KR100951792B1 - Method of distributing time of using contents between personal devices and system based on the same - Google Patents

Abstract

The present invention conforms to existing personal domain systems and uses content that allows a user with multiple devices to freely use digital rights management techniques (DRM) protected content between their devices. A possible time distribution method and a system based thereon. A method of distributing content available time is a method of distributing available time between devices for content protected by digital rights management (DRM), comprising: a first device licensed from a license issuer or a license from the first device; And distributing the available time of the content by communication to the third device through the second device that receives the distribution. Thus, no matter how many devices share content, there is a limit on the total usage time, so illegal sharing cannot occur, and a personal domain system can be created that can block illegal sharing while considering user convenience.

Description

Method of distributing time of using contents between personal devices and system based on the same}

The present invention relates to a method for distributing content available time between personal devices and a system based thereon, and more particularly, to a user who has a plurality of devices, which conforms to an existing personal domain system. A method of distributing content available time that allows free use of content protected by a management technique (DRM) between devices and a system based thereon.

The development of computers and the Internet has created a new market for the distribution of digital content over the network, beyond the content market through the distribution of physical media. However, because digital content is too easy to copy and distribute, illegal sharing over the network has become a serious problem for content creators and distributors.

To solve this problem, digital rights management (DRM) technology has emerged. DRM usually uses encryption of content to block illegal sharing and uses licenses to control content use. It uses several tracking technologies to track and block illegal sharing. However, user convenience has been neglected because the existing DRM has a purpose to enhance protection of contents. One of the most important issues in which user convenience has been ignored is the licensing of specific devices. It is very common for a user to have multiple devices. Nevertheless, it is very inconvenient for the user to use the purchased content on only one device. Therefore, there is a need for a method that can support multiple devices of a user.

The domain system is the most representative method for supporting a plurality of devices of a user, and was originally developed to support sharing of DRM content among various devices on a user home network. In other words, a domain system is a technology that enables a user to use purchased content on multiple devices owned by a user when the user has multiple devices. In the domain system, the ultimate goal of the domain system is to prevent illegal sharing while considering user convenience. However, since content sharing can be turned into illegal sharing, existing domain systems usually prevent illegal sharing by limiting the number of devices that can belong to a domain. In the existing domain system, illegal sharing could be prevented by limiting the number of devices that can be included in the domain. However, it is difficult to establish a reasonable standard for limiting the number of devices. In terms of flexibility, there is a limit, and the explicit limit on the number of devices is a limitation that may be inconvenient for the user, and thus cannot be seen as a solution for achieving the end goal of the domain system. In addition, the existing domain system needs to ensure the number of devices currently registered in the domain and the uniqueness of information about each device. Therefore, a centralized device to guarantee such uniqueness or a technique for ensuring uniqueness of distributed information is provided. need.

Another approach is to limit concurrency, such as smart card-based methods or finding concurrency by recording usage times. The smart card-based method is a method of supporting a plurality of devices by moving a smart card to a device to store a license in a smart card. However, this method requires an additional device called a smart card. In addition, if a user loses a smart card, there may be a problem that all contents cannot be used.

Another way to find concurrent usage by recording usage time is to use concurrent usage by checking whether each device keeps a record of its content usage time and whether there is overlap in the recording each time it connects to another device. How to find out. However, this method only works if all devices have a safe and synchronized clock. In addition, since simultaneous use may occur due to a user's mistake, additional judgment is required to determine whether or not concurrent use is caused by illegality.

As described above, the existing domain system has a limitation in terms of user convenience because it explicitly limits the number of devices of the user. In addition, existing domain systems require additional devices or information matching to ensure uniqueness of information. In addition, the method of supporting multiple devices of a user by limiting simultaneous use can achieve the purpose of not limiting the number of devices, but it requires an additional device called a smart card or every device has a safe and synchronized clock. There is a requirement to be present. This requirement will place additional costs on the service provider or user. In addition, the method of recording the time of use requires an additional process for determining the illegality. Therefore, we need a new method that ensures the convenience of the user but does not follow the problems of the existing methods.

