0178]     To be more specific,  FIG. 7  shows the license processing components of the distribution server  20 , the PC  10   a , the home server  10   c , and the PD  10   b  among the above-mentioned devices shown in  FIG. 2 , as an exemplary configuration of a license processing apparatus on which license processing components are installed.  
         [0179]     On these devices, the above-mentioned various types of license processing components are arranged in a distributed manner. To be more specific, the distribution server  20  has the move component  22  and the storage component  11  for the HDD  411 . The PC  10   a  has the reproduction component  21 , the move component  22 , the copy component  23 , the rent component  24 , the return component  25 , the storage component  11  for the HDD  111 , and the storage component  11  for the removable storage medium  40 . The home server  10   c  has the storage component  11  for the HDD  311 . The PD  10   b  has the reproduction component  21  and the storage component  12  for the removable storage medium  40 .  
         [0180]     In the above-mentioned exemplary installation of license processing components, combining the license processing components arranged in the user device  10  and the distribution server  20  allows the use of content in a variety of cases while executing copyright management.  
         [0181]     For example, combining the storage component  11  and the move component  22  of the distribution server  20  and the storage component  11  of the PC  10   a  allows the distribution (or move) of the content and the license and so on stored in the distribution server  20  to the PC  10   a  to store the distributed content and the license and so on into the HDD  111  of the PC.  
         [0182]     Combining the copy component  23  and the storage component  11  of the PC  10   a  with the storage component  11  of the home server  10   c  allows the copying of the content and licenses and so on stored in the HDD  111  of the PC  10   a  to the home server  10   c  to store the copies into a HDD  311  of the home server  10   c . Further, combining the storage component  11  with the reproduction component  21  of the PC  10   a  allow the reproduction of content stored in the PC  10   a.    
         [0183]     Combining the rent component  24 , the storage component  11  and the storage component  12  in the PC  10   a  allows the renting of the content and the license and so on stored in the HDD  111  of the PC  10   a  to the removable storage medium  40  of the PC  10   a  to store them therein. Further, combining the reproduction component  21  of the PD  10   b  with the storage component  12  after loading the removable storage medium  40  on the PD  10   b  allow the reproduction of the content stored in the removable storage medium  40  on the PD  10   b.    
         [0184]     Thus, the functional configuration of the copyright management block  3  for use in the copyright management system  100  practiced as the present embodiment of the invention has been described. As described above, building the copyright management block  3  by dividing into a plurality of license processing components by the license processing unit suitable for each content use case enhances the universality and expandability of the copyright management block  3 . Consequently, when the copyright management block  3  is designed for and installed on various types of user devices  10 , content and licenses and so on may be transferred between user devices  10  having different installations of the copyright management block  3 , thereby properly executing the use of content and the restriction thereof.  
         [0000]     &lt;5. Data Configuration&gt; 
         [0185]     The following describes a basic data configuration in which data is handled by the copyright management system  100  according to the present embodiment with reference to  FIG. 8 .  FIG. 8  shows the correlation of the basic data to be handled by the copyright management system  100 .  
         [0186]     As shown in  FIG. 8 , the data to be handled by the copyright management system  100  is mainly composed of digital content  301 , a content key  302 , content (or copyright-managed content)  3 , a content ID  304 , and a license  305 .  
         [0000]     (Digital Content  301 )  
         [0187]     The digital content  301  denotes digital data such as video, audio, and text that are subject to copyright management. To be more specific, the digital content  301  includes audio data such as music, talks, and radio programs, video data such as movies, television programs, video programs, photographs, paintings, and graphics, still or moving, and electronic books (E-books), games, and software. In the present embodiment, the music data distributed from the distribution server  20  or the music data ripped from CDs for example are mainly used as an example of the digital content  301  in description; however, the digital content  301  is not limited to these pieces of data. The copyright management system  100  generates the copyright-managed content  303  by encrypting the digital content  301  and executes the copyright management in the system.  
         [0000]     (Content Key  302 )  
         [0188]     The content key  302  is a content cryptographic key for decrypting the encrypted content  303 . For example, the content key  302  is based on a key ring that is a set of one or more secret keys. For example, a specific example of the content key  302  is a set of a secret key for decrypting encrypted audio data and a secret key for decrypting encrypted fringe data. Another specific example of the content key  302  is a set of secret keys that are used for the encryption of video data divided in a time dependent manner.  
         [0189]     As described above, the copyright management system  100  according to the present embodiment encrypts the digital content  301  by use of a secret key so as to ensure the secrecy of the digital content  301 . At this moment, the relationship of the digital content  301  to secret key is equal to m to n, so that one piece of digital content  301  may be encrypted by a plurality of secret keys or a plurality of pieces of the digital content  301  may be encrypted by a single secret key. A set of these secret keys is defined as the content key  302 . Consequently, the relationship of the digital content  301  to the content key  302  becomes equal to m to 1. In the copyright management system  100 , the content key  302  is regarded as equal to one piece of copyright-managed content  303  and handled as the control unit based on use conditions.  
         [0000]     (Content  303 )  
         [0190]     The content  303  is a set of digital content  301  (copyright-managed content) encrypted by one content key  302 . Consequently, the relationship of the content key  302  to the content  303  is equal to one to one. Terms “content  303 ” or “content” as used herein denotes the copyright-managed content that is a set of digital content  301  encrypted by the content key  302 . The use of the content  303  is controlled by the copyright management block  3 , however, as far as the license  305  and the content key  302  are securely managed, the content  303  itself need not always be managed in a secure manner.  
         [0000]     (Content ID  304 )  
         [0191]     The content ID  304  is an identifier that is uniquely given to the content key  302 . Because the relationship of the content key  302  to the content  303  is equal to one to one as described above, the content  303  may be identified by this content ID  304 . Namely, the content ID  304  functions as the content identification information for identifying the content  303 . When this content ID  304  and a command specifying how the content is to be used are entered, the copyright management block  3  according to the present embodiment may control the use of the content  303 .  
         [0000]     (License  305 )  
         [0192]     The license  305  is electronic data representative of the use right of the content  303 . The license  305  describes the use (reproduction, move, or rent) of the content  303  and the use conditions and use statuses associated with the transmission of the content  303 , content key  302 , and the license  305 . The license  305  is given to the content key  302 , defining a plurality of licenses  305  for one content key  302 . Therefore, the relationship of the content key  302  to the content  303  to the license  305  is equal to one to one to n.  
         [0193]     It should be noted that reference numerals  301  through  305  are assigned to digital content, content key, content, contend ID, and license for the sake of description, however, in other portions hereof, these words may be used without reference numerals. Each word used without reference numeral substantially is the same in meaning as the corresponding word defined above.  
         [0000]     &lt;6. License Description&gt; 
         [0194]     The following describes specific examples of license descriptions according to the present embodiment with reference to  FIGS. 9 through 12 .  FIGS. 9 through 12  shows specific examples of license descriptions according to the present embodiment, showing licenses usable for content move, copy, rent, and return control, respectively.  
         [0195]     As shown in  FIGS. 9 through 12 , each license is written with the information necessary for controlling the use (reproduction, move, rent, etc.) of content. In the examples shown in these figures, each license is written, but not exclusively, in XML (extended Markup Language).  
         [0196]     The license in these examples is composed of a license information description section  501  in which the information about the license is written and a use condition description section  502  in which use conditions of this license are written.  
         [0197]     The license information description section  501  describes a content ID indicative of the content to be controlled by the license and indicative of the content key and copyright holder information that is the identification information indicative of a person or a corporation (a service provider for example) that is the copyright holder of the content. The content ID is written in a portion enclosed by &lt;U_ContentID&gt; tags and the copyright holder information is written in a portion enclosed by &lt;Legal Copyright&gt; tags. Writing the content ID to the license allows the relating of the license with the content and content key corresponding to this license. It should be noted that a license issue date for example may be written to the license information description section  501  as the license information.  
         [0198]     The use condition description section  502  describes the use condition information of the content for each content use case (or operation contents), namely for each license processing component. To be more specific, as shown in  FIGS. 9 through 12 , the use condition description section  502  is divided into a reproduction condition description section  521 , a move condition description section  522 , a copy condition description section  523 , a rent condition description section  524 , a return condition description section  525 , and a storage condition description section  511 .  
         [0199]     Thus, describing the use conditions in a divided manner in accordance with the processing functions of the license processing components allows each license processing component to control the use of content by evaluating the use conditions corresponding to itself. For example, the reproduction component  21  evaluates only the reproduction condition description section  521  in the license to control the reproduction of content. The storage component  1  evaluates only the storage condition description section  511  in the license to control the storage of the license and the content key into a storage device.  
         [0200]     The use condition description section  502  need not describes all the above-mentioned use conditions. For example, as shown in  FIG. 9 , the license for content move control may include at least the reproduction condition description section  521 , the move condition description section  522 , and the storage condition description section  511 . As shown in  FIG. 10 , the license for content copy control may include at least the reproduction condition description section  521 , the copy condition description section  523 , and the storage condition description section  511 . Further, as shown in  FIG. 11 , the license for content rent control (or the license of the rent source) may include at least the reproduction condition description section  521 , the rent condition description section  524 , and the storage condition description section  511 . As shown in  FIG. 12 , the license for content return control (or the license for rent) may include at least the reproduction condition description section  521 , the return condition description section  525 , and the storage condition description section  511 .  
         [0201]     It should be noted that a license for rent shown in  FIG. 12  is generated on the basis of a license for rent source shown  FIG. 11 . To be more specific, the license information description section  501 , the reproduction condition description section  521 , and the storage condition description section  511  are extracted from the license of rent source and a newly generated return condition description section  525  is added to the extracted sections to generate a license for rent. When the license for rent thus generated is processed for rent, the same rent ID is written to the return condition description section  525  of the license for rent and rent condition description section  524  of the license for rent source.  
         [0202]     The following describes the contents written to the use condition description section  502  thus configured. The use condition description section  502  is written with content use control parameters, a content use status, and a Property Selection List), for example.  
         [0203]     Each use control parameter controls (whether or not permits or prohibits) the use of content. Namely, the content use parameters are indicative of content use limit count (namely, reproduction limit count, move limit count, copy limit count, and rent limit count), content use time limits (namely, reproduction time limit, move time limit, copy time limit, rent time limit, and return time limit), and the storage limit count and storage time limit of license and content key.  
         [0204]     The use status (hereafter referred to as a status) is information indicative of the current state of the use of content. This status includes a reproduction status including the number of times content has been reproduced, a move status indicative of the number of times content has been moved, a copy status indicative of the number of times content has been copied, a rent status indicative of the number of times content has been rented (or checked out), and a storage status indicative of the number of times the license has been stored.  
         [0205]     The property selection lists is used to restrict the number of license processing components permits to control the use of control by evaluating each use condition of the license. Some pieces of content are desired to be permitted for processing only on the user device  10  having a particular license processing component. To be more specific, some pieces of content may only be reproduced on the user device  10  that has the reproduction component  21  corresponding to reproduction count control. In order to satisfy thus a demand, the present embodiment writes the property selection lists to each license to limit the license processing components capable of processing licenses.  
         [0206]     The property selection list is written to each of the use limit description blocks such as the reproduction condition description section  521  and the move condition description section  522 . Each property selection list at least includes one set of property ID and an action code.  
         [0207]     The property ID is an identifier indicative of the characteristics of each license processing component. The characteristics of the license processing component include the corporation that provided this component, the copyright management scheme on which this component is based, the content type (audio data or video data for example) to be handled by this component, the functions (use limit count function, time limit function, digital data output function, and encryption processing function, for example) of this component, and others, for example. The action describes a list interpretation method in accordance with the characteristics equivalent to the property ID of each license processing component.  
         [0208]     Each license processing component has the property ID corresponding to the characteristic thereof and checks if the license processing component has the same property ID as the property ID written in the above-mentioned property selection list. If the license processing component has this property ID, the license processing component executes an action specified by the above-mentioned action code. The action defines various conditions, thereby controlling the content use in any license processing components.  
         [0209]     Thus, the elements of the license have been described. The following describes, in detail, an exemplary description of the reproduction condition description section  521  of the license shown in  FIG. 9 . The description of the reproduction condition description section  521  of the license shown in  FIG. 9  is as follows.  
                                                   &lt;Play&gt;           &lt;PropertySelectionList&gt;           MagicGateVideo, 0×82 ; CountDownplay, 0×81;           &lt;/PropertySelectionList&gt;           &lt;Parameter&gt;Remain=3, &lt;/Parameter&gt;           &lt;Status&gt;Remain=2, &lt;/Status&gt;           &lt;/Play&gt;           &lt;PropertySelectionList&gt; describes a property                      
 
 selection list associated with content reproduction. For example, “MagicGateVideo” is the property ID indicative of the characteristic of the reproduction component  21  that is capable of handling the reproduction condition description section  521 . “0x82” denotes an action code. This description is indicative that the processing defined in action ID “0x82” is executed for property “MagicGateVideo”. It also is indicative that the processing defined in action code “0x81” is executed for reproduction count limit “CountDownPlay”. 
 
         [0210]     &lt;Parameter&gt; describes a content reproduction control parameter. To be more specific, “Remain=3” denotes a count parameter for executing reproduction count limit and is indicative that the upper limit of reproduction count is “3”. As a result, the reproduction component  21  permits the reproduction of the content corresponding to this license only 3 times on the basis of this license.  
         [0211]     &lt;Status&gt; describes the reproduction status indicative of a reproduction status of content. To be more specific, “Remain=2” denotes a count status indicative of the number of times the content has been reproduced so far and is indicative that the number of times content has been reproduced is “2”. The reproduction component  21  determines whether this count is less than the above-mentioned upper limit. If this count is found less than the upper limit, the reproduction component  21  permits the reproduction of the content. In the example shown above, the reproduction count limit is “3”, so that the content may be reproduced only once more on the basis of this license.  
         [0212]     The following describes a technique of evaluating licenses having the above-mentioned description for example by each of the license processing components.  
         [0213]     Each license processing component references the use condition description of the section corresponding to itself (for example, the reproduction condition description section  521  if this processing component is the reproduction component  21 ) among the use conditions written to the license, thereby executing content use control processing.  
         [0214]     (1) Search the license for the description of use condition:  
         [0215]     First, the license processing component searches the license description for the use condition description of the section (in the case of the reproduction component  21 , the section is reproduction condition description section  521  for example) corresponding to itself. This search operation is executed on the basis of a use condition identification code (&lt;Play&gt; tag for example) written to the license. If the use condition description of the corresponding section is not found in the license, then the license processing component ends the processing without permitting the use of content. On the other hand, if the use condition description of the corresponding section is found, the procedure goes to the next processing (2) below.  
         [0216]     (2) Determination whether to execute processing on the basis of the verification of property selection list:  
         [0217]     Next, the license processing component determines whether to execute the next processing (3) by evaluating the property selection list of the use condition description corresponding to itself. To be more specific, the license processing component executes the processing that accords to the above-mentioned action depending on whether the license processing component itself has the property ID listed in the property selection list of the use condition description. The license processing component executes this processing for the property IDs contained in the property selection list, starting with the top processing and sequentially downward, to determine whether to eventually execute processing (3). Consequently, the installation of each license processing component may be checked for validity and the processing function already installed in each license processing component may be checked for validity.  
         [0218]     (3) Determination whether content use is permitted on the basis of use control parameter and status:  
         [0219]     Next, the license processing component reads the use control parameter and the status values from the use condition description block and applies these values to the use determination function of the license processing component itself, thereby determining whether the use of content satisfies the condition defined in this function. If the condition is found satisfied, the use of content is permitted. If the condition is found not satisfied, the use of content is prohibited. Examples of this control use control include use count control (for example, reproduction count control, storage count control, and move count control) and use time limit control (for example, reproduction time limit control, storage time limit control, and move time limit control).  
         [0220]     The following describes an example in which the reproduction component  21  evaluates the reproduction condition description section  521  to execute reproduction time limit control.  
         [0221]     First, the reproduction component  21  obtains a count parameter (for example, &lt;Parameter&gt;Remain=3 shown in  FIG. 9 ) from the reproduction condition description section  521  for executing reproduction count control. At this moment, if the count parameter is 0, then the reproduction component  21  does not execute reproduction count control. The reproduction component  21  permits the reproduction only when other reproduction conditions are satisfied.  
         [0222]     Next, if the count parameter obtained above is other than 0, then the reproduction component  21  obtains a count status (for example, &lt;Status&gt;Remain=2&gt; shown in  FIG. 9 ) for indicating the number of counts to be reproduced from the reproduction condition description section  521 . Further, the reproduction component  21  compares the count parameter value with the count status value.  
         [0223]     If the count parameter value is found equal to or greater than the count status value, then reproduction component  21  permits the reproduction of content and increments the count status value by 1. On the other hand, if the count parameter value is smaller than the count status value, then the reproduction component  21  prohibits the reproduction of content.  
         [0224]     Thus, an example of reproduction count control processing by the reproduction component  21  has been described. The use count control processing by the use component  2  or storage component  1  is substantially the same as the above-mentioned reproduction count control processing and therefore their detail description will be omitted.  
         [0225]     It should be noted that which use control parameter or status each license processing component references depends on the installation of each license processing component rather than the contents of license description.  
         [0226]     For example, if the reproduction component  21  has a function for reproduction count control, that reproduction component  21  references the count parameter associated with the reproduction count control of the reproduction condition description section  521  to execute reproduction permission control based on the reproduction count. At this moment, if the count parameter associated with reproduction count control is not written to the reproduction condition description section  521 , then the reproduction component  21  uses a default value that may be determined reproducible.  
