KR20080024957A - System for digital contents management and method for providing of drm contents - Google Patents

Abstract

A digital contents management system and a DRM(Digital Rights Management) contents providing method are provided to share copy control information of DRM contents between different DRM systems, maintain a watermark embedded in the DRM contents and embed a new sharable watermark to the DRM contents so as to efficiently apply a watermark to the DRM contents between the different DRM systems. A digital contents management system(200) includes a rights manager(220) and a watermark processor(210). The rights manager confirms copy control information of DRM contents and determines whether the DRAM contents are provided to another system when an object to which the DRM contents are provided is a recordable medium. The watermark processor confirms whether the DRM contents include a watermark and embeds the watermark in the DRM contents when the rights manager determines that the DRM contents are provided to another system.

Description

System for digital contents management and method for providing of DRM contents}

FIG. 1 is a block diagram illustrating a relationship between a plurality of RMB systems providing RDM contents and a RDM device in a domain using RDM contents.

FIG. 2 is a block diagram briefly illustrating an example of a process of receiving DL content from one DLM system in FIG. 1 and interoperating the same with another DL system.

3 is a block diagram showing the configuration of a digital content management system according to an embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a RDM conversion server for converting a RM content having a watermark inserted into a different RM in FIG. 3.

FIG. 5 is a flowchart illustrating a method of providing a DM content to determine whether to provide a DM content by checking copy control information (CCI) of the DM content.

FIG. 6 is a flowchart illustrating a method of providing a DM content that checks a watermark included in the DM content and inserts and provides a new watermark.

<Description of Symbols for Main Parts of Drawings>

10: domain

20: DRM-A System

30: DRM-B system

40: mutual compatibility system

200: digital content management system

210: watermark processor

220: authority management unit

230: CCI Management Department

240: DRM conversion server

The present invention relates to a digital content management system and a method for providing a DM content. More particularly, the present invention relates to a digital content management system using a watermark included in a copy control information (CCI) of a DM content and a water content included in a DM content. The present invention relates to a digital content management system and a method for providing a DM content that can organically manage usage rights of a DM content.

Recently, with the development of information and communication technology, analog media have been digitized, and the digitized contents can be easily distributed through the information communication network. Such digital contents are illegal and unlimited to copy and edit, and the distribution of illegal digital contents is also easy. Accordingly, digital content protection technology has been developed that can restrict illegal copying, editing and distribution of digital content.

Digital content protection technologies include copyright tracking technologies such as Digital Object Identifier (DOI), Watermark, Index (INDECS), and Digital Rights Management (DRM). And copyright management technologies.

DRM (DRM) is a technology that prevents illegal copying, editing, and distribution of digital contents by using encryption techniques and manages the digital contents to be used only by legitimate users. In other words, DRM is a comprehensive digital rights management that includes packaging of content, delivery of content, payment for use of content, monitoring of content, and personalization of content. Configure the system (Digital Rights Management System).

Service providers that provide digital content in such a DRM system adopt a specific DRM during the packaging of the content to encrypt and protect their digital content with DRM content. In addition, the service provider monitors and manages the use status of the DRM content of the user, and the copy control information (CCI) indicating the restriction that the user can copy the DRM content to another device and use the DRM content with the DRM content. To the user together. Therefore, the user can copy and use the DRM content to another device only for the number of copies that can be included in the copy control information.

Meanwhile, watermark is a technique of inserting a bit pattern into digital images, audio, and video files so that copyright information can be identified in order to track illegal copying, forgery, and forgery of digital content. Watermarks are robust watermarks that do not disappear by various variations depending on their utilization, and fragile watermarks that easily disappear by slight variations. Robust watermarks are used as evidence for claiming ownership because they are not lost by many variations of digital content. Soft watermarks, on the other hand, are used to prevent forgery or tampering of digital content because they are easily lost by minor modifications.

In this way, by combining DRM, which prevents illegal copying and editing of digital content, and a watermark that can track illegal copying and forgery of digital content afterwards, the digital content can be protected more securely. do.

However, since the DRM schemes are very diverse and the service providers adopt different DRM schemes, researches on interoperability systems capable of interoperating heterogeneous DRMs have been actively conducted in recent years. Accordingly, there is a need for a technology capable of retaining and embedding a watermark in an interoperable system, as well as a technique of incorporating a watermark into a DRM. In addition, there is a need for a technique for organically managing copy control information (CCI) between different DRM systems in an interoperable system in order to monitor and manage a user's use of DRM content.