The technology related to the domain that can be applied to the system of the present invention is one of the important technologies included in the documents of major standardization bodies such as OMA or Marlin. In addition, related papers and patents are quite valuable research fields. However, in view of the application of the domain system technology to the market, the domain system is not yet applied to the market. However, domain system is closely related to home network technology, so when home network technology begins to be applied to the market, domain system technology will naturally be applied to the market. As a reference, 1) Koster, P., Kamperman, F., Lenoir, P., and Vrielink, K. Identity based DRM: Personal entertainment domain. In Communications and Multimedia Security (CMS), LNCS 3677 (2005), Springer-Verlag, pp. 42-54, 2) Marlin Developer Community. Marlin Architecture Overview, May 2006, 3) Open Mobile Alliance. DRM Specification-Approved Version 2.0., March 2006, 4) Popescu, B. C., Crispo, B., Tanenbaum, A. S., and Kamperman, F. L. A DRM security architecture for home networks. In Proceedings of the 4th ACM workshop on Digital rights management (2004), ACM Press New York, NY, USA, pp. 1-10. 5) van den Heuvel, S., Jonker, W., Kamperman, F., and Lenoir, P. Secure content management in authored domains. In Proceedings of International Broadcasting Conference 2002 (September 2002), pp. 467-474 can be mentioned.

An object of the present invention is to provide a method for distributing content available time between individual devices that can prevent illegal sharing without limiting the number of devices and a system based thereon.

In addition, another object of the present invention is to provide a method for distributing content available time between personal devices and a system based thereon that improve user convenience more than the related art.

The present invention starts from the basic fact that there is a limit to the time a user can use the content. In other words, one user can't use the content for more than 24 hours a day, and more than 720 hours a month (30 days). Based on these basic limitations, the present invention provides a user with a right to use content for a certain period of time over a period of time and between personal devices that can securely distribute the content available time to their own device. A method for distributing content available time and a system based thereon are provided. The content usage time distribution method requires only a connection and synchronization between the device to provide the use time and the device to be provided the use time.

In accordance with one aspect of the invention, there is provided a method of distributing usage time for content protected by digital rights management (DRM) between devices, the method comprising: a first device licensed from a license issuer or from the first device; A method for distributing content available time between devices, the method comprising: distributing available time of content by communication to a third device through a licensed second device.

Preferably, it is possible to protect personal privacy by hiding the type and number of the devices to the service provider.

Preferably, it is possible to use the content more efficiently by dividing the available time of the content into specific units.

Preferably, by assigning a specific number to the usable time unit, it is possible to find a reuse or illegal increase in the usable time, thereby enabling safer use.

Preferably, each device manages a history of available time, exchanges this history information with other devices in the course of communication, and compares them to find duplicate usage time units. It is possible to find out that a reuse attack or an illegal increase attack has occurred.

Preferably, the individual can register the usage rate to each device in advance so that the remaining available time can be automatically distributed with reference to the usage rate of the individual device without the direct intervention of the individual.

Preferably, the available time is stored in a secure storage in each device on an individual license basis to prevent illegal modifications and to indicate that the individual use time is available, complete and discarded. do.

Preferably, a license issuance process is performed between the license issuer and the first device, and the license issuance process is performed by a user authentication process based on a user certificate between the first device, a license server, and a payment server. ; Performing a content selection process of viewing content from the device to the content server and delivering content information from the content server to the device after the user authentication process is performed; Performing a license settlement process including transfer of license costs from the license server to the device, user authentication and payment from the device to the payment server, and payment verification from the payment server to the license server; And issuing a license from the license server to the device, and when receiving the license, the device generates a usage time management data structure and stores it in a predetermined storage in the device.

Preferably, a license delivery process is performed between the devices, and the license delivery process is performed by communication between the devices that the counterpart devices are not tampered with each other through the device authentication process and the user authentication process. Confirming; Thereafter, when the device requesting the license requests a license from the counterpart device, the counterpart device transmits the license to the requesting device; And when the license is delivered, the device generates a usage time management data structure and stores it in a predetermined storage in the device.

Preferably, the process of distributing usage time between the devices may include: confirming that the counterpart devices are not tampered with and the users of each other are identical through device authentication and user authentication through communication between the devices; Determining whether the devices have the same license; Exchanging usage time histories with each other to perform a redistribution process of the remaining available time between the devices; Each device checks whether there is a duplication between the history sent by the other party and its history, and if there is a duplication, it means that a reuse attack or an illegal incremental attack has occurred; And after confirming the overlap of the use time, characterized in that it comprises a step of performing a use time reset process in earnest.

