EWS-005874
`
`Early Warning Services 1018
`IPR of U.S. Pat. No. 8,887,308
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 1 of 9
`
`US 2005/0065891 Al
`
`FIG. 1
`
`line: <o-cx:rights
`1
`2 line:
`xmins;o-ex="http:/odri,nct/1./ODRL-EX"
`3 line;
`xmins;o-dd="http;//odri.net/1 VODRL-DD" |
`4 line:
`xmins:ds="htip://www.w3.org/2000/09/xmldsig#/"
`5 line: >
`6 line: <o-cx:context>
`7 line:
`<o-dd:verston>1.0</o-dd:version>
`8 line; </o-ex:context>
`9 line: <o-cx:agreement>
`10 line:—<o-ex:asset>
`11 line:
`<o-ex:context>
`12 line:
`<o-dd:uid>cid:4567829547@foo.com</o-dd:uid>
`13 line:
`</o-ex:context>
`14 line:
`<ds:KeyInfo>
`15 line:
`<ds:KeyValuc>vUEWR8LzEJociCt+dgll mgg= </ds:KeyValue>
`16 line;
`</ds:Keylnfo>
`l7line:
`-</o-exzasset>
`$line;—<o-ex:permission>
`19 line
`<o-dd:play/>
`20 line:=</o-ex:permission>
`21 line: </o-ex:agreement>
`22 line:</o-ex: rights>
`
`EWS-005875
`
`EWS-005875
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 2 of 9
`
`US 2005/0065891 Al
`
`FIG.2
`
`line: <o-ex:rights
`1
`2 line:
`xmins:o-ex="http://odri.nct/1./ODRL-EX"
`3 line:
`xmins:o-dd="http://odri.net/1. VODRL-DD"
`4 line:
`xmins:ds="http:/Avww.w3.org/2000/09/xmldsigH/"
`5 line: >
`6 line: <o-cx:context>
`7 line:
`<o-dd:version> 1,0</o-dd:version>
`8 line: </o-cx:context>
`9 line: <o-cx:agreement>
`10 line:
`<o-ex:asset>
`11 line:
`<o-ex:context>
`12 Sine:
`<o-dd: uid>cid:4567829547@foo.com</o-dd:uid>
`13 line:
`</o-ex:context>
`14 line:
`<ds:KeyInfo>
`15 line:
`<ds:KeyValuc>vUEWR8LzEJociC+dgl I mgg== </ds:KeyValue>
`16 line:
`</ds:Keyl nfo>
`17 line:=</o-ex:asset>
`18line:—<9-ex:permission>
`19 line;
`<o-dd:display>
`20 line:
`<o-ex:constraint>
`21 line:
`<o-dd:count>1</o-dd:/count>
`22 line:
`</o-cx;constraint>
`23 line:
`<o-ddidisplay>
`20 line:=</o-ex:permission>
`21 line: </o-cx:agreement>
`22 line:</o-ex: rights>
`
`EWS-005876
`
`EWS-005876
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 3 of 9
`
`US 2005/0065891 Al
`
`FIG. 3A
`
`Rights{
`
`Device_ID1; Device_ID2; Device_ID3; ...
