WO2017069412A1

WO2017069412A1 - System and method for electronic book distribution service optimised for cloud environment

Info

Publication number: WO2017069412A1
Application number: PCT/KR2016/010519
Authority: WO
Inventors: 강호갑; 김태현
Original assignee: 주식회사 디알엠인사이드
Priority date: 2015-10-22
Filing date: 2016-09-21
Publication date: 2017-04-27
Also published as: KR20170046941A

Abstract

The present invention relates to a system and a method for an electronic book distribution service that are optimised for a cloud environment, and more specifically to a system and a method for an electronic book distribution service that are optimised for a cloud environment that prevent illegal distribution of electronic books by separately encrypting only license information that is included in an electronic book, and by encrypting an encryption key that is used for the encryption based on a certificate of a receiver having the right to read an electronic book, and at the same time supporting safe protection of electronic books in a cloud environment. The present invention provides electronic book content by encrypting the same based on certificate-related information with respect to a receiver of the electronic book content, and as a result can ensure that only a receiver having a right to read the electronic book content can read the electronic book content, can allow modification of a reading right of the electronic book content based on certificate-related information whenever a receiver is changed, can prevent users other than the receiver from reading the electronic book content, and can prevent illegal distribution of electronic book content.

Description

E-book distribution service system and method optimized for cloud environment

The present invention relates to an e-book distribution service system and method optimized for a cloud environment, and more particularly, to provide a separate encryption of only the license information configured in the e-book, and at the same time read the encryption key used for encryption for the e-book The present invention relates to an e-book distribution service system and method optimized for a cloud environment that encrypts based on a certificate of an authorized recipient and prevents illegal distribution of the e-book, and supports the protection of the e-book even in a cloud environment.

Currently, as more users subscribe to e-books through user terminals, there is an increasing demand for storing e-books scanned on general books in user terminals for convenient reading.

However, such an e-book can be easily copied than a general book due to its characteristics, and can be simultaneously distributed through a communication network, so that the copyright holder (author) or the publisher of the book has a great objection to the scanning of the book.

However, as the demand for e-books on digital devices has soared, the flow of distribution of e-books cannot be rejected, so the current book's copyright holder or publisher cannot prepare for e-books to prevent illegal distribution of e-books. This is a requirement of a content service provider such as a broker or distributor.

Therefore, in order to satisfy the needs of the copyright holder or publisher, the content service provider encrypts and distributes the e-book using digital rights management (DRM), which is the most widely used copyright protection solution. The e-book is protected by using a method of decrypting and reading the e-book through user authentication through a specific decryption client provided by the content service provider.

However, with the emergence of various content service providers, each content service provider encrypts an e-book using its own DRM method. Therefore, an end user who views an e-book must install a decryption client suitable for the method in each DRM. .

That is, when there is no compatibility between different DRMs provided by different content service providers, an end user wants to read e-books provided by different content service providers from a digital device used to read e-books. There is a need to install a plurality of decryption clients, and there is an inconvenience of checking the content service provider of the e-book and reading the e-book only through the decryption client.

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

Therefore, it is possible to alleviate the concern about illegal distribution of the e-book by the copyright holder or the publisher, and improve the convenience of using the e-book for users who use the e-book by using the encryption method among the content service providers. There is a need for a plan for supporting e-books.

[Preceding technical literature]

[Patent Documents]

(Patent Document 1) Korean Registered Patent No. 10-0718702

According to the present invention, only the license information configured in the e-book can be separated and encrypted, and the encryption key used for encrypting the e-book is encrypted as the public key of the receiving object having the authority to view the e-book. The purpose of the present invention is to effectively prevent illegal distribution of e-books by restricting them to view them.

In addition, the present invention provides a different digital content service providers to encrypt the e-book using the same DRM scheme, and encrypts the decryption key used for decryption of the e-book using the device information of the receiving target specific digital device The purpose of this is to prevent e-books from being read even if the e-books are leaked by minimizing the disapproval of the distribution of e-books by the copyright holder or the publisher.

