Abstract:
A method and apparatus for management and transmission of a classified conditional access application to provide Downloadable Conditional Access System (DCAS) service according to disclosed embodiments is an effective managing method according to a type of a conditional access module in a software version in the DCAS. In particular, it relates to a method and apparatus which can continuously provide Pay per View (PPV) service during movement in a DCAS service operator (SO) network, such as maintaining independence of CAS SO in DCAS, provide adaptability to adapt to a variety of policies of the SO, and install an optimum application in a terminal.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2007-0127979, filed on Dec. 11, 2007, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for providing Downloadable Conditional Access System (DCAS) service and managing the same. In particular the present invention relates to a method and apparatus for management and transmission of a classified conditional access application to provide DCAS service. 
     This work was supported by the IT R&amp;D program of MIC/IITA [2007-S-007-01, The Development of Downloadable Conditional Access System]. 
     2. Description of Related Art 
     A Conditional Access System (CAS) is a system that assigns authority to watch fee-based broadcast to only authenticated subscribers. A terminal of the CAS has functions of managing a conditional access key and decoding accessed signal encoded by the conditional access key so as to watch the accessed signal, and the function is referred to as a conditional access module. In a conventional CAS applied to a digital cable broadcast, a conditional access module has been implemented in a cable card form. However, as problems of high cost and inefficient management ability of the cable card is raised, a Downloadable Conditional Access System (DCAS) is suggested. The DCAS safely downloads the conditional access application, namely, conditional access module implemented in software form to an authenticated subscriber terminal, thereby supporting a conditional access service to subscribers and assigning authority to remotely configure or reset a conditional access method to a service operator. 
     Accordingly, the conditional access module of the conventional CAS that is provided off-line is required to be stored in the DCAS, and also an effective method that can safely download a stored conditional access module to an authenticated terminal is required. That is, an effective storage and transmission method according to a feature of a conditional access application. 
     Also, the conventional CAS operates in an integrated environment system where a series of functions required to perform the CAS are closely combined with a CAS service operator, such as setting up conditional access module for a terminal, registering a subscriber, paying for fee-based broadcast, and assigning authorization to view a fee-based broadcast. 
     However, the DCAS manages a conditional access module received from a CAS service provider and downloads the conditional access module to an authenticated terminal, and registers the terminal as a subscriber. Then, the CAS provider performs a subscribing and payment process for the fee-based broadcast, and assigns authorization to view a fee-based broadcast. In this case, the CAS service operator is required to minimize an interface with the DCAS to have security and autonomy. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a method which can improve a problem of a conventional art. A Downloadable Conditional Access System (DCAS) manages a conditional access module received from a CAS service provider. In this case, the CAS service provider is required to minimize an interface with the DCAS to have security and autonomy. 
     Another aspect of the present invention also provides an effective application management method which can store a conditional access application and transmit the same to a plurality of terminals so as to provide adaptability to adapt to a variety of policies of an operator. Because the conditional access application which is a conditional access module based on software should be suitable for a variety of operation environments such as software- or hardware-based terminals, and the like. At the same time, the conditional access application should have an ability to adapt to different conditional access key for charged service depending on a terminal. 
     According to an aspect of the present invention, there is provided a method of controlling DCAS Provisioning System (DPS) including: accessing conditional access application and information for conditional access service; storing the accessed conditional access application in an Integrated Personalization Server (IPS); and providing an Authentication Proxy (AP) with IPS connection information (IPS_Connect_Info) and the conditional access application information to be transmitted to a terminal. 
