KR20090002392A - Method and system for sharing content using external memory - Google Patents

Abstract

The present invention relates to a method and system for sharing contents using an external memory.

To this end, the present invention receives a device list and a public key for each device, encrypts the domain key using the public key to generate one or more device domain keys, and transmits the generated device domain key to the external memory It provides a method for transmitting encrypted content to a network. The present invention also checks the public key of the device, extracts and decrypts a device domain key corresponding to the identified public key from at least one device domain key stored in the external memory, and encrypts the content using the decrypted device domain key. It provides a method for executing an encrypted content to decrypt and execute.

According to the present invention, one content stored in the external memory can be reproduced in a plurality of devices, thereby solving the existing problem of repeatedly paying for one content and efficiently utilizing external memory resources.

Description

Method and system for sharing content using external memory {Method and System for Sharing Contents with Removable Storage}

1 is a view briefly showing the configuration of a content sharing system using an external memory according to an embodiment of the present invention;

2A and 2B are schematic diagrams illustrating an internal structure of an external memory according to an embodiment of the present invention;

3 is a flowchart illustrating a method for transmitting content from a wired / wireless terminal to an external memory according to an embodiment of the present invention;

4 is a flowchart illustrating a method of executing content stored in an external memory in a device according to an embodiment of the present invention.

The present invention relates to a method and system for sharing contents using an external memory. More specifically, the present invention relates to a method and system for using one content in multiple devices using an external memory.

With the recent development of the Internet, the digital content industry has also developed remarkably. This is because digital content is being activated in the Internet. However, there are many side effects caused by this, for example, illegal piracy or unauthorized distribution of digital contents.

In order to eradicate such illegal piracy and unauthorized distribution, digital rights management (DRM) is used.

The DRM method is a method of encrypting paid digital content by using a preset private key or a unique number of a device as an encryption key so that a person who receives paid digital content does not illegally distribute paid digital content. The encrypted digital content may be used only in one device having a unique number used as an encryption key, and may be used only for a predetermined number of times or periods.

Meanwhile, various devices including wired / wireless terminals recently released include various additional functions such as a photographing function, a music playing function, and an image playing function. In addition, the necessity to share content such as photos, videos, music, etc. according to additional functions with other devices has increased.

In order to share and exchange such various contents, a removable memory, a so-called external memory, is used, and various devices are provided with slots for inserting external memory.

However, even if the DRM-encrypted content is shared by using an external memory, it cannot be used in other devices. Therefore, for content that is intended to be used by multiple devices, a plurality of contents encrypted with respective encryption keys for the same content are used. File must be stored in the external memory. Accordingly, the external memory resource is unnecessarily consumed, and the meaning of sharing disappears.

In order to solve such a problem, the present invention provides a method and system for sharing one content in multiple devices using an external memory.

In order to achieve the above technical problem, an encrypted content execution method according to an embodiment of the present invention includes a method of executing encrypted content of an external memory inserted in a device, the method including: (a) checking a public key of a device; (b) extracting a device domain key corresponding to the verified public key from one or more device domain keys stored in the external memory; (c) decrypting the extracted device domain key using the identified public key; And (d) decrypting and executing the content stored in the external memory using the decrypted device domain key.

In addition, a method for transmitting encrypted content to an external memory according to an embodiment of the present invention is a method for transmitting encrypted content from a wired or wireless terminal to an external memory, the method comprising: (a) a device list for executing encrypted content and a device list Receiving a public key for each device configured; (b) generating one or more device domain keys by encrypting each domain key using the content as an identifier with a public key; And (c) transferring the one or more device domain keys to external memory.

In addition, the content sharing system according to an embodiment of the present invention, a system for supporting the sharing of encrypted content using an external memory, the content server for storing and managing the encrypted content; An authentication management server that manages authentication information including a content encryption key used for content encryption; A device management server for managing a list of devices sharing encrypted content; And a public key management server for performing an authentication procedure for the device and managing a public key used for extracting a content encryption key from the authentication information.

