KR20170046941A - Distribution service system and method for electronic book optimized cloud system - Google Patents

Abstract

The present invention relates to an electronic book distribution service system and method optimized for a cloud environment and, more specifically, to an electronic book distribution service system and method which separates only license information configured in electronic books, encrypt the same, prevents illegal distribution of the electronic books by encrypting an encryption key used for the encryption based on a certificate of a receiver who has an access right to the electronic book, and assists secure protection of the electronic books even in a cloud environment at the same time. As the present invention provides electronic book content which is encrypted based on certificate-related information about a reception target of the electronic book content, the electronic book content can be restricted to only the reception target who has an access right to the electronic book content. In addition, the access right to the electronic book content can be changed based on the certificate-related information whenever the reception target is changed, and thus a user other than the reception target is prevented from viewing the electronic book content, thereby preventing the e-book content from being leaked. The electronic book distribution service system comprises: a certificate management server for transmitting public key certificate-related information to a transmitting terminal; a packaging module for generating and transmitting electronic content in which license information and encryption resources are packaged; and a repackaging module for generating new electronic book content by replacing the existing license information with new license information and repackaging the same with the encryption resources, and transmitting the new electronic book content to a receiving terminal.

Description

[0001] The present invention relates to an electronic book distribution service system and method optimized for a cloud environment,

The present invention relates to an electronic book distribution service system and method optimized for a cloud environment, and more particularly, to a system and method for distributing electronic book, The present invention relates to an electronic book distribution service system and method optimized for a cloud environment that protects e-books in a cloud environment while safeguarding illegal circulation of electronic books by encrypting them based on certificates of authorized recipients.

2. Description of the Related Art In recent years, there has been an increasing demand for an electronic book that is scanned from a general book to be stored in a user terminal and conveniently browsed.

However, because of its nature, these ebooks can be copied more easily than general books, and simultaneous distribution through the network is possible, so that the copyright owner (writer) or publisher of the book has a lot of resistance to the scanning act of such books.

However, as the demand for users to use e-books in digital devices increases, the flow of e-book distribution can not be rejected. Therefore, the copyright owner or the publisher of the book now has to prepare a countermeasure for preventing illegal circulation of e- Such as a broker or a distributor of a content service provider.

Accordingly, in order to meet the demands of the copyright owner or the publisher, the content service provider encrypts and distributes the electronic book using DRM (Digital Rights Management), which is the most popular copyright protection solution currently used by the broker or distributor of the electronic book, The e-book is protected by using a method of decrypting the e-book through user authentication through a specific decryption client provided by the content service provider and making it readable.

However, since a variety of content service providers appear, each content service provider encrypts and services the e-book using its own DRM method. Therefore, the end user who browses the e-book must install a decryption client suitable for each DRM scheme .

In other words, since different DRMs provided by different content service providers are not compatible, when an end user wants to browse an electronic book provided by a different content service provider in a digital device used for reading an electronic book, There is a problem that it is necessary to install a plurality of decryption clients, and there is an inconvenience that the contents service provider of the e-book must be identified and the e-book should be browsed only through the decryption client.

In addition, if the end user uploads the encrypted e-book to the cloud server and uses it, only the end user's personal information is leaked, the e-book uploaded to the server becomes defenseless, so that the content service provider strictly restricts the use of such cloud service Thus, there is a problem that the inconvenience to the user's use of the e-book is increased.

Accordingly, it is possible to solve concerns about the illegal circulation of e-books by copyright owners or publishers, and to improve the convenience of e-book use by users who use e-books by unifying encryption methods between content service providers and to securely use the cloud server There is a need for a plan to support the use of e-books.

Korean Patent No. 10-0718702

The present invention provides only the license information that is configured in the electronic book by separating and encrypting it, and at the same time encrypts the encryption key used for encrypting the electronic book as a public key of the reception subject having the right to browse the electronic book, The purpose of the present invention is to effectively prevent illegal circulation of e-books by restricting access to e-books.

In addition, the present invention provides different contents service providers to encrypt an electronic book using the same DRM scheme, encrypts a decryption key used for decrypting an electronic book using device information of an object to be received, It is possible to prevent the reading of the e-book even if the e-book is leaked, and at the same time to minimize the rejection of the e-book circulation by the copyright owner or the publisher.

In addition, the present invention allows a user to conveniently store an e-book on a cloud server so that the e-book can be conveniently used, while at the same time restricting decryption of an e-book only on a user's digital device, It has its purpose to support.

The electronic book distribution service system optimized for the cloud environment according to the embodiment of the present invention issues and stores the public key and the private key certificate information for use of the electronic book contents, A certificate management server for transmitting the public key certificate related information required for encrypting the electronic book content among the certificate information issued corresponding to the receiving terminal to the transmitting terminal upon request of the terminal, Encrypts a plaintext resource constituting an e-book with a predetermined content encryption key (CEK: Content Encryption Key), encrypts the CEK with a public key for CEK included in the public key certificate information, License information including previously stored digital signature information and license information, A packaging module configured to generate and transmit e-book contents packaged with a source and to transmit the e-book content to the transmitting terminal, and to check the electronic signature information and the usage permission information included in the license information when receiving the e-book content, Decrypts the encrypted CEK with the CEK private key included in the stored private key certificate information, encrypts the decrypted CEK with the public key for CEK included in the public key certificate related information received from the certificate management server, The new license information included in the e-book content is replaced with the new license information, and the new e-book content generated by repackaging the new e-book content with the encryption resource is transmitted to the receiving terminal Lt; RTI ID = 0.0 > repackaging < / RTI >

The electronic book distribution service system optimized for the cloud environment includes a CEK private key in the private key certificate issued from the certificate management server at the time of receiving the e-book contents, Decrypts the CEK included in the electronic book content, decrypts the encrypted resource using the corresponding CEK, generates the plain-text resource according to the decryption of the encrypted resource, and provides the electronic book reader to the user And a client module.