         [0227]     On the other hand, if the reproduction component  21  has no function for executing reproduction count control, the reproduction component  21  executes reproduction control regardless of the reproduction control parameter if any associated with the reproduction count control of the reproduction condition description section  521 .  
         [0228]     Thus, each license processing component is configured so as to reference use control parameters and status in accordance with the installation of each license processing component independently of the contents of license description. Consequently, regardless weather or not the installation of each license processing component is, the licenses to be transferred between license processing components may be standardized.  
         [0000]     &lt; 7 . Protocol of License Transmission Between Components&gt; 
         [0229]     As described above, in the copyright management system  100  according to the present embodiment, licenses, content keys and so on are transferred between a plurality of license processing components that are the functional parts of the copyright management block  3 , thereby controlling the use of content. At this moment, the licenses, content keys and so on must be controlled so as to be transferred between proper license processing components in a proper procedure. Otherwise, licenses and so on may be erroneously transferred between license processing components, resulting in a risk of the illegal use of content. For example, if a license and a content key are transmitted directly from a certain storage component  11  to another storage component  12  without undergoing a plurality of copy components  23 , then the number of times copy has been made is not counted although there is a copy count limit as a copy condition of that license, thereby permitting the illegal copying of the license and so on.  
         [0230]     In order to prevent this problem from occurring, the copyright management block  3  according to the present embodiment specifies a transmission protocol for transmitting licenses and so on between license processing components to surely and justly execute the copyright management capabilities.  
         [0231]     The transmission protocol transfers a message including a license, a content key, and so on between license processing components as described above. This transmission protocol does not specify the physical format of each message in its entirety to be transferred between components, but specifies the format of data that make up each message. The definition of a data format facilitates the allocation of mutual operability between different installations of license processing components. For example, if the transfer of a license and so on is desired between a plurality of user devices  10  having different installations of copyright management blocks  3 , a common data format for messages to be handled by the copyright management blocks  3  facilitates the transfer of data including licenses without involving data format conversion.  
         [0232]     It should be noted that the physical format of message may be installation-dependent. This configuration permits the installation of the license transmission protocol suitable for the application environment. For example, it is possible to install a protocol that transmits the data making up a message in a row oriented manner as one example of installation on a communication protocol, for example. It is also possible to install a protocol by entering data making up a message into an argument when installing the protocol as a method call between classes.  
         [0233]     The following describes, in detail, a transmission protocol for transmitting licenses between license processing components, such as mentioned above.  
         [0234]     First, the message transmission between the license processing components according to the present embodiment will be outlined with reference to  FIG. 13 .  FIG. 13  schematically shows the message transmission protocol for transmitting messages between the license processing components.  
         [0235]     The message transmission will be described by use of an example in which the license  305  and the content key  302  corresponding thereto are transmitted from a license processing component  31  of the transmission source (hereafter referred to as a transmission source component  31 ) to a license processing component  32  of the transmission destination (hereafter referred to as a transmission destination component  32 ) as shown in  FIG. 13 , for example. It should be noted that the transmission source component  31  and the transmission destination component  32  may be the storage component  1  or the use component  2 , if the transmission source component  31  is the storage component  1 , the transmission destination component  32  is the use component  2  and, if the transmission source component  31  is the use component  2 , then the transmission destination component  32  is the storage component  1 .  
         [0236]     In the license transmission protocol according to the present embodiment, a message  400  having a predetermined data format is transmitted from the transmission source component  31  to the transmission destination component  32 . This message  400  includes transmission type identification information  310 , component attribute information  320 , transmission-subjected license  305 , and the content key  302  corresponding to this license  305 . Transmitting the message  400  thus configured allows the transmission of these four pieces of data in a correlated manner by attaching the transmission type identification information  310  and the component attribute information  320  to the license  305  and the content key  302 .  
         [0237]     The transmission type identification information  310  is indicative of the type (transfer, show, update  1 , update  2 , or update  3 ) of transmission of the license  305  in between the transmission source component  31  and the transmission destination component  32 . The component attribute information  320  is indicative of the attribute (use or storage) of the transmission source component  31 .  
         [0000]     (Transmission Type Identification Information)  
         [0238]      FIGS. 14A, 14B  and  14 C show the license transmission types for transmission licenses between components according to the present embodiment of the invention. As shown in these figures, there are three major types “transfer”, “show”, and “update” for the license  305  depending on the purpose of transmission of the license  305  and the interaction between the transmission source component  31  and the transmission destination component  32 . Type “update” is further divided into three types “update  1  (request update)”, “update  2  (transfer updated license)”, and “update  3  (notify update completion)”. Consequently, there are five license transmission types in all. The following describes each of these transmission types.  
         [0239]     As shown in  FIG. 14A , “transfer” denotes the transmission of a master copy  305   a  of the license  305 . In the “transfer” of the license  305  from the transmission source component  31  to the transmission destination component  32 , the transmission source component  31  deletes the license  305  stored therein and transmits the master copy  305   a  of the license  305  to the transmission destination component  32 . Consequently, the license  305  may be moved from the transmission source component  31  to the transmission destination component  32 .  
         [0240]     As shown in  FIG. 14B , “show” denotes the transmission of a copy (or a duplication)  305   b  of the license  305 . In the “show” of the license  305  from the transmission source component  31  to the transmission destination component  32 , the transmission source component  31  transmits the copy  305   b  of the license  305  without deleting the license  305  to the transmission destination component  32 . Consequently, the license  305  stored in the transmission source component  31  may be shown to the transmission destination component  32 .  
         [0241]     As shown in  FIG. 14C , “update” denotes the transmission for updating the license  305  held in the transmission source component  31 . In the “update” of the license  305 , the transmission source component  31  shows the copy  305   b  of the license  305  held therein to the transmission destination component  32  to make an update request (“update  1 ”). Next, the transmission destination component  32  updates the received license  305  and transfers the master copy  305   a  of the license  305  to the transmission source component  31  (“update  2 ”). Further, the transmission source component  31  shows the copy  305   b  of the updated license  305  to the transmission destination component  32 , given a notification thereto of the completion of update (“update  3 ”). Consequently, the license  305  held in the transmission source component  31  is updated.  
         [0242]     Thus, the number of types of transmission of the license  305  between the transmission source component  31  and the transmission destination component  32  is five. Therefore, with the license transmission protocol according to the present embodiment, five types of transmission type identification information  310  are set in accordance with five types of transmission.  
         [0243]      FIG. 15  shows a relationship between transmission type IDs, one example of the transmission type identification information  310  according to the present embodiment, and messages. As shown in  FIG. 15 , in accordance with the above-mentioned five types of transmission (transfer, show, update  1 , update  2 , and update  3 ), five types of transmission IDs (0X01, 0x02, 0x03, 0x04, and 0x05) are allocated respectively. These transmission type IDs identify these transmission types and one example of the above-mentioned transmission type identification information.  
         [0244]     Including these transmission type IDs in the message  400  by the transmission source component  31  allows the specification of the transmission type of the license  305  included in the message  400 , thereby transmitting the license  305 .  
         [0245]     The message  400  is classified into five types according to which transmission type IDs included. To be more specific, the message  400  having transmission type ID “0x01” is a message for transferring the master copy of a license. The message  400  having transmission type ID “0x02” is a message for showing the copy (or the duplication) of a license. The message  400  having transmission type ID “0x03” is a message for requesting the update of a license. The message  400  having transmission type ID “0x04” is a message for transferring the updated license. The message  400  having transmission type ID “0x05” is a message for giving a notification of the completion of update. These types of the message  400  will be detailed later with reference to  FIG. 17 .  
         [0246]     Thus, the transmission type identification information  310  (or transmission type IDs) in accordance with the different license transmission types has been described. Transmitting the transmission type identification information  310  along with the license  305  by the transmission source component  31  allows the identification of the transmission type of the transmitted license  305  at the transmission destination component  32  and the execution of the processing of the license  305  in accordance with the identified transmission type.  
         [0000]     (Component Attribute Information)  
         [0247]     As shown in  FIG. 5 , each license processing component is largely divided into two types. One is the storage component  1  (the storage component  11  for example) that stores the license  305  into a storage device thereof and the other is the use component  2  (the reproduction component  21  for example) that uses the license  305 . These attributes are used to prevent the license processing components having the same attribute from being connected each other.  
         [0248]     The component attribute information  320  is indicative of the attribute of the transmission source component  31 . To be more specific, the component attribute information  320  is indicative to which of the storage component  1  and the use component  2  the transmission source component  31  belongs. Each license processing component has the component attribute information  320  to which each license processing component belongs and, at the time of creating a message, includes the component attribute information  320  in this message.  
         [0249]      FIG. 16  shows a relationship between component information IDs, a specific example of the component attribute information  320 , and messages. As shown in FIG.  16 , component attribute ID “0x01” is allocated to the storage component  1  and component attribute ID “0x02” is allocated to the storage component  2 . Namely, the storage component  11 , the storage component  12 , and so on belonging to the storage component  1  shown in  FIG. 5  have the same component attribute ID “0x01” and the reproduction component  21 , the move component  22 , the copy component  23 , the rent component  24 , and the return component  25  belonging to the use component  2  have the same component attribute ID “0x02”.  
         [0250]     Therefore, if the transmission source component  31  belongs to the storage component  1  the message  400  transmitted from this transmission source component  31  includes component attribute ID “0x01”. On the other hand, if the transmission source component  31  belongs to the use component  2 , the message  400  transmitted from this transmission source component  31  includes component attribute ID “0x02”.  
         [0251]     Including the component attribute information  320  made up of these component attribute IDs and so on into the message  400  allows the identification of the attribute of the transmission source component  31  by the transmission destination component  32 , thereby determining that the transmission source component  31  and the transmission destination component  32  have different attributes.  
         [0000]     (Message Types)  
         [0252]     The following describes the types of the message  400  according to the present embodiment. As described above, the message  400  is classified by the above-mentioned transmission types of the license  305 .  FIG. 17  shows the message types and the data making up these types according to the present embodiment.  
         [0253]     As shown in  FIG. 17 , in the present embodiment, the message  400  is classified into five types (transfer message, show message, update request message, update transfer message, and update completion message) in accordance with the above-mentioned five types of transmission of the license  305 . The following describes in detail each of these types of messages.  
         [0000]     (1) Transfer Message  
         [0254]     A transfer message is used to transmit (or transfer) the master copy of a license from the transmission source component  31  to the transmission destination component  32 . Therefore, each transfer message includes transmission type ID “0x01” indicative of “transfer” as the transmission type identification information  310 . The transmission source component  31  may be either the storage component  1  or the use component  2 , so that the transfer message includes component attribute ID “0x01” or “0x02” indicative of “storage” or “use” respectively as the component attribute information  320 .  
         [0000]     (2) Show Message  
         [0255]     A show message is used to transmit (or show) a copy of a license from the transmission source component  31  to the transmission destination component  32 . Therefore, the each show message includes transmission type ID “0x02” indicative of “show” as the transmission type identification information  310 . The transmission source component  31  is limited to the storage component  1 , so that the show message includes component attribute ID “0x01” indicative of “storage” as the component attribute information  320 .  
         [0000]     (3) Update Request Message  
         [0256]     An update request message is used for the source storage component  1  to request the destination use component  2  for updating the license stored in a storage device thereof. Therefore, the each update request message includes transmission type ID “0x03” indicative of “update  1  (update request)” as the transmission type identification information  310 . The transmission source component  31  is limited to the storage component  1 , so that the update request message includes component attribute ID “0x01” indicative of “storage” as the component attribute information  320 . The update request message allows the requested license stored in the destination storage component  1  to be exclusively processed from the simultaneous access by a transfer message. Also, the following update transfer message (4) must be transmitted in response to the update request message.  
         [0000]     (4) Update Transfer Message  
         [0257]     An update transfer message is used to transfer a license updated by the source use component  2  to the above-mentioned storage component  1  that has requested the updating of this license. Therefore, each update transfer message includes transmission type ID “0x04” indicative of “update  2  (transfer of updated license)” as the transmission type identification information  310 . The transmission source component  31  is limited to the storage component  1 , so that the update transfer message includes component attribute ID “0x02” indicative of “use” as the component attribute information  320 . The update transfer message is transmitted upon reception of the above-mentioned update request message (3). Receiving the update transfer message, the storage component  1  that has requested the updating of the license writes the received updated license over the storage device. Also, the following update completion message (5) may be transmitted in response to the update transfer message.  
         [0000]     (5) Update Completion Message  
         [0258]     An update completion message is used to notify the destination use component  2  of the completion of the updating of a license on the storage component  1  that has requested the updating of the license. Therefore, the update completion message includes transmission type ID “0x05” indicative of “update  3  (notification of update completion)” as the transmission type identification information  310 . The transmission source component  31  is limited to the storage component  1 , so that the update completion message includes component attribute ID “0x01” indicative of “storage” as the component attribute information  320 . The update completion message is transmitted upon the overwriting of the updated license in response to the reception of the above-mentioned update transfer message (4). The update completion message is an option and therefore may not always be transmitted. Also, the update completion message may not include the license  305  and the content key  302 .  
         [0259]     Thus, the five types of message according to the present embodiment have been described. It should be noted that other messages (for example, a processing pause message) than the above-mentioned five types of messages may be transmitted between license processing components.  
         [0260]     The following describes the processing of transferring licenses (or the above-mentioned messages) between the license processing components according to the present embodiment.  
         [0000]     (Handleable Transmission Types)  
         [0261]     First, transmission types (namely, message types) that each license processing component according to the present embodiment may handle will be described with reference to  FIG. 18 .  FIG. 18  shows the transmission types that each license processing component according to the present embodiment may handle.  
         [0262]     As shown in  FIG. 18 , handleable license transmission types are preset for each license processing component. In other words, each license processing component may handle only preset message types.  
         [0263]     For example, a first reproduction component (play (updated))  21   a  is one type of the above-mentioned reproduction component  21  and executes normal reproduction control that does not involve the updating of the reproduction status written to a license. The first reproduction component  21   a  (hereafter referred to simply as the reproduction component  21   a ) is capable of receiving a license shown by the storage component  1  (namely, capable of receiving the above-mentioned show message and processing the received show message). The reproduction component  21   a  is incapable of transmitting licenses (or messages) to other license processing components.  
         [0264]     A second reproduction component (reproduction (not updated))  21   b  is one type of the above-mentioned reproduction component  21  and executes reproduction control that involves the update of the reproduction status written to a license. The second reproduction component  21   a  (hereafter referred to simply as the reproduction component  21   a ) is capable of transferring a license subject update with the storage component  1  in order to update the license. To be more specific, the reproduction component  21   b  is capable of receiving the above-mentioned update request message (update  1 ) and update completion message (message  3 ) from the storage component  1  that has requested the updating of the license, processing the received messages, and transmitting the above-mentioned update transfer message (update  2 ) to the storage component  1  that has requested the updating of the license.  
         [0265]     The move component  22  is capable of receiving a license transferred from the storage component  1  and transferring the received license to another storage component  1 . To be more specific, the move component  22  is capable of receiving the above-mentioned transfer message from the source storage component  1 , processing the received message, and transmitting the processed transfer message to the destination source storage component  1 .  
         [0266]     The copy component  23  is capable of receiving a license shown from the storage component  1  and transferring the license to another storage component  1 . To be more specific, the copy component  23  is capable of receiving the above-mentioned show message from the copy source storage component  1  and transmitting the above-mentioned transfer message to the copy destination license processing component.  
         [0267]     The rent component  24  is capable of transferring a license subject to update with the storage component  1  in order to update the license. To be more specific, the rent component  24  is capable of receiving the above-mentioned update request message (update  1 ) and update completion message (update  3 ) from the storage component  1  that has requested the updating of the license and processing the received message. The rent component  24  is also capable of transferring the license, or the above-mentioned transfer message, to the rent destination storage component  1 .  
         [0268]     The return component  25  is capable of receiving a license subject to update with the storage component  1  in order to update the above-mentioned rent source license. To be more specific, the return component  25  is capable of receiving the above-mentioned update request message (update  1 ) and update completion message (update  3 ) from the storage component  1  that has requested the updating of the license, processing the received messages, and transferring the above-mentioned update transfer message (update  2 ) to the update requesting storage component  1 . Further, the return component  25  is capable of receiving the license transferred from the rent destination storage component  1 , namely, receiving the above-mentioned transfer message and processing it.  
         [0269]     A read-only storage component (bind)  16  is one type of the above-mentioned storage component  1  and capable of reading a license and so on from a read-only storage device in which the license is securely stored and showing the license, but incapable of writing a license and so on to a storage device. The read-only storage component  16  is the storage component  12  for the removable storage medium  40  arranged on the PD  10   b  that is a reproduction-only device.  
         [0270]     The read-only storage component  16  is capable of showing the license read from a storage device to the use component  2  (namely, transmitting the above-mentioned message to the use component  2 ) but incapable of receiving a license (or a message) from another license processing component.  
         [0271]     A write-only storage component (bind)  17  is one type of the above-mentioned storage component  1  and capable of writing a license and so on to a storage device for storage, but incapable of reading a license and so on from a storage device. The write-only storage component  17  is used when a service provider preinstalls content, license and so on into the user device  10  or writes content, license and so on to the removable storage medium  40  in advance before distributing on the market, for example.  