In addition, the present invention provides a user with an e-book stored in the cloud server to facilitate the use of the e-book at the same time to limit the decryption of the e-book only in the user's digital device to facilitate illegal distribution The purpose is to apply.

An e-book distribution service system optimized for a cloud environment according to an embodiment of the present invention issues and stores public key and private key certificate information for use of e-book content, and transmits the e-book content to a receiving terminal. A certificate management server for transmitting the public key certificate related information required for encryption of the e-book content among the certificate information issued corresponding to the receiving terminal to the transmitting terminal and a terminal for generating the e-book content upon request of Create an encrypted resource that encrypts the plain text resource constituting the e-book with a predetermined Content Encryption Key (CEK), encrypts the CEK with a public key for CEK included in the public key certificate information, and then encrypts the encrypted CEK. License information including the digital signature information and license information stored in advance and the encryption A packaging module configured to generate and transmit e-book contents packaged from a source, and configured in the transmitting terminal to check the e-signature information and license information included in the license information when the e-book contents are received, thereby enabling the use of the e-book contents. If valid, the encrypted CEK is decrypted with a CEK private key included in the previously stored private key certificate information, and then encrypted with the public key for CEK included in the public key certificate related information received from the certificate management server. Corresponding new license information included in the received e-book content, the existing license information included in the e-book content is replaced with the new license information, and the new e-book content generated by repackaging with the encryption resource is transmitted to the receiving terminal. It may include a repackaging module.

As an example related to the present invention, an e-book distribution service system optimized for the cloud environment is configured in a user terminal and receives a private key for a CEK in a private key certificate stored in a pre-stored private key certificate when the e-book content is received. Decrypting the CEK included in the e-book content using the CEK, decrypting the encryption resource using the CEK, and generating the plain text resource according to the decryption of the encryption resource so that the user can read the e-book. It may be characterized in that it further comprises a client module.

As an example related to the present invention, the CEK private key is encrypted with device information of a terminal corresponding to the CEK private key by at least one of the certificate management server, a repackaging module, and a client module. And the client module decrypts the CEK private key into pre-stored device information, and decrypts the encrypted CEK using the decrypted CEK private key.

As an example related to the present invention, the certificate information may include a CA certificate, the CEK private key, the CEK public key, an electronic signature public key, and an electronic signature private key.

As an example related to the present invention, the packaging module and the repackaging module add electronic signature verification information for confirming the integrity of the electronic book content to the license information, and the repackaging module of the transmitting terminal is configured to perform the electronic signature. The verification information is encrypted with the digital signature private key included in the certificate related information, and the repackaging module and the client module of the receiving terminal decrypt the digital signature verification information by using the digital signature public key included in the previously stored certificate information. It may be characterized by checking the integrity.

As an example related to the present invention, the repackaging module and the client module of the receiving terminal may be configured to decrypt the CEK when the usage period is valid by checking the usage period according to the usage permission information when checking the integrity.

As an example related to the present invention, the client module may transmit and store the e-book content to a predetermined cloud server.

As an example related to the present invention, the certificate management server is provided with a unique device key corresponding to each of the user terminal when the certificate issuance request of the different user terminal, and includes a unique device key corresponding to each user terminal The certificate information is transmitted to each user terminal, and the client module encrypts the private key for CEK included in the certificate information using the unique device key, and encrypts the encrypted device using the unique device key when decrypting the encrypted CEK. And decrypting the encrypted CEK using the decrypted CEK private key after decrypting the CEK private key.

As an example related to the present invention, the e-book distribution service system optimized for the cloud environment further includes a license server that stores license information corresponding to each different terminal including license information, and the repackaging module includes: In order to generate the new e-book content, the license server may request license information of the receiving terminal, and receive license information corresponding to the receiving terminal from the license server.