Disclosure of Invention An object of the present invention is to digitally manage the usage rights of RDM contents among heterogeneous RDM systems using copy control information (CCI) of RDM contents and watermarks included in RML contents. A content management system and a method for providing a DM content are provided.

The digital content management system according to the present invention for achieving the above object is a digital content management system for providing DRM content to another system, wherein the target to which the DM content is provided is a recordable medium. In this case, the authority management unit for determining whether to provide the DM content to the other system by checking the copy control information (CCI) of the DM content and the authority manager will provide the DM content to the other system. If it is determined, it comprises a watermark processor for checking whether a watermark is included in the DM content and inserting a watermark in the DM content.

The other system may be a heterogeneous DLM system that applies a DM applied to the DM content and a different DM.

When the target to which the DM content is provided is the recordable medium, the right management unit may update the copy control information of the DM content and provide the copy control information to a license server of the other system.

On the other hand, the digital content management system may further include a DB conversion server for converting the DM content to the heterogeneous DM.

The DRM conversion server is a metadata generation unit for generating metadata for recording the information on the condition that the watermark is maintained for the conversion of the DRM content, the DRM contents based on the metadata of the heterogeneous A digital conversion converter for converting to a DM, and an initial watermark included in the DM content, and checking a watermark remaining in the RT content converted to the different DM, and checking the remaining watermark It may include a watermark check unit for confirming whether the mark is maintained in the state of the initial watermark.

If the remaining watermark is not maintained in the state of the initial watermark, the DM conversion server converts the DM content by applying another parameter corresponding to a condition in which the watermark is to be maintained, and the remaining The process of checking whether the watermark is maintained in the initial watermark state may be repeatedly performed.

The watermark process checks whether the watermark is included in the DM content, and determines whether to insert an embedded watermark different from the watermark, and inserts the embedded watermark. The watermark generator may include a watermark generator configured to generate the embedded watermark to be inserted into the DM content, and a watermark inserter to encrypt and embed the embedded watermark into the DM content.

Meanwhile, when the watermark included in the DM content is confirmed by the watermark recognition unit, the watermark processor analyzes the watermark and compares the watermark with a list of watermarks previously provided in the watermark process. The apparatus may further include a watermark analyzer.

The watermark processor may further include a watermark request unit for determining whether the request is valid when a request is made to insert the embedded watermark into the DM content from the other system.

If the watermark request unit determines that the request from the other system is valid and specifies a watermark to be inserted, the watermark generator generates the designated watermark, and if the request from the other system is not valid, The watermark generator may generate an arbitrary watermark.

In order to achieve the above object, a method of providing a DM content according to the present invention is a method of providing a DM content for providing a DM content to a heterogeneous DM system, and checking copy control information (CCI) of the DM content. Determining whether to provide the DLM contents to the heterogeneous DLM system; and when the determination result provides the DLM contents to the heterogeneous DLM system, a watermark is inserted into the DLM contents. And converting the DLM content into which the watermark is inserted, into interoperable DLM contents for use in the heterogeneous DLM system.

The determining may include verifying a copy capable number of the DM content using the authority information, and if the copy number remains, provide the DM content to the heterogeneous DM system. May be determined to be.

The inserting of the watermark may include determining whether to insert the watermark in the DM content, and when the watermark is inserted in the DM content, requesting the request of the heterogeneous DM system. The method may include inserting a watermark and inserting an arbitrary watermark when there is no request of the heterogeneous DLM system.

The converting may include finding a parameter corresponding to a condition in which the watermark is to be maintained in the process of converting the DM content into the interchangeable DM content when the water content is included in the DM content, The DM content may be converted according to a variable, and it may be determined whether the watermark is maintained.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

FIG. 1 is a block diagram illustrating a relationship between a plurality of RMB systems providing RDM contents and a RDM device in a domain using RDM contents.

Referring to FIG. 1, a content provider (CP) provides a DRM content to a user, and a user is a DRM device that can interpret a DRM applied by the content provider. The Licensor certifies the user's use of DRM content as a DRM system. A plurality of such DRM systems exist according to the DRM scheme, and FIG. 1 describes the DRM systems 20 and 30, the domain 10, and the interoperable system 40 that apply different DRMs.