In one embodiment of the present invention, the private key for the CEK is encrypted by at least one of the certificate management server, the repackaging module, and the client module using the device information of the terminal corresponding to the private key for the CEK, And the client module decrypts the private key for the CEK with pre-stored device information, and decrypts the encrypted CEK using the decrypted private key for the CEK.

In one embodiment of the present invention, the certificate information includes a CA certificate, a private key for the CEK, a public key for the CEK, a public key for digital signatures, and a private key for digital signatures.

In one embodiment of the present invention, the packaging module and the repackaging module add digital signature verification information for verifying the integrity of the electronic book content to the license information, and the repackaging module of the transmitting terminal transmits the digital signature The revocation module and the client module of the receiving terminal decrypt the digital signature verification information using the public key for digital signature included in the previously stored certificate information, Thereby confirming the integrity.

In one embodiment of the present invention, the repackaging module and the client module of the receiving terminal check the use period according to the usage permission information at the time of integrity verification, and decode the CEK when the usage period is valid.

In one embodiment of the present invention, the client module transmits the e-book content to a predetermined cloud server and stores the e-book content.

In one embodiment of the present invention, the certificate management server assigns different unique device keys corresponding to the respective user terminals when issuing a certificate request of different user terminals, and includes a unique device key corresponding to each user terminal And transmits the certificate information to each user terminal. The client module encrypts the private key for the CEK included in the certificate information using the unique device key, encrypts the private key for the CEK using the unique device key, Decrypting the encrypted private key for the CEK using the decrypted private key for the CEK, and decrypting the encrypted private key using the decrypted private key for the CEK.

As an example of the present invention, the electronic book distribution service system optimized for the cloud environment further includes a license server corresponding to each of the different terminals and storing license information including usage permission information, Requesting license information of the receiving terminal to the license server to generate the new electronic book content, and receiving license information corresponding to the receiving terminal from the license server.

The electronic book distribution service method optimized for a cloud environment according to an embodiment of the present invention issues and stores certificate information for use of electronic book contents, A step in which a certificate management server for transmitting certificate-related information necessary for encrypting the e-book contents among certificate information issued in correspondence with the terminal issues certificate information corresponding to each terminal using e-book contents and transmits the certificate information; , A packaging module configured in the terminal for generating electronic book contents generates an encryption resource in which a plain text resource constituting an electronic book is encrypted with a predetermined content encryption key (CEK: Content Encryption Key) After encrypting with CEK public key, encrypted CEK and pre-stored digital signature information Generating license information including licensing information and e-book content in which the encryption resource is packaged; and transmitting the license information from the packaging module or another terminal to the license information when the e-book content is received from the packaging module or another terminal If the use of the e-book content is valid, decrypts the CEK with the private key for the CEK included in the previously stored certificate information, and transmits the certificate related information received from the certificate management server Encrypts the new license information with the new license information included in the e-book content, encrypts the new license information with the new license information corresponding to the receiving terminal, A new electronic book < RTI ID = 0.0 > It may comprise the step of transmitting to the receiving terminal Massachusetts.

The present invention provides a method of encrypting and providing e-book content based on certificate-related information about a receiving subject of e-book content, thereby limiting access to the e-book content only to a receiving subject having viewing authority for the e-book content At the same time, the viewing authority of the e-book contents can be changed based on the certificate-related information every time the receiving object is changed, thereby preventing other users other than the receiving subject from reading the e-book contents, It is effective.

Also, according to the present invention, e-book content related information is encrypted and transmitted to a recipient based on certificate related information related to a recipient who receives e-book contents each time an e-book content is brokered or circulated, The contents of the e-book content can be clearly identified by supporting the contents of the e-book contents by intermediation or circulation of the e-book contents. In addition, even if the e-book content is leaked, There is an effect that can prevent danger.

In addition, the present invention can provide convenience for use of e-book contents by providing a user to store e-book contents on a cloud server and browse e-book contents at any time using different user terminals, It is possible to restrict access to the e-book content only by the user terminal that issued the e-book content. Thus, the e-book content can be freely accessed through the cloud server without worrying about leakage of the e-book content, It is possible to effectively protect e-book contents from a user who does not exist.

In addition, the present invention enables an author, a publisher, a broker, and a distributor in a distribution process of an e-book to distribute an e-book through the same DRM method, so that a user can browse all e-books using only a single client Thereby providing an effect of enhancing user convenience.