In addition, the external memory according to an embodiment of the present invention is an external memory for providing encrypted content to one or more devices, the content storage module for storing the encrypted content; An authentication information storage module for storing authentication information including a content encryption key for decrypting encrypted content; And a domain key storage module for storing one or more device domain keys used to extract the content encryption key from the authentication information.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

In addition, the term module described herein refers to a unit for processing a specific function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

1 is a diagram briefly illustrating a configuration of a content sharing system using an external memory according to an embodiment of the present invention.

The content sharing system according to the embodiment of the present invention includes an external memory 100, wired and wireless terminals 110 and 112, wired and wireless Internet 130, and a DRM management system 140. In addition, the mobile terminal 112 may include a mobile communication network 120 for connection between the wired and wireless Internet 130.

The external memory 100 stores a plurality of contents and DRM information about the contents. Here, the DRM information includes a device list received from the DRM management system 140 and a domain key encrypted with a device public key of each device.

Here, the public key is a product unique number assigned to each device, and the domain key is a kind of digital signature and a key for identifying each content. In addition, the domain key supports extracting a content encryption key for decrypting content from authentication information delivered from the DRM management system 140. Thus, one piece of content has a common domain key.

Here, the structure of the external memory 100 will be described in detail with reference to FIG. 2.

The wired and wireless terminals 110 and 112 are divided into a wired terminal 110 directly connected to the wired and wireless internet 130 and a wireless terminal 112 connected to the wired and wireless internet 130 through the mobile communication network 120.

The wired terminal 110 is a device such as a personal computer, a wired telephone, or a set-top box, which can be connected to the wired / wireless Internet 130 through a wired wire. The wireless terminal 112 is provided with a communication module and has a wired or wireless connection through the mobile communication network 120. A device such as a mobile terminal, a notebook computer, a PDA, a PMP, or the like connected to the Internet 130 or directly connected to the wired or wireless Internet 130.

The wired and wireless terminals 110 and 112 have an external memory slot for inserting the external memory 100, encrypt the domain key received from the DRM management system 140 with the public key, and transmit the encrypted key to the external memory 100. It encrypts the content received from the content server 142 and stores in the external memory 100.

The wired / wireless Internet 130 connects the wired terminal 110 and the wireless terminal 112 connected through the mobile communication network 120 with the DRM management system 140.

The DRM management system 140 manages registration information of a device that will use the content, transfers device information registered in advance to the wired / wireless terminals 110 and 112, and performs a user authentication process. It serves to provide information. To this end, the DRM management system 140 includes a content server 142, an authentication management server 144, a device management server 146, and a public key management server 148.

The content server 142 is a server that stores and manages content delivered to the wired / wireless terminals 110 and 112 through the wired / wireless internet 130. In addition, the content server 142 is a part that executes an encryption process for copyright management of content delivered to the wired / wireless terminals 110 and 112 through the wired / wireless Internet 130. At this time, a content encryption key (CEK: 'CEK') is used to encrypt the content.

Here, the content server 142 may be operated by a separate content provider, and thus the content server 142 may exist at a location separate from the location of the DRM management system 140.

The authentication management server 144 manages authentication information (RO: Right Object, hereinafter referred to as 'RO') including a CEK used for content encryption.

The device management server 146 is a server that manages information about devices registered in advance. That is, the server stores and manages a list of devices registered in advance, types of devices, and the like, in order to use the contents stored in the external memory 100 according to an exemplary embodiment of the present invention.

In addition, the content according to an embodiment of the present invention may be shared among a plurality of devices, but may be shared among a predetermined group (eg, a company unit, a department unit, a department unit, etc.) set in advance. As such, when the contents according to the present invention are shared between specific groups, the device management server 146 stores and manages user information or information on wired and wireless terminals corresponding to each group.

The public key management server 148 is a server connected to the device management server 146 to perform authentication for a user, a wired / wireless terminal, or a device that has provided content, and to manage and provide a public key of a device registered in advance. . To this end, the public key management server 148 may be connected with the manufacturer of each device.

Here, device information stored in the device management server 146 and the public key management server 148 through the input / output unit may be configured to connect separate input / output units to the device management server 146 and the public key management server 148. It can be implemented to edit and modify group information and public keys.