Here, the contents are represented by the DRM-A system 20 and the DRM-B system 30 to distinguish the plurality of DRM systems, and included in the DRM-A system 20 and the DRM-B system 30. It is also expressed in the same manner to distinguish.

The DRM-A system 20 includes a DRM-A content server 21 corresponding to a content provider, a DRM-A license server 22 corresponding to an authenticator, and a DRM-A device 12 corresponding to a DRM device. . The DRM-B system 30 also includes a DRM-B content server 31, a DRM-B license server 32, and a DRM-B device 13. The DRM-A content server 21 provides the DRM-A content, and the DRM-B content server 31 provides the DRM-B content.

The DRM-A content server 21 and the DRM-B content server 31 package content such as video and audio media into a DRM in a specific manner and provide the same to the user. The packaging of the content includes metadata representing information of the content and information on encryption, and a key for decryption.

The DRM-A license server 22 and the DRM-B license server 32 generate and manage licenses representing user's authority to use specific content. That is, the metadata of the content is received from the DRM-A content server 21 and the DRM-B content server 31 to hold the management information of the content, and the user's information is received to generate a license for the content. To the user.

Meanwhile, the DRM-A device 12 and the DRM-B device 13 may form a domain 10 representing an area where DRM content is available. In addition, the domain 10 may include a management device 14 capable of managing and interworking the DRM-A device 12 and the DRM-B device 13.

The domain 10 is a basic unit of the DRM Trusted Framework, and means a DRM application area to which the DRM system is practically applied. In this case, the DRM application area may mean an area of physical concept or may mean an area logically designated. In order to form the domain 10, a local network in which devices 12 to 14 belonging to the domain 10 can interoperate with each other must be formed, and the local network can also be connected to an external wide area network such as the Internet. Should be interlockable.

In this case, the DRM-A device 12 and the DRM-B device 13 may be media devices capable of playing DRM content such as video, TV, audio, PDA, and MP3 player. The management device 14 temporarily stores the DRM content, sets the authority for the domain 10, and manages the authority of each of the devices 12 and 13 connected to the domain 10. It can be a server acting as a. Of course, the management device 14 only serves to monitor and control the DRM-A device 12 and the DRM-B device 13, and the domain manager may exist in another independent web server or server providing DRM content. have.

Meanwhile, the management device 14 converts the DRM-A content provided to the DRM-A device 12 into DRM-B content and provides a license for the conversion server and the DRM-A content provided to the DRM-B device 13. It can also serve as a compatible right mediator with a license for DRM-B content. As such, the management device 14 may be an interoperability system 40 that interoperates DRM content with heterogeneous DRMs or may serve as part of the interoperability system 40. Interoperability system 40 may be configured with a variety of modules required to convert DRM content and compatible licenses. These modules may be gathered in one server, such as the management device 14, or may be distributed in the content servers 21 and 31, the license servers 22 and 32, and the devices 12 to 14.

As described above, the domain 10, the DRM-A system 20, the DRM-B system 30, and the interoperable system 40 may include physically or conceptually overlapping regions, and overlap each other. Instead of being configured separately, the parts are linked to the communication network 50 so as to interoperate with each other.

As described above, a process of providing DRM contents with mutual compatibility in a system composed of a plurality of DRM systems and an interoperable system 40 will be described.

FIG. 2 is a block diagram briefly illustrating an example of a process of receiving DL content from one DLM system in FIG. 1 and interoperating the same with another DL system.

Referring to FIG. 2, the DRM-A system 20 provides the DRM-A content provided by the DRM-A device 12 to the DRM-B device 13 so as to be compatible with each other.

The DRM-A content server 21 provides the packaged DRM-A content to the management device 14 of the domain 10. The DRM-A content provided to the management device 14 is stored in the DRM content library 121. At this time, the DRM-A content server 21 provides metadata about the DRM-A content to the DRM-A license server 22. Upon request from the management device 14, the DRM-A license server 22 generates a license for the DRM-A content using the metadata and user information for the DRM-A content and provides it to the management device 14. do.

On the other hand, the management device 14 includes a DRM management system 110 that interprets the packaged DRM content and manages the license for the DRM content. The DRM management system 110 analyzes the DRM content stored in the DRM content library 121 to generate the unpacked content 111.