         [0272]     The write-only storage component  17  is capable of receiving a license from the use component  2  (namely, receiving the above-mentioned transfer message and processing it), but incapable of transmitting a license (or a message) to another license processing component.  
         [0273]     A read/write-enabled storage component (bind)  18  is one type of the above-mentioned storage component  1  and capable of reading, writing, storing, and rewriting (or updating) a license and so on with a storage device. The read/write-enabled storage component  18  is the storage component  11  for a HDD or the storage component  12  for the removable storage medium  40  arranged on the PC  10   a , for example.  
         [0274]     The read/write-enabled storage component  18  is capable of receiving a license transferred from the use component  2  and a license transferred from the use component  2  for update. To be more specific, the read/write-enabled storage component  18  is capable of receiving the above-mentioned transfer message and the above-mentioned update transfer message (update  2 ) from the use component  2  and processes the received messages. Also, the read/write-enabled storage component  18  is capable of transmitting a license read from a storage device to the use component  2  for transfer, show, or update. To be more specific, the read/write-enabled storage component  18  is capable of transmitting the above-mentioned transfer message, the above-mentioned show message, the above-mentioned update request message (update  1 ), and the above-mentioned update completion message (update  3 ) to the use component  2 .  
         [0275]     Thus, in accordance with the processing capabilities of its own, each license processing component has a preset transmission type of licenses that may be inputted and outputted. Therefore, licenses may be transferred with proper transmission types when message transfer is made between license processing components.  
         [0000]     (Functional Configurations of Components)  
         [0276]     The following describes functional configurations of the transmission source component  31  and the transmission destination component  32  for transferring the information (or messages) about licenses between license processing components according to the present embodiment, with reference to  FIG. 19 .  FIG. 19  is a block diagram illustrating functional configurations associated with the message transmission by the transmission source component  31  and the transmission destination component  32  according to the present embodiment.  
         [0277]     As shown in  FIG. 19 , the transmission source component  31  has a license acquisition block  352 , a transmission type determination block  354 , an attribute information acquisition block  356 , a message creation block  358 , and a message transmission block  360 .  
         [0278]     The license acquisition block  352  obtains the above-mentioned license subject to transmission and the content key corresponding to this license. The processing function of the license acquisition block  352  differs when the transmission source component  31  is the storage component  1  and the use component  2 . The following specifically describes this difference.  
         [0279]     If the transmission source component  31  is the storage component  1 , the license acquisition block  352  reads a license and its content key from the license &amp; content key storage block  6  in response to a transmission command (a message creation command) issued from the component management block  5 , thereby obtaining the license subject to transmission and its content key. At this moment, the transmission source component  31  searches the license &amp; content key storage block  6  by the content ID included in the above-mentioned transmission command to obtain the license with that content ID written to the license information description section  501  as the license to be transmitted. Further, the license acquisition block  352  also obtains the content key associated with that license by the content ID. It should be noted that the transmission source component  31  may return the information indicative whether the license corresponding to the content ID is found or not to the component management block  5 . Also, if the license &amp; content key storage block  6  is a storage device such as the HDD  111  or the removable storage medium  40  and the transmission source component  31  is the use component  2 , then the license &amp; content key storage block  6  need not be arranged.  
         [0280]     On the other hand, if the transmission source component  31  is the use component  2 , then the license acquisition block  352  obtains a license and its content key from the message received from another storage component  1 , thereby obtaining the above-mentioned license subject to transmission and its content key.  
         [0281]     The license acquisition block  352  outputs the license and its content key obtained as described above to the message creation block  358 .  
         [0282]     The transmission type determination block  354  determines the transmission type of the above-mentioned license subject to be transmitted from the transmission source component  31  to the transmission destination component  32 . At this moment, the transmission type determination block  354  may determine the transmission type on the basis of the transmission type command information included in the transmission command (for example, the message creation command) received from the component management block  5  or use a predetermined transmission type in accordance with the processing function of the transmission source component  31 .  
         [0283]     For example, if the transmission source component  31  is capable of transmitting a license with a plurality of transmission types (namely, if capable of transmitting a plurality of types of messages, for example, if the transmission source component  31  is the read/write-enabled storage component  18  shown in  FIG. 18 ), the transmission type determination block  354  determines the transmission type on the basis of the transmission type command information received from the component management block  5 . On the other hand, if the transmission source component  31  is limited to a certain handleable transmission type (for example, if the transmission source component  31  is the use component  2  such as the move component  22 ), then the transmission type determination block  354  uses the predetermined transmission type.  
         [0284]     The transmission type determination block  354  outputs the transmission type identification information  310  (or the transmission type identifier ID) indicative of the transmission type thus determined to the message creation block  358 .  
         [0285]     The attribute information acquisition block  356  obtains the component attribute information  320  indicative of the attribute of the transmission source component  31 . As described above, each license processing component is the storage component  1  or the use component  2  and has the component attribute information  320  (namely, the component attribute ID indicative of “storage” or “use”) indicative of the attribute of itself. The attribute information acquisition block  356  reads the component attribute information  320  of the transmission source component  31  and outputs the component attribute information  320  to the message creation block  358 .  
         [0286]     The message creation block  358  links the license subject to transmission and its content key received from the license acquisition block  352 , the transmission type identification information  310  received from the transmission type determination block  354 , and the component attribute information  320  to create a message and outputs the created message to the message transmission block  360 .  
         [0287]     The message transmission block  360  transmits the messaged received from the message creation block  358  to the transmission destination component  32 . At this moment, the message transmission block  360  may use any data security technology (for example, the attachment of digital signatures) so as to prevent the message from being altered.  
         [0288]     As shown in  FIG. 19 , the transmission destination component  32  has a message reception block  370 , a message verification block  372 , a license evaluation block  374 , a license processing block  376 , and a license update block  378 .  
         [0289]     The message reception block  370  receives the above-mentioned message from the transmission source component  31  and outputs the received message to the message verification block  372 .  
         [0290]     The message verification block  372  checks the received message for validity on the basis of the transmission type identification information  310  and component attribute information  320  included therein, thereby enabling or disabling the processing of the license included in that message.  
         [0291]     To be more specific, the message verification block  372  executes the processing and verification based on a data security technology on the message received from the message reception block  370  and then extracts the transmission type identification information  310 , the component attribute information  320 , the license, and the content key from the processed and verified message.  
         [0292]     Also, the message verification block  372  checks the received message for validity (namely, if this message has been transmitted with a proper transmission type) on the basis of the transmission type identification information  310  extracted from the message and the transmission type identification information indicative of a transmission type receivable by the transmission destination component  32  (this is called a first verification standard).  
         [0293]     To be more specific, the transmission destination component  32  has transmission type IDs indicative of receivable transmission types as shown in  FIG. 18 . Therefore, the message verification block  372  matches the transmission type ID extracted from the message against the transmission type ID indicative of a receivable transmission type. If a match is found, the message verification block  372  determines the received message to be valid. On the other hand, if a mismatch is found, the message verification block  372  determines the received message to be invalid, thereby preventing the license extracted from that message from being processing.  
         [0294]     The first verification standard of the message verification block  372  thus configured allows the transmission destination component  32  to process only the license that has been transmitted with a predetermined transmission type preset in accordance with the function of the transmission destination component  32 .  
         [0295]     In addition, the message verification block  372  checks the received message for validity (namely, if the transmission of the license is proper or not) on the basis of the component attribute information  320  extracted from the message and the component attribute information indicative of the attribute of the transmission destination component  32  itself (this is called a second verification standard). If a mismatch is found between the attribute of the transmission source component  31  and the attribute of the transmission destination component  32 , the message verification block  372  determines that the message is valid; if a match is found, the message verification block  372  determines that the message is invalid.  
         [0296]     To be more specific, the transmission destination component  32  has a component attribute ID indicative of the component attribute (“storage” or “use”) of its own. For example, if the transmission destination component  32  is the storage component  1 , then the transmission destination component  32  has component attribute ID “0x01” indicative of component attribute “storage”. If the transmission destination component  32  is the use component  2 , the transmission destination component  32  has component attribute ID “0x02” indicative of component attribute “use”.  
         [0297]     Therefore, the message verification block  372  matches the component attribute ID extracted from the message against the component attribute ID indicative of the attribute of the transmission destination component  32  itself. If a mismatch is found, the message verification block  372  determines the received message to be valid. If a match is found, the message verification block  372  determines the received message to be invalid and prevents the license extracted from that message from being processed.  
         [0298]     The verification function based on the second verification standard of the message verification block  372  thus configured allows the storage component  1  to process only the licenses received from the use component  2  and the use component  2  to process only the licenses received from the storage component  1 .  
         [0299]     It should be noted that, rather than having the component attribute ID indicative of the component attribute of the transmission destination component  32  itself as described above, the transmission destination component  32  may have the component attribute ID indicative of any component attribute that is handleable by the transmission destination component  32 . In this case, the message verification block  372  matches the component attribute ID extracted from the message against the component attribute ID indicative of the above-mentioned handleable component attribute. If a match is found, the message verification block  372  determines the received message to be valid, if a mismatch is found, the message verification block  372  determines the received message to be invalid.  
         [0300]     Thus, the message verification block  372  checks the messages for validity on the basis of the above-mentioned two verification standards. If both the standards are satisfied, then the message verification block  372  allows the processing of the license and its content key extracted from each message. If one or both of the standards are not satisfied, the message verification block  372  prohibits the processing of the license and its content key extracted from that dissatisfactory message and causes an error notification for example.  
         [0301]     If the message verification block  372  permits the processing of the license and so on, the license evaluation block  374  evaluates the use condition of the section corresponding to the function of the transmission destination component  32  among the use conditions (reproduction condition, storage condition, move condition, and so on) written to the license, thereby controlling the use (reproduction and so on) of the content corresponding to that license and the processing (storage, move, and so on) of that license. To be more specific, if the use condition of that license is found satisfied by the above-mentioned evaluation, the license evaluation block  374  permits the use of the above-mentioned content and the processing of that license and so on, otherwise, the license evaluation block  374  prohibits the processing of the use of the above-mentioned content and the processing of that license and so on.  
         [0302]     If the license evaluation block  374  permits the processing of the license, the license processing block  376  processes the license and its content key in accordance with the function of the transmission destination component  32 . For example, if the transmission source component  31  is the storage component  1 , then the license processing block  376  stores that license and its content key into a storage device. If the transmission source component  31  is the use component  2 , then the license processing block  376  directs the reproduction of the content corresponding to that license or the transmission (or transfer) of the license corresponding to another storage component  1  and the content corresponding to that license. If the transmission source component  31  is the rent component  24 , the license processing block  376  functions also as a license creation block for creating licenses for rent on the basis of the rent source license.  
         [0303]     The license update block  378  updates the status written to the license on the basis of a command from the license evaluation block  374 . For example, the license update block  378  increases the number of times the reproduction status written to the license has been reproduced or the number of times the move status has been moved.  
         [0304]     Thus, the functional configurations of the transmission source component  31  and the transmission destination component  32  have been described. It should be noted that, for the convenience of description,  FIG. 19  shows a functional block associated with message transmission processing from the transmission source component  31  and a functional block associated with message reception processing and the subsequent processing for the transmission destination component  32 . Actually, however, the transmission source component  31  and the transmission destination component  32  may execute both message transmission processing and message reception processing, in this case, each of the transmission source component  31  and the transmission destination component  32  has a functional block associated with the processing of both.  
         [0000]     &lt;8. License Transmission Method&gt; 
         [0305]     The following describes a method transmitting the information (or messages) associated with a license between the transmission source component  31  and the transmission destination component  32  according to the present embodiment, with reference to  FIG. 20 .  FIG. 20  shows a timing chart indicative of the method of, license transmission between the transmission source component  31  and the transmission destination component  32  according to the present embodiment.  
         [0306]     As shown in  FIG. 20 , first, in step S 10 , the transmission source component  31  receives a transmission command (step S 10 ). If the transmission source component  31  is the storage component  1 , the transmission command is a message creation command received from the component management block  5 . This message creation command includes transmission type specification information and a content ID. On the other hand, if the transmission source component  31  is the use component  2  such as the move component  22  for example, a message received from the storage component  1  plays a role of a transmission command, for example. Thus, the transmission source component  31  that has received a transmission command executes message creation processing steps S 12  through S 18 .  
         [0307]     Next, in step S 12 , the transmission source component  31  determines the transmission type of the license subject to transmission (step S 12 ). The transmission type determination block  354  of the transmission source component  31  determines the transmission type on the basis of the transmission command and the preset data in accordance with the purpose of the transmission by the transmission source component  31  as described above and generates the transmission type identification ID indicative of the determined transmission type. For example, in the transfer of the master copy of the license, transmission type determination block  354  generates transmission type identifier ID “0x01” indicative of transmission type “transfer”.  
         [0308]     Further, in step S 14 , the transmission source component  31  obtains the component attribute information  320  indicative of the attribute of the transmission source component  31  itself (step S 14 ). As described above, the attribute information acquisition block  354  of the transmission source component  31  reads and obtains the component attribute ID indicative of the attribute of the transmission source component  31  itself, this component attribute ID being held therein. For example, if the transmission source component  31  is the storage component  1 , the component attribute ID is “0x01”.  
         [0309]     It should be noted that the attribute information acquisition block  356  may determine whether the transmission source component  31  is the storage component  1  or the use component  2 , set the component attribute of the transmission source component  31 , and generate the component attribute ID.  
         [0310]     Then, in step S 16 , the transmission source component  31  obtains the license subject to transmission and the content key corresponding to that license (step S 16 ). As described above, if the transmission source component  31  is the storage component  1 , the license acquisition block  352  searches the license &amp; content key storage block  6  by the content ID included in the message transmission command for the license subject to transmission and the content key corresponding thereto. If the transmission source component  31  is the use component  2 , then the license acquisition block  352  obtains the license and content key extracted from the message received from the storage component  1  and manipulated as required (for example, update by the license update block  378  and creation of the rent source license by the license processing block  376 ).  
         [0311]     It should be noted that the processing sequence of steps S 12  through S 16  may be other than the sequence described above.  
         [0312]     Next, in step S 18 , the transmission source component  31  creates a message (step S 18 ). The message creation block  358  of the transmission source component  31  links the license and the content key subject to transmission and its content obtained above, the transmission type identification information  310  (or the transmission type ID) determined above, and the component attribute information  320  (or the component attribute ID) obtained above to create a message.  
         [0313]     Further, in step S 20 , the transmission source component  31  transmits the created message to the transmission destination component  32  (step S 20 , license transmission step). To be more specific, the message transmission block  360  of the transmission source component  31  transmits the above created message to the transmission destination component  32  specified by the component management block  5 . It should be noted that one message may be transmitted only to one transmission destination component  32  at a time. This setup prevents illegal license duplication and illegal content use from occurring.  
         [0314]     Then, in step S 22 , the transmission destination component  32  receives the message from the transmission source component  31  (step S 22 ). Immediately after the reception of the message, the following message verification processing S 24  through S 28  (verification steps) are executed before processing the license included in this message, thereby checking the message for validity.  
         [0315]     First, in step S 24 , the transmission destination component  32  takes data out of the received message (step S 24 ). To be more specific, the message verification block  372  of the transmission destination component  32  executes data security processing and verification processing on the received message and then extracts the transmission type identification information  310  (transmission type ID), the component attribute information  320  (component attribute ID), the license, and the content key from that message.  
         [0316]     Next, in step S 26 , the transmission destination component  32  checks the message for validity on the basis of the transmission type that is the first verification standard. To be more specific, the message verification block  372  of the transmission destination component  32  matches the transmission type ID extracted from the message against the transmission type ID (preset) receivable by the transmission destination component  32 . If a match is found, it indicates that the transmitted message is valid (namely, the license has been transmitted with a proper transmission type), upon which the procedure goes to step S 28 . On the other hand, if a mismatch is found, it indicates that the transmitted message is invalid (namely, the license has been transmitted with an invalid transmission type), thereby disabling the processing of the license extracted from that message. This causes an error end.  
         [0317]     In step S 28 , the transmission destination component  32  checks the message for validity on the basis of the component attribute that is the second verification standard (step S 28 ). To be more specific, the message verification block  372  matches the component attribute ID extracted from the message against the component attribute ID indicative of the attribute of the transmission destination component  32 . If a mismatch is found, it indicates that the transmitted message is valid (namely, the license has been transmitted from the proper transmission source). In this case, the processing of the license extracted from that message is permitted, upon which the procedure goes to step S 30 . On the other hand, if a match is found, it indicates that the transmitted message is invalid (namely, the license has been transmitted from an illegal transmission source). In this case, the processing of the license extracted from that message is prohibited, upon which an error end is caused.  
         [0318]     It should be noted that the sequence of steps S 26  through S 28  is not restricted to that mentioned above; for example, step S 28  may be executed before step S 26 .  
         [0319]     Then, in step S 30 , the transmission destination component  32  processes the license and content key extracted from the message (step S 30 ). For example, the license evaluation block  374  of the transmission destination component  32  evaluates that license to determine whether to permit the processing (move or storage for example) of that license or whether to permit the use (reproduction or move for example) of that license and the content key thereof. Thus, the use of the content corresponding to the transmitted license is controlled.  