`
`}
`
`FIG. 3B
`
`TRANSMIT
`CONTENT WITH
`LICENSE
`INFORMATION
`TO DEVICE
`
`S10
`
`EXTRACT
`IDENTIFIERS
`
`COMPARE
`EXTRACTED
`
`IDENTIFIERS TO
`DEVICE IDENTIFIER
`
`$12
`
`S11
`EXTRACTED IDENTIFIER
`
`REPRODUCE CONTENTIF
`DEVICE IDENTIFIER
`CORRESPONDS TO
`
`S13
`
`EWS-005877
`
`EWS-005877
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 4 of 9
`
`US 2005/0065891 Al
`
`FIG. 4A
`
`Rights{
`
`Domain-ID;
`
`}
`
`FIG. 4B
`
`TRANSMIT CONTENT
`INCLUDING LICENSE
`INFORMATION TO
`
`S20
`
`EXTRACT LOGICAL
`DOMAIN IDENTIFIER
`
`S21
`
`S22
`
`DEVICE
`
`
`
`
`
`COMPARE EXTRACTED
`LOGICAL DOMAIN
`IDENTIFIER TO DEVICE
`IDENTIFIER
`
`
`
`REPRODUCE CONTENTIF
`DEVICE IDENTIFIER
`CORRESPONDS TO
`EXTRACTED LOGICAL DOMAIN
`IDENTIFIER
`
`S23
`
`EWS-005878
`
`EWS-005878
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 5 of 9
`
`US 2005/0065891 Al
`
`FIG. 4C
`
`
`
`TRANSMIT CONTENT
`INCLUDING LICENSE
`INFORMATION TO
`DEVICE
`
`EXTRACT INFORMATION
`REGARDING NUMBER OF
`REPRODUCTION TIMES
`
`DETERMINE IF CONTENT
`CAN BE REPRODUCED
`BASED ON EXTRACTED
`INFORMATION
`
`530
`
`S31
`
`S32
`
`
`
`
`
`
`REPRODUCE CONTENTIF
`IT IS DETERMINED
`CONTENT CAN BE
`REPRODUCED
`
`
`
`/ $33
`
`TRANSMIT MODIFIED
`INFORMATION REGARDING
`NUMBER OF REPRODUCTION
`TIMES
`
`S34
`
`EWS-005879
`
`EWS-005879
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 6 of 9
`
`US 2005/0065891 Al
`
`FIG. 5A
`
`
`)
`
`Rights Issuer
`(DRM Serviceprovider)
`
`530
`
`CR500
`
`540
`
`
`
`500
`
`Domain
`
`EWS-005880
`
`EWS-005880
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 7 of 9
`
`US 2005/0065891 Al
`
`FIG. 5B
`
`RECEIVE CONTENT
`INCLUDING LICENSE
`INFORMATION AT
`SERVER
`
`EXTRACT LICENSE
`
`INFORMATION
`
`
`
`542
`
`DETERMINE WHETHER A DEVICE
`REQUESTING TO REPRODUCE THE
`CONTENT IS AUTHORIZED IS BASED
`ON EXTRACTED INFORMATION
`
`
`
`
`
`
`PROVIDE CONTENT TO
`DEVICEIF IT IS DETERMINED
`
`
`DEVICE IS AUTHORIZED
`
`
`S43
`
`MODIFY STATUS VALUES OF
`
`LICENSE INFORMATION
`
`S44
`
`EWS-005881
`
`EWS-005881
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 8 of 9
`
`US 2005/0065891 Al
`
`FIG. 5C
`
`RECEIVE CONTENT
`INCLUDING LICENSE
`INFORMATION AT
`SERVER
`
`S50
`
`
`
`DIVIDE LICENSE INFORMATION
`INTO ACCESS RIGHTS AND
`
`ASSIGN ACCESS RIGHTS TO
`DEVICE(S)
`
`
`
`951
`
`
`
`
`
`TRANSMIT ACCESS RIGHTS TO
`DEVICE(S)
`
`REPRODUCE CONTENT AT
`DEVICE(S)
`
`S53
`
`$52
`
`EWS-005882
`
`EWS-005882
`
`

`

`Patent Application Publication Mar. 24,2005 Sheet 9 of 9
`
`US 2005/0065891 Al
`
`FIG. 6A
`
`Rights{
`
`Device 5;
`
`}
`
`FIG. 6B
`
`TRANSMIT CONTENT
`INCLUDING LICENSE
`INFORMATION TO
`DEVICE
`
`S60
`
`
`
`EXTRACT INFORMATION
`REGARDING NUMBER OF
`DEVICES AUTHORIZED TO
`REPRODUCE THE CONTENT
`
`
`
`S61
`
`
`
`
`DETERMINE IF CONTENT
`CAN BE REPRODUCED
`BASED ON EXTRACTED
`INFORMATION
`
`
`
`REPRODUCE CONTENTIF
`IT IS DETERMINED
`CONTENT CAN BE
`REPRODUCED
`
`
`
`S63
`
`TRANSMIT MODIFIED
`INFORMATION REGARDING
`NUMBEROF DEVICES
`AUTHORIZED TO REPRODUCE
`THE CONTENT
`
`S64
`
`EWS-005883
`
`EWS-005883
`
`

`

`US 2005/0065891 Al
`
`Mar. 24, 2005
`
`METHOD OF GRANTING DRM LICENSE TO
`SUPPORT PLURAL DEVICES
`
`[0015] The <interval> element represents a period of time
`for which the content can be used, and its start point is the
`time whenthe contentis first used. For example, if the value
`BACKGROUND OF THE INVENTION
`of the <interval> element is expressed as ‘10 d,’ the content
`can be freely used for 10 days fromafirst use of the content.
