KR20060021842A - Transferring content between digital rights management systems - Google Patents

Abstract

The invention relates to a method, system and computer program product for transferring encrypted content (1) and a corresponding license (4) that are contained in a first device (3) that uses a first Digital Rights Management (DRM) system of a first or second type to a second device (7) that uses a second DRM system of a first or second type, wherein said encrypted content (1) obeys the content format of said first DRM system; wherein said corresponding license (4) obeys the Rights Expression Language of said first DRM system; wherein one of said devices (3) provides an Application Programming Interface (API) (6) for importing and/or exporting said encrypted content (1) and said corresponding license (4); and wherein the other device (7) provides an application (8) for transferring (13, 14) said encrypted content (1) and said corresponding license (4).

Description

Transferring content between digital rights management systems

The present invention relates to an encrypted content and a corresponding license included in a first device using a first type or second type of first digital rights management (DRM) system. 2 relates to a method for transmitting to a second device using a DRM system. Wherein the encrypted content is in accordance with the content format of the first DRM system; The corresponding license is in accordance with the Rights Expression Language (REL) of the first DRM system.

Portable wireless network operators and content providers have already sold small video clips and computer games for information and entertainment, as well as ring tones and icons that personalize a user's mobile phone. The business of downloading ringing tones and logos over the air interface of a portable wireless network has already reached € 1.5 billion in Europe in 2000, especially in the future with more sophisticated audio / calling formats, multimedia messaging service (MMS). It is expected to grow further in connection with the improved transmission capabilities provided and the development of more advanced portable multimedia terminals.

In the case of ring tones, portable wireless network operators have recently acted as billing tollers by providing their charging platform for many content retailers. Content such as ringtones to be downloaded is generally protected by a "forward-lock". That is, the content can only be used on the mobile phone from which it was downloaded (and paid) and cannot be transferred to another mobile phone. The simplest approach to this "Digital Rights Management" (DRM) is called delivery control. If the forward-lock is released, the alternative control mechanism is "use control." In this case, the usage rights for the content are represented by portable rights vouchers that are created and distributed separately from the content objects. Payment charges will be collected in exchange for vouchers issued. At the core of the control is the middleware of the mobile phone. The user must present the content object and associated vouchers prior to playing or storing the downloaded media. The great advantage of usage control is that content can be widely distributed by peer-to-peer communication among mobile phone users in a large community. Once downloaded, the content can be transferred to other mobile phones, in which case the user must purchase a portable rights voucher prior to delivering the content.

The key components of a DRM system that can manage content retail systems based on usage restrictions are:

A voucher server (VS) operated by an operator acting as a content retailer or content retailer. The VS registers the content with a mobile phone DRM system and issues vouchers.

If the content server CS is operated in an aggregation mode, it is operated by the content retailer or its content partners. The CS includes content that can be downloaded.

The DRM broker is run by the bill collector. Here the bill collector will be the operator. The broker is effectively a "rights-clearing feature" in a portable payment solution via interfaces to payment systems.

The content retailers (VS and CS owners) enter into contracts for payment and exchange of rights with the operator (the owner of the DRM broker) by agreeing to pay a percentage of each exchanged transaction. The content retailer's VS knows all of its unique content in circulation. The owner of the CS must register each content object that he wants to import into the portable DRM system. In essence, registration of content means that CS sends the content object to the VS. VS generates a unique Content ID and encrypts the content into a DRM specific content package. The entire process of encrypting the content and generating vouchers (licenses) for the encrypted content is in accordance with the rights expression language (REL) of the DRM system.

Browsing and downloading of registered content occurs directly between the CS and the user regardless of the purchase process of the voucher. Once downloaded, the registered content will be freely transferred from the terminal to the terminal. When the user wants to deliver the registered content, the terminal checks whether a voucher with a related content ID exists in the terminal. If no such voucher exists, the terminal initiates a payment and rights exchange process through a payment service provider.

The purchase of the voucher is performed by the DRM based on the VS address. Once the user agrees to pay, the DRM broker clears the payment and requests a voucher from the VS. The rights exchange process is completed by the DRM broker sending the voucher generated by the VS to the user.

