KR20080009951A - Digital rights management method and system thereof - Google Patents

Abstract

A DRM(Digital Rights Management) method and a system thereof are provided to allow a user to use a selected block or view section, and display contents different from each preference or age of the user for the same DRM contents by dividing DRM contents protected by encryption into a plurality of blocks or view sections. A device(110) selects the view sections or the blocks of the DRM contents including a plurality of view sections or blocks, and a CP(Content Provider) transmits the DRM contents and right information allowing contents use to only the selected view sections to the device. The CP transmits the DRM contents, and the right information playing the sections corresponding to the selected blocks and skipping the sections not corresponding to the selected blocks to the device.

Description

Digital rights management method and system thereof

1 is a view showing an example of a system to which a digital rights management method according to the present invention is applied;

2 is a message sequence chart provided in a schematic description of a digital rights management method according to the present invention;

3 is a view showing the configuration of a general DCF,

4 is a diagram of a DCF block structure used in the digital rights management method according to the present invention;

5 and 6 are a flow chart provided in the description of the digital rights management method according to the present invention, and

7 to 11 are views for explaining the digital rights management method according to the present invention with the user interface provided in the device.

Explanation of symbols on the main parts of the drawings

110: device 120: content publisher

130: authority issuer

The present invention relates to a digital rights management method and system, and more particularly, digital rights management to divide a DRM content into a plurality of blocks or view sections so that only a user selected block or view section can be used. It relates to a method and a system thereof.

Even if it is infinitely repeated, the original quality is not damaged at all, it is easy to modify and copy, and the digital characteristics and advantages such as the transmission and distribution of a large amount of work in a short time by using a high-speed communication network are possible. It is digitizing at an early rate. However, these digital features and advantages also act as a violation of the original author's rights and interests in the work.

That is, even if a copy is identical to the original, it weakens the willingness to purchase the original, and it is easy to steal the copyrighted work because it is easy to modify and copy without the author's consent. Can spread quickly, making even legal control impossible. These negative factors can reduce the morale of the authors and reduce their willingness to produce them, which in turn causes them to hesitate to digitize their works.

As a result, digital copyrighted works are required to have technical protection devices that can effectively manage copyrights while fully utilizing the advantages of digital. Digital rights management (DRM) has emerged due to this necessity. Digital rights management refers to technologies and services that enable the safe and convenient distribution of digital content for the purpose of protecting the intellectual property of digital content.

The digital rights management method used to prevent illegal use of digital content by using such digital rights management uses a method of converting digital content to be protected into encrypted data in a package form using encryption technology. Therefore, in order to use digital content protected by digital rights management, that is, DRM content, right-rights objects used for decryption of DRM content to be used through authentication procedures, etc. must be obtained.

Examples of digital rights management methods include Microsoft's DRM and OMA DRM (Open Mobile Alliance Digital Rights Management). In the case of OMA DRM, V2.0 is announced. In the case of OMA DRM V2.0, the DRM content and the right information for the DRM content can be physically separated, and the right information used for decrypting the DRM content is divided between the device and the right issuer. It is stipulated to be obtained through mutual authentication of.

However, according to the current OMA DRM V2.0 protocol and the OMA Rights Expression Language (REL), a method of dividing a single DRM content into a plurality of blocks or view sections and allowing the user to use only the selected block or view section is provided. It is not prescribed. For example, in a DRM content in which two movies A and B are combined, the user may select to view either A or B or both A and B according to a user's selection. In addition, there may be cases in which a specific block may be restricted from being viewed in DRM content according to age.

In such a case, since there is no other plan for the content provider or the authority issuer, the provision of various services using the DRM content is restricted.

Accordingly, an object of the present invention is to provide a digital rights management method and system for dividing DRM content into a plurality of blocks or view sections, and enabling to provide only a block or view section selected by a user. It is about.

In accordance with another aspect of the present invention, there is provided a digital rights management method, comprising: selecting a view section to be used for DRM content in which a plurality of view sections are set, the DRM content, and information corresponding to the selected view section; Receiving the usage rights information of the DRM content including, and Permitting the use of the DRM content only for the selected view period, according to the usage rights information.

In addition, the digital rights management method according to the present invention for achieving the above object comprises the steps of selecting a block to be used for the DRM content divided into a plurality of blocks, the DRM content and the information including the information corresponding to the selected block Receiving usage right information of the DRM content, and reproducing a section corresponding to the selected block in the DRM content, and skipping a section corresponding to the unselected block according to the usage right information.

On the other hand, the digital rights management system according to the present invention, a device for selecting a view section to be used for the DRM content with a plurality of view sections, and the DRM content and the use of the DRM content only for the selected view section And a content provider for transmitting the usage right information to the device.