Preferably, the step of performing the usage time resetting process may be performed manually by the user or automatically by the redistribution rate pre-entered by the user. It is characterized by resetting its available time by calculating the usage time that it can have from the relative value of.

According to another aspect of the invention, there is provided a system capable of sharing digital rights management (DRM) protected content that a person has a right to use between multiple personal devices, wherein the person can use the content for a particular period of time. Within a total time range, there is provided a system comprising a storage for distributing available time by communication between the personal devices to each device and storing information about the distributed available time.

Preferably, the system to which the devices are applied is a personal domain system.

Preferably, the individual can directly select the type and number of devices that can use the content by distributing their own content available time to each device.

According to still another aspect of the present invention, there is provided a communication capable device capable of downloading a content protected by a digital rights management (DRM), which a user has a right to use, to share by communication with another device. The distributed availability, including a repository for distributing the available time by communication between the personal devices and storing information about the distributed available time, within the total time frame for which content is available during this particular period of time. Provided is a communication capable device capable of using content within a time range.

In the method of distributing content available time among personal devices proposed by the present invention and a system based on the same, even if a user distributes content available time to many devices, the total number is constant, so the service provider is responsible for illegal content sharing. There is no need to worry. In addition, even from the user's point of view, the content can be used freely on any device without any limitation, thereby ensuring higher convenience. In addition, the proposed method of distributing content available time between personal devices and a system based thereon require only a connection between a device to provide time and a device to receive time for content available time distribution. It does not require information synchronization techniques with other devices. In addition, the proposed method does not require additional equipment, such as a smart card, which is advantageous in terms of cost and does not require that all devices have a secure and synchronized clock. Finally, no further steps are needed to determine whether it is illegal.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic diagram for schematically illustrating a system based on a method for distributing content available time between personal devices according to the present invention.

In FIG. 1, a user requests a license 111 from the server 100 using device 1 101, one of device 1 101, device 2 102, and device 3 103, which is one of his devices. The server 100 then provides a license to the device 1 101 (112). This license may include, for example, the copyright of the digital content as well as the total available time of the digital work.

As shown in FIG. 1, the license acquired in the device 1 101 and the total available time are shared between the device 1 101 and the device 2 102 through a request 113 and a delivery 114 process. May be shared between the device 1 101 and the device 3 103 through the request 118 and the forwarding 117 process, and between the device 2 102 and the device 3 103. 115 or 116 and can be shared through the transfer (116 or 115) process.

2 is a schematic diagram illustrating a device certificate issuing flow applied to the present invention.

As shown in FIG. 2, all devices 201, such as device 1 101, device 2 102, and device 3 103 of FIG. 1, prove that they have not been tampered with, and ensure confidential communication. In order to request a device certificate from the device certificate issuing server 200 (211) to be issued (212). At this time, the device certificate issuing server 200 generates a new device certificate revocation list each time a tampered device is found and quickly distributes it to each device.

3 is a schematic diagram illustrating a user certificate issuance flow applied to the present invention.

In FIG. 3, all devices 302, such as device 1 101, device 2 102, and device 3 103 of FIG. 1, have a user certificate to prove that they are owned by a particular user 301. The user certificate issuing server 300 requests (311) and is issued (316).

As shown in FIG. 3, this user certificate is a user authentication process, requesting 312 and 313 to the user 301 from the user certificate issuing server 300 to the user 301 via the device 302. Only after passing through 314 and 315 can it be installed in the device 302.

Accordingly, all devices and servers in FIGS. 1-3 should have a means of connecting to at least one other device or server in order to receive content or licenses. This means could be a connection via wired or wireless LAN, or other means such as USB or Bluetooth. At least one of the user's devices must be able to connect to the remote server to purchase licenses or receive content.

4 is a structural diagram of a content usage time management data structure applied to the present invention.