According to an embodiment of the present invention, an e-book distribution service method optimized for a cloud environment issuing and storing certificate information for use of e-book content, and receiving the request at the request of a transmitting terminal to deliver the e-book content to a receiving terminal. Issuing and transmitting certificate information corresponding to each terminal using e-book contents by a certificate management server for transmitting certificate-related information necessary for encrypting the e-book content among the certificate information issued corresponding to the terminal to the transmitting terminal; The packaging module configured to generate the e-book content generates an encryption resource that encrypts the plain text resource constituting the e-book with a predetermined content encryption key (CEK) and is included in the previously stored certificate information. Encrypted CEK and pre-stored digital signature information after encrypting with public key for CEK Generating license information including license information and the e-book content in which the encryption resource is packaged, and the repackaging module configured in the transmitting terminal receives the e-book content from the packaging module or another terminal in response to the license information. The certificate related information received from the certificate management server after decrypting the CEK with the CEK private key included in the previously stored certificate information when the electronic signature information and the license information included in the electronic book contents are valid. Encrypt with a public key for CEK included in the included in the new license information received corresponding to the receiving terminal, replace the existing license information included in the e-book content with the new license information and repackaging with the encryption resource New ebook book created by It may comprise the step of transmitting to the receiving terminal Massachusetts.

According to the present invention, the e-book contents can be encrypted and provided based on the certificate-related information on the e-book contents receiving target. At the same time, whenever the recipient is changed, the authority to view the e-book contents can be changed based on the certificate-related information, thereby preventing the leakage of the e-book contents by preventing other users from viewing the e-book contents. It works.

In addition, the present invention encrypts the e-book content-related information based on the certificate-related information associated with the recipient receiving the e-book content at every mediation or distribution of the e-book content and transmits the e-book content-related information to the recipient to use the certificate-related information only on the recipient side. By providing mediation or distribution of book contents, not only can it clearly identify the material responsible for the unauthorized distribution of e-book contents, but even if it is leaked, the e-book contents can be restricted only by the recipient's certificate-related information. There is an effect that can prevent the danger.

In addition, the present invention provides the user with the convenience of using the e-book content by storing the e-book content in the cloud server and providing the user can view the e-book content at any time using different user terminals, certificate information The e-book contents can be restricted to only the user terminal that has been issued. Therefore, the e-book contents can be freely used through the cloud server without fear of leaking the e-book contents. E-book content can be effectively protected from the missing user.

In addition, the present invention supports authors, publishers, intermediaries, and distributors in the distribution process of the e-book to distribute the e-books through the same DRM method so that the user can view all the e-books using only a single client. By supporting it, the user's convenience can be improved.

1 is a block diagram of an e-book distribution service system optimized for a cloud environment according to an embodiment of the present invention.

2 is a flow chart for a certificate issuing process according to an embodiment of the present invention.

3 is a block diagram of certificate information according to an embodiment of the present invention.

4 is a conceptual view of the operation of the repackage module according to an embodiment of the present invention.

5 is a conceptual diagram illustrating an encryption process for e-book content according to an embodiment of the present invention.

6 is a conceptual diagram illustrating an e-book distribution process of an e-book distribution system optimized for a cloud environment according to an embodiment of the present invention.

7 is a conceptual diagram of operation of a client module according to an embodiment of the present invention.

8 to 10 are flowcharts illustrating an e-book distribution service method optimized for a cloud environment according to an embodiment of the present invention.

11 is a conceptual diagram of the use of e-book content using a cloud server in different user terminals according to an embodiment of the present invention.

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

1 is a block diagram of an e-book distribution service system optimized for a cloud environment according to an embodiment of the present invention, as shown, the terminal 110 for generating an e-book, the terminal 120 for distributing or brokering an e-book. 130 and the certificate management server 1 for issuing a certificate through a communication network corresponding to the user terminal 140, respectively, and stores the license information for each of the different terminals (110, 120, 130, 140) and the terminal In the request, it may include a license management server (2) for transmitting the license information corresponding to the terminal to the terminal through a communication network.

In addition, the e-book distribution service system optimized for the cloud environment is configured in the terminal 110 corresponding to the writer or publisher among the terminals (110, 120, 130, 140) for the first packaging (packaging) of the e-book content The packaging module 100 and the transmitting terminal for transmitting the e-book content among the terminals (110, 120, 130, 140) is configured to repackage or repackage the e-book content through an encryption and decryption process After the packaging) is configured in the repackaging module 200 for transmitting the e-book content generated according to this and the user terminal 140 of each of the terminals (110, 120, 130, 140) to decode the e-book content It may include a client module 300 for viewing.