1 is a block diagram of an electronic book distribution service system optimized for a cloud environment according to an embodiment of the present invention;
FIG. 2 is a flowchart of a certificate issuing process according to an embodiment of the present invention; FIG.
3 is a configuration diagram of certificate information according to an embodiment of the present invention;
4 is a conceptual diagram illustrating the operation of the repackaging module according to the embodiment of the present invention.
5 is a conceptual diagram illustrating an encryption process for electronic book contents according to an embodiment of the present invention.
FIG. 6 is a conceptual diagram illustrating an electronic book distribution process of an electronic book distribution system optimized for a cloud environment according to an embodiment of the present invention. FIG.
7 is a conceptual diagram illustrating the operation of a client module according to an embodiment of the present invention;
8-10 are flowcharts of an ebook distribution service method optimized for a cloud environment according to an embodiment of the present invention.
11 is a conceptual diagram illustrating utilization of e-book contents using cloud servers in different user terminals according to an embodiment of the present invention.

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

FIG. 1 is a block diagram of an electronic book distribution service system optimized for a cloud environment according to an embodiment of the present invention. As shown in FIG. 1, a terminal 110 for generating an electronic book, a terminal 120 A certificate management server 1 for issuing a certificate through a communication network corresponding to the user terminal 130 and the user terminal 140 and for storing license information for the different terminals 110, 120, 130 and 140, And a license management server 2 for transmitting the license information corresponding to the terminal to the terminal through a communication network when requested by the terminal.

The electronic book distribution service system optimized for the cloud environment is configured in the terminal 110 corresponding to an author or a publisher of each of the terminals 110, 120, 130 and 140 to initially package the electronic book contents, And a transmitting terminal for transmitting e-book contents among the terminals 110, 120, 130, and 140. The e-book contents may be repackaged or re- The electronic book contents are decrypted by the repackaging module 200 and the user terminal 140 among the terminals 110, 120, 130 and 140 to transmit the generated electronic book contents after packaging And may include a client module 300 to browse.

The author / publisher terminal 110 corresponding to the author or publisher who has the authority to create an e-book, as shown in FIG. 2, may be provided with the electronic book generation module 111 and the packaging module 100, And a repackaging module (200).

The electronic book creation module 111 generates a plain text resource corresponding to the electronic book and provides the same to the packaging module 100. The electronic book creation module 111 provides the electronic book broker terminal 120 or the electronic book publisher terminal 130 The electronic book distributor terminal 120 can receive contract information and identification information for the electronic book brokering terminal 120 or the electronic book distribution terminal by communicating with the electronic book brokering management module 121 or the electronic book distribution management module 131, To the packaging module 100 together with the plain text resource.

At this time, the contract information may include license permission information for an e-book brokerage e-book brokerage period (use period) or e-book broker's use permission period for e-book circulation, May refer to e-book related data.

Then, the packaging module 100 receives the plain-text resource and the identification information, generates a content encryption key (CEK) for encrypting the plain-text resource, and transmits the plain-text resource to the corresponding CEK Generates the encryption resource and generates the master e-book content by packaging the license information (L) corresponding to the preset artist / publisher terminal 110 and the encryption resource, Lt; / RTI >

In this case, the master e-book content may be an e-book content that is initially generated, and the packaging module 100 may transmit the identification information on the receiving subject of the e-book content to the repackaging module 200 have.

Also, the packaging module 100 adds the CEK to the license information, stores certificate information on the certificate issued from the certificate management server 1, and stores the certificate information from the storage unit configured in the artist / publisher terminal 110 The CEK public key included in the certificate information may be extracted and the CEK may be encrypted using the public key for the CEK.

Meanwhile, the repackaging module 200 may receive the master e-book content and the identification information, and may transmit the identification information to the license management server 2 that integrally manages the license information of each terminal.

Accordingly, the license management server 2 extracts license information (L1) stored in advance for the e-book broker or ebook distributor corresponding to the identification information on the basis of the identification information, and stores the license information (L1) To the artist / publisher terminal (110).

The repackaging module 200 may then replace the license information L included in the master e-book content with the license information L 1 received from the license management server 2.

At this time, the license information received from the license management server 2 may include the license information.

In the above-described configuration, the e-book creation module 111 communicates with the license management server 2 via the communication network, and based on the contract information received together with the identification information, Or the license information to the license management server 2 so that the license information stored in advance for the electronic book distributor is updated.

Accordingly, the repackaging module 200 separates the license information L and the encryption resource from the master e-book content and stores the license information L and the encryption resource in the master e-book content, which corresponds to the reception subject of the master e-book content received from the license management server 2 The license information L1 may be replaced with the license information L1 corresponding to the destination of the master e-book content, and the existing license information L included in the master e-book content may be replaced with the license information L1 ), And re-packages the encrypted content together with the encryption resource to generate brokerage e-book content.

Also, the repackaging module 200 may transmit the intermediation e-book contents to the repackaging module 200 included in the terminals 120 and 130 corresponding to the e-book broker or the ebook distributor.

At this time, the repackaging module 200 receives from the certificate management server 1, which issues and manages a certificate for each of the terminals 110, 120, 130 and 140, Related information C1 corresponding to the electronic book distributor, and encrypt the license information based on the certificate-related information C1.

For example, the repackaging module 200 extracts the private key for the CEK from the certificate information stored in the storage unit of the artist / publisher terminal 110, and extracts the existing license information L using the private key for the CEK The decrypted CEK may be decrypted using the public key for CEK included in the certificate related information, and the re-encrypted CEK may be included in the replaced license information (L1) . The detailed configuration thereof will be described below.