     According to an aspect of the present invention, there is provided a method of controlling an AP including: performing mutual authentication with respect to a terminal; obtaining information for an identifier and configuration environment of the authenticated terminal; and providing the authenticated terminal with IPS_Connect_Info and setup information to download a conditional access application. 
     According to an aspect of the present invention, there is provided a method of controlling a terminal of DCAS including: performing a series of authentication processes with an AP; being provided with IPS_Connect_Info and setup information according to the authentication; and downloading application from an IPS according to the provided information to implement the application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects of the present invention will become apparent and more readily appreciated from the following detailed description of certain exemplary embodiments of the invention, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  illustrates a configuration of a Downloadable Conditional Access System (DCAS) and downloading process of a conditional access application according to an example embodiment of the present invention; 
         FIG. 2  illustrates classified types of conditional access applications according to an example embodiment of the present invention; 
         FIG. 3  is a flowchart illustrating an identifying process of a conditional access image file to be transmitted from an Authentication Proxy (AP) to an authenticated terminal according to an example embodiment of the present invention; and 
         FIG. 4  illustrates a downloading process of a conditional access application to verify a network movement charged subscriber and to support a Pay per View (PPV) service according to an example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below in order to explain the present invention by referring to the figures. 
     When detailed descriptions related to a well-known related function or configuration are determined to make the spirits of the present invention ambiguous, the detailed descriptions will be omitted herein. Also, terms used throughout the present specification are used to appropriately describe exemplary embodiments of the present invention, and thus may be different depending upon a user and an operator&#39;s intention, or practices of application fields of the present invention. Therefore, the terms must be defined based on descriptions made through the present invention. 
       FIG. 1  illustrates a configuration of DCAS and downloading process of a conditional access application according to an example embodiment of the present invention. 
     The DCAS and downloading process of the conditional access application according to an example embodiment of the present invention is described below referring to  FIG. 1 . 
     As shown in  FIG. 1 , the DCAS system includes a CAS service  110 , a DPS  120  that plays role of a manager, an AP  130  that plays a role of a window of a server and an authentication server with respect to a terminal, and an IPS  140  that plays a role of a transmitting server of the CAS. An example embodiment with respect to the above is as follows. 
     The CAS server  110  provides the DPS  120  with a conditional access application and relevant information in operation S 101 , then the DPS  120  that receives the conditional access application and relevant information stores the accessed conditional access application in an IPS  140  in operation S 102 , and provides the AP  130  with either IPS_Connect_Info or the conditional access application to be transmitted to a terminal. 
     After that, the AP  130  goes through a series of authentication process with respect to the terminal in operation S 104 , and provides the terminal with IPS_Connect_Info and setup information to download a conditional access application in operation S 105 . 
     According to the providing of the IPS_Connect_Info and setup information, the terminal downloads the conditional access application from the IPS  140  and sets up and implements the conditional access application according to indication previously provided by the AP  130 , thereby starting the conditional access service in operation S 106 . 
     In this case, in operation S 101 , the CAS server  110  provides the DPS  120  of the DCAS with an image file of a Conditional Access Application (CA Image file) that is required to be set up in a terminal to provide conditional access service. In this case, the CAS server  110  also provides image file type information, setup information, and an operation environment of the subject terminal together with unique information for a terminal that subscribes and pays for a fee-based broadcast. Information that server  110  provides to the DPS  120  is as shown in &lt;Table 1&gt;. 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Field_Name 
                 Description 
               