Based on the above-described configuration, when describing the respective components in detail, as shown, the writer / publisher terminal 110 corresponding to the author or publisher with the e-book generation authority is e-book generation module 111 and packaging module 100 And a repackaging module 200.

The e-book generation module 111 generates a plain text resource corresponding to the e-book and provides it to the packaging module 100, and the e-book broker terminal 120 or the e-book distributor terminal 130, which is the target of the e-book, is provided. And the contract information and identification information for the e-book broker terminal 120 or the e-book distributor terminal in communication with the e-book mediation management module 121 or the e-book distribution management module 131, the identification information May be transmitted to the packaging module 100 together with the plain text resource.

In this case, the contract information may include the license information for the license period (use period) for the e-book mediation of the e-book broker or the license period for the e-book distribution of the e-book distributor, the plain text resource is E-book may refer to data.

Thereafter, the packaging module 100 receives the plain text resource and identification information, generates a Content Encryption Key (CEK) for encrypting the plain text resource, and then uses the corresponding CEK to copy the plain text resource. Generates an encryption resource by encrypting, and packaging the license information (L) corresponding to the pre-set author / publisher terminal 110 and the encryption resource to generate a master e-book content to the repackaging module 200 Can transmit

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

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

On the other hand, the repackaging module 200 may receive the master e-book content and identification information, and transmit the identification information to the license management server (2) that collectively manages the license information of each terminal.

Accordingly, the license management server 2 extracts the pre-stored license information L1 for the e-book broker or e-book distributor corresponding to the identification information based on the identification information, and extracts the license information L1. The writer / publisher terminal 110 may transmit the information.

Thereafter, the repackaging module 200 may replace the license information L included in the master e-book content with the license information L1 received from the license management server 2.

In this case, the license information received from the license management server 2 may include the license information.

In addition, in the above-described configuration, the e-book generating module 111 communicates with the license management server 2 through a communication network and based on the contract information received with the identification information, the e-book broker corresponding to the contract information. Alternatively, the contract information may be transmitted to the license management server 2 so that license information stored in advance for the e-book distributor is updated.

Accordingly, the repackaging module 200 separates license information (L) and encryption resources from the master e-book content, and corresponds to a reception target of the master e-book content received from the license management server 2. Receiving the license information (L1) can replace the existing license information (L) included in the master e-book content with the license information (L1) corresponding to the receiving target of the master e-book content, the license information (L1) ) Can be encrypted and repackaged together with the encryption resource to generate an e-book content for mediation.

In addition, the repackaging module 200 may transmit the intermediary e-book content to the repackaging module 200 included in the terminal (120, 130) corresponding to the e-book broker or e-book distributor.

At this time, the repackaging module 200 is an e-book broker that is the target of receiving the mediation e-book content from the certificate management server 1 for issuing and managing certificates for each terminal (110, 120, 130, 140) or Receive the certificate-related information (C1) corresponding to the e-book distributor, and encrypt the license information based on the certificate-related information (C1).

For example, the repackaging module 200 extracts a CEK private key from the certificate information stored in the storage unit of the writer / publisher terminal 110, and uses the CEK private key to extract the existing private key. The encrypted CEK may be decrypted, the decrypted CEK may be re-encrypted using the CEK public key included in the certificate-related information, and the re-encrypted CEK is included in the replaced license information (L1). You can. Detailed configuration thereof will be described below.

The e-book broker terminal 120 may include an e-book mediation management module 121 and a repackaging module 200. The e-book mediation management module 121 may receive the e-book contents for mediation. As described above, the contract information and the identification information may be received through the communication with the e-book distribution management module 131 configured in the target e-book distribution management terminal 130, and the contract information may be transferred to the license management server 2. ) Can be updated so that the pre-stored license information corresponding to the e-book distributor based on the contract information is updated.