The e-book broker terminal 120 may include an e-book brokering management module 121 and a repackaging module 200. The e-book broker management module 121 may receive the brokerage e-book content 120 It is possible to receive the contract information and the identification information as described above through communication with the electronic book distribution management module 131 constituted in the electronic book distribution management terminal 130 as an object and to transmit the contract information to the license management server 2 ) So that the license information stored in advance corresponding to the ebook distributor can be updated based on the contract information.

Also, the repackaging module 200 configured in the e-book broker terminal 120 separates and decrypts the license information L1 from the intermediation e-book contents, and decrypts the license information L1 from the e-book intermediation management module 121 License information L2 corresponding to the e-book publisher terminal 130, which is an object of receiving the intermediary e-book contents, is received from the license management server 2 based on the received identification information and included in the intermediary e-book contents The electronic book content L1 can be replaced with the license information L2 corresponding to the electronic book publisher terminal, encrypted and re-packaged together with the encryption resource to generate intermediary e-book content, To the distributor terminal 130.

At this time, the repackaging module 200 configured in the e-book broker terminal 120 receives the certificate-related information C2 corresponding to the e-book distributor, which is the target of receiving the intermediation e-book content, from the certificate management server 1 , And encrypt the license information (L2) based on the certificate related information (C2).

The repackaging module 200 configured in the e-book reader terminal 120 may operate in the same manner as the repackaging module 200 configured in the artist / publisher terminal 110 described above.

The electronic book distribution terminal 130 may include an electronic book distribution management module 131 and a repackaging module 200. The electronic book distribution management module 131 may receive the electronic book contents The client terminal 300 can receive the contract information and the identification information through the communication with the client module 300 constituting the target user terminal 140 and transmits the contract information to the license management server 2, And update the license information corresponding to the user of the user terminal 140 based on the information.

The repackaging module 200 configured in the ebook publisher terminal 130 separates and decrypts the license information L2 from the brokering ebook contents and transmits the license information L2 from the ebook circulation management module 131 And receives license information (L3) corresponding to the user terminal (140), which is an object of receiving the intermediary e-book content, from the license management server (2) based on the received identification information, It is possible to replace the license information L2 with the license information L3 corresponding to the user terminal 140, encrypt the license information and re-package the license information together with the encryption resource to generate e-book content for the user, 140, respectively.

At this time, the repackaging module 200 configured in the ebook publisher terminal 130 receives the certificate-related information C3 corresponding to the user who is the target of receiving the intermediation e-book content from the certificate management server 1, The license information may be encrypted based on the certificate related information C3.

The repackaging module 200 configured in the electronic book publisher terminal 130 can operate in the same manner as the repackaging module 200 configured in the artist / publisher terminal 110 and the electronic book broker terminal 120 have.

Accordingly, the client module 300 configured in the user terminal 140 can restore the plain text resource corresponding to the e-book by decrypting the e-book contents for the user, and can transmit the corresponding plain text resource to the user terminal 140 So that the user can browse the e-book.

At this time, the client module 300 may receive and store the certificate information C4 issued from the certificate management server 1, and may decrypt the e-book content for the user based on the certificate information C4 have.

In the above-described configuration, the certificate information issued from the certificate management server 1 may include public key and private key certificate information, and the public key certificate information includes a public key for CEK encryption for CEK encryption, The private key certificate information may include a private key for CEK decryption for decrypting the encrypted CEK.

Therefore, the public key for CEK described in the present invention may mean the public key for CEK encryption, and the private key for CEK may refer to the private key for CEK decryption.

Meanwhile, in the above-described system configuration, a receiving terminal receiving e-book contents among the terminals 110, 120, 130, and 140 and corresponding e-book contents among the terminals 110, 120, The repackaging module 200 configured in the sending terminal that transmits the encrypted content encrypts the plain text resource constituting the e-book contents and transmits the CEK to the sending terminal having the repackaging module 200 configured in advance The electronic signature information is added to the license information, and the encrypted electronic signature information is encrypted and transmitted to the receiving terminal, thereby enabling the e-book broker or the distributor to identify the responsibility for unauthorized distribution of the e-book contents, thereby preventing unauthorized distribution in advance And encrypts based on the certificate-related information of the receiving terminal so that repackaging and browsing of the e-book contents can be performed only at the receiving terminal There can be provided so as to be described in detail based on the configuration described above also this through 2 to 4.

2 and 6, each of the terminals 110, 120, 130, and 140 includes a certificate installation module 10, and the certificate installation module 10, (10) transmits certificate issuance request information for a certificate issuance request to the certificate management server (1) (S1), and the certificate management server (1) A public key and a private key for CEK (content encryption key) used for encryption and decryption of CEK, a public key and a private key for digital signature for encryption and decryption of digital signature verification information added for verification of the digital signature, Generates certificate information including a certificate authority (CA) certificate (S2), stores the certificate information in the certificate DB by matching with the identification information of the terminal included in the certificate issuance request information, The certificate information can be transmitted to the terminal that has sent (S3).

3, the certificate installation module 10 configured in each of the terminals 110, 120, 130, and 140 includes a public key and a private key pair for digital signatures, a private key and a public key pair for CEK, And receives the certificate information including the CA certificate, and stores the certificate information in the storage unit of the terminal in which the certificate installation module 10 is configured.