               
                   
               
             
             
               
                 CA Image_Id 
                 CA Image Identifier 
               
               
                 CA Image_Type 
                 Default|Common|Individual 
               
               
                 Target_Host_Conf 
                 s/w version and h/w version of a terminal 
               
               
                 Target_Host_Id 
                 Identifier of a subscriber terminal of fee-based 
               
               
                   
                 broadcast, being effective when a CA 
               
               
                   
                 Image_Type is individual. 
               
               
                 CA 
                 version, size, directory configuration, setup 
               
               
                 Image_Code_Metadata 
                 information, and Bound_Sub_CA Image_Id 
               
               
                   
                 of CA Image Code 
               
               
                 CA Image_Code 
                 Binary image code 
               
               
                   
               
             
          
         
       
     
       FIG. 2  illustrates classified types of conditional access applications according to an example embodiment of the present invention. 
     The conditional access application according to an example embodiment of the present invention is described below referring to  FIG. 2 . 
     As shown in  FIG. 2 , the conditional access application is classified as Default Conditional Access Application Image (Default CA Image)  201 , Common Conditional Access Application Image (Common CA Image)  202 , and Individual Conditional Access Application Image (Individual CA Image)  203  according to unique information based on a level of a terminal. 
     The Default CA Image  201  may universally be installed in each terminal including a terminal with the lowest capability and may generally include a description engine. The Common CA Image  202  is separately installed according to configuration information of a terminal, such as software-based or hardware-based. 
     A CAS  110  generates the Common CA Image  202  every time a possible terminal configuration is generated, and transmits the Common CA Image  202  to a DPS  120 . Terminal configuration information of the Default CA Image  201  is the same as that of the Common CA Image  202  which has the lowest capability. The Default CA Image  201  and the Common CA Image  202  represent access qualification of a terminal authenticated by a Service Operator (SO). 
     The Individual CA Image  203  may include unique conditional access key information for a terminal that pays for charged conditional access broadcast to watch the same. 
     Upon completion of subscribing and paying for the fee-based broadcast, the CAS server  110  generates the Individual CA Image  203  and transmits the same to the DPS  120 . 
     A type of the conditional access application may be implemented as a binary patch type or a separate CA Image type that provides service by performing a one-time download. That is, the Common CA Image  202  may be implemented as a patch type with respect to the Default CA Image  201  and an Individual CA Image  203  may be implemented as a patch type with respect to the Common CA Image  202 . In this case, a subordinate image patched in a Bound_Sub_CA Image_Id of CA Image_Code_Metadata is required to be marked. 
     The CAS server  110  may provide either all of the three types of conditional access applications or a portion of the three types of the conditional access applications. For example, when the CAS server  110  is reluctant to distributed conditional access key information through the DCAS, the CAS server  110  may merely provide the Default CA Image  201  or the Common CA Image  202 . 
     Whether the conditional access application is implemented as a binary patch or which type of conditional access applications is supported is flexibly determined depending on policy of a CAS SO and the DCAS. 
     The DPS  120  stores a conditional access image file in the IPS  140  in operation S 102 . In this case, a storage mechanism (1 copy, n copy) and delivery mechanism (broadcast/multicast/unicast, DSM-CC/TFTP/HTTP) that is suitable for a type of the conditional access image file are selected according to policy of the DCAS, and also stored in the corresponding IPS  140  by designating the same storage mechanism and delivery mechanism. For example, the Default CA Image  201  may be multicasted or unicasted to every terminal and the unicast method may be selected for the Individual CA Image  203 . 
     In operation S 103 , the IPS  140  provides the DPS  120  with IPS_Connect_Info which includes location information where the conditional access application is actually stored. 
     The DPS  120  manages the IPS_Connect_Info and an indicator (IPS_Id) of the IPS  140  where each conditional access image file is stored. Also, the DPS  120  manages a list of charged subscribers where the Individual CA Image  203  is set up. 
     In operation S 104 , the DPS  120  provides the AP  130  with the IPS_Connect_Info to be transmitted to the authenticated terminal, information (CA Image_Code_Metadata) that is required to set up the conditional access image file and the indicator (Assigned_IPS_Id) of the IPS  140  where the conditional access application image file is stored. Also the DPS  120  provides charged subscriber terminal information which the AP  130  is in charge of. 
     In operation S 105 , the AP  130  goes through an authentication process with respect to the terminal and obtains information for an identifier and configuration environment of the authenticated terminal. 
     Information that the DPS  120  provides to the AP  130  is as shown in Table 2. 
     