In addition, the repackaging module 200 configured in the e-book broker terminal 120 separates and decodes the license information L1 from the intermediary e-book content, and decodes the e-book broker management module 121. Based on the received identification information, the license information (L2) corresponding to the e-book distributor terminal 130 that is the reception target of the intermediary e-book content is received from the license management server 2 and included in the intermediary e-book content. Replacing the existing license information (L1) with the license information (L2) corresponding to the e-book distributor terminal and encrypting and repackaging together with the encryption resource to generate a mediation e-book content, this e-book It may be transmitted 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 that is the receiving target of the intermediary e-book content from the certificate management server (1) The license information L2 may be encrypted based on the certificate related information C2.

In addition, the repackage module 200 configured in the e-book broker terminal 120 may operate in the same manner as the repackage module 200 configured in the above-described author / publisher terminal 110.

Meanwhile, the e-book distributor terminal 130 may include an e-book distribution management module 131 and a repackaging module 200, and the e-book distribution management module 131 receives the mediation e-book content. As described above, the contract information and the identification information may be received through communication with the client module 300 configured in the target user terminal 140, and the contract information may be transmitted to the license management server 2 to transmit the contract information. The license information corresponding to the user of the user terminal 140 may be updated based on the information.

In addition, the repackaging module 200 configured in the e-book distributor terminal 130 separates and decodes the license information L2 from the intermediary e-book contents, and decodes the e-book distribution management module 131. Based on the received identification information, the license information L3 corresponding to the user terminal 140 that is the reception target of the mediation e-book content is received from the license management server 2 and is included in the mediation e-book content. The license information L2 may be replaced with the license information L3 corresponding to the user terminal 140 and encrypted, and then repackaged together with the encryption resource to generate an e-book content for the user. 140).

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

In addition, the repackaging module 200 configured in the e-book distributor terminal 130 may operate in the same manner as the repackaging module 200 configured in the above-described author / publisher terminal 110 and the e-book broker terminal 120. have.

Accordingly, the client module 300 configured in the user terminal 140 may restore the plain text resource corresponding to the e-book by decoding the user e-book content, and converts the plain text resource into the user terminal 140. It can be provided through the user to read the e-book.

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

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

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

Meanwhile, in the above-described system configuration, the receiving terminal receiving the e-book content among the

terminals

110, 120, 130, and 140, and the corresponding e-book content among the

terminals

110, 120, 130 are sent to the receiving terminal. The repackaging module 200 configured in the transmitting terminal transmits a plain text resource constituting the e-book content and corresponds to a CEK used for encrypting the plain text resource and a transmitting terminal configured with the repackaging module 200. By adding the stored e-signature information to the license information and encrypting it and transmitting it to the receiving terminal, the e-book agent or distributor can check the responsibility for unauthorized distribution of the e-book contents, thereby preventing unauthorized distribution in advance. And encrypting based on certificate-related information of the receiving terminal, repackaging and reading of e-book content is possible 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.

First, FIG. 2 is a flow chart of a certificate issuing process, and as shown in FIGS. 2 and 6, each of the

terminals

110, 120, 130, and 140 includes a certificate installation module 10. (10) transmits certificate issuing request information for a certificate issuing request to the certificate management server 1 (S1), and the certificate management server 1 is the certificate issuance request information based on the certificate issuing target A public key and private key for CEK (content encryption key) used for encrypting and decrypting the CEK, a public key and private key for digital signature for encrypting and decrypting digital signature verification information added for verification of the electronic signature; After generating certificate information including a CA (Certificate Authority) certificate (S2) and matching the identification information of the terminal included in the certificate issuing request information stored in the certificate DB, the certificate issuance request information The certificate information may be transmitted to the sender terminal (S3).

Through this, the certificate installation module 10 configured in each terminal (110, 120, 130, 140) is a public key and private key pair for digital signature, CEK private key and public key pair, as shown in FIG. Receiving certificate information including a CA certificate, the certificate installation module 10 may be stored in the storage unit of the terminal.