`[0001] This application is based on and claims priority
`from Korean Patent Application No. 10-2003-0064861, filed
`on Sep. 18, 2003 with the Korean Intellectual Property
`Office, the disclosure of which is incorporated herein in its
`entirety by reference.
`
`[0016] The <accumulated> element represents a maxi-
`mally accumulated time of the use of the content. For
`example, if the <accumulated> elementhas a value of ‘10h,’
`the total reproduction time of the content should not exceed
`10 hours.
`
`[0002]
`
`1. Field of the Invention
`
`[0017] The <start> and <end> elements are described in
`pairs, and indicate that content can be freely used from the
`date specified in the <start> element to the date specified in
`the <end> element.
`
`invention relates to Digital Rights
`[0003] The present
`Management (DRM)licenses, and more particularly, to a
`method of granting a DRM license to support a plurality of
`devices capable of processing digital information.
`[0018] Heretofore, typical DRM_techniques include
`
`
`[0004]
`2. Description of the Prior Art
`Microsoft’s DRM, Open Mobile Alliance (OMA) DRM,and
`the like. In such techniques, content is generally allowed to
`be reproduced through only one device to which a license is
`bound. Thus, there is inconvenience in that if a user pos-
`sesses a plurality of devices,
`the user cannot reproduce
`portions of content on more than one of the devices, using
`the content and a license correspondingthereto.
`
`[0005] Generally, according to conventional DRM tech-
`niques, content can be reproduced through only one device,
`depending on the content purchased by a consumer and the
`details of a license for the content.
`
`in conventional DRM environ-
`In other words,
`[0006]
`ments, consumers are provided with content by content
`providers and purchaselicenses for the content. At this time,
`each of the licenses is adapted to be effective for only one
`device. In this regard, there are a device binding scheme and
`a user binding scheme.
`
`In the device binding scheme, a license purchased
`[0007]
`by consumers depends on devices and only a relevant device
`is authorized to reproduce the content. On the contrary, in
`the user binding scheme, licenses purchased by consumers
`depend on users, and for example, there is a scheme using
`subscriber identification module (SIM) cards or smart cards.
`
`[0009] Lines 1 to 5 represent the beginning of the DRM
`license,
`and
`describe
`information
`regarding XML
`namespace for providing information on interpretation of
`XML.
`
`[0010] Lines 6 to 8 describe information regarding the
`version of a DRM system to which the DRM license is
`applied.
`
`[0011] Lines 9 to 21 contain content information and the
`details of the DRM license, and are expressed using <asset>
`and <permission> elements.
`
`[0012] The <asset> element describes, in lines 11 to 13, an
`identifier of the content to which the DRM licenseis applied,
`and describes, in lines 14 to 16, information on a content
`encryption key (CEK) with which encrypted content can be
`decrypted.
`
`[0013] The <permission> element describes, in lines 18 to
`20, that content can be reproduced.