A DRM system for controlling the delivery of protected portions of digital content on a computing device is disclosed in WO 00/058811 A2. The DRM system has a license (voucher) store, a license evaluator and a state store. The license store stores the purchased digital license on the computing device. The license evaluator determines whether certain licenses stored in the license store correspond to the required digital content and which of those corresponding licenses are valid, review the license rules for each of those valid licenses, and so do so Based on the license rules set forth above, it is determined whether such license permits the requesting user to deliver the requested digital content in the manner sought. The state store maintains state information corresponding to each license in the license store. Wherein the state information is generated and updated by the license evaluator as necessary.

Modern DRM systems are based on the assumption that the rendering of digital content should be limited to the terminal from which the voucher is downloaded. However, if each of several terminals is controlled by the DRM system, if the user who owns several terminals wants to deliver the digital content that has already been paid on two or more of the terminals, the user must deliver the content. You will be forced to purchase more vouchers for each terminal. Even more undesirable is that if the DRM systems implemented by the terminals are not compatible with each other, then it is impossible to transfer the content between the terminals. This is because the DRM system of the terminal will not be able to decrypt the content and will not be able to identify the DRM broker that allows the purchase of the corresponding voucher.

In view of these shortcomings of the latest DRM systems, an object of the present invention is therefore to provide a method for transferring content between DRM systems.

An object of the present invention is to provide an encrypted content and a corresponding license included in a first device using a first type or second type of first digital rights management (DRM) system to a second type of DRM of a first type or a second type. 10. A method of transmitting to a second device using a system, wherein the encrypted content is in accordance with a content format of the first DRM system; The corresponding license is in accordance with a rights expression language (REL) of the first DRM system; One of the first device and the second device provides an application programming interface (API) for importing and / or exporting the encrypted content and the corresponding license; And another one of the first device and the second device provides an application for transmitting the encrypted content and the corresponding license, wherein the method of transmitting comprises: establishing a connection between the devices; Authorizing access to the API, and transmitting, by the application, the encrypted content and the corresponding license from the first device to the second device via the API. Is achieved by proposing. Once a physical and logical connection is established between both DRM systems, the operating system of the device providing the API allows the application provided by the other device to access the import / export functionality and thus encrypt The transfer of the content and the corresponding license can be performed by the application. The transfer of content and licenses may be from the device providing the API to another device or vice versa. It is also possible for both devices to provide an API and / or the application.

For example, the device providing the application in such a case can be used as a kind of intermediate storage device in transferring encrypted content and corresponding license, for example, from a source terminal such as a mobile phone to a target terminal such as a mobile phone or a multi-media player. . The encrypted content according to the content format of the first DRM system used by the source terminal and the encrypted content in the source terminal (first device) were purchased from the VS through the DRM broker to enable delivery of the encrypted content. The corresponding license (voucher) is transmitted to the intermediate storage device (second device) using its own DRM system (second DRM system). The transmission is performed by an application provided by the intermediate storage device and uses an API provided by the source terminal. Upon transmission again, the encrypted content and the corresponding license are transferred from the intermediate storage device (now the first device) to the target terminal (now the second device). The target terminal also executes its own DRM system. In addition, the transmission is performed by an application provided by the intermediate storage medium and uses an API currently provided by the target terminal. Thus in both transmissions the source terminal and the target terminal represent the device providing an API, and in both transmissions the intermediate storage device provides an application for transmitting encrypted content and a corresponding license. Indicates.

According to the present invention, the content transmission method preferably further includes the step of verifying the integrity of the application to permit the application to access the API only when the integrity is verified. In order to prevent the intrusive use of the application, the application's access to other protected functions of the API is allowed only if the application has proven its integrity.

According to the invention, the content transmission method preferably further comprises the step of storing the encrypted content and the corresponding license on the second device.

Both the first device and the second device may be included in a single device, for example a single electronic device composed of several integrated components such as a mobile phone or a multi-media player.

According to the present invention, the first DRM system and the second DRM system may be the same type of system. Both DRM systems are compatible. Thus, the encrypted content and the corresponding license can be transferred without any modification between both DRMs.

Alternatively, the first DRM system may be a first type of system and the second DRM system may be a second type of system. At this time, both DRM systems are incompatible with each other. Thus, the encrypted content and the corresponding licenses to be transmitted must be further processed in order to allow delivery of content on the second device.

According to the invention, it is preferable that the content transmission method further comprises the step of modifying the license in the first device or the second device. After transferring the encrypted content and the corresponding license from the first device to the second device, a license in the first DRM system of the first device may, for example, re-transmit the license from the first device even though it is possible to retransmit the content. It can be modified so that it is no longer possible to transmit to the three devices. It is also conceivable that the license in the first device is deleted after each transfer so that delivery of encrypted content is possible only on one device at a time.