In addition, the digital rights management system according to the present invention, a device for selecting a block to be used for the DRM content divided into a plurality of blocks, and the DRM content and the section corresponding to the selected block in the DRM content is reproduced, The section corresponding to the block not selected includes a content provider for transmitting usage right information to the device to skip.

In order to achieve the above object, the present invention provides a computer-readable recording medium recording a program for executing the method on a computer.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

The digital rights management method according to the present invention is basically applied to a mobile communication environment based on the Open Mobile Alliance (OMA) standard, but is not necessarily limited thereto and may be applied to other communication environments that satisfy the conditions according to the present invention. Do.

1 shows an example of a system to which a digital rights management method according to the present invention is applied. Referring to FIG. 1, the system includes a device 110, a content issuer 120, and a rights issuer 130.

The device 110 uses the DRM content and, if necessary, is a device capable of transmitting the DRM content stored in another device. The device 110 includes a terminal such as a mobile phone or a personal digital assistant (PDA). The device 110 is communicatively connected to the content publisher 120 through a network such as a mobile communication network, and downloads DRM content protected by digital rights management (DRM) from the content publisher 120. Then, the device 110 receives the right information (Rights Object) used to decrypt the downloaded DRM content through the authentication process with the right issuer 130, and the like.

The device 110 may use the downloaded DRM content by decrypting the encrypted DRM content by using content encryption key information included in the usage right information received from the authority issuer 130.

As shown in FIG. 1, the device 110 may receive the DRM content and the usage right information from the content issuer 120 and the authority issuer 130, respectively. It may be received simultaneously or sequentially from a content provider.

2 is a message sequence chart provided in the schematic description of the digital rights management method according to the present invention. In FIG. 2, an example of downloading both DRM content and usage right information of the DRM content from one content provider will be described. Referring to FIG. 2, the device 110 is communicatively connected to the content provider 140 through a predetermined network to search for content that the content provider 140 may provide (S200). By the searching process, the content to be downloaded is selected (S205), and purchase information about the selected content is downloaded (S210).

At this time, if a plurality of view sections or blocks are set in the selected content, the view or block to be used is selected from the plurality of set view sections or blocks, and the costs required for setting and using the use conditions are paid (S210). The condition for using the content includes the period of use, the number of times of use, and the like of the selected content.

When the view section or block to be used is selected and the usage condition setting and the cost of the content are settled, the selected DRM content and usage right information according to the set condition are downloaded from the content provider 140 (S220). The device 110 installs a usage right using the downloaded usage right information (S235). By this process, when the DRM content is downloaded and a usage right is installed, the user can use only the selected view section or block in the downloaded DRM content, and the use of the unselected view section or block is restricted.

Meanwhile, as shown in FIG. 3, a general DCF (Discrete Media) composed of a fixed DCF header, an OMA DRM header, a content object container, and the like for controlling DRM content divided into a plurality of view sections or blocks used in the present invention. Profile) is used to add newly defined OMADRMControlInfo box.

The OMADRMControlInfo box defines the control information of the content. The format is as follows.

  aligned (8) class OMADRMControInfo extends FullBox ('ctrl', version, 0) {string ControlHeaders []; // contains view headers and block headers}

The OMADRMControlInfo box contains the following view headers and block headers. View headers are used to define views of content, and block headers are used to define restricted blocks within content.

  View = "View" ":" view-uri view-uri = token

  Block = "Block" ":" block-id ":" startpos ":" length block-id = token startpos = * digit length = * digit

In Table 2, View-uri is a unique identifier and is a Uniform Resource Identifier (URL) according to RFC2339. In Table 3, block-id is a unique identifier, and startpos and length are defined by numbers.

If the Discrete Media Headers Box is modified in the DCF structure using the ControlInfo box as described above, a diagram of the modified DCF box structure is shown in FIG. 4.

aligned (8) class OMADRMDiscreteHeaders extends FullBox ('odhe', version, flags) {unsigned int (8) ContentTypeLength // Content Type Length char ContentType []; // Content Type String OMADRMCommonHeaders CommonHeaders; // Common headers (same as with PDCF) if (flags & 0x000001) {UserDataBox UserData; // ISO User Data Box (optional)} if (flags & 0x000002) { OMADRMControlInfo ControlInfo ; // OMA DRM Control Info (optional) } }

The Discrete Media Headers Box includes a DCF format and a Common Herader box, and optionally includes a user-data box. In the present invention, a ControlInfo box is included here.