       
         
               
               
               
             
               
               
               
               
             
               
               
             
               
               
               
             
               
               
               
               
             
               
               
             
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Field_Name 
                 Description 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 CA 
                 CA Image_Table 1   
                 CA Image_Id 
                 CA Image Identifier 
               
               
                 Image 
                   
                 Target_Host_Conf 
                 s/w version and h/w version 
               
               
                 List 
                   
                   
                 of a terminal 
               
               
                   
                   
                 Assigned_IPS_Id 
                 Delivery_mechanism 
               
               
                   
                   
                   
                 (DSM- 
               
               
                   
                   
                   
                 CC|TFTP|HTTP| . . . ) 
               
               
                   
                   
                   
                 IPS_Connect_Info 
               
               
                   
                   
                   
                 (URI = server address + 
               
               
                   
                   
                   
                 location of folder + file 
               
               
                   
                   
                   
                 name) 
               
               
                   
                   
                 CA 
                 version, size, directory 
               
               
                   
                   
                 Image_Code_Methadata 
                 configuration, setup 
               
               
                   
                   
                   
                 information, and 
               
               
                   
                   
                   
                 Bound_Sub_CA Image_Id 
               
               
                   
                   
                   
                 of CA Image Code 
               
             
          
           
               
                   
                 . . . 
               
             
          
           
               
                   
                 CA Image_Table n   
                 . . . 
               
             
          
           
               
                 Charged 
                 Subscriber_Info 1   
                 CA Image 
                 CA Image Identifier 
               
               
                 Subscriber 
                   
                 Target_Host_Id 
                 Subscriber terminal 
               
               
                 List 
                   
                   
                 Identifier 
               
             
          
           
               
                   
                 . . . 
               
             
          
           
               
                   
                 Subscriber_Info n   
               
               
                   
                   
               
             
          
         
       