When the first DRM system is a system of a first type and the second DRM system is a system of a second type, the encrypted content and the corresponding license are received by the application from the first device through the API. And transmitting to the second device, transcoding the license for the encrypted content from the REL of the first DRM system to the REL of the second DRM system, and transmitting the encrypted content to the first DRM. Preferably, transcribing from the content format of the system to the content format of the second DRM system. The encrypted content is thus decrypted according to the content format of the first DRM system and then encrypted (transmitted) according to the content format of the second DRM system. Very similarly, the license is decoded according to the REL of the first DRM system and then encoded (transcoded) according to the REL of the second DRM system. The transcribed content is then delivered to the second device using the second DRM system with the transcoded license, even though the first DRM system and the second DRM system are inherently incompatible. It can be used in the second device. The transcribed content and transcoded license now follow the content format and REL of the second DRM system, respectively, and are then stored on the second device.

According to the present invention, the device providing the API may be a multi-media device such as a mobile phone, a media player or a personal digital assistant. In addition, the device for providing an application may be a mass storage medium that may be inserted into the device for providing an API or connected to the device for providing an API by a wired or wireless link.

It is further an object of the invention to be achieved by a computer program product comprising software code portions which perform the steps of the method described above when the computer program product is executed on a computer, which can be loaded directly into the internal memory of the digital computer. Can be. The digital computer may be represented, for example, as a micro-processor forming part of one of the devices.

Furthermore, an object of the present invention is to provide an encrypted content and a corresponding license included in a first device using a first type or second type of first digital rights management (DRM) system, the first type or the second type. A content delivery system for transmitting to a second device using a second DRM system, wherein the encrypted content conforms to a content format of the first DRM system; The content license system according to the rights expression language (REL) of the first DRM system,

Means for establishing a connection between the devices, an application programming interface (API) for importing and / or exporting the encrypted content and corresponding license, and an application for transmitting the encrypted content and corresponding license via the API. Wherein the API is provided by one of the first device and the second device, and the application is achieved by a content delivery system provided by the other of the first device and the second device.

According to the invention, the content delivery system preferably further comprises means for verifying the integrity of the application.

According to the invention, the content delivery system preferably further comprises means for storing said encrypted content and said corresponding license in said second device.

According to the present invention, both the first device and the second device can be included in a single device.

According to the present invention, the first DRM system and the second DRM system may be the same type of system.

Alternatively, the first DRM system may be a first type of system and the second DRM system may be a second type of system.

The content delivery system according to the present invention may further comprise means for modifying the license in the first device or the second device.

If the first DRM system is a DRM system of a first type and the second DRM system is a DRM system of a second type, the content delivery system is responsible for REL of the first DRM system. Means for transcoding from a second DRM system to a REL of the second DRM system, and means for transcoding the encrypted content from a content format of the first DRM system to a content format of the second DRM system.

The means for transcoding and transcripting are advantageously provided by the application.

According to the present invention, the device providing the API may be a multi-media device such as a mobile phone, a media player or a personal digital assistant. In addition, the device for providing an application may be a mass storage medium that may be inserted into the device for providing an API or connected to the device for providing an API by a wired or wireless link.

Such and other embodiments of the present invention will be apparent from and elucidated with reference to the embodiments described below.

1 is a schematic illustration of an embodiment of the invention in which encrypted content and corresponding licenses are transferred from a first device having a first DRM system to a second device having a second DRM system.

1 is a view schematically showing an exemplary embodiment of the present invention. The content 1 encrypted by VS according to the content format of the first DRM system is downloaded to the content storage unit 2 of the first device 3. The user of the first device 3 has also purchased a license 4 so that the content can be delivered on the first device 3. The license is generated by the VS of the first DRM system according to the REL of the first DRM system and stored in the license storage unit 5. If the content 1 is to be delivered on the first device 3, the license evaluator, not shown in FIG. 1, causes the license storage 5 to cause the user of the first device 3 to have the content. It is checked whether it contains a predetermined license allowing the delivery of (1). The first device 3 provides an API 6 which can be used for importing and / or exporting the content 1 and the license 4 and granting access to other protected functions.