         [0320]     Thus, the method of license transmission between the license processing components according to the present embodiment and the method of license processing between the transmission source component  31  and the transmission destination component  32  have been described. These novel methods allow the transmission source component  31  to attach transmission type identification information and transmission source component attribute information to the license subject to transmission and transmit this license to the transmission destination component  32  and the transmission destination component  32  to check the license transmission for validity on the basis of the received transmission type identification information and component attribute information, thereby permitting the processing of the received license only when the license transmission is found valid. Following the above-mentioned license transmission protocol allows the transmission of licenses with proper transmission types to proper components, thereby making difficult any attempts of illegal license processing and illegal content use beyond a scope specified in each license.  
         [0321]     The following describes a specific example in which licenses are properly transferred between a plurality of license processing components in accordance with the above-mentioned transmission protocol, with reference to  FIG. 21 .  FIG. 21  schematically illustrates a specific example in which licenses are transferred between a plurality of license processing components according to the present embodiment.  
         [0322]      FIG. 21  shows an example in which the move component  22  is combined with the storage component  12  and storage component  11  to move a license and a content key thereof from the removable storage medium  40  to the HDD  111 .  
         [0323]     The transmission protocol according to the present embodiment specifies that the move of a license be executed through the move component  22  and the license be transferred so as not to remain at the transmission source. Therefore, in order to move a license in the example shown in  FIG. 21 , it is required for the storage component  12  to transmit a transfer message  401  (transmission type “transfer”, component attribute “storage”) to the move component  22  and then the move component  22  to transmit a transfer message  402  (transmission type “transfer”, component attribute “use”) to the storage component  11 .  
         [0324]     This transmission protocol may prohibit the illegal move of licenses. For example, if it is practicable that a license is directly transmitted between the directly interconnected storage component  12  and storage component  11 , then the license may be illegally moved without counting the number of times move has made. However, as described above, the storage component  12  is configured to receive only the messages that include component attribute “use” and process the messages thus received. Consequently, if a transfer-message  403  (transmission type “transfer”, component attribute “storage”) is transmitted from the storage component  12  to the storage component  11 , the storage component  11  cannot receive this transfer message  403  to store in the HDD  111 . Consequently, the above-mentioned transmission protocol may prevent the illegal move of licenses by directly interconnecting the storage component  12  and the storage component  11  without use of the move component  22 .  
         [0325]     If it is practicable to transmit (namely, show) a copy of a license from the storage component  12  to the move component  22  to move the license to the storage component  11 , the license is illegally moved with the master copy left in the removable storage medium  40 . However, as described above, the move component  22  is configured to receive and process only the message that includes transmission type “transfer”. Therefore, if a show message  404  (transmission type “show”, component attribute “storage”) is transmitted from the storage component  12  to the move component  22 , the storage component  12  cannot receive this message to execute the move of license. Consequently, the above-mentioned transmission protocol is able to prevent the illegal move of each license with the master copy thereof left at the move source storage component  12 .  
         [0000]     &lt;9. Method of Controlling Content Reproduction&gt; 
         [0326]     The following describes methods of controlling the reproduction of content. These methods are a normal reproduction control method that does not involve the updating of a reproduction status written to a license and a reproduction control method that involves this updating.  
         [0000]     (Method of Content Reproduction Control not Involving License Update)  
         [0327]     First, a content reproduction control method that does not involve license update according to the present embodiment will be outlined with reference to  FIG. 22 .  FIG. 22  schematically illustrates an outline of the content reproduction control method that does not involve license update according to the present embodiment.  
         [0328]     As shown in  FIG. 22 , the PC  10   a  has the reproduction component  21   a  (refer to  FIG. 8 ) for executing normal reproduction control not involving the updating of reproduction status and the storage component  11  for a HDD and the storage component  12  for a removable storage media.  
         [0329]     By use of the storage component  11  and the reproduction component  21   a  and on the basis of a license and a content key thereof stored in the HDD  111 , the  10   a  thus configured may control the reproduction of the content corresponding to that license.  
         [0330]     To be more specific, the storage component  11  reads a license and a content key thereof from the HDD  111  to create a show message (transmission type “show”, transmission source component attribute “storage”) and transmits the created message to the reproduction component  21   a . In this case, the master copies of the license and content key K are left stored in the HDD  111 . The reproduction component  21   a  checks the update request message received from the storage component  11  to evaluate the license included in this show message, thereby determining whether the content is reproducible. If the content is found reproducible, then the reproduction component  21   a  reads the content from the HDD  111  and decrypts the content by the content key extracted from the show message, thereby making the content ready for reproduction.  
         [0331]     Also, by use of the storage component  12  and the reproduction component  21   a  and on the basis of a license and a content key thereof stored in the HDD  111 , the  10   a  thus configured may control the reproduction of the content corresponding to that license in the same manner as the above-mentioned case of the HDD  111 .  
         [0332]     It should be noted that in the above-mentioned two ways of reproduction control processing in the PC  10   a , the content subject to reproduction may be stored in either the HDD  111  or the removable storage medium  40  and therefore is not dependent on the storage location of the corresponding license.  
         [0333]     On the other hand, the PD  10   b  has the reproduction component  21   a  and the storage component  12 . It is assumed here that the removable storage medium  40  storing the above-mentioned license, the content key thereof, and the corresponding content is provided to the PD  10   b  from the PC  10   a.    
         [0334]     By use of the storage component  12  and the reproduction component  21   a  and on the basis of the above-mentioned license and content key thereof stored in the removable storage medium  40 , the PD  10   b  thus configured may control the reproduction of the content stored in the removable storage medium  40 .  
         [0335]     To be more specific, the storage component  12  of the PD  10   b  reads a license and a content key thereof from the HDD  111  to create a show message (transmission type “show”, transmission source component attribute “storage”) and transmits the created show message to the reproduction component  21   a . In this case, the master copies of these license and content key K are left stored in the removable storage medium  40 . The reproduction component  21   a  checks the show message received from the storage component  12  to evaluate the license included in this message, thereby determining whether the above-mentioned content is reproducible. If the content is found reproducible, then the reproduction component  21   a  reads the content from the removable storage medium  40  and decrypts the content by the content key extracted from the above-mentioned show message, thereby making the content ready for reproduction.  
         [0336]     The following describes in detail a processing flow of the above-mentioned normal content reproduction control method involving no license update according to the present embodiment, with reference to  FIG. 23 .  FIG. 23  is a timing chart indicative of a processing flow of the above-mentioned normal content reproduction control method involving no license update according to the present embodiment.  
         [0337]     First, as shown in  FIG. 23 , the application  4  receives a request for the reproduction of user-specified content from a user (step S 102 ). Next, the application  4  extracts a content ID from a content file in which the content requested for reproduction is stored (step S 104 ). Further, the application  4  transmits the content ID and reproduction control command information including use information indicative that the content use is “reproduction” to the component management block  5 , thereby instructing the component management block  5  to control the reproduction of the content corresponding to that content ID (step S 106 ).  
         [0338]     Next, on the basis of the above-mentioned reproduction control command information received from the application  4 , the component management block  5  starts executing reproduction control to instruct the storage component  11 , storage component  12 , and so on for search for the license corresponding to the received content ID (step S 108 ). This search instruction is effected by transmitting the content ID and a search command to the storage component  11 , storage component  12 , and so on. The storage components subject to this search instruction may be limited to one or more storage components in the same user device  10  as the component management block  5  or may include storage components in other user devices  10  connected by the local line  30   b  for example.  
         [0339]     The storage component  11 , the storage component  12 , and so on instructed for search check, on the basis of the content ID received from the component management block  5 , the corresponding storage devices (the HDD  111 , the removable storage medium  40 , and so on) for the license corresponding to the above-mentioned content ID (step S 110 ). If the corresponding license is found, the storage component  11  reads this license from the storage device and transmits the license to the component management block  5  (step S 112 ). At this moment, as a result of the search, one storage component  1  may transmit one or more licenses or a plurality of storage components  11 ,  12 , and so on each may transmit one or more licenses. It should be noted that, if none of the storage component  11 , storage component  12 , and so on stores the license corresponding to the above-mentioned content ID, the reproduction of the content is prohibited, upon which the reproduction control processing ends.  
         [0340]     Further, of the plurality of license processing components, the component management block  5  determines the storage component  11  and the reproduction component  21   a  subject to load (or start-up) (step S 114 ). To be more specific, the component management block  5  has a license rehearsal evaluation function for example to evaluate, in a rehearsal manner, the reproduction condition of the content received from one or more storage components  1  in accordance with the above-mentioned search instruction. On the basis of a result of this rehearsal evaluation, the component management block  5  determines, as the components subject to load, one storage component  1  and one reproduction component  21  suitable for the reproduction of the content requested for reproduction.  
         [0341]     For example, if it receives a plurality of licenses in accordance with the above-mentioned search command, the component management block  5  selects the license that is optimum to the user and determines the storage component  11  storing the selected license to be subject to load. Also, if the reproduction is permitted on the basis of the selected license, the component management block  5  determines whether the updating of the reproduction status is involved. If the updating is found not involved, the component management block  5  determines the reproduction component  21   a  that does not execute the update processing to be subject to load. On the other hand, if the updating is found involved, the component management block  5  determines the reproduction component  21   b  capable of executing the update processing to be subject to load.  
         [0342]     In what follows, it is assumed that a license involving no update is selected and the storage component  11  and the reproduction component  21   b  be selected as subject to load in step S 114 .  
         [0343]     Next, the component management block  5  gives a load command to the storage component  11  and the reproduction component  21   a  determined above as subject to load, thereby starting up these components (step S 116 ). Consequently, the storage component  11  and the reproduction component  21   a  cross authenticate each other, thereby forming a secure route, SAC (Secure Authenticated Channel) for example, between these components (step S 118 ).  
         [0344]     Further, the component management block  5  gives a command to the storage component  11  to create a show message (step S 120 ). To be more specific, this message creation command is affected by transmitting the content ID received from the above-mentioned application  4  and transmission type specification information to the storage component  11 . This transmission type specification information specifies the transmission type (namely, the type of the message to be created) of the license. Because the reproduction control processing involving no update is executed in the present processing flow, the transmission type specification information is indicative of “show”. The message creation command thus configured allows the component management block  5  to instruct the storage component  11  to transmit a copy of the license corresponding to the above-mentioned content ID to the reproduction component  21   a  (namely, transmit the show message including that license).  
         [0345]     Next, in response to the above-mentioned message creation command, the storage component  11  creates a show message for transmitting the license and content key corresponding to the above-mentioned content ID (step S 122 ). To be more specific, the storage component  11  reads the license and content key corresponding to the above-mentioned content ID from the storage device (the HDD  111  for example) of its own. Next, the storage component  11  links the license and the content key, transmission type ID “0x02” indicative of “show” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the storage component  11  itself, thereby creating a show message.  
         [0346]     Further, the storage component  11  transmits the show message thus created to the reproduction component  21   a  (step S 124 ). In response, the reproduction component  21   a  receives this show message from the storage component  11 . Thus, in the transmission of a show message, the storage component  11  is equivalent to the above-mentioned transmission source component  31  and the reproduction component  21   a  is equivalent to the above-mentioned transmission destination component  32 .  
         [0347]     Then, the reproduction component  21   a  checks the show message received from the storage component  11  for validity (step S 126 ). This show message verification checks if the transmission type ID extracted from the above-mentioned show message is “0x02” indicative of transmission type “show” and the component attribute ID extracted from the above-mentioned show message is “0x01” indicative of component attribute “storage”. Because this verification is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , detail description of the verification processing will be omitted. If the above-mentioned show message is found valid as a result of the above-mentioned message verification, then the reproduction component  21   a  permits the processing of the license extracted from the above-mentioned show message, upon which the procedure goes to step S 128 . On the other hand, if the show message is found invalid, the reproduction component  21   a  prohibits the processing of this license, upon which the reproduction control processing ends.  
         [0348]     Next, the reproduction component  21   a  evaluates the license extracted from the above-mentioned show message to determine whether the above-mentioned content requested for reproduction is reproducible (step S 128 ). In this license evaluation processing, the reproduction component  21   a  evaluates the reproduction condition written to the reproduction condition description section  521  to determine whether the reproduction condition is satisfied or not, as described above.  
         [0349]     If the reproduction condition is found satisfied as a result of this evaluation, then the reproduction component  21   a  permits the reproduction of the above-mentioned content requested for reproduction. Then, the reproduction component  21   a  reads the content from the content storage block  7  such as the HDD  111  and decrypts the content by the content key extracted from the above-mentioned show message, thereby transmitting the decrypted content to the application  4  in the reproducible state (step S 130 ). Consequently, the application  4  reproduces the received content data (step S 132 ).  
         [0350]     On the other hand, if the reproduction condition is found not satisfied in step S 126 , then the reproduction component  21   a  prohibits the reproduction of the content and notifies the application  4  thereof (not shown).  
         [0000]     (Method of Content Reproduction Control Involving License Update)  
         [0351]     The following describes the method of content reproduction control that involves the updating of license. First, an outline of this method according to the present embodiment will be described with reference to  FIG. 24 .  FIG. 24  schematically illustrates an outline of this method.  
         [0352]     As shown in  FIG. 24 , the PC  10   a  has the reproduction component  21   b  (refer to  FIG. 8 ) for executing reproduction control involving the updating of license reproduction status and the storage component  11  for a HDD.  
         [0353]     The PC  10   a  thus configured is capable of transmitting and receiving three messages for example of which transmission type is “update” between the storage component  11  and the reproduction component  21   b , thereby executing the reproduction control involving license update.  
         [0354]     To be more specific, the storage component  11  reads the license and its content key from the HDD  111  to create an update request message (transmission type “update  1 ”, transmission source component attribute “storage”) and transmits the created message to the reproduction component  21   b . In this case, the master copies of the license and its content key K are left stored in the HDD  111 . The reproduction component  21   b  checks the update request message received from the storage component  11  to evaluate the license included in this message, thereby determining whether this content is reproducible or not.  
         [0355]     If the license is found reproducible as a result of the above-mentioned verification, then the reproduction component  21   b  updates the reproduction status of the license, creates an update transfer message (transmission type “update  2 ”, transmission source component attribute “use”) including the updated license, and transmits the created message to the storage component  11 . The storage component  11  verifies the update transfer message received from the reproduction component  21   b  and writes the license included in the update transfer message over the license stored in the HDD  111 .  
         [0356]     Further, the storage component  11  creates an update completion message (transmission type “update  3 ”, transmission source component attribute “storage”) including the updated license and transmits the created message to the reproduction component  21   b . The reproduction component  21   b  verifies the update completion message received from the storage component  11 , reads the content from the HDD  111 , and decrypts the content by the content key extracted from the update completion message, thereby making the content reproducible.  
         [0357]     The following describes in detail a processing flow of the content reproduction control method involving license update according to the present embodiment, with reference to  FIG. 25 .  FIG. 25  is a timing chart indicative of a processing flow of this method.  
         [0358]     As shown in  FIG. 25 , the processing of steps S 202  through S 214  in this reproduction control processing (with update) is substantially the same as the processing of steps S 102  through S 114  of the reproduction control processing (without update) described above with reference to  FIG. 23 , so that detail description thereof will be omitted.  
         [0359]     It is assumed here that, in step S 214 , the license involving the updating of the reproduction status be selected and the storage component  11  and the reproduction component  21   b  capable of executing the reproduction control involving the updating of the reproduction status be determined as subject to load.  
         [0360]     Next, the component management block  5  gives a load command to the storage component  11  and the reproduction component  21   b  both subject to load determined above (step S 216 ), starting up these components. The storage component  11  and the reproduction component  21   b  cross authenticate each other, thereby forming a secure communication route, SAC for example, between these components (step S 218 ).  
         [0361]     Further, the component management block  5  instructs the storage component  11  to create an update request message (step S 220 ). To be more specific, this message creation command is affected by transmitting the content ID received from the above-mentioned application  4  and transmission type specification information to the storage component  11 . This transmission type specification information specifies the transmission type (namely, the type of the message to be created) of the license. Because the reproduction control processing involving update is executed in this processing flow, the transmission type specification information is indicative of transmission type “update  1 ”. The message creation command thus configured allows the component management block  5  to instruct the storage component  11  to transmit a copy of the license corresponding to the above-mentioned content ID to the reproduction component  21   b.    
         [0362]     Next, in response to the above-mentioned message creation command, the storage component  11  creates an update request message for transmitting the license and content key corresponding to the above-mentioned content ID (step S 222 ). To be more specific, the storage component  11  reads the license and content key corresponding to the above-mentioned content ID from the storage device (the HDD  111  for example) corresponding to the storage component  11  itself. Further, the storage component  11  links the license and content key thus read, transmission type ID “0x03” indicative of “update  1 ” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the storage component  11  itself, thereby creating an update request message.  
         [0363]     In addition, the storage component  11  transmits the update request message thus created to the reproduction component  21   b  (step S 224 ). In response, the reproduction component  21   b  receives the update request message from the storage component  11 . Thus, in the update request message transmission processing (step S 224 ), the storage component  11  is equivalent to the above-mentioned transmission source component  31  and the reproduction component  21   b  is equivalent to the transmission destination component  32 .  
         [0364]     Then, the reproduction component  21   b  checks the update request message received from the storage component  11  for validity (step S 226 ). This update request message verification checks if the transmission type ID extracted from the above-mentioned update request message is “0x03” indicative of transmission type “update  1 ” and the component attribute ID extracted from the above-mentioned update request message is “0x01” indicative of component attribute “storage”. Because this verification is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , detail description of the verification processing will be omitted. If the above-mentioned update request message is found valid as a result of the above-mentioned message verification, then the reproduction component  21   b  permits the processing of the license extracted from the above-mentioned update request message, upon which the procedure goes to step S 228 . On the other hand, if the update request message is found invalid, the reproduction component  21   b  prohibited the processing of this license, upon which the reproduction control processing ends.  