Here, the content server 142, the authentication management server 144, the device management server 146, and the public key management server 148 may be implemented as respective hardware devices, and each function may be implemented in one hardware device. It may be implemented to be separated accordingly.

2A is a block diagram schematically illustrating the internal structure of an external memory according to an embodiment of the present invention.

The external memory 100 according to an embodiment of the present invention includes a content storage module 210 for storing content and a DRM storage module 220 for storing encryption and decryption related data.

The content storage module 210 stores the encrypted content received from the content server 142 through the wired / wireless Internet 130.

The DRM storage module 220 stores data for decrypting encrypted content, and includes an authentication information storage module 222 and a domain key storage module 224.

The authentication information storage module 222 stores a RO including a CEK for decrypting the encrypted content. Here, the CEK included in the RO is decrypted using the domain key, and for this purpose, the authentication information storage module 222 receives a domain key for the device to execute content from the domain key storage module 224.

The domain key storage module 224 is a part for storing a domain key for each device. That is, for each device registered in advance in the DRM management system 140, if the wired and wireless terminals 110 and 112 respectively encrypt the domain key using the public key of each device, each encrypted domain key is an external memory. And stored in the domain key storage module 224 of (100).

In a content sharing system in which N devices are registered, the domain key storage module 224 of the external memory 100 may include N devices from the first device domain key storage module 2242 to the Nth device domain key storage module 2246. It includes a domain key storage module.

The structure of the external memory 100 may be implemented in hardware and software. When implemented in software, the content storage module 210, the DRM storage module 220, the authentication information storage module 220, and each device domain key storage module 2242 to 2246 may be implemented in the form of a folder in a directory structure. .

As described above, the internal structure of the external memory implemented in the form of directories and folders is shown in FIG. 2B.

3 is a flowchart illustrating a method of transmitting content from a wired / wireless terminal to an external memory according to an embodiment of the present invention.

In the content sharing system according to an embodiment of the present invention, before the wired / wireless terminals 110 and 112 deliver the content received from the DRM management system 140 to the external memory 100, the user may want to use the content list. It should be registered to the DRM management system 140 in advance. At this time, in registering the device list with the DRM management system 140, a public key assigned to each device is also input.

The registered device list is transmitted to the device management server 146 and stored, and the input public key is stored in the public key management server 148 (S310).

When the device list and the public key of each device are stored in the DRM management system 140, and a content transmission request for using the content from the user is input to the wired / wireless terminal 110. 112 (S320), the input content transmission request is The wired / wireless Internet 130 transmits the DRM management system 140. Through such a process, the wired and wireless terminals 110 and 112 are connected to the DRM management system 140 (S330).

The wired and wireless terminals 110 and 112 accessing the DRM management system 140 receive a registered device list and a public key of each device from the device management server 146 of the DRM management system 140 (S340).

Receiving the device list and the public key of each device, the wired and wireless terminals 110 and 112 encrypt the domain key for the entire registered device by using the respective public key (S350) and externally encrypt the encrypted domain key. Transfer to the memory 100. The encrypted domain key transmitted to the external memory 100 is stored in the domain key storage module 224 (S360).

The wireless terminals 110 and 112 receive content from the content server 142 of the DRM management system 140. At this time, the content transmitted from the content server 142 is encrypted with CEK. In addition, the wired and wireless terminals 110 and 112 receive an RO for decrypting the encrypted content from the authentication management server 144 of the DRM management system 140. Then, the received content and the RO are transmitted to the external memory 100 and stored. At this time, the content transmitted to the external memory 100 is stored in the content storage module 210, and the RO is stored in the authentication information storage module 222 (S370).

Here, the reception of the content and the RO according to step S370 may be performed simultaneously with the step S340.

Through such a process, the wired / wireless terminal 110 may transmit the encrypted content and data related to decryption of the encrypted content to the external memory 100.

4 is a flowchart illustrating a method of executing content stored in an external memory in a device according to an embodiment of the present invention.

According to the description of FIG. 3, the external memory 100 storing content and decryption related data may be inserted into various devices.

When a request for using content stored in a user is received in a device into which the external memory 100 is inserted (S410), the device 100 first checks its public key (S420).