Also shown in FIG. 1 is a second device 7 comprising an application 8. The second device 7 comprises an application 8 as executable code or source code and takes over the content 1 and the license 4 from a first DRM system used by the first device 3. It can be assumed to be a suitable mass storage medium such as a memory card or a memory stick. For this purpose, the second device provides a content storage 9 and a license storage 10. When the second device 7 is connected to the first device 3 physically, for example by a physical wrap connection 11, the operating system of the first device 3 is connected to the second device 7. Check the integrity of the application 8 included in the < RTI ID = 0.0 > 8 < / RTI > to authorize the application 8 to access the API 6 of the first device 3 via a logical secure connection 12. Check it. While the logical secure connection 12 is established, the DRM agent of the application and the first DRM system performs mutual authentication and also confirms that one side is not invalidated. When the logical secure connection 12 is established, the application 8 requests the content 1 and the license 4 from the content storage 2 and the license storage 5 of the first DRM system. do.

According to the type of the second DRM system used in the second device 7, the content 1 must be transcribed in a translation instance 13 before being stored in the content storage 9. The license must be transcoded in a transcoding instance 14 before being stored in the license storage 10. Only when the second DRM system and the first DRM system are of the same type, no transcoding and transcrypting is required. The crypting step includes decrypting the content encrypted by the VS of the first DRM system according to the content format of the first DRM system, and encrypting the decrypted content according to the content format of the second DRM system. Include. Very similarly, the transcoding step includes decoding the license coded by the VS of the first DRM system according to the REL of the first DRM system, and coding the decoded license according to the REL of the second DRM system. Steps. Information about both the encryption scheme and the scheme of license codes is required for the transcription and transcoding process. In other words, both operations must be authorized to at least to some extent by the content retailer who is the intellectual property owner of the content. Thus, the content 1 and the corresponding license 4 are successfully transferred from the first device 3 to which they were downloaded to the second device 7. If the second device 7 is a simple memory card inserted in the first device 3 and the memory card 7 possesses only simple transcoding / translation and storage capabilities, then the second device It is not possible to deliver the content on (7). However, the memory card 7 may be detached from the first device 3 and inserted into a third device such as a multi-media player. At that time, the transfer of the content and license is performed from the memory card 7 back to the third device. When the DRM system of the third device, that is, the third DRM system is not the same type of DRM system as used in the memory card 7, the content 1 and the license 4 are transferred to the memory card 7. Note that in transmitting from the third apparatus to the third apparatus, more transcription and transcoding are required. That is, the transcoding and transcription instances then also require information about the encryption scheme and license code scheme of the third DRM system. However, when the content 1 and the license 4 are transferred to a third device, the license evaluator of the third device is to receive the encrypted content 1 and the corresponding license 4 according to the third DRM system. Thus it is possible to deliver the content 1 on the third device.

The present invention has been described so far by the above preferred embodiment. It should be noted that there are alternative methods and modifications that are apparent to those skilled in the art and can be implemented without departing from the technical scope and spirit of the appended claims. For example, the transcrypting and transcoding operations may be performed in one step each instead of decrypting first and then encrypting or decoding first and then re-encoding. This means that full knowledge of the encryption process and license code scheme is not disclosed by the content retailers, and only mathematical procedures for transcoding and transcoding from one particular DRM system to another specific DRM system are available. There is a further advantage in that it is required to implement Sean and transcoding instances 13, 14. It will be readily appreciated that the second device 7 can be connected to the first device by a wireless link such as a Bluetooth link or an infrared link. If the second device 7 is an intermediate for transferring the content 1 and the corresponding license 4 from the first device 3 with the first DRM system to the third device with the third DRM system If used as a storage medium, it is effective to reduce the amount of transcription and transcoding by making the DRM system used on the second device 7 the same type as the first DRM system or the third DRM system. The second device 7 does not necessarily need to be a simple memory card, but it also includes an application that performs the transcoding and transcription and / or a multi-media player or mobile phone which includes an API which performs import / export. Can be represented. The transmission of the content 1 and the corresponding license 4 can then take place directly between two cellular phones or between the cellular phone and the multi-media player, for example on the basis of Bluetooth, infrared or cable link. Modifications of licenses purchased in the source DRM system may also provide various possible embodiments. The license may be removed after being sent to the second DRM system or modified in the sense of a counter, i.e. only two more transfers of the license are possible.