`
`FIG.2 is an exemplary view illustrating the struc-
`[0014]
`ture of another conventional DRM license. Lines 19 to 23
`
`describe that content can be reproduced, but only once. A
`<constraint> element in line 20 may include elements such
`as <interval>, <accumulated>, <start>, <end> and/or
`<count>.
`
`[0020] According to another exemplary embodiment of
`the present invention,there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising transmitting content from
`[0008] FIG.1is an exemplary view illustrating the struc-
`the server to at least one of the plurality of devices, the
`ture of a conventional DRM license that is expressed in
`content containing license information that includes identi-
`Extensible Markup Language (XML).
`fiers for two or more of the plurality of devices capable of
`reproducing the content respectively, extracting the identi-
`fiers included in the license information from the received
`
`SUMMARYOF THE INVENTION
`
`[0019] According to an exemplary embodiment of the
`present
`invention,
`there is provided a license structure
`enabling reproduction of digital contents through a plurality
`of devices, and a method of reproducing digital content
`through plural devices using the license structure.
`
`content, and whenthe extracted identifier corresponds to an
`identifier of the device, reproducing the content by the
`device.
`
`[0021] According to another exemplary embodiment of
`the present invention,there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising transmitting content from
`the server to at least one of the plurality of devices, the
`content containing license information that
`includes an
`identifier for identifying a logical domain to which two or
`moreof the plurality of devices capable of reproducing the
`content belong extracting the identifiers included in the
`license information from the received content, and when the
`extracted identifier correspondsto an identifier of the logical
`domain to which a device intending to reproduce the content
`belongs, reproducing the content by the device.
`
`[0022] According to another exemplary embodiment of
`the present invention,there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising transmitting content from
`the server to at least one of the plurality of devices, the
`content containing license information that includes infor-
`mation regarding a number of reproduction times of the
`
`EWS-005884
`
`EWS-005884
`
`

`

`US 2005/0065891 Al
`
`Mar. 24, 2005
`
`content, extracting the information on the numberof repro-
`duction times included in the license information from the
`received content, when it is determined from the extracted
`information that
`the device intending to reproduce the
`content can reproduce the content, reproducing the received
`content by the device, and transmitting modified information
`on the numberof reproduction times and the license from the
`device to other devices so that they can extract the modified
`information on the numberof reproduction times and use the
`content.
`
`[0023] According to another exemplary embodiment of
`the present invention, there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising transmitting content from
`the server to at least one of the plurality of devices, the
`content containing license information that includes infor-
`mation regarding a numberof devices capable of reproduc-
`ing the content, extracting the information on the numberof
`devices included in the license information from the
`received content, when it is determined from the extracted
`information that
`the device intending to reproduce the
`content can reproduce the content, reproducing the received
`content by the device, and transmitting modified information
`on the numberof devices and the license from the device to
`other devices so that they can extract the modified informa-
`tion on the number of devices and use the content.
`
`[0024] According to another exemplary embodiment of
`the present invention, there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising receiving content and
`license information on the content by the server adapted to
`manage a logical domain to which two or more of the
`plurality of devices capable of reproducing the content
`belong verifying by the server the received license informa-
`tion, if one of the plurality of devices requests the content,
`and providing the requested content by the server to the
`device and updating status valuesof the license information,
`if it is verified that the license is a legitimate license.
`
`[0025] According to another exemplary embodiment of
`the present invention, there is provided a method of granting
`a digital rights management license between a server and a
`plurality of devices, comprising receiving content and
`license information on the content by a server adapted to
`manage a logical domain to which two or more of the
`plurality of devices capable of reproducing the content
`belong,splitting the received license information into pieces
`of license information for the respective devices which
`belong to the logical domain,
`transmitting the pieces of
`license information and the received content to relevant one
`or more of the plurality of devices, and reproducing the
`content according to the received pieces of license informa-
`tion.