         [0365]     Next, the reproduction component  21   b  evaluates the license extracted from the above-mentioned update request message to determine whether the above-mentioned content requested for reproduction is reproducible (step S 228 ). In this license evaluation processing, the reproduction component  21   b  evaluates the reproduction condition written to the reproduction condition description section  521  to determine whether the reproduction condition is satisfied or not, as described above. This reproduction condition evaluation processing evaluates reproduction conditions such as reproduction count limit and reproduction time limit and references the reproduction status written to the reproduction condition description section  521  as required.  
         [0366]     If the reproduction condition is found not satisfied as a result of this evaluation, the reproduction component  21   b  prohibits the reproduction of the content requested for reproduction and notifies the application  4  thereof (not shown).  
         [0367]     On the other hand, if the reproduction is found satisfied, the reproduction component  21   b  permits the reproduction of the content requested for reproduction and updates the reproduction status of this license in accordance with the permission of reproduction. To be more specific, in reproduction count control, the reproduction component  21   b  rewrites the reproduction status such that the number of reproduction has been made is increment by one in accordance of one time of reproduction permission.  
         [0368]     Next, in order to make a response to the above-mentioned update request message, the reproduction component  21   b  creates an update transmission message for transmitting a license with the above-mentioned reproduction status updated (hereafter referred to as an “updated license”) and the content key thereof (step S 230 ). To be more specific, the reproduction component  21   b  links the above-mentioned updated license and the content key extracted from the above-mentioned update request message, transmission type ID “0x04” indicative of “update  2 ” that is a transmission type denoting the transfer of the updated license and component ID “0x02” indicative of “use” that is the attribute of the reproduction component  21   b  itself, thereby creating an update transfer message.  
         [0369]     Further, the reproduction component  21   b  transmits the update transfer message thus created to the storage component  11  (step S 232 ). In response, the storage component  11  receives this update transfer message from the reproduction component  21   b . Thus, in the processing of transmitting the update transfer message (S 232 ), the reproduction component  21   b  is equivalent to the above-mentioned transmission source component  31  and the storage component  11  is equivalent to the above-mentioned transmission destination component  32 .  
         [0370]     Then, the storage component  11  checks the update transfer message received from the reproduction component  21   b  for validity (step S 234 ). This update transfer message verification checks if the transmission type ID extracted from the above-mentioned update transfer message is “0x04” indicative of transmission type “update  2 ” and component attribute ID extracted from the above-mentioned update transfer message is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification processing described above with reference to  FIG. 20 , so that the detail description thereof will be omitted. If the above-mentioned update transfer message is found valid as a result of this message verification, then the storage component  11  permits the storage of the updated license extracted from the above-mentioned update transfer message and the procedure goes to step S 326 . On the other hand, if the update transfer message is found invalid, then the storage component  11  prohibits the processing of the updated license, upon which the reproduction control processing ends.  
         [0371]     Next, the storage component  11  updates the license stored in the storage device (step S 236 ). To be more specific, the storage component  11  writes the updated license extracted from the above-mentioned update transfer message over the license (the unupdated license received in the above-mentioned update request message) stored in the storage device (the HDD  111  for example) of the storage component  11 .  
         [0372]     Further, in order to make a response to the above-mentioned update transfer message, the storage component  11  creates an update completion message for the notification of the update completion of the license (step S 238 ). To be more specific, the storage component  11  reads the updated license and the content key thereof from the storage device (the HDD  111  for example) of itself. Next, the storage component  11  links the updated license and its content key, transmission type ID “0x05” indicative of “update  3 ” that is a transmission type denoting the license update completion notification, and component attribute ID “0x01” indicative of “storage” that is the attribute of the storage component  11  itself, thereby creating an update completion message.  
         [0373]     Next, the storage component  11  transmits the update completion message thus created to the reproduction component  21   b  (step S 240 ). In response, the reproduction component  21   b  receives the update completion message from the storage component  11 . Thus, in the update completion message transmission processing (S 240 ), the storage component  11  is equivalent to the above-mentioned transmission source component  31  and the reproduction component  21   b  is equivalent to the above-mentioned transmission destination component  32 .  
         [0374]     Then, the reproduction component  21   b  checks the update completion message received from the storage component  11  for validity (step S 242 ). This update completion message verification checks if the transmission type ID extracted from the above-mentioned update completion message is “0x05” indicative of transmission type “update  3 ” and component attribute ID extracted from the above-mentioned update completion message is “0x01” indicative of component attribute “storage”. This verification processing is executed in substantially the same procedure as the message verification processing described above with reference to  FIG. 20 , so that the detail description thereof will be omitted. If the above-mentioned update completion message is found invalid as a result of this message verification, then, because the execution of the updating of the license cannot be confirmed, the reproduction component  21   b  prohibits the reproduction of the content requested for reproduction, upon which the reproduction control processing ends.  
         [0375]     On the other hand, if the update completion message is found valid, the reproduction component  21   b  reads the content of which reproduction has been permitted by the license evaluation of step S 228  (namely, the content requested for reproduction) from the content storage block  7  such as the HDD  111 , decrypts this content by the content key extracted from the update completion message, and transmits the decrypted content to the application  4  in a reproducible manner (step S 244 ). Consequently, the application  4  executes the reproduction of the decrypted content data (step S 246 ).  
         [0376]     Thus, the content reproduction control methods (with and without license update) according to the present embodiment have been described. According to the license reproduction control methods, messages including licenses and content IDs thereof may be transferred between the storage component  11  and the reproduction component  21 , thereby preferably controlling the reproduction of content. At this moment, the component that receives these messages checks the received message for validity, so that the illegal transmission of licenses and so on may be prevented from occurring.  
         [0377]     In addition, the content and license formats, the transmission protocol of that license, and the basic functions of each component are standardized, so that portable licenses may be transferred also between the user devices  10  having copyright management blocks  3  different installations, thereby preferably executing the control of content reproduction. Especially, the present embodiment is advantageous in that a license stored in a certain user device  10  may be transferred to another user device  10  connected to the former user device  10  via the network  30  in a physically remote manner to preferably control the reproduction by use of the reproduction component  21  of the latter user device  10 .  
         [0000]     &lt;10. License Move Method&gt; 
         [0378]     The following describes a license move method according to the present embodiment. In this license move method, in order to control the move of content between a plurality of storage devices, two storage components  1  and one move component  22  are used to move a license from the first storage device, the source of move, to the second storage device, the destination of move.  
         [0379]     First, the license move method according to the present embodiment will be outlined with reference to  FIG. 26 .  FIG. 26  outlines the license move method in which a license is moved between the two storage devices in the PC  10   a  according to the present embodiment.  
         [0380]     As shown in  FIG. 26 , the PC  10   a  includes the move component  22 , the storage component  11  (the first storage component) for the HDD  111  that is one example of the first storage device, the source of move, and the storage component  12  (the second storage component) for the removable storage medium  40  that is one example of the second storage device, the destination of move.  
         [0381]     The PC  10   a  thus configured is capable of transferring transfer messages for transmitting the master copy of license between the storage components  11  and  12  and the move component  22 , thereby moving a license and a content key thereof from the HDD  111 , the source of move, to the removable storage medium  40 , the destination of move.  
         [0382]     To be more specific, the storage component  11  for HDD transmits (namely, transfers) the master copies of the license and the content key thereof to the move component  22 . That is, the storage component  11  reads the license and the content key thereof from the HDD  111 . Next, the storage component  11  creates a first transfer message (transmission type “transfer”, transmission source component attribute “storage”) including the license and the content key thereof and transmits the created message to the move component  22 . At this moment, the storage component  11  deletes the license and the content key thereof from the HDD  111 .  
         [0383]     The move component  22  checks the first transfer message received from the storage component  11  and evaluates the license included in this message to determine whether the license and the content key are movable. If the license and the content key are found movable, then the move component  22  updates the move status of the license by counting the move count as required and transfers the license and so on to the storage component  12  for the removable storage medium  40 . To be more specific, the move component  22  creates a second transfer message (transmission type “transfer”, transmission source component attribute “use”) including the license and the content key received from the storage component  11  and transmits the created second transfer message to the storage component  12 .  
         [0384]     The storage component  12  checks the second transfer message received from the move component  22  and evaluates the license included in this message to determine whether the license and the content key may be stored in the removable storage medium  40 . If the license and the content key are found storable, then the storage component  12  writes the license and the content key to the removable storage medium  40  for storage.  
         [0385]     Thus, transferring transfer messages between the two storage components, the storage component  11  and the storage component  12 , and the move component  22  allows the move of the license and so on between two storage devices, the storage devices  111  and the storage device  40 . It should be noted that the above-mentioned first transfer message is equivalent to the first message and the above-mentioned second transfer message is equivalent to the second message.  
         [0386]     In addition, use of the above-mentioned license move method allows the move of licenses and content keys thereof between various types of devices in a complex manner as shown in  FIG. 27 .  FIG. 27  outlines the license move method for moving licenses and so on between a plurality of devices according to the present embodiment.  
         [0387]     As shown in  FIG. 27 , the move component  22  of the distribution server  20  transmits a transfer message (transmission type “transfer”, transmission source component attribute “use”) including a license and so on read from a storage device (not shown) of the distribution server  20  to the storage component  12  of the mobile phone  10   h  that is one of the user devices  10 . Next, the storage component  12  of the mobile phone  10   h  checks the received transfer message and writes the license and so on included in this transfer message to the removable storage medium  40  for storage. Thus, the license and so on stored in the distribution server  20  may be downloaded to the mobile phone  10   h.    
         [0388]     Further, the above-mentioned removable storage medium  40  is unloaded from the mobile phone  10   h  and loaded on a first PC  10   a - 1 . The first PC  10   a - 1  is able to move the license and so on stored in the removable storage medium  40  to the HDD  111  of a second PC  10   a - 2  via the PC  10   a - 1  and the network  30 .  
         [0389]     To be more specific, the storage component  12  creates a transfer message (transmission type “transfer”, transmission source component attribute “storage”) including the license and so on read from the removable storage medium  40  and transmits the created transfer message to the move component  22  of the first PC  10   a - 1 . Further, the move component  22  of the first PC  10   a - 1  checks the received transfer message and evaluates the move condition of the license extracted from this transfer message. If the move condition is found satisfied, then the move component  22  creates a transfer message (transmission type “transfer”, transmission source component attribute “use”) including the license and so on extracted from the transfer message and transmits the created transfer message to the storage component  11  of the second PC  10   a - 2  via the network  30 . In response, the storage component  11  of the second PC  10   a - 2  checks the received transfer message and writes the license and so on included in the checked transfer message to the HDD  111  for storage.  
         [0390]     Thus, arranging the move component  22  and the storage components  11  and  12  on various devices and transferring transfer messages between these components as described above allow the move of licenses and content keys thereof within a scope of the license move conditions.  
         [0391]     The following describes in detail a processing flow of the above-mentioned license move method according to the present embodiment with reference to  FIG. 28 .  FIG. 28  is a timing chart indicative of a processing flow of the license move method according to the present embodiment.  
         [0392]     As shown in  FIG. 28 , the application  4  receives a request for moving a user-specified piece of content from the user (step S 302 ). Next, the application  4  extracts the content ID from a content file of the content requested for move (step S 304 ). Further, the application  4  transmits move control command information to the component management block  5  to instruct the component management block  5  to execute the move control of the content requested for move, namely the move control of the license and the content key thereof corresponding to that content (step S 306 ). This move control command information includes the above-mentioned content ID, use information indicative the use of content is “move”, and information for specifying a storage device from which the license and the content key are moved (a first storage device) and a storage device to which the content and the license are moved (a second storage device), for example.  
         [0393]     Next, on the basis of the above-mentioned move control command information received from the application  4  for example, the component management block  5  determines a license processing component subject to load (or start up) (step S 308 ). For example, the component management block  5  determines, as components subject to load, the move component  22 , the storage component  11  corresponding to the move source storage component specified by the above-mentioned move control command information (hereafter referred to as a move source storage component  11 ), and the storage component  12  corresponding to the storage device of the move destination specified by that information (hereafter referred to as a move destination storage component  12 ). It should be noted that, in this processing of determining components subject to load, the component management block  5  may search for a storage component holding the license and content key thereof corresponding to the content requested for move in the same manner as steps S 108  through S 114  shown in  FIG. 23  for example, thereby determining the obtained storage component as the component subject to load.  
         [0394]     Further, the component management block  5  gives a load command to the storage components  11  and  12  and the move component  22  determined as the storage components subject to load, thereby starting up these components (step S 310 ). Consequently, the move source storage component  11  and the move component  22  and the move component  22  and the move destination storage component  12  cross authenticate each other, thereby forming a secure communication route, SAC for example, between these components (step S 312 ).  
         [0395]     In addition, the component management block  5  gives a command to the move source storage component  11  to create a transfer message (step S 314 ). To be more specific, this message creation command is affected by transmitting the content ID and transmission type specification information received from the application  4  to the move source storage component  11 . In the present processing flow, license move processing is executed, so that the above-mentioned transmission type specification information is indicative of transmission type “transfer”. This message creation command allows the component management block  5  to instruct the move source storage component  11  to transmit the master copy of the license corresponding to the above-mentioned content ID to the move component  22 .  
         [0396]     Next, in response to the above-mentioned message creation command, the move source storage component  11  creates a transfer message (a first message) for transferring the license and the content key thereof corresponding to the above-mentioned content ID (step S 316 ). To be more specific, the move source storage component  11  reads the license and the content key thereof corresponding to the above-mentioned content ID from the move source storage device (the HDD  111  for example) of its own. Next, the move source storage component  11  links the license and the content key thus read, transmission type ID “0x01” indicative of “transfer” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the move source storage component  11  itself, thereby creating the transfer message.  
         [0397]     Further, the move source storage component  11  invalidates (or deletes) the above-mentioned license and content key thereof stored in the move source storage device (the HDD  111  for example) (step S 318 ). Thus, invalidating the license and so on stored in the move source storage device before transmitting the transfer message in next step S 320  may prevent an unauthorized user for example from interfering the license invalidation processing by illegal measures after the transmission of the transfer message, as a result of which the license and so on exist on both the move source and the move destination.  
         [0398]     Then, the move source storage component  11  transmits the transfer message created in step S 316  to the move component  22  (step S 320 ). In response, the move component  22  receives this transfer message from the move source storage component  11 . Thus, in the transfer message transmission processing (S 320 ), the move source storage component  11  is equivalent to the above-mentioned transmission source component  31  and the move component  22  is equivalent to the above-mentioned transmission destination component  32 .  
         [0399]     Next, the move component  22  checks the transfer message received from the move source storage component  11  for validity (step S 322 ). This transfer message verification processing checks if transmission type ID extracted from the above-mentioned transfer message is “0x01” indicative of transmission type “transfer” and component attribute ID extracted from the above-mentioned transfer message is “0x01” indicative of component attribute “storage”. This verification is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned transfer message is found valid as a result of the above-mentioned verification processing, then the move component  22  permits the processing of the license extracted from the transfer message, upon which the procedure goes to step S 324 . On the other hand, if the transfer message is found invalid, then the move component  22  prohibits the processing of this license, upon which the move processing ends.  
         [0400]     Further, the move component  22  evaluates the license extracted from the above-mentioned transfer message to determine whether the license and the content key thereof are movable (step S 324 ). In this license evaluation processing, the move component  22  evaluates the move condition written to the move condition description section  522  of that license to determine whether the move condition is satisfied. In this determination, the move condition such as move count limit or move time limit is checked and, as required, the move status written to the move condition description section  522  is referenced.  
         [0401]     If the move condition is found dissatisfied as a result of the above-mentioned evaluation, then the move component  22  prohibits the move of the license and content key thereof extracted from the above-mentioned transfer message and notifies the application  4  thereof (not shown).  
         [0402]     On the other hand, if the move condition is found satisfied, then the move component  22  permits the move of the license and content key thereof extracted from the above-mentioned transfer message and, as required, updates the move status of that license. To be more specific, in the control of move count for example, the move component  22  rewrites the move status so as to increment the number of times move has been made by one every time the move is permitted.  
         [0403]     Next, the move component  22  creates a transfer message (a second message) for transferring the license and content key thereof permitted for move (step S 326 ). To be more specific, if the license (move) status permitted for move has been updated, the move component  22  links the license permitted for move (if the move status has been update, the updated license), the content key permitted for move, transmission type ID “0x01” indicative of transmission type “transfer”, and component attribute ID “0x02” indicative of “use” that is the attribute of the move component  22  itself, thereby creating the transfer message.  
         [0404]     In addition, the move component  22  transmits the transfer message thus created to the move destination storage component  12  (step S 328 ). In response, the move destination storage component  12  receives the above-mentioned transfer message from the move component  22 . Thus, in the transfer message transmission processing (S 328 ), the move component  22  is equivalent to the transmission source component  31  and the move destination storage component  12  is equivalent to the transmission destination component  32 .  
         [0405]     Then, the storage component  12  checks the transfer message received from the move component  22  for validity (step S 330 ). This transfer message verification processing checks if transmission type ID extracted from the above-mentioned transfer message is “0x01” indicative of transmission type “transfer” and component attribute ID is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification described above with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned transfer message is found valid as a result of the above-mentioned verification, then the move destination storage component  12  permits the processing of the license extracted from the above-mentioned transfer message, upon which the procedure goes to step S 334 . On the other hand, if the above-mentioned transfer message is found invalid, then the move destination storage component  12  prohibits the processing of the license, upon which the move processing ends.  