When the public key is confirmed, the domain key storage module 224 of the external memory 100 checks the device domain key storage module corresponding to the public key and extracts the domain key stored in the identified device domain key storage module. In operation S430, the extracted domain key is decrypted using the public key identified in operation S420.

The device then calls the RO from the authentication information storage module 222. When the RO is called, the CEK is extracted from the RO by using the decrypted domain key in operation S430 (S440), and the content is decrypted using the extracted CEK. The decrypted content is played back on the corresponding device (S450).

In this manner, one content stored in the external memory can be played on a plurality of devices.

In the above description, a method of executing one content stored in the external memory in a plurality of devices has been described. However, the content stored in the external memory or the shared storage medium, etc. may be used to be shared within a member of a predetermined group. It may be. In this case, instead of a method of performing encryption and decryption using a public key, a method of performing encryption and decryption using a unique number assigned to each member may be used. Further, in performing encryption and decryption using the unique number assigned to the member, the method may further include receiving a unique number from the user.

In addition, in the above description, a validity period may be set for content stored and shared in the external memory, and a period may be set so that the content is no longer shared when the validity period expires.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, a single content stored in an external memory can be reproduced in a plurality of devices, and thus a conventional problem that a content user has to pay a duplicate content in order to execute a single content in a plurality of devices. I can solve it.

In addition, in order to execute the same content in a plurality of devices, by solving the conventional problem that the resource of the external memory is consumed by storing the same content encrypted with each encryption key in a plurality of external memory, the external memory resource can be efficiently used. It can be used as an effect.

Claims (10)

In the method of executing the encrypted content of the external memory inserted in the device, (a) identifying a public key of the device, where the public key is a unique number assigned to the device; (b) extracting a device domain key corresponding to the public key from at least one device domain key stored in the external memory, where the device domain key is a content identifier encrypted by a public key; (c) decrypting the device domain key extracted in step (b) using the public key; And (d) decrypting and executing contents stored in the external memory using the decrypted device domain key; Encrypted content execution method of the external memory including a. The method of claim 1, Step (d) is, (d1) extracting a content encryption key from authentication information using the decrypted device domain key; And (d2) encrypting and executing the encrypted content using the extracted content encryption key; Encrypted content execution method of the external memory including a. In the method for transmitting encrypted content from the wired or wireless terminal to the external memory, (a) receiving a list of devices that execute the encrypted content and a public key for each device included in the device list, where the public key is a unique number assigned to each device; (b) generating one or more device domain keys by encrypting domain keys that use the content as identifiers with the public keys, respectively; And (c) transferring the one or more device domain keys to the external memory Encrypted content transmission method to an external memory including a. The method of claim 3, Transmitting the encrypted content and authentication information, wherein the authentication information includes a content encryption key for decrypting the encrypted content to the external memory. Encrypted content transmission method to the external memory further comprising. The method according to claim 3 or 4, Prior to step (a), Registering a device with the content and a public key of the device; Encrypted content transmission method to the external memory further comprising. In a system that supports sharing of encrypted content using an external memory, A content server for storing and managing the encrypted content; An authentication management server managing authentication information including a content encryption key used for encrypting the content; A device management server managing a list of devices sharing the encrypted content; And A public key management server that performs an authentication procedure for the device and manages a public key used to extract the content encryption key from the authentication information, where the public key is a unique number assigned to each device. Content sharing system comprising a. The method of claim 6, Input / output unit for editing and modifying the device information and the public key stored in the device management server and the public key management server Content sharing system further comprising. An external memory for providing encrypted content to one or more devices, A content storage module for storing encrypted content; An authentication information storage module for storing authentication information including a content encryption key for decrypting the encrypted content; And A domain key storage module that stores one or more device domain keys used to extract the content encryption key from the authentication information, where the device domain key is a content identification key encrypted by a public key that is a device's unique number External memory including a. The method of claim 8, And the external memory includes as many domain key storage modules as the number of devices for which the contents are used. The method of claim 8, The content storage module, the authentication information storage module and the domain key storage module is implemented in the form of a folder of a directory structure.

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