`
`[0029] FIG. 3A is an exemplary view illustrating a
`description of a plurality of device identifiers in the structure
`of a DRM license according to an exemplary embodimentof
`the present invention;
`
`[0030] FIG. 3B is a flowchart illustrating an exemplary
`method of granting a DRM license by providing identifiers
`of devices capable of reproducing content according to an
`exemplary embodiment of the present invention;
`
`[0031] FIG. 4A is an exemplary view illustrating a
`description of a specific domain identifier in the structure of
`a DRMlicense according to an exemplary embodiment of
`the present invention;
`
`[0032] FIG. 4B is a flowchart illustrating an exemplary
`method of granting a DRM license by providing a domain
`identifier for identifying a domain incorporating a plurality
`of devices capable of reproducing content according to an
`exemplary embodiment of the present invention;
`
`[0033] FIG. 4C is a flowchart illustrating an exemplary
`method of granting a DRM licenseby providing information
`regarding the number times the content can be reproduced
`according to an exemplary embodiment of the present
`invention;
`
`[0034] FIG. 5A is an exemplary diagram showing man-
`agement of a DRM license by a DRMserver, according to
`an exemplary embodiment of the present invention;
`
`[0035] FIG. 5B is a flowchart illustrating management of
`a DRMlicense by the DRM server according to an exem-
`plary embodimentof the present invention;
`
`[0036] FIG. 5C is a flowchartillustrating management of
`a DRM license by the DRM server according to another
`exemplary embodiment of the present invention;
`
`[0037] FIG. 6A is an exemplary view illustrating the
`structure of a DRM license for limiting the number of
`devices authorized to reproduce contents, according to an
`exemplary embodimentof the present invention; and
`
`[0038] FIG. 6B is a flowchart illustrating an exemplary
`method of granting a DRM licenseby providing information
`limiting the numberof devices authorized to reproduce the
`content according to an exemplary embodiment of the
`present invention.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`[0039] Hereinafter, methods of granting a DRM license to
`support a plurality of devices according to exemplary
`embodimentsof the present invention will be described with
`reference to the accompanying drawings.
`
`[0040] DRM licenses may be classified into two cases: a
`first case with varying status values and a second case with
`non-varying status values. In other words, if <start> and
`<end> elements are described, content can be used at any
`time during a relevant period of time specified by the
`elements. Thus, relevant status values do not vary. However,
`if there is a limitation on the numberofuse times of content,
`as in line 21 of FIG. 2, the relevant value varies whenever
`[0027] FIG.1is an exemplary view illustrating the struc-
`the content is used. The present invention will be described
`ture of a conventional DRM license;
`in connection with methods that can be applied to both the
`first case in which the status values of a DRM license vary
`and the second case in which the status values do not vary,
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0026] The above and other objects and features of the
`present invention will become apparent from the following
`description of exemplary embodiments given in conjunction
`with the accompanying drawings, in which:
`
`[0028] FIG. 2 is an exemplary view illustrating the struc-
`ture of another conventional DRM license;
`
`EWS-005885
`
`EWS-005885
`
`

`

`US 2005/0065891 Al
`
`Mar. 24, 2005
`
`as described above. In addition, the structure of a DRM
`license to be described later can be expressed in XML or
`implemented with a separate objector data structure depend-
`ing on the DRM environment.
`
`logical domain identifier to an identifier of the device (S22).
`If the identifier of the device corresponds to the extracted
`logical domain identifier, the device is authorized to repro-
`duce the content (S23).
`
`[0041] FIG. 3A is an exemplary view illustrating a
`description of a plurality of device identifiers in the structure
`of a DRM license according to an exemplary embodimentof
`the present
`invention. This corresponds to a method of
`describing unique identifiers for devices capable of repro-
`ducing content. Therefore, only devices corresponding to the
`device identifiers described in the structure of the DRM
`
`license have rights to access the content. In other words, a
`user having devices with a DRM function usually purchases
`a license structure, which has a description of reproduction
`details for a plurality of devices, from a license issuer. In the
`license structure, unique identifiers for devices that are
`authorized to reproduce content are described. Accordingly,
`if a device has an identifier corresponding to one of the
`device identifiers described in the license structure,
`the
`device can reproduce the relevant content. Such a method
`may be properly applied to the structure of a DRM license
`in which status values of the DRM license do not vary.