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

Meanwhile, FIG. 4 is a flowchart illustrating an e-book content delivery process and a repackaging process between a transmitting terminal and a receiving terminal. The repackaging module 200 configured in the transmitting terminal among the

terminals

110, 120, 130, and 140 is shown in FIG. When receiving the e-book content from another terminal or the packaging module 100, the encryption resource and license information may be separated from the e-book content.

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

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

Meanwhile, the repackaging module 200 of the transmitting terminal may communicate with the certificate management server 1 to transmit the identification information about the reception target (receiving terminal) of the e-book content to the certificate management server 1. have.

Accordingly, the certificate management server 1 may receive certificate-related information extracted from certificate information matched with the identification information among the certificate information stored in the certificate DB 11. In this case, the certificate-related information may include a CEK public key and a digital signature private key of the receiving terminal, and the certificate management server 1 receives the digital signature private key in an encrypted state corresponding to the identification information. After decrypting the device information of the certificate related information can be transmitted.

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

In this case, when the repackaging module 200 of the transmitting terminal is configured in the e-book broker terminal 120 or the e-book distributor terminal 130, the repackaging module 200 is applied to the e-book content received from the other terminal. The encrypted CEK (E_CEK) may be extracted from the included license information, and the encrypted CEK (E_CEK) is encrypted by the CEK public key of the transmitting terminal in the repackaging module 200 configured in the other terminal.

Therefore, 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. The CEK private key E_PK may be decrypted with preset device information to generate a CEK private key.

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

In addition, the repackaging module 200 of the transmitting terminal may encrypt the decrypted CEK with the public key for the CEK 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 may provide the receiving terminal by encrypting the CEK included in the e-book content with the CEK public key of the receiving terminal, thereby pairing the CEK public key with the CEK public key. By providing the decryption of the CEK (E_CEK) encrypted with the CEK private key of the receiving terminal it can support the access to the CEK only in the receiving terminal.

In addition, 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 and then receives it from the other terminal. License information (L) included in the e-book content can be replaced with the new license information (L1) received from the license management server (2).

In this case, the new license information L1 may include license information about a license period of the e-book content corresponding to the receiving terminal.

In addition, the repackaging module 200 of the transmitting terminal may add the pre-stored digital signature information to the new license information (L1), the digital signature verification information for verifying the integrity of the digital signature information and license information May be generated and added to the new license information L1.

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

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

Through the above-described configuration, the repackaging module 200 of the transmitting terminal repackages the encryption resource extracted from the e-book content received from the other terminal and the new license information to generate the e-book content (e-book content 1). And, it may be transmitted to the repackaging module 200 of the receiving terminal.

Accordingly, the repackaging module 200 configured in the receiving terminal extracts the public key for electronic signature from the storage unit 400 when receiving the e-book content (e-book content 1) from the transmitting terminal and then the e-book content. The digital signature verification information encrypted from the license information included in the can be decrypted with the public key for digital signature, and the integrity of the digital signature information and the license information included in the license information can be determined based on the decrypted digital signature verification information. .

In addition, the repackaging module 200 configured in the receiving terminal checks the content of the transmitting terminal and the electronic signature on the basis of the digital signature information, and determines whether the period expires based on the license period according to the license information. If expired, the decryption and transmission (distribution) of the e-book content may be stopped.

On the other hand, when the electronic 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. The license information (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) that is receiving the book content, and the repackaging module described above. Re-package the license information L2 of the next receiving terminal (second receiving terminal) and the encryption resource generated according to the operation of 200 to generate new e-book content (e-book content 2). The new e-book content (e-book content 2) may be transmitted 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 a CEK (E_CEK) encrypted with a CEK private key of the next receiving terminal (second receiving terminal), and the receiving terminal (first). Digital signature information of the receiving terminal) and digital signature verification information generated based on the same, and usage permission information corresponding to the next receiving terminal (second receiving terminal) may be included, and the digital signature verification information may be included in the next receiving terminal. It can be encrypted with the digital signature private key of 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) to operate in the same manner as the operation configuration of the repackaging module 200 described above. Can be.