In addition, the certificate management server 1 and the certificate installation module 10 or the repackaging module 200 configured in the terminal may store the digital signature private key, the private key for CEK, and the CA certificate from the certificate information stored in the storage unit And encrypted by device information corresponding to the terminal (S2).

4 is a flowchart illustrating an e-book content delivery process and a repackaging process between a transmitting terminal and a receiving terminal, wherein the repackaging module 200 configured in the transmitting terminal of each of the terminals 110, 120, 130, When receiving the e-book content from another terminal or the packaging module 100, the e-book content can be separated from the encrypted resource and the license information.

At this time, the e-book contents may include an encryption resource generated by encrypting the plain text resource with the CEK as shown in FIGS. 4 and 5, and license information.

The license information may include the CEK, and may include digital signature verification information for verifying the integrity of the digital signature information and the usage permission information corresponding to the transmitting terminal and the digital signature information and the usage permission information. have.

The repackaging module 200 of the transmitting terminal may communicate with the certificate management server 1 to transmit the identification information to the receiving object (receiving terminal) of the electronic book contents to the certificate management server 1 have.

Accordingly, the certificate management server 1 can receive the certificate-related information extracted from the certificate information stored in the certificate DB 11 matching the identification information. In this case, the certificate related information may include a public key for the CEK and a private key for digital signature of the receiving terminal, and the certificate management server 1 may transmit the private key for digital signature in the encrypted state to a receiving terminal And transmits the decrypted certificate information.

Accordingly, the repackaging module 200 of the transmitting terminal can encrypt the CEK with the public key for the CEK, as shown in FIGS. 4 and 5.

If the repackaging module 200 of the transmitting terminal is configured in the e-book dealer terminal 120 or the ebook publisher terminal 130, the repackaging module 200 may store the e- The encrypted CEK (E_CEK) can be extracted from the license information included in the revoked packet, and the encrypted CEK (E_CEK) is encrypted with the CEK public key of the transmitting terminal in the repackaging module 200 configured in the other terminal.

Accordingly, the repackaging module 200 of the transmitting terminal extracts the CEK private key (E_PK) encrypted with the device information from the certificate information stored in the storage unit 400 of the transmitting terminal to decrypt the encrypted CEK And decrypts the encrypted private key for E-CK (E_PK) with predetermined device information to generate a private key for CEK.

Next, the repackaging module 200 of the transmitting terminal can decrypt the encrypted CEK (E_CEK) using the private key for the CEK, thereby generating the CEK.

Also, the repackaging module 200 of the transmitting terminal can encrypt the decrypted CEK with the CEK public key of the receiving terminal included in the certificate related information received from the certificate management server 1 as described above.

That is, the repackaging module 200 of the transmitting terminal can encrypt the CEK included in the e-book contents with the public key for the CEK of the receiving terminal, and provide the CEK to the receiving terminal, The CEK (E_CEK) encrypted with the private key for the CEK of the receiving terminal can be decrypted, so that the receiving terminal can support access to the CEK.

The repackaging module 200 of the transmitting terminal transmits the identification information of the receiving terminal to the license management server 2 to receive the license information L1 corresponding to the receiving terminal, The license information L included in the electronic book content can be replaced with the new license information L1 received from the license management server 2. [

At this time, the new license information (L1) may include usage permission information for the license period of the electronic book contents corresponding to the receiving terminal.

In addition, the repackaging module 200 of the transmitting terminal may add the previously stored digital signature information to the new license information L1, and the digital signature verification information for verifying the integrity of the digital signature information and the usage permission information And add it to the new license information L1.

In addition, the repackaging module 200 of the transmitting terminal may receive, from the certificate management server 1, the digital signature verification information using the digital signature private key included in the certificate related information received corresponding to the identification information of the receiving terminal Can be encrypted.

Also, the repackaging module 200 of the transmitting terminal may add the CEK (E_CEK) encrypted with the private key for the CEK of the receiving terminal to the new license information L1.

Through the above-described configuration, the repackaging module 200 of the transmitting terminal re-packages the encrypted resource extracted from the electronic book contents received from the other terminal and the new license information to generate e-book content (e-book content 1) And transmits it to the repackaging module 200 of the receiving terminal.

Accordingly, the repackaging module 200 configured in the receiving terminal extracts the encrypted public key for digital signature from the storage unit 400 upon receiving the electronic book content (electronic book content 1) from the transmitting terminal, It is possible to decrypt the encrypted digital signature verification information in the license information included in the license information with the digital signature public key and to determine the integrity of the digital signature information and the license information included in the license information based on the decrypted digital signature verification information .

Also, the repackaging module 200 configured in the receiving terminal checks the contents of the sending terminal and the digital signature based on the digital signature information, determines whether the period expires based on the usage permission period according to the usage permission information, And when it has expired, decryption and transmission (distribution) of the e-book contents can be stopped.

On the other hand, when the digital signature information is valid and the period according to the license information is valid, the receiving terminal (first receiving terminal) receiving the e-book content (e-book content 1) from the transmitting terminal operates as a transmitting terminal , The repackaging module 200 of the receiving terminal (first receiving terminal) operating as the transmitting terminal operates in the same manner as the configuration of the repackaging module of the transmitting terminal described above, (L1) included in the e-book content (e-book content 1) is replaced with the license information (L2) of the next receiving terminal (second receiving terminal) receiving the book content and the above- (E-book content 2) by repackaging the license information (L2) of the next receiving terminal (second receiving terminal) generated according to the operation of the terminal 200 and the encryption resource And can transmit the new e-book content (e-book content 2) to the next receiving terminal (second receiving terminal).