`
`[0042] FIG. 3B is a flowchart illustrating an exemplary
`method of granting a DRM license by providing unique
`identifiers for a plurality of devices capable of reproducing
`content. Initially, content including license information is
`transmitted from a DRMserverto at least one of a plurality
`of devices (S10). The license information includes identifi-
`ers for at
`least
`two devices capable of reproducing the
`content, e.g., as shown in FIG. 3A. The device extracts the
`identifiers included in the license information (S11) and
`compares the extracted identifiers to an identifier of the
`device (S12). If the identifier of the device corresponds to
`one of the extracted identifiers, the device is authorized to
`reproduce the content (S13).
`
`[0043] FIG. 4A is an exemplary view illustrating a
`description of a specific domain identifier in the structure of
`a DRMlicense according to an exemplary embodiment of
`the present
`invention. This corresponds to a method of
`describing a unique identifier for a specific domain incor-
`porating devices capable of reproducing content. Therefore,
`only the devices that are incorporated in the domain corre-
`sponding to the domain identifier described in the structure
`of the DRM license haverights to access the content. Such
`a method maybe properly applied to the structure of a DRM
`license in which status values of the DRM license do not
`vary.
`
`[0044] The DRMlicense structure illustrated in FIGS. 3A
`or 4A may beprovided by a content provider or a separate
`license creator and does not require installation of an addi-
`tional DRMserver on the userside.
`
`[0045] FIG. 4B a is flowchart illustrating an exemplary
`method of granting a DRM license by providing a logical
`domain identifier for identifying a domain incorporating
`devices capable of reproducing content. Initially, content
`including license information is transmitted from a DRM
`server to at least one of a plurality of devices (S20). The
`license information includes an identifier for identifying a
`logical domain to which at least two devices capable of
`reproducing the content belong, e.g., as shown in FIG. 4A.
`The device extracts the logical domain identifier included in
`the license information (S21) and compares the extracted
`
`[0046] FIG. 4C is a flowchart illustrating an exemplary
`method of granting a DRM licenseby providing information
`regarding the numbertimes the content can be reproduced.
`Initially, content including license informationis transmitted
`from a DRMserverto at least one of a plurality of devices
`(S30). The license information includes an information
`regarding a numberof times the content may be reproduced.
`The device extracts the information regarding the numberof
`times the content may be reproduced (S31) and determines
`whether
`the content may be reproduced based on the
`extracted information (S32). If device determines the con-
`tent can be reproduced, the device reproduces the content
`(S33). The device then transmits modified/rpdated informa-
`tion regarding the number of times the content can be
`reproduced to other devices so that the other devices can
`extract the modified information and use the contentif the
`numberof uses has not been exhausted (S34).
`
`[0047] FIG. 5A is an exemplary diagram showing man-
`agement of a DRM license by a DRMserver, according to
`an exemplary embodiment of the present invention.
`
`[0048] Specifically, an identifiable domain 500 includes a
`plurality of devices 530, 540 and 550 capable of reproducing
`content, and a DRM server 520 for managing licenses for
`content received from the outside. Meanwhile, a license
`creator (DRM service provider) 510 provides a license
`structure (rights) 560 for the relevant content. Alternatively,
`a content provider that provides the content may also
`provide the license structure together therewith. The DRM
`server 520 manages the license and license status informa-
`tion related thereto. Therefore, the management of DRM
`licenses shown in FIG. 5A can be applied regardless of
`whether the status values of a given license vary.