As described above, the present invention encrypts e-book content-related information based on the certificate-related information related to the recipient who receives the e-book content at every intermediary or distribution of the e-book content, and transmits the e-book content related information to the recipient only. By supporting mediation or distribution of e-book content, the user can clearly identify the responsibility for unauthorized distribution of the e-book content and restrict access to only the recipient's certificate information even if it is leaked. The risk of leakage of content can be prevented.

On the other hand, when the above-described configuration is summarized through FIG. 6, as shown in FIG. 6, each terminal 110, 120, 130, 140 is configured with a certificate installation module 10 to obtain a certificate from the certificate management server (1) It can be issued and stored, the terminal 110 of the writer / publisher generates the above-described e-book content through the packaging module 100, the electronic book content when the writer / publisher's terminal 110 operates as a transmitting terminal E-book intermediary / distributor terminal receiving the 120, 130 is operated as a receiving terminal.

Accordingly, the repackaging module 200 included in the terminal 10 of the writer / publisher is an e-book for the e-book broker /

distributor terminal

120, 130 corresponding to the receiving terminal from the license management server 2. Receiving the license information of the agent / distributor, the electronic signature information of the author / publisher terminal and the digital signature verification information generated based on this can be added to the license information of the e-book agent / distributor.

In addition, the repackaging module 200 included in the author / publisher terminal extracts the encrypted CEK from the license information included in the master e-book content, decrypts the encrypted CEK and stores the CEK in the certificate management server ( Encrypted with the CEK public key corresponding to the e-book broker / distributor terminal (120, 130) received from 1) added to the license information of the e-book broker / distributor, and digital signature verification information included in the license information The electronic device may encrypt with the digital signature private key corresponding to the electronic book broker / distributor terminal (120, 130) received from the certificate management server (1).

Thereafter, the repackaging module 200 included in the writer / publisher terminal 110 extracts an encryption resource from the master e-book content, repackages it with the license information of the e-book broker / distributor, and e-book content for mediation. After generating the e-book may be transmitted to the broker / distributor terminal (120, 130).

In this case, the repackaging module 200 included in the writer / publisher terminal 110 may perform partial information based on certificate-related information corresponding to the e-book broker / distributor according to the above-described process of the existing license information in the master e-book content. Of course, it may be repackaged with the encryption resource by replacing with the encrypted license information of the e-book agent / distributor.

On the other hand, the e-book broker / distributor terminal (120, 130) may be transmitted to the user terminal 140 when receiving the intermediary e-book content, wherein the e-book broker / distributor terminal (120, 130) is sent It operates as a terminal, and the user terminal 140 operates as a receiving terminal.

Accordingly, the repackaging module 200 configured in the e-book broker /

distributor terminal

120, 130 receives license information of the user for the user terminal 140 corresponding to the receiving terminal from the license management server 2. The electronic signature information of the electronic book broker / distributor and the electronic signature verification information generated based on the electronic book broker / distributor may be added to the license information of the user.

In addition, the repackaging module 200 included in the e-book broker / distributor terminal (120, 130) extracts the encrypted CEK from the license information contained in the e-book content for the intermediary, the certificate stored in advance the encrypted CEK Decrypted by the CEK private key included in the information, and encrypts the CEK generated according to the CEK public key corresponding to the user terminal 140 received from the certificate management server 1 to add to the license information of the user The digital signature verification information included in the license information may be encrypted with a digital signature private key corresponding to the user terminal 140 received from the certificate management server 1.

Subsequently, the repackaging module 200 included in the e-book broker /

distributor terminal

120 or 130 extracts an encryption resource from the intermediary e-book content and repackages it with the license information of the user. After generating content, the content may be transmitted to the user terminal 140.

In the above configuration, when the certificate management server 1 transmits the digital signature private key to the terminal requesting the certificate related information, the digital signature private key is based on the device information of the terminal stored in advance corresponding to the digital signature private key. By decrypting, the certificate-related information can be transmitted to the requesting terminal.