In addition, in the digital rights management method according to the present invention, in order to set a plurality of view sections or blocks, a <control> element is newly defined and used in the rights object used basically. The <control> element describes the control information for the DRM content controlled by the <view> and <allow> elements via the <context> child element.

 Element <! ELEMENT o-ex: control (o-ex: view, o-ex: allow)>   Semantics  The <control> element specifies the control information for the DRM Content governed by the containing <view> element and <allow> elements via the <context> child element.

The following <view> element describes the view section that the user has permission to, and the <allow> element describes the block to which the user has access.

 Element  <! ELEMENT o-dd: view (o-ex: context)>  Semantics The <view> element specifies the views only for which user has right. It does so by binding content to the view identifier specified via its <context> child element. The DRM Agent MUST NOT grant access to the DRM Content unless no views exist for the content or one of the view identity (s) to which the use of Content is constrained matches the view identities associated with the content.

 Element <! ELEMENT o-dd: allow (o-ex: context)>  Semantics The <allow> element specifies the blocks only for which user has right to access. It does so by binding content to the block identifier specified via its <context> child element. The DRM Agent MUST NOT grant access to the parts of the DRM Content which are blocked by block identifiers unless one of the block identifier (s) matches the block identitifires associated with the content

And, if the <context> element is included in the <view> element and the <allow> element as follows, the <context> element is modified to include one or more <uid> elements.

 Element <! ELEMENT o-ex: context (o-dd: version ?, o-dd: uid *)>  Semantics The <context> element contains the optional <version>, and <uid> elements. As the name already indicates, it provides context sensitive information for use within the context of its parent element. The semantics of its child elements depend on the parent element in which the <context> element is used. These are different if the <context> element is a child element of the <rights>, <asset>, <individual>, <system>, or <inherit> element. Please see the corresponding descriptions of the individual child elements. A <context> element MUST NOT contain more than one <uid> element unless the <context> element is contained in the <individual> element or <view> element or <allow> element.

[Table 9] shows an example of permission information in which permission of a plurality of view sections and blocks is set including newly defined <contorl>, <view>, and <allow> elements. Here, the usage right information is described in OMA Rights Expression Language (REL) based on Extensible Markup Language (XML).

1: <o-ex: rights 2: xmlns: o-ex = "http://odrl.net/1.1/ODRL-EX" 3: xmlns: o-dd = "http://odrl.net/1.1/ ODRL-DD "4: xmlns: oma-dd =" http://www.openmobilealliance.com/oma-dd "5: xmlns: ds ="http://www.w3.org/2000/09/xmldsig#"6: xmlns: xenc ="http://www.w3.org/2001/04/xmlenc#"> 7: <o-ex: context> 8: <o-dd: version> 2.0 </ o-dd : version> 9: <o-dd: uid> RightsObjectID </ o-dd: uid> 10: </ o-ex: context> 11: <o-ex: agreement> 12: <o-ex: asset o- ex: id = "Asset-1"> 13: <o-ex: context> 14: <o-dd: uid> ContentID1 </ o-dd: uid> 15: </ o-ex: context> 16: < o-ex: digest> 17: <ds: DigestMethod Algorithm = "http://www.w3.org/2000/09/xmldsig#sha1"/> 18: <ds: DigestValue> DCFHash </ ds: DigestValue> 19 : </ o-ex: digest> 20: <ds: KeyInfo> 21: <xenc: EncryptedKey> 22: <ds: KeyInfo> 23: <ds: RetrievalMethod URI = "REKReference"/> 24: </ ds: KeyInfo > 25: <xenc: EncryptionMethod Algorithm = "http://www.w3.org/2001/04/xmlenc#kw-aes128"/> 26: <xenc: CipherData> 27: <xenc: CipherValue> EncryptedCEK </ xenc : CipherValue> 28: </ xenc: CipherData> 29: </ xenc: EncryptedKey> 30: </ d s: KeyInfo> 31: </ o-ex: asset> 32: <o-ex: permission> 33: <o-dd: play> 34: <o-ex: constraint> 35: <o-ex: control> 36: <o-ex: view> 37: <o-ex: context> 38: <o- dd : uid > ViewID1 </ o- dd : uid > 39: <o- dd : uid > ViewID2 </ o- dd : uid > 40: </ o-ex: context> 41: </ o-ex: view> 42: <o-ex: allow> 43: <o-ex: context> 44: <o- dd : uid > BlockID1 </ o- dd : uid > 45: <o- dd : uid > BlockID2 </ o- dd : uid > 46: </ o-ex: context> 47: </ o-ex: allow> 48: </ o-ex: control> 49: <o-dd: count> 1 </ o-dd: count> 50: </ o-ex: constraint> 51: <o-dd: play /> 52: </ o-ex: permission> 53: </ o-ex: agreement> 54: </ o-ex: rights>

In Table 9, lines 1 to 6 represent the DRM permission structure, and describe information on an XML namespace representing information for XML interpretation. Lines 7 through 10 describe the version information of the DRM system to which the DRM permission is applied.