The unpacked content 111 may include a contents packaging header indicating information and size of contents included in addition to the contents, metadata indicating packaging information of the contents, encrypted contents, and the like. In this case, the content packaging header may include information indicating whether content protection means other than DRM is included, such as a watermark. The metadata may include information on the watermark included in the content.

In addition, the DRM management system 110 is provided with a write token 112 with a license for using the DRM-A content from the DRM-A license server 22. The light token 112 interoperates with a license provided by a license server of the DRM system as a medium for storing authorization information on the DRM content in the interoperable system 40. The write token 112 includes information about a certificate of content, Copy Control Information (CCI), an Account Identifier (Ac_ID), a Domain Identifier (Do_ID), and the like. The certificate of content indicates that the content is legally generated and provided, and the copy control information (CCI) indicates whether the content can be copied to another device and used as one of the policies for the use of the content. The account identifier (Ac_ID) and the domain identifier Do_ID represents an authenticated user and domain 10.

Therefore, in the interoperability system 40, the DRM license server may verify authorization information on the DRM content included in the write token 112 to authenticate the use of the DRM content provided by another DRM system. In addition, the interoperability system 40 updates the authorization information for the DRM content included in the write token 112 and provides the license server of each DRM system, thereby providing authentication information for the use of the DRM content between different DRM systems. Make it shareable.

The DRM management system 110 of the management device 14 provides the unpacked content 111 and the license to the DRM-A device 12 so that the DRM-A device 12 can use the DRM-A content.

When the DRM-A content is used by the DRM-B device 13, the DRM management system 110 may enable the DRM-B device 13 to use the unpacked content 111 in the interoperable system 40. B is converted into DRM-B content to which the B is applied and provided to the DRM-B device 13. The DRM management system 110 provides the write token 112 for the DRM-A content to the DRM-B license server 32 through the interoperability system 40, and the DRM-B license server 32 The authority information included in the write token 112 is checked and a valid license is generated in the DRM-B device 13 and provided to the DRM-B device 13.

As described above, the DRM management system 110 is included in the management device 14, so that the management device 14 interprets the DRM content and holds the authority information. However, the domain 10 is subordinate without the management device 14. The DRM devices 12 and 13 may be configured only, and the DRM management system 110 may also exist in each DRM device so that each DRM device may interpret the DRM contents and retain the authority information. That is, the configuration of the management device 14 shown in FIG. 2 may be the configuration of the DRM-A device 12 and the DRM-B device 13.

Hereinafter, by checking the authority information of the DRM-A content provided by the DRM-A system 20, it manages the copy control information (CCI), interprets the DRM-A content and inserts a watermark to the DRM-B system 30. The system provided by) is demonstrated.

3 is a block diagram showing the configuration of a digital content management system according to an embodiment of the present invention.

Referring to FIG. 3, as described above, the DRM-A system 20 includes a DRM-A license server 22, a DRM-A content server 21, and a DRM-A device 12. The B system 30 includes a DRM-B license server 32, a DRM-B content server 31, and a DRM-B device 13. In this case, the DRM-A content server 21 may generate a watermark, insert the watermark into the content, and package the content having the watermark embedded therein to generate the DRM-A content. The DRM-A system 20 and the DRM-B system 30 are relayed to each other by the digital content management system 200.

The digital content management system 200 checks whether the watermark is included in the DRM content, inserts a new watermark, the watermark processor 210, the rights management unit 220 for checking and managing the authority information of the DRM content, and the DRM content. CCI management unit 230 that manages the copy control information (CCI) and the DRM content usage policy and a conversion server 240 for converting the DRM content into heterogeneous DRM.

The watermark process 210 includes a watermark recognizer 211 for checking whether a watermark is included in the DRM content, a watermark analyzer 212 for analyzing the watermark included in the DRM content, and a watermark analyzer 212. A watermark list 213 for providing information on a normal watermark, a watermark requesting unit 214 for confirming a watermark insertion request from the DRM system, and a watermark generation for generating a watermark suitable for DRM contents. The unit 215 includes a watermark inserting unit 216 for inserting the generated watermark into the DRM content, and a content binding unit 217 for providing related information to the watermarked DRM content.