As described above with reference to FIG. 1, the method for distributing content available time between personal devices according to the present invention divides the use time by a predetermined time unit for the safe and efficient distribution of the use time of the content by the license allowed from the server 100. The distribution process is performed on a unit basis. In FIG. 4, the content usage time management data structure applied to the present invention blocks reuse attacks or illegal increase attacks on usage time by assigning a unique number value to each individual unit value (401).

As shown in FIG. 4, each device maintains a history of usage time owned or used. This information is used to detect reuse attacks and illegal growth attacks during redistribution of time of use. Numbers for individual time units of the individual licenses 410 are separately managed, and before use (411), after use (412), and discarded time units (413) are managed separately. History information is stored in secure storage 400 within the user device. This content usage management material is made up of each device and device or server, and more precisely, information on the total usage time between the devices licensed from the server and the time spent between the devices licensed on the server and other devices. And distribution information about the usage time between the device and another device that have been distributed usage time from a device licensed in the server.

5 is a flowchart illustrating a license issuance flow applied to the present invention.

As shown in FIG. 5, a device 500, a license server 502, and a payment server 503, such as the device 1 101, the device 2 102, and the device 3 103 of FIG. 1, for issue of a license. ) Performs a user authentication process 513 based on the user certificate. After the user authentication process is performed, the content selection process of the content viewing 510 from the device 500 to the content server 501 and the transfer of content information 511 from the content server 501 to the device 500, and the license server. License cost transfer 512 from 502 to device 500 and user authentication and payment 512 from device 500 to payment server 503 and payment confirmation to license server 502 of payment server 503 ( After going through a license payment process including 514, a license issuance 515 is performed from the license server 502 to the device 500. At this time, when receiving a license, the device 500 generates a usage time management data structure and stores it in a predetermined storage in the device (516).

6 is a license structure diagram applied to the present invention.

Through the license structure shown in FIG. 6, since the license is protected by the user public key (600), only the device 500 having the user certificate can decrypt the license.

As shown in FIG. 6, the license 600 includes a license identifier 610, a content identifier 611, user rights information 612, a content encryption key 613 encrypted with a user's public key, and a unit of use time. The size 614 and the total number 615 of usage time units allowed for the user are included. The license is protected by the signature of the license server of integrity.

7 is a flowchart of requesting and receiving a license between devices applied to the present invention.

In FIG. 7, for the process of transferring a license between the devices 700 and 701, the devices 700 and 701 are not tampered with each other through the device authentication process 710 and the user authentication process 711. Make sure that is the same. Thereafter, when the device 700 requesting the license requests the license 712 to the counterpart device 701, the counterpart device 701 transfers the license to the request device 700 (713). At this time, when receiving the license, the device 700 generates a usage time management data structure and stores it in a predetermined storage in the device (714).

8 is a flowchart for distributing usage time between devices applied to the present invention.

In FIG. 8, the devices 800 and 801 confirm that the counterpart devices have not been tampered with and have the same user through the device authentication process 810 and the user authentication process 811. In addition, the devices determine whether each license is the same (812). After this process, the devices 800 and 801 exchange their usage time history with each other to perform a redistribution process of the remaining available time of each other (813). Each device checks whether there is a duplication in the history sent by the other party and its history (814). If there is a duplication, it means that a re-use attack or an illegal growth attack has taken place and you must punish it. This may be a strong punishment, such as a prohibition on use of the device, or it may be a light punishment that prohibits the use of available time units with the corresponding number (412 in FIG. 4). After checking the overlap of usage time, the usage time reset process 816 is performed in earnest. This process may be performed manually by the user or automatically through the redistribution rate previously input by the user (815). When automatically proceeding, the devices reset their available time by calculating the use time they can have based on the relative value of the remaining available time and the redistribution rate.

As described above, the method for distributing content available time between personal devices according to the present invention and a system based thereon are for obtaining a device certificate for a device authentication process and for obtaining a user certificate for proving that the device is a user device. The process of purchasing content using the device, the process of distributing licenses between devices, and the distribution of available time between devices. By providing a user, the user can freely distribute the content available time allocated to the user to his device.

According to the present invention, no matter how many devices share content, there is a limit on the total usage time, so illegal sharing cannot occur. In addition, this limit is not unreasonable from the user's point of view because the limit on the total usage time is a basic restriction not set by the service provider. Through this, it is possible to create a personal domain system that can block illegal sharing while considering user convenience.