Claims (20)

Encrypt the encrypted content 1 and the corresponding license 4 contained in the first device 3 using a first type or second type of first digital rights management (DRM) system of the first or second type. A content transmission method for transmitting to a second device 7 using a second DRM system, The encrypted content (1) is in accordance with the content format of the first DRM system; The corresponding license (4) is in accordance with the rights expression language (REL) of the first DRM system; One of the first device and the second device provides an application programming interface (API) 6 for importing and / or exporting the encrypted content (1) and the corresponding license (4); The other of the first device and the second device provides an application 8 for transmitting the encrypted content 1 and the corresponding license 4, the method of content delivery Establishing a connection between the devices (11, 12); Authorizing the application (8) to access the API (6); And Transmitting the encrypted content 1 and the corresponding license 4 by the application 8 from the first device 3 to the second device 7 via the API 6. Content delivery method, characterized in that. The method of claim 1, The content delivery method further comprises the step of verifying the integrity of the application 8 and authorizing the application 8 to access the API 6 only when the integrity is verified. . The method according to claim 1 or 2, The content delivery method further comprises the step of storing (9, 10) the encrypted content (1) and the corresponding license (4) in the second device (7). The method according to any one of claims 1 to 3, The first device (3) and the second device (7) are both contained in a single device. The method according to any one of claims 1 to 4, And the first DRM system and the second DRM system are the same type of system. The method according to any one of claims 1 to 4, Wherein the first DRM system is a first type of system and the second DRM system is a second type of system. The method according to any one of claims 1 to 6, The content transmission method further comprises the step of modifying the license on the first device (3) or on the second device (7). The method according to claim 6 or claim 7, wherein The sending of the encrypted content 1 and the corresponding license 4 by the application 8 from the first device 3 to the second device 7 via the API 6 are: Transcoding (14) the license (4) for the encrypted content from the REL of the first DRM system to the REL of the second DRM system; And Transcribing (13) the encrypted content (1) from the content format of the first DRM system to the content format of the second DRM system. The method according to any one of claims 1 to 3 and 5 to 8, The first device 3 providing the API 6 is a multi-media device such as a mobile phone, a media player or a personal digital assistant, and the second device 7 providing the application is the API 6. Is a mass storage medium which can be inserted into the first device 3 providing the API or connected to the first device 3 providing the API 6 by a wired or wireless link 11. Characterized in that the content transmission method. A computer program product that can be loaded directly into an internal memory of a digital computer, comprising: software code portions for performing the steps of any one of claims 1 to 9 when the computer program product is executed on a computer. Computer program product. Encrypt the encrypted content 1 and the corresponding license 4 included in the first device 3 using the first type or second type of first digital rights management (DRM) system of the first or second type. A content delivery system for transmitting to a second device 7 using a second DRM system, The encrypted content (1) is in accordance with the content format of the first DRM system; The corresponding license 4 is in accordance with the rights expression language (REL) of the first DRM system, and the content delivery system is Means for establishing a connection between the devices (3, 7); An application programming interface (API) 6 provided by one of said devices (3, 7) for importing and / or exporting said encrypted content (1) and said corresponding license (4); And An application 8 provided by the other of the devices 3, 7, and transmitting the encrypted content 1 and the corresponding license 4 via the API 6. Content delivery system. The method of claim 11, The content delivery system further comprises means for verifying the integrity of the application. The method according to claim 11 or 12, wherein The content delivery system further comprises means (9, 10) for storing the encrypted content (1) and the corresponding license (4) in the second device. The method according to any one of claims 11 to 13, The first device (3) and the second device (7) are both contained in a single device. The method according to any one of claims 11 to 14, And the first DRM system and the second DRM system are the same type of system. The method according to any one of claims 11 to 14, Wherein the first DRM system is a first type of system and the second DRM system is a second type of system. The method according to any one of claims 11 to 16, The content delivery system further comprises means for modifying the license on either the first device or the second device. The method according to claim 16 or claim 16, wherein The content delivery system is: Means (14) for transcoding said license (4) for said encrypted content (1) from a REL of a first DRM system to a REL of a second DRM system; And Means (13) for transcribing said encrypted content (1) from the content format of said first DRM system to the content format of said second DRM system. The method of claim 18, The transcoding means (14) and the transcribing means (13) are provided by the application (8). The method according to any one of claims 11 to 13 and 15 to 19, The first device 3 providing the API 6 is a multi-media device such as a mobile phone, a media player or a personal digital assistant and the second device 7 providing the application provides the API. A mass storage medium which can be inserted into the first device (3) or connected to the first device (3) providing the API by a wired or wireless link.

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