The watermark recognizer 211 checks the content packaging header, metadata, and encrypted content included in the packaging of the DRM-A content. The watermark recognition unit 211 may check whether the watermark is included in the DRM-A content and information on the size of the included watermark in the content packaging header. In addition, the watermark recognizer 211 may check the characteristics of the DRM and metadata of the watermark included in the DRM-A content in the metadata. Meanwhile, the watermark recognizing unit 211 may determine whether to insert a new watermark in the DRM-A content according to a preset policy and determine whether to proceed with the subsequent watermark insertion procedure. Thereafter, the new watermark inserted in the watermark process 210 is referred to as an embedded watermark.

When the watermark included in the DRM-A content is confirmed, the watermark analyzer 212 analyzes the position, size, and nature of the watermark. The watermark analyzer 212 obtains accurate information on the characteristics of the watermark by comparing the analyzed watermark with a normal watermark provided in advance in the watermark list 213. Meanwhile, the watermark list 213 acquires and updates information on the watermark used by the service provider or the watermark used by each DRM system from time to time to efficiently analyze the watermark.

The watermark request unit 214 checks whether there is a legitimate request to insert a watermark into the DRM-A content from the system receiving the DRM-A content, that is, the DRM-B system 30. At this time, the insertion request of the watermark may be from the DRM-B license server 32 or the management device 14 serving as a domain administrator managing the domain 10. In addition, the watermark embedding request may be requested by specifying a watermark to be inserted into the DRM-A content.

The watermark generation unit 215 generates a designated watermark if there is a watermark specified in the watermark insertion request, and generates an arbitrary watermark if there is no designated watermark or if the watermark insertion request is invalid. In this case, it is preferable that any watermark is selected to be in harmony with the characteristics of the watermark analyzed by the watermark analyzer 212. That is, the watermark included in the DRM-A content overlaps with the location of the embedded watermark so as to prevent difficulty in extracting the watermark. When the watermark included in the DRM-A content is a robust watermark, The embedded watermark may be selected as a fragile watermark so that the security policy of the watermark can be efficiently implemented. Such arbitrary watermark may be provided by an algorithm to be selected according to the characteristics of the watermark included in the DRM-A content.

The watermark inserting unit 216 encrypts and embeds the embedded watermark generated by the watermark generating unit 215 in the DRM-A content. In this case, the watermark inserting unit 216 may generate metadata including information on the inserted watermark and provide the metadata to the content binding unit 217 together with the DRM-A content in which the watermark is inserted.

The content binding unit 217 links the DRM-A content with the watermark, metadata including information about the DRM-A and the watermark, and related information such as a content packaging header updated with the watermark insertion. Provided to the B system 30. Meanwhile, the content binding unit 217 provides the DRM-A content and related information related thereto to the DRM conversion server 240 so that the DRM-A content can be smoothly converted into the DRM-B content.

Meanwhile, the right management unit 220 receives the write token 112 from the DRM-A system 20 and checks the right information on the DRM-A content. In particular, when the DRM-B device 13 of the DRM-B system 30 that receives the DRM-A content is a recordable medium that downloads and uses the DRM-A content, the rights management unit 220 writes the write token. The copy control information (CCI) included in the 112 and the CCI management unit 230 is checked to determine whether to provide the DRM-A contents. That is, the copy control information (CCI) includes a copy capable number indicating how many times the DRM content can be copied and used, and the rights management unit 220 displays the DRM- if the copyable number remains. If the A content is provided to the DRM-B device 13, and the number of possible copies remains, the DRM-A content is not provided. When the DRM-A content is provided as a recordable medium, the right management unit 220 updates the copy control information (CCI) of the write token 112 and the CCI management unit 230, and copies it to the license server of each DRM system. Control information (CCI) is provided to manage future use of DRM-A content.