         [0406]     Next, the move destination storage component  12  evaluates the license extracted from the above-mentioned transfer message to determine whether the license and the content key thereof may be stored in the second storage device (step S 332 ). In this license evaluation processing, the move destination storage component  12  evaluates the storage condition written to the storage condition description section  511  of that license as described above to see if the storage condition is satisfied or not. In this storage condition evaluation processing, the storage condition such as storage count limit or storage time limit for example and, as required, the storage status written to the storage condition description section  511  is referenced.  
         [0407]     If the storage condition is found dissatisfied as a result of this evaluation, then the move destination storage component  12  prohibits the storage of the license extracted from the above-mentioned transfer message, thereby executing a pause sequence.  
         [0408]     On the other hand, if the storage condition is found satisfied, then the move destination storage component  12  permits the storage of the license and content key thereof extracted from the above-mentioned transfer message and, as required, updates the storage status of that license. To be more specific, in the storage count control, the move destination storage component  12  rewrites the storage status so as to increment the number of times storage has been made by one every time the above-mentioned storage permission is made.  
         [0409]     Then, the move destination storage component  12  writes the license and content key thereof permitted for storage to the second storage device (the removable storage medium  40  for example) corresponding to the storage component  12  (step S 334 ).  
         [0410]     Thus, the license and the content key thereof corresponding to the content requested for move are moved from the first storage device to the second storage device. When the move of the license and so on has been completed, the move destination storage component  12  transmits a move completion notification to the component management block  5  (step S 336 ) for example and, in response, the component management block  5  transmits a content move permission to the application  4  (step S 338 ), for example.  
         [0411]     Consequently, in response to the content move permission received from the component management block  5 , the application  4  moves the content requested for move from the first application device to the second application device (step S 340 ). To be more specific, the application  4  reads the content from the first storage device, writes this content to the second storage device, and deletes this content from the first storage device, for example.  
         [0412]     Thus, the flow of processing by the license move method according to the present embodiment has been described. According to the license move method described above, a message including a content and a content ID may be transferred between the move source and move destination storage components  11  and  12  and the move component  22  to preferably control the move and the license and content concerned. At this moment, the message receiving component checks each message for validity every time it is received, thereby preventing the illegal transmission of licenses and so on.  
         [0413]     In addition, the content and license formats, the transmission protocol of that license, and the basic functions of each component are standardized, so that licenses may be transferred in a portable manner between the user devices  10  having copyright management blocks  3  of different installations, thereby preferably controlling the move of licenses and content. Especially, the present embodiment is advantageous that licenses and content may be preferably moved between physically remotely interconnected user devices  10  via the network  30  without dependent on the installations of the copyright management blocks  3  of these user devices  10 . Therefore, the novel configuration enhances the portability of content between user devices  10 , which in turn enhances the user convenience.  
         [0000]     &lt;11. License Copy Method&gt; 
         [0414]     The following describes a method of copying or duplicating licenses. This license copy method is used to control the duplication of content between a plurality of storage devices, to be more specific, two storage components, the component  1  and the copy component  23 , are used to copy a license stored in a copy source first storage device to a copy destination second storage device.  
         [0415]     First, an outline of the license copy method according to the present embodiment will be described with reference to  FIG. 29 .  FIG. 29  outlines the license copy method for copying a license between two storage devices of the PC  10   a  according to the present embodiment.  
         [0416]     As shown in  FIG. 29 , the PC  10   a  includes the copy component  23 , the storage component  11  (a first storage component) for the HDD  111 , one example of a first storage device providing the copy source, and the storage component  12  (a second storage component) for the removable storage medium  40 , one example of a second storage device providing the copy destination.  
         [0417]     The PC  10   a  thus configured transmits and receives transfer messages for transmitting a show message for transmitting a copy of each license and a transfer message for transmitting the master copy of each license between the storage components  11  and  12  and the copy component  23 , thereby copying a license and a content key thereof from the copy source HDD  111  to the copy destination removable storage medium  40 .  
         [0418]     To be more specific, the storage component  11  for HDD transmits (namely, shows) the copies of a license and a content key thereof to the copy component  23 . Namely, the storage component  11  reads a license and a content key thereof from the HDD  111 . Next, the storage component  11  creates a show message (transmission type “show”, transmission source component attribute “storage”) including these license and content key and transmits the created show message to the copy component  23 . At this moment, the storage component  11  does not delete the license and the content key stored in the HDD  111 .  
         [0419]     The copy component  23  checks the show message received from the storage component  11  and then evaluates the license included in this show message, thereby determining whether these license and copy content may be copied. If these license and content key are found copyable, the copy component  23  updates the copy status of the license by counting copy count as required and transfers the license and so on to the storage component  12  for the removable storage medium  40 . To be more specific, the copy component  23  creates a transfer message (transmission type “transfer”, transmission source component attribute “use”) including the license and content key received from the above-mentioned storage component  11  and transmits the created transfer message to the storage component  12 .  
         [0420]     The storage component  12  checks the transfer message received from the copy component  23  and then evaluates the license included in the checked transfer message to determine whether these license and content key may be stored in the removable storage medium  40 . If these license and content key are found storable, the storage component  12  writes these license and content key to the removable storage medium  40  for storage.  
         [0421]     Thus, transferring a show message and a transfer message between two storage components, the storage component  11  and the storage component  12  and the copy component  23 , allows the copying of a license and so on between two storage devices, the HDD  111  and the removable storage medium  40 . It should be noted that the above-mentioned show message is equivalent to the first message and the above-mentioned transfer message is equivalent to the second message.  
         [0422]     As with the move processing described above with reference to  FIG. 27 , arranging the copy component  23  and the storage components  11  and  12  on various devices in a distributed manner and transferring a show message and a transfer message between these components allow the copying of these license and content key within a scope in which the license copy condition is satisfied.  
         [0423]     The following describes a processing flow of the license copy method according to the present embodiment with reference to  FIG. 30 .  FIG. 30  is a timing chart indicative of the processing flow of the license copy method according to the present embodiment.  
         [0424]     As shown in  FIG. 30 , the application  4  receives a request for copying the user-specified content from the user (step S 402 ). Next, the application  4  extracts the content ID from a content file of the content requested for copying (step S 404 ). Further, the application  4  transmits copy control command information to the component management block  5  to instruct the component management block  5  to execute copy control on the content requested for copying, namely, on the license and the content key thereof corresponding to that content (step S 406 ). This copy control command information includes the above-mentioned content ID, use information indicative that content use is “copy”, and information for specifying the copy source storage device (the first storage device) and the copy destination storage device (the second storage device) between which the content and so on are copied, for example.  
         [0425]     Next, on the basis of the copy control command information received from the application  4  for example, the component management block  5  determines a license processing component subject to load (or start up) (step S 408 ). For example, the component management block  5  determines, as the component subject to load, the copy component  23 , the storage component  11  corresponding to the copy source storage device specified by the above-mentioned copy control command information (hereafter referred to as a copy source storage component  11 ), and the storage component  12  corresponding to the specified copy destination storage device (hereafter referred to as a copy destination storage component  12 ). It should be noted that, in this processing of determining components subject to load, the component management block  5  may search for storage components the license and content key thereof corresponding to the content requested for copying on the basis of the content ID as with above-mentioned steps S 108  through S 114  shown in  FIG. 23  for example, thereby determining the storage components subject to load.  
         [0426]     Further, the component management block  5  gives a load command to the storage components  11  and  12  and the copy component  23  determined above as the storage components subject to load, thereby starting up these storage components (step S 410 ). Consequently, the copy source storage component  11  and the copy component  23  and the copy component  23  and the copy destination storage component  12  cross authenticate each other, thereby forming a secure communication route, SAC for example, between these components (step S 412 ).  
         [0427]     In addition, the component management block  5  instructs the copy source storage component  11  to create a show message (step S 414 ). To be more specific, this message creation command is affected by transmitting the content ID received from the application  4  and transmission type specification information to the copy source storage component  11 . In the present processing flow, license copy processing is executed, so that the above-mentioned transmission type specification information is indicative of transmission type “show”. This message creation command allows the component management block  5  to instruct the copy source storage component  11  to transmit a copy of the license corresponding to the content ID to the copy component  23 .  
         [0428]     Next, in response to the above-mentioned message creation command, the copy source storage component  11  creates a show message (or a first message) for transferring the license and content key thereof corresponding to the above-mentioned content ID (step S 416 ). To be more specific, the copy source storage component  11  reads the license and content key thereof corresponding to the above-mentioned content ID from the storage device (the HDD  111  for example) corresponding to itself. Further, the copy source storage component  11  links these license and content key thus read, transmission type ID “0x02” indicative of “show” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the copy source storage component  11  itself, thereby creating a show message.  
         [0429]     It should be noted that, unlike the above-mentioned license move processing, the license copy method does not invalidate (or delete) the above-mentioned license and content key thereof stored in the copy source storage device (the HDD  111  for example).  
         [0430]     Then, the copy source storage component  11  transmits the show message created in step S 416  to the copy component  23  (step S 420 ). In response, the copy component  23  receives this show message from the copy source storage component  11 . Thus, in the show message transmission processing (S 420 ), the copy source storage component  11  is equivalent to the transmission source component  31  and the copy component  23  is equivalent to the transmission destination component  32 .  
         [0431]     Next, the copy component  23  checks the show message received from the copy source storage component  11  for validity (step S 422 ). This show message verification processing checks if the transmission type ID extracted from the above-mentioned show message is “0x02” indicative of transmission type “show” and the component attribute ID extracted from the above-mentioned show message is “0x01” indicative of component attribute “storage”. This verification processing is executed in substantially the same procedure as the message verification processing described with reference to FIG.  20 , so that detail description thereof will be omitted. If the above-mentioned show message is found valid as a result of the message verification processing, then the copy component  23  permits the processing of the license extracted from the above-mentioned show message, upon which the procedure goes to step S 424 . On the other hand, if the above-mentioned show message is found invalid, the copy component  23  prohibits the processing of that license, upon which the copy processing ends.  
         [0432]     Further, the copy component  23  evaluates the license extracted from the show message to determine whether these license and content key may be copied (step S 424 ). This license evaluation processing evaluates the copy condition written to the copy condition description section  523  of that license to determine whether the copy condition is satisfied. In this copy condition evaluation, the copy condition such as copy count limit or copy time limit for example is evaluated and, as required, the copy status written to the copy condition description section  523  is referenced.  
         [0433]     If the copy condition is found dissatisfied as a result of the evaluation, then the copy component  23  prohibits the copying of these license and content key extracted from the above-mentioned show message and notifies the application  4  thereof (not shown).  
         [0434]     On the other hand, if the copy condition is found satisfied, then the copy component  23  permits the copying of these license and content key extracted from the above-mentioned show message and, as required, updates the copy status of that license. To be more specific, in copy count control for example, the copy component  23  rewrites the copy status so as to increment the number of times copy has been made by one every time copying is permitted.  
         [0435]     Next, the copy component  23  creates a transfer message (or a second message) for transferring these license and content key permitted for copy (step S 426 ). To be more specific, the copy component  23  links the license permitted for copy (if the copy status has been updated, the updated license), the content key permitted for copy, transmission type ID “0x01” indicative of transmission type “transfer”, and component attribute ID “0x02” indicative of “use” that is the attribute of the copy component  23  itself, thereby creating a transfer message.  
         [0436]     Further, the copy component  23  transmits the created transfer message to the copy destination storage component  12  (step S 428 ). In response, the copy destination storage component  12  receives the transfer message from the copy component  23 . Thus, in the transfer message transmission processing (S 428 ), the copy component  23  is equivalent to the above-mentioned transmission source component  31  and the copy destination storage component  12  is equivalent to the above-mentioned transmission destination component  32 .  
         [0437]     Then, the copy destination storage component  12  checks the transfer message received from the copy component  23  for validity (step S 430 ). This transfer message verification processing checks if the transmission type ID extracted from the above-mentioned transfer message is “0x01” indicative of transmission type “transfer” and the component attribute ID extracted from the above-mentioned transfer message is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification described above with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned transfer message is found valid as a result of the above-mentioned verification processing, then the copy destination storage component  12  permits the processing of the license extracted from the above-mentioned transfer message, upon which the procedure goes to step S 434 . On the other hand, if the above-mentioned transfer message is found invalid, then the copy destination storage component  12  prohibits the processing of that license, upon which the copy processing ends.  
         [0438]     Next, the copy destination storage component  12  evaluates the license extracted from the above-mentioned transfer message to determine whether these license and content key may be stored in the second storage device (step S 432 ). This license evaluation processing evaluates the storage condition written to the storage condition description section  511  of that license, thereby determining whether the storage condition is satisfied or not, as described before. In this storage condition evaluation processing, the storage condition such as storage count limit or storage time limit for example is evaluated and, as required, the storage status written to the storage condition description section  511  is referenced.  
         [0439]     If the storage condition is found dissatisfied as a result of this evaluation, then the copy destination storage component  12  prohibits the storage of the license extracted from the above-mentioned transfer message, thereby executing a pause sequence.  
         [0440]     On the other hand, if the storage condition is found satisfied, the copy destination storage component  12  permits the storage of these license and content key extracted from the above-mentioned transfer message and, as required updates the storage status of that license. To be more specific, in storage count control for example, the storage destination storage component  12  rewrites the storage status so as to increment the number of times storage has been made by one every time storage is permitted.  
         [0441]     Then, the copy destination storage component  12  writes the above-mentioned license and content key permitted for storage to the second storage device (the removable storage medium  40  for example) corresponding to the storage component  12  itself (step S 434 ).  
         [0442]     Thus, these license and content key requested for copying are copied from the first storage device to the second storage device. When the copying of the license and so on has been completed, the storage destination storage component  12  notifies the component management block  5  thereof (step S 436 ). In response, the component management block  5  gives a content copy permission to the application  4  (step S 438 ).  
         [0443]     Consequently, in response to the notification of the permission of content copying received from the component management block  5 , the application  4  copies the above-mentioned content requested for copying from the first storage device to the second storage device (step S 440 ). To be more specific, the application  4  reads that content from the first storage device and writes that content to the second storage device without deleting that content from the first storage device, for example.  
         [0444]     Thus, the processing flow of the license copy method according to the present embodiment has been described. According to this license copy method, a message including a license and a content ID may be transferred between the copy source storage component  11  and the copy destination storage component  12  and the copy component  23 , thereby preferably controlling the copying of the license and the corresponding content. At this moment, the message receiving component checks the received message for validity every time it is received, thereby preventing the illegal transmission of licenses and so on.  
         [0445]     In addition, the content and license formats, the transmission protocol of that license, and the basic functions of each component are standardized, so that licenses may be transferred in a portable manner between the user devices  10  having copyright management blocks  3  of different installations, thereby preferably controlling the copying of licenses and content. Especially, the present embodiment is advantageous that licenses and content may be preferably copied between physically remotely interconnected user devices  10  via the network  30  without dependent on the installations of the copyright management blocks  3  of these user devices  10 . Therefore, the novel configuration enhances the portability of content between user devices  10 , which in turn enhances the user convenience.  
         [0000]     &lt;12. License Rent Method&gt; 
         [0446]     The following describes a license rent method according to the present embodiment. In this license rent method, for the purpose of controlling the renting of content between a plurality of storage devices, two components, the storage component  1  and the rent component  24 , are used to update a rent source license stored in a first storage device that is the rent source, a license for rent is created on the basis of this updated rent source license, and the created license for rent is rented to a second storage device that is the rent destination. This rent processing is equivalent to the check-out processing of SDMI.  
         [0447]     First, the license rent method according to the present embodiment will be outlined with reference to  FIG. 31 .  FIG. 31  shows an outline of the license rent method for renting licenses between two storage devices in the PC  10   a  according to the present embodiment.  
         [0448]     As shown  FIG. 31 , the PC  10   a  has the rent component  24 , the storage component  11  (or a first storage component) for the HDD  111 , one example of the first storage device providing the rent source, and the storage component  12  (or a second storage component) for the removable storage medium  40 , one example of the second storage device providing the rent destination.  
         [0449]     The PC  10   a  thus configured is capable of transmitting and receiving updated messages between the rent source storage component  11  and the rent component  24  to update a rent source license  307  stored in the HDD  111  that is the rent source, thereby creating a license for rent  308 . Also, the PC  10   a  is capable of renting the above-mentioned license for rent  308  to the removable storage medium  40  by transmitting a transfer message from the rent component  24  to the rent destination storage component  12 .  
         [0450]     To be more specific, the rent source storage component  11  reads the rent source license  307  and the content key thereof from the HDD  111  to create an update request message (transmission type “update  1 ”, transmission source component attribute “storage”) and transmits the created update request message to the rent component  24 . It should be noted that the rent source license  307  is a license written with a rent condition, a reproduction condition, and storage condition as a use condition (refer to  FIG. 11 ).  
         [0451]     Next, the rent component  24  checks the update request message received from the rent source storage component  11  and then evaluates the rent source license  307  included in this message, thereby determining whether the rent source license  307  and the content key thereof are rentable. If these license and content data are found rentable, the rent component  24  updates the rent status of the rent source license  307  to create an update transfer message (transmission type “update  2 ”, transmission source component attribute “use”) including the updated rent source license and the content key thereof, thereby transmitting the created update transfer message to the rent source storage component  11 .  