Lines 11 to 54 include content information and specific contents of the DRM permission, and are expressed by <asset> and <permission> elements, respectively.

The <asset> element describes the identifier of the content to which the DRM license is applied in lines 12 to 31, and content encryption key (CEK) information capable of decrypting encrypted DRM content in lines 20 to 30. It describes. In addition, the <permission> element describes that DRM content can be reproduced in lines 32 to 44. FIG.

The <constraint> element on line 34 may include elements such as <interval>, <accumulated>, <start>, <end>, <count>, and the like. The <interval> element indicates a period of time that the content can be used, and the start time point is when the content is used for the first time. The <Accumlated> element indicates a time when the use of the content can be accumulated to the maximum. The <start> and <end> elements are described together, stating that they can be used freely from the date specified by <start> to the date specified by <end>. And, <count> describes the number of times available.

 Lines 35 to 48 are parts related to view section or block setting, and lines 36 to 41 and lines 42 to 47 define newly defined <view> and <allow> elements in the present invention as described above. Set the view section and block that are allowed. Table 9 shows the use of the view sections of ViewID1 and ViewID2 and the use of blocks of BlockID1 and BlockID2 using the <view> and <allow> elements.

5 and 6 are flowcharts provided to explain a content usage process in a device in which DRM content and its usage rights are installed according to the digital rights management method according to the present invention. First, FIG. 5 illustrates a case where a playback request is made for DRM content in which a plurality of view sections are set. Referring to FIG. 5, if there is a content reproduction request in a device in which DRM content and its usage right are installed (S300), first, it is determined whether a restriction condition such as a usage period or the number of times is satisfied (S305).

If it is determined that the constraint condition is satisfied, it is determined whether the view section requested to play the content is the selected view section (S310). In the case of the selected view, the content is played back (S315). By this process, the content is played only for the view section selected by the user in the DRM content in which the plurality of view sections are set.

 6 illustrates a case in which content usage is limited in units of blocks in DRM content divided into a plurality of blocks. Referring to FIG. 6, if there is a content playback request in a device where DRM content and its view authority are installed (S400), first, it is determined whether a restriction condition such as a usage period or a number of times is satisfied (S405).

If it is determined that the constraint condition is satisfied, the mobile station moves to the first block of the corresponding DRM content (S410), determines whether it is the selected block (S415), and if it is the selected block, plays the block (S420). When the playback of the first block is finished, the process moves to the next block (S430). If the block is the selected block, the playback is performed. If the block is not selected, the process of moving to the next block is repeated until the content ends. .

By this process, the content is played for the selected block, and the block that is not selected is moved to the next block without playing.

7 to 11 are views for explaining the digital rights management method according to the present invention with the user interface provided in the device. First, FIG. 7 is a diagram illustrating an example of a user interface used in a process of downloading content and usage right information from a device.

Referring to FIG. 7A, a user interface displayed on a screen of a device may include a status display area 501 of a device, an area 503 indicating a current menu item, and a submenu item of a current menu item. Area 505 and a selection area 507 for menu selection and returning to the previous menu. 5 (a) shows '3. 3' in a submenu item of the 'Internet' menu item. Go to URL 'is selected, and FIG. 5B illustrates a process of inputting "http: //www.video.c", which is a URL (Uniform Resource Locator) address of a content provider to be accessed. FIG. 7C illustrates a process of selecting one of contents provided by a content provider connected by the input URL address, and FIG. 7D illustrates a menu for inputting purchase information on the selected content. Indicates the process of downloading.

As shown in (e) of FIG. 7, a menu for inputting purchase information includes items 509, 511, and 513 for selecting a desired view section among three view sections, View1, View2, and View3. As shown in FIG. 7F, other usage counts 515, content use start time and end time 517 and 519, and time 521 for maximum use of content may be input.

According to the use condition, a credit card number 523 and a password 525 are input through the cost settlement screen as shown in FIG. After this process, as shown in FIG. 7H, the usage rights corresponding to the selected content and the selected view section are downloaded. 7 (i) is a screen showing that the download of the selected content and usage rights thereof are completed.