     
     Also, in operation S 106 , the AP  130  transmits DownloadInfo DCAS message to the authenticated terminal, the DownloadInfo DCAS message includes the IPS_Connect_Info and the image file set up information (CA Image_Code_Methdata) to download the conditional access image. In this case, a process illustrated in  FIG. 3  is performed to determine a conditional access image that is suitable for the authenticated terminal. 
       FIG. 3  is a flowchart illustrating an identifying process of a conditional access image file to be transmitted from an AP to an authenticated terminal according to an example embodiment of the present invention. 
     The AP  130  identifies the authenticated terminal identifier in operation S 301 , and then verifies whether the terminal is a charged subscriber in operation S 302 . 
     When the terminal is included in a charged subscriber list as a result of the verification, an Individual CA Image having CA Image_ID corresponding to the subscriber terminal is identified and its relevant information is transmitted to the terminal. That is, when the terminal is a charged subscriber, an individual image identifier corresponding to the terminal and image information corresponding to the corresponding image identifier (IPS_Connect_Info and setup information) are identified in operation S 303  and S 304 , and the image information is provided to the terminal in operation S 305 . Also, an IPS corresponding to the corresponding image identifier is commanded to perform a download in operation S 306 , thereby completing the process. 
     However, when the authenticated terminal is not a subscriber, configuration information of the authenticated terminal is checked in operation S 307 , and a common or default image identifier corresponding to the terminal is identified in operation S 308 . In this case, when the terminal has the lowest capability, a Default CA Image  201  is selected, and when the terminal is different from the lowest specifications, a Common CA Image  202  corresponding to the configuration of the terminal is selected and its relevant information is transmitted to the terminal. 
     After identification of the identifier, a purchasing report message from the terminal is requested in operation S 309 . When the purchasing report message having a purchasing record is received and the terminal is identified as a subscriber terminal from a DPS, in operation S 310  it is determined whether the terminal is a subscriber that has been subscribing and paying for a previous network and thus, operations S 303  through S 306  is processed, otherwise, the process is ended. 
       FIG. 4  illustrates downloading process of a conditional access application to verify a network movement charged subscriber and to support a Pay per View (PPV) service according to an example embodiment of the present invention. 
     The downloading process of the conditional access application to verify the network movement charged subscriber and to support the PPV service according to an example embodiment of the present invention is described below referring to  FIG. 4 . 
     As shown in  FIG. 4 , the present invention may support to maintain fee-based broadcasting viewing authority even when a terminal moves between AP networks of the same DCAS service operator. When the terminal that has been connected to an AP 1   131  and receiving fee-based broadcast tries to connect to an AP 2   132  and to receive authentication, although the terminal is a subscriber, information of the terminal may be missing in charged subscriber information of the currently connected AP 2   132 . To overcome the limit, the AP 2   132  verifies whether purchasing record exists and also verifies, from a DPS  120 , whether a terminal which reports that there is a purchasing record is included in a complete charged subscriber list of the DCAS, even when it is determined that a common or default type of a conditional access image is stored in the terminal. When the terminal is verified as a charged subscriber terminal of another AP, charged subscriber information of the terminal is renewed and the terminal is managed so that the terminal can maintain charged-viewing with the existing charged subscriber information. As described above, when the terminal is a fee-based broadcasting subscriber, the present invention supports to use the same CAS even after the terminal&#39;s movement within the network. 
     To perform the above-mentioned process, after the terminal completes subscribing and paying for the fee-based broadcast in operation S 401 , a CAS server  110  provides the DPS  120  with Individual CA Image and relevant information in operation S 402 . 
     After the providing of the DPS  120  with Individual CA Image and the relevant information, the DPS  120  provides an IPS  140  with the Individual CA Image in operation S 403 , receives IPS_Connect_Info in operation S 404 , and provides the AP 1   113  with setup and download information of the Individual CA Image for the terminal that completes paying in operation S 405 . 
     In operation S 406 , the AP 1   131  that receives the information performs mutual authentication with respect to the subscriber terminal of an existing network that completes paying. After mutual authentication, the IPS  140  and CA Image relevant information (Download Info DCAS message) is provided to the terminal in operation S 407 , at the same time, the IPS  140  is commanded to transmit image in operation S 408 . Thereafter, the Individual CA Image may be downloaded from the IPS  140  in operation  409 , and the Individual CA Image is installed in the terminal in operation S 410 . 
     According to the above-mentioned process, when a terminal that has been using a variety of service of DCAS Network  1  moves to a DCAS network  2  of the same DCAS service operator, mutual authentication between the terminal and a new AP 2  is performed in operation S 421  as in operation S 406 . After the authentication, the AP 2  provides the new terminal in the new network with the IPS  140  and CA Image relevant information (DownloadInfo DCAS message) to download a Common CA Image in operation S 422 . After the AP 2  transmits a transmission command to the IPS  140 , the Common CA Image (DownloadCommon DCAS meg.) is downloaded from the IPS  140  in operation S 424 . Then, a purchasing report message is provided to verify whether the terminal is a subscriber of an existing network in operation S 425 . According to the purchasing report message, whether the terminal is a charged subscriber that moves from another DCAS Network in operation S 426  is verified, and the IPS  140  and CA Image relevant information is provided to download an Individual CA Image in operation S 427 . The AP 2  command the IPS  140  to transmit a new Individual CA Image in operation S 258 , the terminal performs a download of a suitable Individual CA Image for the DCAS Network  2  in operation S 259 . Through the above operations S 421  to S 429 , the existing terminal subscriber that moves to a new network can maintain Individual CA Image and fee-based broadcasting viewing authority. Also, continuous service is provided to the existing terminal subscriber. Where change of an Individual CA Image code caused by DCAS Network movement is not required, operations S 428  through S 429  may be omitted. 
     The method for management and transmission of a classified conditional access application to provide DCAS service according to example embodiments may be recorded in computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The media and program instructions may be those specially designed and constructed for the purposes of example embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape: optical media such as CD ROM disks and DVD; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of example embodiments. 
     Although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.