         [0452]     Further, the rent source storage component  11  checks the update transfer message received from the rent component  24  and then writes the updated rent source license  307  included in the update transfer message over the rent source license  307  stored in the HDD  111 . Then, the rent source storage component  11  creates an update completion message (transmission type “update  3 ”, transmission source component attribute “storage”) including the updated rent source license  307  and the content key thereof and transmits the created message to the rent component  24 .  
         [0453]     Next, the rent component  24  checks the update completion message received from the storage component  11  and creates the license for rent  308  on the basis of the rent source license  307 . This license for rent  308  is a license written with the rent condition, reproduction condition, and storage condition extracted from the rent source license  307  and a newly created return condition (refer to  FIG. 12 ). Then, the rent component  24  creates a transfer message (transmission type “transfer”, transmission source component attribute “use”) including the created license for rent  308  and the content key thereof and transmits the created message to the rent destination storage component  12 .  
         [0454]     Next, the rent destination storage component  12  checks the transfer message received from the rent component  24  and evaluates the license for rent  308  included in this message, thereby determining whether the license for rent  308  and the content key thereof may be stored in the removable storage medium  40 . If these license  308  and content key are found storable, then the rent destination storage component  12  writes these license for rent  308  and content key thereof to the removable storage medium  40 .  
         [0455]     Thus, transferring an update message and a transfer message between the rent source storage component  11  and the rent destination storage component  12  and the rent component  24  allows the renting of the license for rent  308  and the content key thereof from the HDD  111  that is a storage device of the rent source to the removable storage medium  40  that is a storage device of the rent destination. It should be noted that the above-mentioned update request message is equivalent to the first message, the above-mentioned transfer message is equivalent to the second message, and the above-mentioned update transfer message is equivalent to the third message.  
         [0456]     Also, the rent component  24  writes the same rent ID to both the updated rent source license  307  and the license for rent  308  in advance, thereby relating the rent source license  307  with the license for rent  308 . This allows the preferable execution of license return processing to be described later.  
         [0457]     As with the move processing described with reference to  FIG. 27 , arranging the rent component  24  and the rent source and rent destination storage components  11  and  12  on various devices in a distributed manner and transferring an update message and a transfer message between these components allow the renting of these license for rent and content key within a scope in which the license rent condition is satisfied.  
         [0458]     The following describes a processing flow of the license rent method according to the present embodiment with reference to  FIGS. 32A and 32B .  FIGS. 32A and 32B  are timing charts indicative of a processing flow of the license rent method according to the present embodiment.  
         [0459]     As shown in  FIGS. 32A and 32B , the application  4  receives a request for renting user-specified content from the user (step S 502 ). Next, the application  4  extracts content ID from a content file of the content requested for rent (step S 504 ). Then, the application  4  transmits rent control command information to the component management block  5  to instruct the component management block  5  to control the renting of the content requested for rent, namely the renting of the license corresponding to that content and the content key thereof (step S 506 ). This rent control command information includes the above-mentioned content ID, use information indicative that content use is “rent”, and information for specifying a content and license rent source storage device (or the first storage device) and rent destination storage device (or the second storage device), for example.  
         [0460]     Next, the component management block  5  determines a license processing component subject to load (or start up) on the basis of the above-mentioned rent control command information received from the application  4 , for example (step S 508 ). For example, the component management block  5  determines, as the components subject to load, the rent component  24 , the storage component  11  corresponding to the rent source storage device specified by the above-mentioned rent control command information (hereafter referred to as a rent-source storage component  11 ), and the storage component  12  corresponding to the rent destination storage device specified by that information (hereafter referred to as a rent destination storage component  12 ). It should be noted that, in this processing of determining components subject to load, the component management block  5  may also search, by the content ID, for the storage components storing the license and content key thereof corresponding to the content requested for rent in the substantially the same procedure as steps S 108  through S 114  shown in  FIG. 23  for example, thereby determining the components subject to load.  
         [0461]     Further, the component management block  5  gives a load command to the storage components  11  and  12  and rent component  24  determined as the components subject to load, thereby starting up these components (step S 510 ). Consequently, the rent source storage component  11  and the rent component  24  and the rent component  24  and the rent destination storage component  12  cross authenticate each other, thereby forming a secure communication route, SAC for example, between these components (step S 512 ).  
         [0462]     In addition, the component management block  5  instructs the rent source storage component  11  to create an update request message (step S 514 ). To be more specific, this message creation command is affected by transmitting the content ID received from the application  4  and transmission type specification information to the rent source storage component  11 . In the present processing flow, license rent processing involving the updating of the rent source license is executed, so that the above-mentioned transmission type specification information is indicative of transmission type “update  1 ”. This message creation command allows the component management block  5  to instruct the rent source storage component  11  to transmit a copy of the rent source license corresponding to the above-mentioned content ID to the rent component  24 .  
         [0463]     Next, in response to the above-mentioned message creation command, the rent source storage component  11  creates an update request message (or a first message) for transferring the rent source license and content key thereof corresponding to the above-mentioned content ID (step S 516 ). To be more specific, the rent source storage component  11  reads the rent source license and content key thereof corresponding to the above-mentioned content ID from the storage device (the HDD  111  for example) corresponding to itself. Further, the rent source storage component  11  links these rent source license and content key thus read, transmission type ID “0x03” indicative of “update  1 ” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the rent source storage component  11  itself, thereby creating an update request message.  
         [0464]     Then, the rent source storage component  11  transmits the update request message created in step S 516  to the rent component  24  (step S 518 ). In response, the rent component  24  receives this update request message from the rent source storage component  11 . Thus, in the update request message transmission processing (S 518 ), the rent source storage component  11  is equivalent to the transmission source component  31  and the rent component  24  is equivalent to the transmission destination component  32 .  
         [0465]     Next, the rent component  24  checks the update request message received from the rent source storage component  11  for validity (step S 520 ). This update request message verification processing checks if the transmission type ID extracted from the above-mentioned update request message is “0x03” indicative of transmission type “update  1 ” and the component attribute ID extracted from the above-mentioned update request message is “0x01” indicative of component attribute “storage”. This verification processing is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned update request message is found valid as a result of the message verification processing, then the rent component  24  permits the processing of the rent source license extracted from the above-mentioned update request message, upon which the procedure goes to step S 522 . On the other hand, if the above-mentioned update request message is found invalid, the rent component  24  prohibits the processing of that license, upon which the rent processing ends.  
         [0466]     Next, the rent component  24  evaluates the rent source license extracted from the above-mentioned update request message to determine whether these rent source license and content key may be rented (step S 522 ). This rent source license evaluation processing evaluates the rent condition written to the rent condition description section  524  of that rent source license, thereby determining whether the rent condition is satisfied or not. In this rent condition evaluation processing, the rent condition such as rent count limit or rent time limit for example is evaluated and, as required, the rent status written to the rent condition description section  524  is referenced.  
         [0467]     If the rent condition is found dissatisfied as a result of the evaluation, then the rent component  24  prohibits the renting of these rent source license and content key extracted from the above-mentioned update request message and notifies the application  4  thereof (not shown). On the other hand, if the rent condition is found satisfied, then the rent component t  24  permits the renting of these rent source license and content key extracted from the above-mentioned update request message, upon which the procedure goes to step S 524 .  
         [0468]     Next, in response to the permission of the renting of the above-mentioned rent source license, the rent component  24  newly generates a rent source ID (step S 524 ) This rent source ID is a unique identifier that is generated on a rent processing basis.  
         [0469]     In addition, in response to the permission of the renting of the above-mentioned rent source license, the rent component  24  updates the rent status of the rent source license (step S 526 ). To be more specific, the rent component  24  additionally writes the rent ID created above to the rent status in the rent condition description section  524  of that rent source license. Also, in executing rent count control for example, the rent component  24  rewrites the above-mentioned rent status so as to increment the number of times rent has been made by one every time rent is permitted.  
         [0470]     Next, in order to responds to the above-mentioned update request message, the rent component  24  creates an update transmission message (or a third message) for transmitting the rent source license with the rent condition updated (hereafter referred to as an updated rent source license) and the content key thereof (step S 528 ). To be more specific, the rent component  24  links the above-mentioned updated rent source license, the content key extracted from the above-mentioned update request message, transmission type ID “0x04” indicative of transmission type “update  2 ” denoting the transfer of the updated license, and component attribute ID “0x02” indicative of “use” that is the attribute of the rent component  24  itself, thereby creating an update transfer message.  
         [0471]     Further, the rent component  24  transmits the update transfer message thus created to the rent source storage component  11  (step S 530 ). In response, the rent source storage component  11  receives this update transfer message from the rent component  24 . Thus, in the update transfer message transmission processing (S 530 ), the rent component  24  is equivalent to the above-mentioned transmission source component  31  and the rent source storage component  11  is equivalent to the above-mentioned transmission destination component  32 .  
         [0472]     Then, the rent source storage component  11  checks the update transfer message received from the rent component  24  for validity (step S 532 ). This update transfer message verification processing checks if the transmission type ID extracted from the above-mentioned update transfer message is “0x04” indicative of transmission type “update  2 ” and the component attribute ID extracted from the above-mentioned update transfer message is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification described above with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned update transfer message is found valid as a result of the above-mentioned verification processing, then the rent source storage component  11  permits the storage of the license extracted from the above-mentioned update transfer message, upon which the procedure goes to step S 534 . On the other hand, if the above-mentioned update transfer message is found invalid, then the rent source storage component  11  prohibits the processing of that license, upon which the rent processing ends.  
         [0473]     Next, the rent source storage component  11  updates the rent source license stored in the rent source storage device (step S 534 ). To be more specific, the rent source storage component  11  writes the updated rent source license extracted from the above-mentioned update transfer message over the rent source license (the unupdated rent source license received in the above-mentioned update request message) stored in the rent source storage device (the HDD  111  for example).  
         [0474]     Further, in order to make a response to the above-mentioned update transfer message, the rent source storage component  11  creates an update completion message for the notification of the completion of the updating of the rent source license (step S 536 ). To be more specific, the rent source storage component  11  reads the updated rent source license and the content key thereof from the rent source storage device. Next, the rent source storage component  11  links the updated rent source license and its content key, transmission type ID “0x05” indicative of “update  3 ” that is a transmission type denoting the rent source license update completion notification, and component attribute ID “0x01” indicative of “storage” that is the attribute of the rent source storage component  11  itself, thereby creating an update completion message.  
         [0475]     Next, the rent source storage component  11  transmits the update completion message thus created to the rent component  24  (step S 538 ). In response, the rent component  24  receives the update completion message from the rent source storage component  11 . Thus, in the update completion message transmission processing (S 538 ), the rent source storage component  11  is equivalent to the above-mentioned transmission source component  31  and the rent component  24  is equivalent to the above-mentioned transmission destination component  32 .  
         [0476]     Then, the rent component  24  checks the update completion message received from the rent source storage component  11  for validity (step S 540 ). This update completion message verification checks if the transmission type ID extracted from the above-mentioned update completion message is “0x05” indicative of transmission type “update  3 ” and component attribute ID extracted from the above-mentioned update completion message is “0x01” indicative of component attribute “storage”. This verification processing is executed in substantially the same procedure as the message verification processing described above with reference to  FIG. 20 , so that the detail description thereof will be omitted. If the above-mentioned update completion message is found invalid as a result of this message verification, then, because the execution of the updating of the rent source license cannot be confirmed, the rent component  24  prohibited the renting of the content requested for rent, upon which the rent processing ends.  
         [0477]     On the other hand, if the above-mentioned update completion message is found valid, the rent component  24  creates a license for rent on the basis of the updated rent source license (step S 544 ).  
         [0478]     To be more specific, the rent component  24  extracts the license information description section  501  in which the content ID is written, the reproduction condition description section  521 , and the storage condition description section  511  from the updated rent source license to create the base for a license for rent. At this moment, if the extraction of the reproduction condition description section  521  or the storage condition description section  511  fails, then the rent processing ends. Next, the rent component  24  newly creates the rent condition description section  524  written with the return condition of the license for rent and additionally writes this rent condition description section  524  to the above-mentioned base of the license for rent, thereby providing a license for rent. Further, the rent component  24  adds the rent ID created in step S 524  to the return status of the rent condition description section  524 , upon which the creation of a license for rent is completed.  
         [0479]     Next, the rent component  24  creates a transfer message (a second message) for transferring the above-mentioned license for rent and the content key thereof (step S 546 ). To be more specific, the rent component  24  links the above-mentioned created license for rent, the content key extracted from the above-mentioned update completion message, transmission type ID “0x01” indicative of transmission type “transfer” and component attribute ID “0x02” indicative of “use” that is the attribute of the rent component  24  itself, thereby creating a transfer message.  
         [0480]     Further, the rent component  24  transmits the created transfer message to the rent destination storage component  12  (step S 546 ). In response, the rent destination storage component  12  receives the transfer message from the rent component  24 . Thus, in the transfer message transmission processing (S 546 ), the rent component  24  is equivalent to the above-mentioned transmission source component  31  and the rent destination storage component  12  is equivalent to the above-mentioned transmission destination component  32 .  
         [0481]     Then, the rent destination storage component  12  checks the transfer message received from the rent component  24  for validity (step S 548 ). This transfer message verification processing checks if the transmission type ID extracted from the above-mentioned transfer message is “0x01” indicative of transmission type “transfer” and the component attribute ID extracted from the above-mentioned transfer message is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification described above with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned transfer message is found valid as a result of the above-mentioned verification processing, then the rent destination storage component  12  permits the processing of the license for rent extracted from the above-mentioned transfer message, upon which the procedure goes to step S 534 . On the other hand, if the above-mentioned transfer message is found invalid, then the rent destination storage component  12  prohibits the processing of that license, upon which the rent processing ends.  
         [0482]     Next, the rent destination storage component  12  evaluates the license for rent extracted from the above-mentioned transfer message to determine whether this license for rent and content key may be stored in the second storage device (step S 550 ). In this license-for-rent evaluation processing, the rent destination storage component  12  evaluates the storage condition written to the storage condition description section  511  of that license for rent, thereby determining whether the storage condition is satisfied or not, as described before. In this storage condition evaluation processing, the storage condition such as storage count limit or storage time limit for example is evaluated and, as required, the storage status written to the storage condition description section  511  is referenced.  
         [0483]     If the storage condition is found dissatisfied as a result of this evaluation, then the rent destination storage component  12  prohibit the storage of the license for rent extracted from the above-mentioned transfer message, thereby executing a pause sequence.  
         [0484]     On the other hand, if the storage condition is found satisfied, the rent destination storage component  12  permits the storage of these license for rent and content key extracted from the above-mentioned transfer message and, as required, updates the storage status of that license for rent. To be more specific, in storage count control for example, the storage destination storage component  12  rewrites the storage status so as to increment the number of times storage has been made by one every time storage is permitted.  
         [0485]     Then, the storage destination storage component  12  writes the above-mentioned license for rent and content key permitted for storage to the above-mentioned rent destination storage device (step S 552 ).  
         [0486]     Thus, these license and content key requested for renting are rented from the rent source storage device (or the first storage device) to the rent destination storage device (or the second storage device). When the renting of the license and so on has been completed, the storage destination rent component  12  notifies the component management block  5  thereof (step S 554 ) for example. In response, the component management block  5  gives a content rent permission to the application  4  (step S 556 ).  
         [0487]     Consequently, in response to the notification of the permission of content renting received from the component management block  5 , the application  4  rents the above-mentioned content requested for renting from the rent source storage device to the rent destination storage device (step S 558 ). To be more specific, the application  4  reads that content from the rent source storage device and writes that content to the rent destination storage device.  
         [0488]     Thus, the processing flow of the license rent method according to the present embodiment has been described. According to this license rent method, a message including a license and a content ID may be transferred between the rent source storage component  11  and the rent destination storage component  12  and the rent component  24 , thereby preferably controlling the renting of the license and the corresponding content. At this moment, the message receiving component checks the received message for validity every time it is received, thereby preventing the illegal transmission of licenses and so on.  
         [0489]     In addition, the content and license formats, the transmission protocol of that license, and the basic functions of each component are standardized, so that licenses may be transferred in a portable manner between the user devices  10  having copyright management blocks  3  of different installations, thereby preferably controlling the renting of licenses and content. Especially, the present embodiment is advantageous that licenses and content may be preferably rented between physically remotely interconnected user devices  10  via the network  30  without dependent on the installations of the copyright management blocks  3  of these user devices  10 . Therefore, the novel configuration enhances the portability of content between user devices  10 , which in turn enhances the user convenience.  
         [0000]     &lt;13. License Return Method&gt; 
         [0490]     The following describes a license return method according to the present embodiment. In this license return method, in order to control the return of content between a plurality of storage devices, two storage components  11  and  12  and the return component  25  are used to delete a license for rent stored in the second storage device that is the rent destination and update a license for rent stored in the first storage device that is the rent source, thereby returning the license for rent to the first storage device. This return processing is equivalent to the check-in processing of SDMI.  
         [0491]     First, the outline of the license return method according to the present embodiment will be described with reference to  FIG. 33 .  FIG. 33  shows an outline of the license return method of returning licenses for rent between the two storage devices arranged in the PC  10   a  according to the present embodiment.  
         [0492]     As shown in  FIG. 33 , the PC  10   a  has the return component  25 , the storage component  11  (or a first storage component) for the HDD  111 , one example of the first storage device that is the rent source (or the return destination), and the storage component  12  (or a second storage component) for the removable storage medium  40 , one example of the second storage device that is rent destination (or the return source).  