At this time, the license information L2 included in the new e-book content (e-book content 2) includes CEK (E_CEK) encrypted with the private key for the CEK of the next receiving terminal (second receiving terminal) And the digital signature verification information generated based on the digital signature information and the usage permission information corresponding to the next receiving terminal (second receiving terminal), and the digital signature verification information may be transmitted to the next receiving terminal (The second receiving terminal).

Thereafter, the repackaging module 200 configured in the next receiving terminal (second receiving terminal) receives the new e-book content (e-book content 2) and operates in the same manner as the operability of the repackaging module 200 .

As described above, the present invention encrypts e-book content related information based on certificate related information related to a recipient who receives e-book content each time an e-book content is brokered or circulated, and transmits the encrypted e-book content related information to the recipient. The contents of the e-book contents can be clearly identified, and even if the e-book contents are leaked, the contents of the e-book contents can be restricted only by the information related to the certificate of the recipient, The risk of leakage of the content can be prevented.

6, each of the terminals 110, 120, 130 and 140 has a certificate installation module 10 configured to receive a certificate from the certificate management server 1 And the terminal 110 of the artist / publisher generates the above-described e-book contents through the packaging module 100. When the terminal 110 of the artist / publisher operates as a transmitting terminal, The e book broker / distributor terminal 120, 130 receiving the e-book broker / distributor terminal 120 operates as a receiving terminal.

Accordingly, the repackaging module 200 included in the terminal 10 of the artist / publisher receives the electronic book from the license management server 2 to the electronic book broker / distributor terminal 120, 130 corresponding to the receiving terminal The electronic signature information of the artist / publisher terminal and the digital signature verification information generated based on the digital signature information of the artist / publisher terminal can be added to the license information of the electronic book broker / distributor.

Also, the repackaging module 200 included in the author / publisher terminal extracts the encrypted CEK from the license information included in the master ebook content, decrypts the encrypted CEK, and transmits the CEK to the certificate management server 1 encrypted by the public key for CEK corresponding to the electronic book broker / distributor terminal 120, 130 received from the electronic book broker / distributor terminal 120, 130, adds the electronic signature verification information included in the license information to the license information of the electronic book broker / Can be encrypted with the private key for digital signature corresponding to the e-book broker / distributor terminal (120, 130) received from the certificate management server (1).

Thereafter, the repackaging module 200 included in the artist / publisher terminal 110 extracts the encryption resource from the master e-book contents and repackages the e-book with the license information of the e-book broker / And then transmits the created electronic book to the electronic book dealer / distributor terminal 120 or 130.

At this time, the repackaging module 200 included in the artist / publisher terminal 110 reads the existing license information from the master e-book contents in accordance with the above-described process, based on the certificate-related information corresponding to the e-book broker / May be replaced with the license information of the e-book broker / distributor encrypted and repackaged together with the encryption resource.

Meanwhile, the e-book broker / distributor terminal 120, 130 may transmit the intermediary e-book contents to the user terminal 140 when receiving the brokerage e-book contents, And the user terminal 140 operates as a receiving terminal.

Accordingly, the repackaging module 200 configured in the e-book broker / distributor terminals 120 and 130 receives the license information of the user for the user terminal 140 corresponding to the receiving terminal from the license management server 2 And add the electronic signature information of the electronic book broker / distributor to the license information of the user and the digital signature verification information generated based thereon.

Also, the repackaging module 200 included in the electronic book brokers / distributor terminals 120 and 130 extracts the encrypted CEK from the license information included in the brochure e-book contents, Encrypts the generated CEK with the public key for CEK corresponding to the user terminal 140 received from the certificate management server 1, adds the generated CEK to the license information of the user And encrypt the digital signature verification information included in the license information with the private key for digital signature corresponding to the user terminal 140 received from the certificate management server 1. [

Thereafter, the repackaging module 200 included in the eBook brokers / distributor terminals 120 and 130 extracts the encryption resource from the brokering e-book contents, re-packages it together with the license information of the user, And may transmit the content to the user terminal 140 after the content is generated.

In the above-described configuration, when the certificate management server 1 transmits the digital signature private key to the terminal requesting the certificate related information, the certificate management server 1 transmits the digital signature private key And transmit the certificate related information to the requesting terminal.

The user terminal 140 includes a client module 300 for receiving the user e-book content and allowing the user to browse contents of the e-book content. The client module 300 includes a user interface The encrypted CEK and the digital signature verification information included in the electronic book contents for the electronic book contents are decrypted and the encryption resource is decrypted based on the decrypted CEK and the digital signature verification information to generate the plain text resource and then the user can browse the electronic book. Will be described in detail.

As shown in the figure, the client module 300 configured in the user terminal 140 separates the license information from the e-book content for the user when receiving the e-book content for the user, Key to verify the integrity of digital signature information and license information.

When the integrity is verified, the client module 300 stops viewing the e-book contents for the user when the usage period according to the usage permission information has expired. If the usage period is valid, the client module 300 stores Extracts the encrypted private key for the CEK from the certificate information stored in the storage unit 500 and decrypts the encrypted private key for the CEK using the device information of the predetermined user terminal 140. [

Also, the client module 300 can decrypt the encrypted CEK using the decrypted private key for CEK, decrypt the encrypted resource included in the user e-book content using the decrypted CEK, have.