1 is a schematic diagram for schematically illustrating a system based on a method for distributing content available time between personal devices according to the present invention.

2 is a schematic diagram illustrating a device certificate issuing flow applied to the present invention.

3 is a schematic diagram illustrating a user certificate issuance flow applied to the present invention.

4 is a structural diagram of a content usage time management data structure applied to the present invention.

5 is a flowchart illustrating a license issuance flow applied to the present invention.

6 is a license structure diagram applied to the present invention.

7 is a flowchart of requesting and receiving a license between devices applied to the present invention.

8 is a flowchart for distributing usage time between devices applied to the present invention.

Claims (15)

delete delete delete delete A method for distributing available time between devices for content protected by digital rights management (DRM), Distributing the available time of the content by communication to a third device through a first device licensed from a license issuer or a second device licensed from the first device, each device being used By managing the history of available time, exchanging this history information with other devices in the course of communication, and comparing them, we find duplicate units of usage time. A method of distributing content available time between each of the above devices, which can be found to have occurred. A method for distributing available time between devices for content protected by digital rights management (DRM), Distributing the available time of the content by communication to a third device through a first device licensed from a license issuer or a second device licensed from the first device, wherein each device is individually A method of distributing time to use content among the devices, characterized in that the remaining available time can be automatically distributed by referring to the use rate of individual devices without the direct intervention of the individual by registering the usage rate in the. The method according to claim 5 or 6, wherein the available time is stored in a separate storage unit in a secure storage in each device to prevent illegal modifications, and the use time, use completion, and retirement states of the individual use time units are determined. And distributing content available time between the devices. The process of claim 5 or 6, wherein a license issuance process is performed between the license issuer and the first device. Performing a user authentication process based on a user certificate between the first device, a license server, and a payment server; Performing a content selection process of viewing content from the device to the content server and delivering content information from the content server to the device after the user authentication process is performed; Performing a license settlement process including transfer of license costs from the license server to the device, user authentication and payment from the device to the payment server, and payment verification from the payment server to the license server; And The license issuance from the license server to the device is performed, and when the license is delivered, the device generates a usage time management data structure and stores it in a predetermined storage in the device. How to distribute content available time. The process of claim 5 or 6, wherein a license delivery process takes place between the devices. Confirming that the counterpart devices have not been tampered with and are identical to each other through device authentication and user authentication with each other by means of communication between the devices; Thereafter, when the device requesting the license requests a license from the counterpart device, the counterpart device transmits the license to the requesting device; And When receiving a license, the device generates a usage time management data structure and stores it in a predetermined storage in the device. 7. The process of claim 5 or 6, wherein the process of distributing usage time between devices Confirming that the counterpart devices are not tampered with and the users of each other are identical through device authentication and user authentication with each other through communication between the devices; Determining whether the devices have the same license; Exchanging usage time histories with each other to perform a redistribution process of the remaining available time between the devices; Each device checks whether there is a duplication between the history sent by the other party and its history, and if there is a duplication, it means that a reuse attack or an illegal incremental attack has occurred; And And after checking the overlap of usage time, performing a usage time reset process in earnest. The method of claim 10, wherein the resetting of the usage time may be performed manually by the user or automatically through a redistribution rate previously input by the user. And resetting the available time of the content by calculating the use time which the user can have based on the relative value of the redistribution rate and the redistribution rate. In the content available time distribution system among each of the devices capable of sharing digital rights management (DRM) protected content that the individual has a right to use between a plurality of personal devices, A storage for distributing the available time by communication between the personal devices to each device and storing information on the distributed available time, within the total time frame over which the individual can use the content for a particular period of time. Thus, each device manages a history of available time, finds duplicate usage time units by exchanging this history information with other devices in the course of communication, and compares them, thereby making a history of available time. And a content reuse time distribution system among the devices, characterized in that the reuse attack or the illegal increase attack has occurred. 13. The system of claim 12, wherein the system to which the devices are applied is a private domain system. 13. The method of claim 12, wherein an individual distributes his / her own content available time to each device, thereby distributing content available time between the devices for which the individual can directly select the type and number of devices that can use the content. system. delete

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