`
`[0049] FIG. 5B is a flowchart illustrating management of
`a DRM license by the DRM server 520. Initially, content
`including license information is received by the server 520
`(S40). The license information includes information regard-
`ing whether the devices 530, 540 and 550 are authorized to
`reproduce the content. The server 520 extracts the license
`information (S41) and determines whether the one of the
`devices 520, 530 and 540 requesting to reproduce is autho-
`rized to reproduce the content based on the extracted infor-
`mation (S42). If the server 520 determines the requesting
`device is authorized to reproduce the content, the server 520
`provides the content to the device (S43) and updates the
`license information (S44).
`
`[0050] For example, in the case where the license infor-
`mation includes domain identifier for identifying a domain
`incorporating devices capable of reproducing content as
`shown in FIG.4A, by performing an authentication process
`between the DRM server 520 and the devices 530, 540 and
`550, it is checked whether the devices are authorized devices
`belonging to the domain 500. Thereafter,
`the process of
`generating an encryption key for protecting information
`transmitted/received between the DRM server 520 and the
`devices 530, 540 and 550 is performed. Then, one of the
`devices requests the DRM server 520 to authorize the device
`to access the content. In response to the request, the DRM
`server 520 determines whetherthe device that has requested
`
`EWS-005886
`
`EWS-005886
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`

`

`US 2005/0065891 Al
`
`Mar. 24, 2005
`
`the access to the content is described in the license structure
`of the DRM server 520. If it is determined that the device is
`
`described therein, the device is authorized to reproduce the
`content, and status values of the license are then changed/
`updated accordingly.
`
`[0051] The DRM server 520 may also divide the license
`into respective rights constructing the license and assigns
`resultant rights to the devices 530, 540 and 550 that it
`managessuchthat the devices 530, 540 and 550 can then use
`the content within the scope of the assigned nghts, respec-
`tively. As shown in FIG. 5C, the DRM server 520 receives
`content and license information (S50) and divides the
`1. A method of granting a digital rights management
`license information into access rights which are assigned to
`license between a server andaplurality of devices, the
`the respective devices 530, 540 and 550 (S51). The DRM
`method comprising:
`server 520 then transmits the access rights to the devices
`530, 540 and 550 which reproduce the content according to
`the access rights (S52 and S53).
`
`of devices using a license structure for reproducing DRM
`content, so that content users can more conveniently utilize
`the content in various DRM environments.
`
`[0056] Although the present invention has been described
`in connection with the exemplary embodiments illustrated in
`the accompanying drawings, those skilled in the art can
`make various substitutions, modifications and changes with-
`out departing from the scope of the present invention. Thus,
`the present
`invention is not
`limited to the exemplary
`embodiments and the drawings.
`
`Whatis claimedis:
`
`transmitting content from the serverto at least one device
`of the plurality of devices,
`the content comprising
`license information that includes identifiers for at least
`two devices of the plurality of devices capable of
`reproducing the content respectively;
`
`extracting the identifiers included in the license informa-
`tion from the content received at the least one device;
`and
`
`[0052] For example, if the license relates to playback time,
`the server 520 splits the total playback time into playback
`times for the respective devices and assigns the resultant
`playback times to the devices 530, 540 and 550. As another
`example, if the license relates to the number of reproduction
`times, the server 520 splits the total number of reproduction
`times into numbers of reproduction times for the respective
`devices, and assigns the resultant numbers of reproduction
`times to the devices 530, 540 and 550.
`
`if an extracted identifier correspondsto an identifier of the
`at least one device, reproducing the content by the at
`least one device.
`[0053] FIG. 6A is an exemplary view illustrating the
`2. A method of granting a digital rights management
`structure of a DRM license for limiting the number of
`license between a server andaplurality of devices, the
`devices authorized to reproduce content, according to an
`method comprising:
`exemplary embodiment of the present invention. Specifi-
`cally, this corresponds to a method by which, without a
`description of identifiers of devices authorized to reproduce
`content in the structure of the DRM license, information
`regarding how many devices are authorized to reproduce the
`content is described and the DRM server 520 shown in FIG.