         [0493]     The PC  10   a  thus configured transmits a transfer message from the rent destination storage component  12  to the return component  25  to delete the above-mentioned license for rent  308  from the removable storage medium  40  and transfers an update message between the rent source storage component  11  and the return component  25  to update the rent source license  307  stored in the rent source HDD  111 , thereby returning the license for rent  308  to the HDD  111 .  
         [0494]     To be more specific, first, the rent destination storage component  12  reads the license for rent  308  subject to return and the content key thereof from the removable storage medium  40  to create a transfer message (transmission type “transfer”, transmission source component attribute “storage”) and transmits the created transfer message to the return component  25 . At this moment, the storage component  12  deletes the license for rent  308  and the content key thereof from the removable storage medium  40 .  
         [0495]     On the other hand, the rent source storage component  11  reads the rent source license  307  and the content key thereof from the HDD  111  to create an update request message (transmission type “update  1 ”, transmission source component attribute “storage”) and transmits the created update request message to the return component  25 . It should be noted that the rent source license  307  corresponds to the above-mentioned license for rent  308  subject to return and the same rent ID is allocated to both the rent source license  307  and the license for rent  308  to relate them each other.  
         [0496]     Next, the return component  25  checks the transfer message received from the rent destination storage component  12  and the update request message received from the rent source storage component  11  to evaluate the license for rent  308  extracted from the transfer message, thereby determining whether the license for rent  308  and the content key thereof may be returned. If these license and content key are found returnable, then the return component  25  updates the rent status of the rent source license  307  extracted from the above-mentioned update request message to create an update transfer message (transmission type “update  2 ”, transmission source component attribute “use”) including the updated license and content key, thereby transmitting the created update transfer message to the rent source storage component  11 .  
         [0497]     Then, the rent source storage component  11  checks the update transfer message received from the return component  25  and then writes the updated rent source license  307  included in the update transfer message over the rent source license  307  stored in the HDD  111 .  
         [0498]     Thus, transferring an update message and a transfer message between the rent destination and rent source storage components  11  and  12  and the return component  25  allows the returning of the license for rent  308  and the content key thereof from the removable storage medium  40  that is the rent destination storage device to the HDD  111  that is the rent source storage device, thereby incrementing the rent count of the rent source license by one. It should be noted that the above-mentioned update request message is equivalent to the first message, the above-mentioned transfer message is equivalent to the second message, and the above-mentioned update transfer message is equivalent to the third message. Also, by matching the rent source license  307  against the license for rent  308  on the basis of the rent ID, the return component  25  is capable of returning licenses for rent to proper rent source storage devices.  
         [0499]     The following describes a processing flow of the license return method according to the present embodiment with reference to  FIGS. 34A and 34B .  FIGS. 34A and 34B  are timing charts indicative of the processing flow of this license return method.  
         [0500]     As shown in  FIGS. 34A and 34B , the application  4  receives a request for returning the user-specified content from the user (step S 602 ). Next, the application  4  extracts the content ID from a content file of the content requested for return (step S 604 ). Further, the application  4  transmits return control command information to the component management block  5  to control the return of the content requested for return, namely, the return of the license and content key thereof corresponding to that content (step S 606 ). This return control command information includes the above-mentioned content ID, use information indicative that content use is “return”, and information for specifying a content and license return source storage device (or the first storage device) and return destination storage device (or the second storage device), for example.  
         [0501]     Next, the component management block  5  determines a license processing component subject to load (or start up) on the basis of the above-mentioned return control command information received from the application  4 , for example (step S 608 ). For example, the component management block  5  determines, as the components subject to load, the return component  25 , the storage component  11  corresponding to the rent source storage device specified by the above-mentioned return control command information (hereafter referred to as a rent source storage component  11 ), and the storage component  12  corresponding to the rent destination storage device specified by that information (hereafter referred to as a rent destination storage component  12 ). It should be noted that, in this processing of determining components subject to load, the component management block  5  may also search, by the content ID, for the storage components storing the license and content key thereof corresponding to the content requested for return in the substantially the same procedure as steps S 108  through S 114  shown in  FIG. 23  for example, thereby determining the components subject to load.  
         [0502]     Further, the component management block  5  gives a load command to the storage components  11  and  12  and rent component  25  determined as the components subject to load, thereby starting up these components (step S 610 ). Consequently, the rent source storage component  11  and the return component  25  and the return component  25  and the rent destination storage component  12  cross authenticate each other, thereby forming a secure communication route, SAC for example, between these components (step S 612 ).  
         [0503]     In addition, the component management block  5  transmits a first message creation command to the rent destination storage component  12  to create a transfer message (step S 614 ). To be more specific, this first message creation command is affected by transmitting the content ID received from the application  4  and transmission type specification information to the rent destination storage component  12 . In this step, the transfer for returning a license for rent is instructed, so that the above-mentioned transmission type specification information is indicative of transmission type “transfer”. This first message creation command allows the component management block  5  to instruct the rent destination storage component  12  to transmit the master copy of the rent source license corresponding to the above-mentioned content ID to the rent component  25 .  
         [0504]     Next, in response to the above-mentioned message creation command, the rent destination storage component  12  creates a transfer message (or a second message) for transferring the rent source license and content key thereof corresponding to the above-mentioned content ID (step S 616 ). To be more specific, the rent destination storage component  12  reads the license for rent and content key thereof corresponding to the above-mentioned content ID from the rent source storage device (the removable storage medium  40  for example) corresponding to itself. Further, the rent destination storage component  12  links these license for rent and content key thus read, transmission type ID “0x01” indicative of “transfer” that is the transmission type specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the rent destination storage component  12  itself, thereby creating a transfer message.  
         [0505]     Further, the rent destination storage component  12  invalidates (or deletes) the above-mentioned license for rent and content key thereof stored in the rent destination storage device (step S 618 ). Thus, invalidating the license and so on stored in the rent destination storage device before transmitting the transfer message in next step S 620  may prevent an unauthorized user for example from interfering the license invalidation processing by illegal measures after the transmission of the transfer message, as a result of which the license and so on exist in the rent destination storage device.  
         [0506]     Then, the rent destination storage component  12  transmits the transfer message created in step S 616  to the return component  25  (step S 620 ). In response, the return component  25  receives this transfer message from the rent destination storage component  12 . Thus, in the transfer message transmission processing (S 620 ), the rent destination storage component  12  is equivalent to the above-mentioned transmission source component  31  and the return component  25  is equivalent to the above-mentioned transmission destination component  32 .  
         [0507]     Next, the return component  25  checks the transfer message received from the rent destination storage component  12  for validity (step S 622 ). This transfer message verification processing checks if transmission type ID extracted from the above-mentioned transfer message is “0x01” indicative of transmission type “transfer” and component attribute ID extracted from the above-mentioned transfer message is “0x01” indicative of component attribute “storage”. This verification is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , so that detail description thereof will be omitted. If the above-mentioned transfer message is found valid as a result of the above-mentioned verification processing, then the return component  25  permits the processing of the license for rent extracted from the transfer message, upon which the procedure goes to step S 624 . In this case, the return component  25  may notify the component management block  5  of the completion of the return of the license for rent, for example. On the other hand, if the transfer message is found invalid, then the return component  25  prohibits the processing of this license for rent, upon which the return processing ends.  
         [0508]     Further, the return component  25  evaluates the license for rent extracted from the above-mentioned transfer message to determine whether the license for rent and the content key thereof are returnable (step S 632 ). In this license evaluation processing, the return component  25  evaluates the return condition written to the return condition description section  525  of that license for return to determine whether the return condition is satisfied. In this determination, the return condition such as return time limit is checked and, as required, the return status written to the return condition description section  525  is referenced.  
         [0509]     If the return condition is found dissatisfied as a result of the above-mentioned evaluation, then the return component  25  prohibits the return of the license for rent and content key thereof extracted from the above-mentioned transfer message, thereby executing a pause sequence. On the other hand, if the return condition is sound satisfied, the return component  25  permits the returning of the license for rent and the content key thereof extracted from the above-mentioned transfer message, upon which the procedure goes to step S 626 .  
         [0510]     Next, the component management block  5  gives a second message creation command to the rent source storage component  11  to create an update request message (step S 626 ). To be more specific, this second message creation command is affected by transmitting the content ID received from the application  4  and transmission type specification information to the rent source storage component  11 . In this step, the transmission involving the update of a rent source license is instructed, so that the above-mentioned transmission type specification information is transmission type “update  1 ”. This second message creation command allows the component management block  5  to instruct the rent source storage component  11  to transmit a copy of the rent source license corresponding to the above-mentioned content ID to the return component  25 .  
         [0511]     Further, in response to the second message creation command, the rent source storage component  11  creates an update request message (or a first message) for transmitting the rent source license and content key thereof corresponding to the above-mentioned content ID (step S 628 ). To be more specific, the rent source storage component  11  reads the rent source license and content key thereof corresponding to the above-mentioned content ID from the rent source storage device corresponding to itself (the HDD  111  for example). In addition, the rent source storage component  11  links the rent source license and content key thus read, transmission type ID “0x03” indicative of transmission type “update  1 ” specified by the component management block  5 , and component attribute ID “0x01” indicative of “storage” that is the attribute of the rent source storage component  11  itself, thereby creating an update request message.  
         [0512]     Then, the rent source storage component  11  transmits the update request message created in step S 628  to the return component  25  (step S 630 ). In response, the return component  25  receives the above-mentioned update request message from the rent source storage component  11 . Thus, in the transmission of the update request message (S 630 ), the rent source storage component  11  is equivalent to the transmission source component  31  and the return component  25  is equivalent to the transmission destination component  32 .  
         [0513]     Next, the return component  25  checks the update request message received from the rent source storage component  11  for validity (step S 632 ). This update request message verification checks if the transmission type ID extracted from the above-mentioned update request message is “0x03” indicative of transmission type “update  1 ” and the component attribute ID extracted from the above-mentioned update request message is “0x01” indicative of component attribute “storage”. Because this verification is executed in substantially the same procedure as the message verification processing described with reference to  FIG. 20 , detail description of the verification processing will be omitted. If the above-mentioned update request message is found valid as a result of the above-mentioned message verification, then the return component  25  permits the processing of the rent source license extracted from the above-mentioned update request message, upon which the procedure goes to step S 622 . On the other hand, if the update request message is found invalid, the return component  25  prohibits the processing of this license, upon which the return processing ends.  
         [0514]     It should be noted that, in the example of the processing flow shown in  FIGS. 34A and 34B , steps S 614  through S 624  are executed before steps S 626  through S 632 ; it is also practicable to execute steps S 614  through S 624  after steps S 626  through S 632 , for example.  
         [0515]     Next, the return component  25  matches the rent ID written to the return condition description section  525  of the above-mentioned license for rent against the rent ID written to the rent condition description section  524  of the above-mentioned rent source license to see if there is a match between both the IDs (step S 634 ). If a match is found, the return processing continues, the procedure going to step S 636 . On the other hand, if a mismatch is found, the return processing is paused. This rent ID matching processing allows the prevention of erroneous return processing from being executed if the license for rent does not correspond to the rent source license.  
         [0516]     Further, in response to the above-mentioned rent source license return permission, the return component  25  updates the rent status of the rent out license (step S 636 ). To be more specific, the return component  25  deletes the rent ID written to the rent status of the rent source license. If rent count control is executed, the return component  25  rewrites the rent status so as to decrement the number of times rent has been made by one (or increment the rentable count by one), which is written to the rent status of the rent source license.  
         [0517]     Next, in order to respond to the above-mentioned update request message, the return component  25  creates an update transmission message (or a third message) for transmitting the rent license with the rent status updated in step S 636  (hereafter referred to as an updated rent source license) and the content key thereof (step S 638 ). To be more specific, links the above-mentioned updated rent source license, the content key extracted from the above-mentioned update request message, transmission type ID “0x04” indicative of transmission type “update  2 ” denoting the transfer of an updated license, and component attribute ID “0x02” indicative of “use” that is the attribute of the return component  25  itself, thereby creating an update transfer message.  
         [0518]     Further, the return component  25  transmits the update transfer message thus created to the rent source storage component  11  (step S 640 ). In response, the rent source storage component  11  receives the above-mentioned update transfer message from the return component  25 . Thus, in the update transfer message transmission processing (S 640 ), the return component  25  is equivalent to the transmission source component  31  and the rent source storage component  11  is equivalent to the transmission destination component  32 .  
         [0519]     Next, the rent source storage component  11  checks the update transfer message received from the return component  25  for validity (step S 642 ). This update transfer message verification checks if the transmission type ID extracted from the above-mentioned update transfer message is “0x04” indicative of transmission type “update  2 ” and component attribute ID extracted from the above-mentioned update transfer message is “0x02” indicative of component attribute “use”. This verification processing is executed in substantially the same procedure as the message verification processing described above with reference to  FIG. 20 , so that the detail description thereof will be omitted. If the above-mentioned update transfer message is found valid as a result of this message verification, then the rent source storage component  11  permits the storage of the updated rent source license extracted from the above-mentioned update transfer message and the procedure goes to step S 644 . On the other hand, if the update transfer message is found invalid, then the rent source storage component  11  prohibits the processing of the updated rent source license, upon which the return processing ends.  
         [0520]     Next, the rent source storage component  11  updates the rent source license stored in the rent source storage device (step S 644 ). To be more specific, the storage component  11  writes the updated rent source license extracted from the above-mentioned update transfer message over the rent source license (the unupdated rent source license received in the above-mentioned update request message) stored in the rent source storage device (the HDD  111  for example). It should be noted that, in the example of the return processing flow shown in  FIG. 34 , the rent source storage component  11  does not transmit an update completion message to the return component  25  in response to the update transfer message; but it is also practicable that the rent source storage component  11  returns an update completion message.  
         [0521]     Thus, the license for rent requested for return and content key thereof are returned from the rent destination storage device (the second storage device) to the rent source storage device (the first storage device) When the return of the license and so on has been completed, the rent source storage component  11  transmits a return completion notification to the component management block  5  (step S 646 ), for example. In response to this return completion notification, the component management block  5  notifies the application  4  of the return permission of content (step S 648 ).  
         [0522]     Consequently, in response to the notification of content return permission received from the component management block  5 , the application  4  returns the above-mentioned content requested for return from the rent destination storage device to the rent source storage device (step S 650 ). To be more specific, the application  4  deletes the above-mentioned content from the rent destination storage device.  
         [0523]     Thus, the processing flow of the license return method according to the present embodiment has been described. According to this license return method, messages including a license and a content ID may be transferred between the rent source and rent destination storage components  11  and  12  and the return component  25  to preferably control the returning of these license and content. At this moment, the message receiving component checks each received message for validity every time it is received, thereby preventing the illegal transmission of licenses and so on.  
         [0524]     In addition, the content and license formats, the transmission protocol of that license, and the basic functions of each component are standardized, so that licenses may be transferred in a portable manner between the user devices  10  having copyright management blocks  3  of different installations, thereby preferably controlling the renting of licenses and content. Especially, the present embodiment is advantageous that licenses and content may be preferably rented between physically remotely interconnected user devices  10  via the network  30  without dependent on the installations of the copyright management blocks  3  of these user devices  10 . Therefore, the novel configuration enhances the portability of content between user devices  10 , which in turn enhances the user convenience.  
         [0525]     Thus, the copyright management system, components thereof, and operation methods thereof according to the present embodiment of the invention have been described in detail. According to this copyright management system, at least the storage component  1  and the at least the use component  2  among the license processing components proving the basic functions of the copyright management block may be combined to transfer licenses in between, thereby executing the restriction in use fro each use case. Also, each license is written with a use condition for each use case in a divided manner and the description of the use condition is standardized. This novel configuration allows the transfer of these licenses between a plurality of license processing components in a portable manner interconnected via the network  30 . Consequently, the components for executing content use control may be arranged, in a distributed manner, on a plurality of user devices  10  interconnected via the network  30 .  
         [0526]     In the security of content keys, a content key security standard is described in each license in advance. Each content key is convertibly distributed within a scope of this standard, regardless of the type of installation of the copyright management block. This configuration allows the interconnection of a plurality of copyright management systems having different installations of the copyright management block  3  via the network  30 , thereby transferring licenses and content between these copyright management systems in a portable manner to execute copyright management. Consequently, user convenience and the degree of freedom of content user may be enhanced, thereby promoting the popularization of the copyright management system according to the present embodiment.  
         [0527]     While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purpose only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.  
         [0528]     For example, in the above-mentioned embodiment, the transmission type attribute information, the transmission source component attribute information, and the license and content key thereof are transmitted at the same time in one message. It is also practicable that these pieces of information and the license and content key thereof may be transmitted at different times as far as there are related with each in some manner. Also, the content key may not always be transmitted along with its license.  
         [0529]     The use component  2  is not restricted to the above-mentioned examples of the reproduction component. For example, the use component  2  may be a divide component for controlling the dividing of content, a combine component for controlling the combining of content, a convert component for controlling the converting of a license by use of a content key, or an export component for outputting a license in accordance with another copyright management scheme or another storage scheme.  
         [0530]     The above-mentioned embodiment of the present invention is applicable to a copyright management system that controls content use on the basis of licenses and, more particularly, to a copyright management system that allows the portable transfer of content between a plurality of user devices having different installations of copyright management blocks.  
         [0531]     While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purpose only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.