At this time, the CCI management unit 230 obtains the copy control information (CCI) from the write token 112 and manages the usage policy of the DRM content applied to the copy control information (CCI). The DRM content usage policy applied to copy control information (CCI) includes free copy, area limited copy, time limited copy, and never copy. There is this. Infinite copy permission allows DRM contents to be copied and used regardless of the place and number of times. Area limit copy permission allows copying between devices in the same domain 10 without restriction. The permission is to designate the number of times that the DRM content can be copied so that the DRM content can be copied to other devices by the number of times, and copying is prohibited to copy the DRM content. The number of times that can be copied is designated as 'infinite' in the infinite copy allowance, 'infinity' when the domain identifier (Do_ID) is verified, and '0' when the domain identifier (Do_ID) is not checked in the limit copy allowance. In copy permission, it can be specified as 'n', and in copy permission, it can be '0'. Accordingly, the CCI management unit 230 may apply a differentiated usage policy to the DRM content, thereby differentiating whether or not the corresponding DRM content is provided.

The DRM conversion server 240 converts the watermarked DRM content into heterogeneous DRM by the watermark processor 210. That is, the DRM-A content with the watermark inserted from the DRM-A system 20 is provided to the watermark processor 210, and the DRM-A content with the embedded watermark is inserted by the watermark processor 210. When provided to the conversion server 240, the DRM conversion server 240 applies the DRM-B to use the DRM-A content in the DRM-B system 30 while the inserted watermark and the embedded watermark are maintained. To convert. Detailed description thereof will be given in FIG. 4.

Hereinafter, the DRM conversion server 240 for converting the DRM content inserted into the watermark by the DRM system and the watermark processor 210 into the heterogeneous DRM while maintaining the watermark will be described.

FIG. 4 is a block diagram illustrating a configuration of a RDM conversion server for converting a RM content having a watermark inserted into a different RM in FIG. 3.

Referring to FIG. 4, the DRM conversion server 240 includes a watermark checking unit 241 for checking the state of the watermarks included in the DRM content, and metadata regarding conditions under which the watermark is to be maintained during the conversion of the DRM content. It is composed of a metadata generation unit 242 for generating a DRM conversion unit 243 for converting the DRM content into heterogeneous DRM based on the metadata.

The watermark checker 241 checks the initial watermark included in the DRM content provided from the watermark processor 210. The initial watermark may be at least one of a watermark inserted in the DRM-A system 20 and an embedded watermark embedded in the watermark processor 210. In this case, the watermark processor 210 may be provided with information on an algorithm and characteristics of the initial watermark.

The watermark checker 241 checks the watermark remaining in the DRM content converted into the heterogeneous DRM by the DRM converter 243. That is, the watermark checking unit 241 checks the signal of the watermark from the DRM content converted by the parameters applied to the DRM conversion and finds a parameter corresponding to a condition in which the initial watermark is to be maintained. The watermark checking unit 241 provides a parameter corresponding to a condition for maintaining the initial watermark to the metadata generating unit 242 and converts the watermark remaining in the DRM content converted according to the parameter into the initial watermark. By comparison, it is determined whether the remaining watermark is the same as the initial watermark.

The metadata generator 242 generates metadata about a condition for maintaining the initial watermark based on a parameter corresponding to a condition for maintaining the initial watermark provided from the watermark checker 241. The metadata may include information about the extent of the parameter corresponding to the range in which the remaining watermark is detected and the degree to which the initial watermark is maintained according to the parameter.

The DRM converting unit 243 provides the watermark checking unit 241 with parameters applied to the DRM conversion and performs DRM conversion according to each parameter so that the watermark checking unit 241 maintains the initial watermark. Allows you to find the corresponding parameter. In addition, the DRM converter 243 obtains information on a condition in which the initial watermark is to be maintained from the metadata generated by the metadata generator 242, and converts the DRM content into heterogeneous DRM according to a corresponding parameter. do. In this case, when the watermark checking unit 241 determines that the watermark remaining in the converted DRM content is not maintained in the state of the initial watermark, the DRM conversion unit 243 corresponds to a condition for maintaining the initial watermark. Convert the DRM content by applying different parameters. This DRM conversion is repeatedly performed until the remaining watermark remains the same.

Hereinafter, a DRM content providing method for providing DRM content between heterogeneous DRM systems and managing usage rights of the DRM content using copy control information (CCI) of the DRM content and a watermark included in the DRM content will be described. .

FIG. 5 is a flowchart illustrating a method of providing a DM content to determine whether to provide a DM content by checking copy control information (CCI) of the DM content.

Referring to FIG. 5, when providing DRM content between DRM systems applying heterogeneous DRMs, the rights management unit 220 of the digital content management system 200 checks the light token 112 indicating the rights information of the DRM content. (S10). At this time, the rights management unit 220 may check whether the user has a right to use the DRM content by checking the certificate, the copy control information (CCI), the account identifier and the domain identifier of the content included in the write token 112.