FIG. 8 is a diagram illustrating a case where a content execution request is requested for an unselected view section. In FIG. 8, (a) shows a process of selecting a type of content to be used, and (b) shows a process of selecting a content title to be used in the selected content type. FIG. 8C illustrates a case where View3 is selected from among three view sections of View1, View2, and View3, and (d) shows that there is no use right for the selected 'View3'.

9 is a diagram for explaining a case where a content reproduction request for a selected view section is requested. In FIG. 9, (a) shows a process of selecting a type of content to be used, and (b) shows a process of selecting a content title to be used in the selected content type. 6C illustrates a case where View1 is selected from among three view sections of View1, View2, and View3, and (d) shows a screen on which content corresponding to the selected 'View1' is being played.

10 is a diagram for describing a case in which any one of a plurality of blocks is selected. Referring to FIG. 10, (a) indicates '3.' in the submenu item of the 'Internet' menu item. Go to URL 'is selected, and (b) shows a process of inputting a Uniform Resource Locator (URL) of a content provider to be accessed. 10 (c) shows a process of selecting one of contents provided by a content provider connected by the input URL address, and (d) shows a process of downloading a menu for inputting purchase information on the selected content. Indicates.

As shown in (e) of FIG. 10, a menu for inputting purchase information includes items 801, 803, and 805 for selecting a desired block among three blocks of BlockID1, BlockID2, BlockID3, and FIG. As shown in (f), other usage counts 807, content use start time and end time 809, 811, and time 813 at which use of content can be accumulated can be inputted.

According to the use condition, a credit card number 815 and a password 817 are input through the payment screen, as shown in FIG. After the above process, as shown in Fig. 10H, the usage rights corresponding to the selected content and the selected block are downloaded. 10 (i) is a screen showing that the selected content and usage right information thereof have been downloaded.

11 illustrates a case in which the selected block is reproduced. In FIG. 11, (a) shows a process of selecting a type of content to be used, and (b) shows a process of selecting a content title to be used in the selected content type. (C) of FIG. 6 is a screen that warns that a predetermined section is not playable in the selected content, (d) is a screen showing a case where a section corresponding to the selected block is played, and (e) is a block not selected. This is a screen showing a case in which the section corresponding to the skip is not reproduced. And (f) again shows the screen being reached and played back.

By the above process, only the view section or block selected in the DRM content can be reproduced.

On the other hand, the present invention can also be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and also include those implemented in the form of carrier waves such as transmission over the Internet. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

As described above, according to the present invention, the DRM content protected by encryption may be divided into a plurality of view sections or blocks, and may be provided so that the user can use only the view sections or blocks selected by the user. Therefore, different contents may be played for the same DRM content according to the user's taste or age. In addition, the present invention can be easily implemented with a simple change of software without changing the hardware.

Claims (14)

Selecting a view section to be used for DRM content in which a plurality of view sections are set; Receiving usage rights information of the DRM content including the DRM content and information corresponding to the selected view section; And And allowing the use of the DRM content only for the selected view period according to the usage right information. The method of claim 1, The permission information is digital rights management method, characterized in that described in Rights Expression Language (REL) according to the OMA standard. The method of claim 2, And the identifier for setting the view section is a <view> element. Selecting a block to be used for the DRM content divided into a plurality of blocks; Receiving usage right information of the DRM content including the DRM content and information corresponding to the selected block; And And reproducing a section corresponding to the selected block in the DRM content and skipping a section corresponding to the unselected block according to the usage right information. The method of claim 4, wherein The permission information is digital rights management method, characterized in that described in Rights Expression Language (REL) according to the OMA standard. The method of claim 5, And the identifier for setting the view interval is an <allow> element. Generating usage rights information on the DRM content including information on a selected view period among the plurality of view sections in the DRM content in which a plurality of view sections are set; And And transmitting the DRM content and the usage right information. The method of claim 7, wherein And receiving the DRM content and the usage right information, and allowing the use of the DRM content only for the selected view section according to the usage right information. Generating usage rights information on the DRM content including information on a selected block among the plurality of blocks in the DRM content divided into a plurality of blocks; And And transmitting the DRM content and the usage right information. The method of claim 9, Receiving the DRM content and the usage right information, reproducing a section corresponding to the selected block according to the usage right information, and skipping a section corresponding to the unselected block; How to manage digital rights. A device for selecting a view section to be used for DRM content in which a plurality of view sections are set; And And a content provider configured to transmit the DRM content and usage right information for enabling the use of the DRM content only to the selected view section to the device. A device for selecting a block to be used for the DRM content divided into a plurality of blocks; And And a content provider for transmitting usage rights information to the device to play the DRM content and a section corresponding to the selected block in the DRM content, and to skip a section corresponding to the unselected block. Digital rights management system. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 3. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 4 to 6.

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