Accordingly, the client module 300 can generate a plain-text resource by decrypting the encrypted resource, load the plain-text viewer interface and display the plain-text resource on the display of the user terminal 140 so that the user can view the plain- can do.

As described above, according to the present invention, e-book content is encrypted and provided based on the certificate-related information about the reception subject of the e-book content, so that the e-book content can be viewed only at the reception subject having the reading right for the e-book content And at the same time, the viewing authority of the e-book contents can be changed based on the certificate-related information every time the receiving object is changed, thereby preventing other users other than the receiving subject from browsing the e-book contents, Can be effectively prevented.

In addition, all the encryption and decryption methods described in the present invention can use the same DRM (Digital Rights Management) method. Accordingly, the present invention can be applied to a DRM system in which all the writers, publishers, brokers, So that the user can browse all e-books using only a single client, thereby enhancing the user's convenience.

8 to 10 are flow charts of an electronic book distribution service method optimized for a cloud environment according to an embodiment of the present invention.

8 is a flow chart of an electronic book packaging process of a packaging module. As shown in the figure, the packaging module 100 generates a CEK for encrypting a plain text resource (S11) May be encrypted based on the CEK to generate an encryption resource (S12).

Then, the packaging module 100 can encrypt the CEK based on the public key for CEK included in the certificate information stored in advance in the terminal generating the electronic book content (S13).

Next, the packaging module 100 generates license information including the encrypted CEK, and packages the encrypted license information together with the encrypted resource to generate e-book contents (S14).

FIG. 9 is a flowchart of an electronic book repackaging process of the repackaging module 200. As shown in the figure, the repackaging module 200 decrypts e-book contents received from the packaging module or another terminal, (S21), and it is possible to check whether the certificate information exists in the storage unit of the terminal configured with the repackaging module 200 (S22).

Then, the repackaging module 200 determines whether the e-book content is the master e-book content received from the terminal corresponding to the author / publisher (S23) (S25). If it is not the master e-book content (S23), the license period is checked based on the license information included in the e-book content (S24). If the period is expired, The reading of the book content is terminated, and if the period is valid, the private key for CEK may be extracted from the pre-stored certificate information (S25).

Next, the repackaging module 200 decrypts the encrypted CEK using the private key for the CEK (S26), and transmits the decrypted CEK to the certificate management server (1) And can receive the certificate-related information of the corresponding receiving terminal.

Thereafter, the repackaging module 200 encrypts the CEK using the public key for the CEK of the receiving terminal included in the certificate-related information (S27), and transmits the encrypted CEK to the recipient terminal from the license management server 2 After adding the digital signature and the digital signature verification information for verifying the integrity of the digital signature to the received license information, encrypting the digital signature verification information with the digital signature private key of the receiving terminal contained in the certificate related information, And the CEK encrypted with the public key for the CEK of the receiving terminal may be added to the new license information (S28).

Also, the repackaging module 200 may replace the existing license information of the received e-book content with new license information, re-package the encryption resource and the new license information to generate new e-book content, To the receiving terminal (S29).

In the above-described configuration, the license information may be stored in the receiving terminal, and the repackaging module 200 configured in the transmitting terminal may directly request the receiving terminal for the license information corresponding to the receiving terminal, And may receive the license information corresponding to the terminal.

10, the client module 300 extracts encrypted resource and license information by decrypting the received e-book content (S31). The client module 300 extracts the encrypted resource and license information from the received e- The client module 300 may determine whether certificate information exists in the storage unit of the user terminal (S32).

When the certificate information exists, the client module 300 decrypts the encrypted digital signature verification information included in the license information with the digital signature public key included in the certificate information, and transmits the digital signature information included in the corresponding license information, Checking the usage period of the license information based on the usage permission information (S33), stopping the reading of the e-book content when the period has expired, and if the period is valid, extracting the certificate information stored in the storage unit The encrypted private key for CEK can be extracted (S34).

At this time, the client module 300 decrypts the encrypted private key for the CEK using preset device information, and decrypts the encrypted CEK included in the license information using the decrypted private key for the CEK (S35) .

Next, the client module can decrypt the encrypted resource using the decrypted CEK, thereby generating the plain-text resource (S36).

Then, the client module 300 displays the plain text resource through the viewer and provides the user with browsing contents of the e-book (S37).

Meanwhile, as shown in FIG. 11, the client module 300 may transmit and store the e-book contents to a predetermined cloud server 3.

Accordingly, when a user uses different user terminals, each terminal can store certificate information in a storage unit, and the client module 300 configured in each terminal receives the e-book contents from the cloud server 3 The encryption resource included in the e-book content is decrypted through the operation as described above to generate a plain text resource, and the plain text resource can be displayed through the viewer to provide the user with an electronic book to be browsed.

That is, the present invention can provide convenience for using e-book contents by providing the user to store the e-book contents in the cloud server 3 and browse the e-book contents at any time using different user terminals , It is possible to limit the reading of the e-book content only to the user terminal that has issued the certificate information, so that the e-book content can be freely utilized through the cloud server 3 without worrying about leakage of the e-book content.