Subsequently, the rights management unit 220 determines whether the target medium to receive the DRM content is a recordable medium to download and use the DRM content (S20). At this time, if the target medium is not a recordable medium, the rights management unit 220 determines that the DRM content is provided without processing the copy control information (CCI).

If the target medium to which the DRM content is to be provided is the recordable medium, the rights management unit 220 checks the copy control information (CCI) included in the CCI management unit 230 and the write token 112 (S30). At this time, the authority manager 220 may check the usage policy of the DRM content applied to the copy control information (CCI) by the CCI manager 230. That is, the rights management unit 220 has any usage policy of free copy, area limited copy, time limited copy, and never copy to DRM content. Check if it applies.

The right management unit 220 determines whether the number of copy times specified according to the usage policy of the DRM content remains (S40). At this time, the right management unit 220 determines not to provide the DRM content when the number of possible copies remaining, and determines that the DRM content is provided when the remaining number of copies remaining, and subtracts the number of possible copies.

On the other hand, the rights management unit 220 determines whether the copy control information (CCI) is included in the write token (112) (S50). Since the DRM system providing the DRM content does not provide the copy control information (CCI), the copy token 112 may not include the copy control information (CCI).

As a result of the determination, when the copy control information (CCI) is not included in the write token 112, the authority manager 220 generates the copy control information (CCI) in the write token 112 (S55). When the copy token 112 includes the copy control information (CCI), the right management unit 220 provides the DRM content and updates the copy control information (CCI) by subtracting the copyable number. (S60).

Subsequently, the rights management unit 220 transmits the copy control information (CCI) to the license server of the DRM system that receives the DRM content (S70). In this case, the copy control information (CCI) is reflected in the write token 112, so that it can be provided to the license server of another DRM system, so that the rights management unit 220 can manage subsequent use of the DRM content. .

As described above, when the rights management unit 220 determines that the DRM content is provided to the heterogeneous DRM system, the watermark processor 210 proceeds to insert a new watermark in the DRM content.

FIG. 6 is a flowchart illustrating a method of providing a DM content that checks a watermark included in the DM content and inserts and provides a new watermark.

Referring to FIG. 6, when the DRM content is provided, the watermark processor 210 first determines whether to insert a new watermark in the DRM content (S110). In this case, whether to insert a new watermark may be determined according to a preset policy. If the new watermark is not inserted, the watermark processor 210 binds the DRM content to the target medium without proceeding with the insertion of the watermark.

Subsequently, the watermark processor 210 determines whether there is a watermark included in the DRM content (S120). In this case, the watermark processor 210 may obtain information on the watermark from the content packaging header and metadata included in the packaging of the DRM content.

As a result of the determination, when there is a watermark included in the DRM content, the watermark processor 210 analyzes the watermark included in the DRM content (S125). In this case, the watermark processor 210 may analyze the watermark included in the DRM content by comparing the information on the watermark that can be obtained from the provider providing the watermark or the provider providing the DRM content.

Subsequently, the watermark processor 210 determines whether there is a legitimate watermark insertion request from the DRM system receiving the DRM content (S130). At this time, the watermark processor 210 checks whether the DRM system, which receives the DRM content, requests the watermark to be inserted.

As a result of the determination, when there is a legitimate watermark insertion request and the watermark to be inserted is designated, the watermark processor 210 generates the designated request watermark (S140). If there is no legitimate watermark insertion request or the watermark to be inserted is not specified, the watermark processor 210 generates an arbitrary watermark (S145). At this time, the arbitrary watermark allows a watermark to be generated that can be harmonized with the characteristics of the watermark first inserted into the DRM content.

When the request watermark or any watermark is generated, the watermark processor 210 encrypts the watermark and inserts the watermark into the DRM content (S150). At this time, the watermark processor 210 generates metadata including information on the watermark inserted into the DRM content.

The watermark processor 210 binds the watermarked DRM content to the target DRM system (S160). In this case, the DRM content having the watermark inserted therein is converted into heterogeneous DRM while the watermark is maintained by the DRM conversion server 240 described above.