`
`transmitting content from the serverto at least one device
`of the plurality of devices,
`the content comprising
`license information that includes an identifier for iden-
`
`tifying a logical domain to which at two devices of the
`plurality of devices capable of reproducing the content
`belong;
`
`extracting the identifier included in the license informa-
`tion from the content received by the at
`least one
`device; and
`
`5A manages the numberof the devices. FIG. 6A showsthat
`a maximum five devices are authorized to reproduce the
`content. According to the method of specifying the number
`of devices shown in FIG. 6A, the DRM server 520 can
`efficiently manage a license even if unique identifiers of the
`devices are not specified, a new device is added, or a device
`is removed.
`
`if an extracted identifier correspondsto an identifier of the
`logical domain to which the at least one device intend-
`ing to reproduce the content belongs, reproducing the
`illustrating an exemplary
`[0054] FIG. 6B is flowchart
`content by the at least one device.
`method of granting a DRM license by transmitting infor-
`3. A method of granting a digital rights management
`mation regarding the numberof devices authorized to repro-
`license between a server andaplurality of devices, the
`duce the content. Initially, content including license infor-
`method comprising:
`mation is transmitted from a server to at least one of a
`plurality of devices (S60). The license information includes
`an information regarding the numberof devices authorized
`to reproduce the content, e.g., as shown in FIG. 6A. The
`device extracts the information regarding the number of
`devices authorized to reproduce the content
`(S61) and
`determines whether the content may be reproduced based on
`the extracted information (S62). If device determines the
`content can be reproduced, the device reproduces the content
`(S63). The device then transmits modified/updated informa-
`tion regarding the number of devices which can reproduce
`the content to other devices so that the other devices can
`extract the modified information and use the contentif the
`number of devices has not been exhausted (S64).
`
`transmitting content from the serverto at least one device
`of the plurality of devices,
`the content comprising
`license information that includes information regarding
`a numberof times the content can be reproduced;
`
`least one device the information
`the at
`extracting at
`regarding the number of times the content can be
`reproduced includedin the license information from the
`content received by the at least one device;
`
`if it is determined from the information extracted by the
`at least one device that the at least one device can
`reproduce the content, reproducing the content by the at
`least one device; and
`
`there is an
`invention,
`[0055] According to the present
`advantage in that content can be executed througha plurality
`
`transmitting the license information including modified
`information regarding the numberof times the content
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`EWS-005887
`
`EWS-005887
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`

`

`US 2005/0065891 Al
`
`Mar. 24, 2005
`
`can be reproduced from the at least one device to other
`devices of the plurality of devices so that the other
`devices can extract the modified information regarding
`the numberof reproduction times and use the content.
`4. A method of granting a digital rights management
`license between a server and a plurality of devices,
`the
`method comprising:
`
`transmitting content from the server to at least one device
`of the plurality of devices,
`the content comprising
`license information that includes information regarding
`a number of devices authorized to reproduce the con-
`tent;
`
`server, if it is determined that the at least one device is
`authorized to reproduce the content.
`6. The method as claimed in claim 5, wherein the license
`information comprises information regarding a number of
`times of the content can be reproduced.
`7. The method as claimed in claim 5, wherein the license
`information comprises information regarding a number of
`devices authorized to reproduce the content.
`8. The method as claimed in claim 5, wherein the license
`information comprises information regarding a total repro-
`duction time for which the content can be reproduced.
`9. A method of granting a digital rights management
`license between a server andaplurality of devices, the
`extracting the information regarding the number of
`devices included in the license information from the
`method comprising:
`content received by the at least one device;
`
`if it is determined from the information extracted by the
`at least one device that the at least one device can
`
`reproduce the content, reproducing the received content
`by the at least one device; and
`
`transmitting the license information including modified
`information regarding the number of devices autho-
`rized to reproduce the content from the at least one
`device to other devices of the plurality of devices so
`that the other devices can extract the modified infor-
`
`mation regarding the number of devices and use the
`content.
`
`5. A method of granting a digital rights management
`license between a server and a plurality of devices,
`the
`method comprising:
`
`receiving content and li