At this time, when issuing the certificate information corresponding to the user, the certificate management server 1 assigns different unique device keys corresponding to different user terminals and transmits them to the user terminal in the certificate information , So that each user terminal can store certificate information including a unique device key corresponding to itself.

Also, the certificate management server 1 and the client module 300 may encrypt and store the private key for the CEK based on the inherent device key.

Accordingly, the certificate management server 1 and the client module 300 decrypt the private key for the CEK encrypted using the unique device key, and use the decrypted private key for the CEK to decrypt the CEK of the e-book content It can be decoded.

Thus, the present invention can restrict the e-book contents to be read by each user terminal only when the same user is issued a certificate corresponding to different user terminals.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

1: Certificate management server 2: License management server
3: Cloud server 100: Packaging module
200: repackaging module 300: client module

Claims (10)

The electronic book content and the private key certificate information for the use of the e-book content and for storing the electronic book content and the private key certificate information, A certificate management server for transmitting information on a public key certificate necessary for encryption to the transmitting terminal;
And generating an encryption resource that is configured in the terminal for generating the e-book content and is encrypted with a predetermined content encryption key (CEK: Content Encryption Key), and the CEK is included in the public key certificate information A packaging module for generating and transmitting license information including encrypted CEK, pre-stored digital signature information, and license information, and e-book contents packaged with the encryption resource after encrypting the encrypted content using the public key for CEK; And
Wherein the digital signature information and the usage permission information included in the license information are checked at the time of receiving the e-book content, and when the use of the e-book content is valid, the encrypted CEK is stored in the previously stored private key certificate information Encrypts the decrypted content with a public key for CEK included in the public key certificate related information received from the certificate management server, incorporates the decrypted content into the new license information received corresponding to the receiving terminal, And a repackaging module for replacing the existing license information included in the new license information with the new license information and repackaging the new e-book content together with the encryption resource to the receiving terminal, Service system.
The method according to claim 1,
When receiving the e-book contents, decrypts the CEK included in the e-book contents using the CEK private key in the private key certificate issued from the certificate management server and stored in the private key certificate stored in the user terminal, Further comprising a client module for decrypting the encrypted resource and generating the plain-text resource in accordance with the decryption of the encrypted resource, so as to allow the user to browse the electronic book, .
The method of claim 2,
The CEK private key is encrypted by at least one of the certificate management server, the repackaging module, and the client module with the device information of the terminal corresponding to the private key for the CEK,
Wherein the repackaging module and the client module decrypt the CEK private key with pre-stored device information and decrypt the encrypted CEK using the decrypted private key for CEK. Distribution service system.
The method of claim 2,
Wherein the certificate information includes a CA certificate, a private key for the CEK, a public key for the CEK, a public key for an electronic signature, and a private key for an electronic signature.
The method of claim 4,
Wherein the packaging module and the repackaging module add digital signature verification information to the license information for checking the integrity of the electronic book content,
Wherein the repackaging module of the transmitting terminal encrypts the digital signature verification information with the private key for digital signature included in the certificate related information, and the repackaging module and the client module of the receiving terminal encrypt the digital signature And decrypting the digital signature verification information using a public key to confirm the integrity of the electronic book.
The method of claim 5,
Wherein the repackaging module and the client module of the receiving terminal check the use period according to the usage permission information when the integrity check is performed and decrypt the CEK when the usage period is valid.
The method of claim 2,
Wherein the client module transmits and stores the e-book contents to a predetermined cloud server.
The method of claim 2,
The certificate management server assigns different unique device keys corresponding to the respective user terminals at the time of requesting certificate issuance of different user terminals, and transmits certificate information including unique device keys corresponding to the respective user terminals to each user terminal In addition,
The client module encrypts the private key for the CEK included in the certificate information using the unique device key, decrypts the private key for the CEK using the unique device key when decrypting the encrypted CEK, And decrypts the encrypted CEK using the decrypted private key for CEK.
The method according to claim 1,
And a license server for storing license information corresponding to different terminals and including license information,
Wherein the repackaging module requests license information of the receiving terminal to the license server to generate the new electronic book content and receives license information corresponding to the receiving terminal from the license server. Optimized ebook distribution service system.
A certificate issuing unit for issuing and storing certificate information for use of the e-book content, and a certificate required for encrypting the e-book content among the certificate information issued in correspondence with the receiving terminal, Issuing certificate information corresponding to each terminal using e-book contents and issuing certificate information, the certificate management server transmitting related information to the transmitting terminal;
The packaging module configured in the terminal generating the electronic book contents generates an encryption resource in which the plain text resource constituting the electronic book is encrypted with a predetermined content encryption key (CEK), and the CEK Generating license information including encrypted CEK, pre-stored digital signature information, and license information, and e-book content in which the encryption resource is packaged, And
The repackaging module configured in the transmitting terminal checks the digital signature information and the usage permission information included in the license information when receiving the electronic book content from the packaging module or another terminal, and when the use of the electronic book content is valid, Encrypted with the CEK private key included in the previously stored certificate information, encrypted with the public key for CEK included in the certificate related information received from the certificate management server, and included in the received new license information corresponding to the receiving terminal , Replacing the existing license information included in the electronic book content with the new license information, repackaging the new electronic book content together with the encrypted resource, and transmitting the new electronic book content to the receiving terminal
Wherein the e-book distribution service is optimized for a cloud environment.

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