As mentioned above, preferred embodiments of the present invention have been described in detail, but those skilled in the art to which the present invention pertains should understand the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that various modifications or changes can be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

In providing DRM contents to heterogeneous DRM systems, it is determined whether to provide DRM contents by checking copy control information (CCI) of DRM contents, and providing copy control information (CCI) to a license server of heterogeneous DRM systems. Thus, copy control information (CCI) can be shared and managed between heterogeneous DRM systems. In addition, by maintaining a watermark included in the DRM content and inserting a new shareable watermark, the watermark can be efficiently applied to the DRM content even among heterogeneous DRM systems.

Claims (14)

In the digital content management system for providing DRM content to other systems, A rights management unit for determining whether to provide the DM content to the other system by checking the copy control information (CCI) of the DM content when the object to which the DM content is provided is a recordable medium; And If the rights management unit determines that the DM content is to be provided to the other system, check whether the watermark is included in the DM content and insert a watermark in the DM content. A processor; Digital content management system comprising a. The digital content management system as claimed in claim 1, wherein the other system is a heterogeneous RMB system that applies a RM applied to the RM content and a different RM. The system of claim 2, wherein the authority management unit updates the copy control information of the DM content when the object to which the DM content is provided is a recordable medium, and transmits the copy control information to a license server of the other system. Digital content management system, characterized in that provided. The digital content management system of claim 2, further comprising a DB conversion server for converting the DM content into the heterogeneous DB. The method of claim 4, wherein the RDM conversion server A metadata generator for generating metadata in which information about a condition under which the watermark is to be maintained is converted for the conversion of the DM content; A DM conversion unit for converting the DM content into the other DM based on the metadata; And Check the initial watermark included in the DM content, check the watermark remaining in the DM content converted into the heterogeneous DLM, and determine whether the remaining watermark remains in the state of the initial watermark. Digital content management system comprising a; watermark verification unit for confirming. 6. The method of claim 5, wherein when the remaining watermark is not maintained in the state of the initial watermark, the DM conversion server applies the other parameter corresponding to the condition in which the watermark is to be maintained. Converting and repeating the process of checking whether the remaining watermark remains in the initial watermark state. The watermark processing apparatus of claim 1, wherein the watermark process comprises: a watermark recognizer configured to check whether the watermark is included in the DM content, and determine whether to insert an embedded watermark different from the watermark; A watermark generator configured to generate the embedded watermark to be inserted into the DM content when the embedded watermark is inserted; And And a watermark inserter for encrypting and embedding the embedded watermark in the DM content. The watermark method of claim 7, wherein when the watermark included in the DM content is confirmed by the watermark recognition unit, the watermark is analyzed and compared with a watermark list previously provided in the watermark process. Mark analysis unit; Digital content management system further comprises. The digital content management method of claim 7, further comprising: a watermark request unit which determines whether the request is valid when a request is made to insert the embedded watermark into the DM content from the other system. system. 10. The apparatus of claim 9, wherein, when the watermark request unit determines that the request of the other system is valid and specifies a watermark to be inserted, the watermark generator generates a designated watermark, and the request of the other system is If not, the watermark generation unit generates an arbitrary watermark. In the DM content providing method for providing a DM content to a different DM system, Checking copy control information (CCI) of the DM content to determine whether to provide the DM content to the heterogeneous DM system; As a result of the determination, when providing the DM content to the heterogeneous DL system, inserting a watermark into the DM content; And And converting the DM content into which the watermark is inserted, into mutually compatible DL content that can be used in the heterogeneous RMB system. 12. The method of claim 11, wherein the determining comprises determining a copy capable number of the DM content from the authority information, and when the copy number remains, RM content providing method, characterized in that determined to provide to the DM system. The method of claim 11, wherein the embedding of the watermark comprises: determining whether to insert a watermark in the DM content; And As a result of the determination, when the watermark is inserted into the DM content, the requesting watermark is inserted when there is a request of the heterogeneous DLM system, and an arbitrary watermark is inserted when the request of the heterogeneous DLM system is not requested. RDM content providing method comprising a. 12. The method of claim 11, wherein the converting comprises: a medium corresponding to a condition in which the watermark is to be maintained in the process of converting the DM content into the compatible DM content when the water content is included in the DM content; And finding a variable, converting the DM content according to the parameter, and checking whether the watermark is maintained.

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