On the other hand, the user terminal 140 is configured to receive the user e-book content for the client module 300 to support the user to view the contents of the e-book content is configured, the client module 300 is the user After decrypting the encrypted CEK and e-signature verification information included in the e-book content for the e-book content, and decrypting the encryption resource based on this, the plain text resource can be generated and the user can read the e-book. It explains in detail.

As shown in the drawing, the client module 300 configured in the user terminal 140 separates license information from the user e-book content upon receiving e-book content for the user and publishes the digital signature verification information for the electronic signature in the license information. By decrypting with a key, the integrity of digital signature information and license information can be verified.

Thereafter, when the integrity is verified, the client module 300 stops reading the e-book contents for the user when the usage period according to the license information expires, and stores the configured user terminal 140 when the usage period is valid. The encrypted CEK private key may be extracted from the certificate information stored in the unit 500, and the encrypted CEK private key may be decrypted using the preset device information of the user terminal 140.

In addition, the client module 300 may decrypt the encrypted CEK using the decrypted CEK private key, and decrypt the encryption resource included in the user e-book content using the decrypted CEK. have.

Through this, the client module 300 may generate a plain text resource by decrypting an encryption resource, and loads a preset viewer interface and displays the plain text resource on the display of the user terminal 140 so that the user can view the plain text resource. can do.

As described above, the present invention enables the reading of the e-book contents only by the receiving target having the authority to read the e-book contents by providing the e-book contents by encrypting the electronic book contents based on the certificate related information on the receiving object of the e-book contents. At the same time, the e-book contents can be changed based on the certificate-related information whenever the recipient is changed, and the e-book contents can be leaked by preventing other users from viewing the e-book contents. Can be effectively prevented.

In addition, the encryption and decryption method described in the present invention can all use the same digital rights management (DRM) method, through which the present invention is the same DRM method all authors, publishers, intermediaries and distributors in the distribution process of the e-book E-books can be distributed through this, and this enables users to browse all e-books using only a single client, thereby increasing user convenience.

First, FIG. 8 is a flowchart illustrating an e-book packaging process of a packaging module. As shown in the drawing, the packaging module 100 generates a CEK for encrypting a plain text resource (S11) and the plain text resource corresponding to the e-book. May be encrypted based on the CEK to generate an encryption resource (S12).

Thereafter, the packaging module 100 may encrypt the CEK based on the CEK public key included in the certificate information previously stored in the terminal generating the e-book content (S13).

Next, the packaging module 100 may generate license information including the encrypted CEK and package the package information together with the encryption resource to generate e-book content (S14).

9 is a flowchart illustrating an e-book repackaging process of the repackaging module 200. As illustrated, the repackaging module 200 decompresses an e-book content received from a packaging module or another terminal, and encrypts and licenses information. Extracting (S21), the repackaging module 200 can determine whether the certificate information is present in the storage of the configured terminal (S22).

Subsequently, the repackaging module 200 determines whether the e-book contents are master e-book contents received from a terminal corresponding to the writer / publisher, and when the e-book contents are master e-book contents (S23). If a private key for the user can be extracted (S25), and not the master e-book content (S23), the license period is checked based on the license information included in the e-book content (S24). After reading the book contents, if the period is valid, the CEK private key may be extracted from the stored certificate information (S25).

Next, the repackaging module 200 decrypts the encrypted CEK using the CEK private key (S26), and the certificate management server 1 relates to the certificate of the receiving terminal for encrypting the CEK and the digital signature. By requesting the information, the certificate related information of the corresponding receiving terminal may be received.

Thereafter, the repackaging module 200 encrypts the CEK using the CEK public key of the receiving terminal included in the certificate related information (S27), and corresponds to the receiving terminal from the license management server 2. After adding the digital signature and digital signature verification information for verifying the integrity of the digital signature to the received license information, the new signature information is encrypted by encrypting the digital signature verification information with the digital signature private key of the receiving terminal included in the certificate related information. It may generate and add the CEK encrypted with the CEK public key of the receiving terminal to the new license information (S28).

In addition, the repackaging module 200 may replace the existing license information of the received e-book content with new license information, and repackage the encryption resource and the new license information to generate new e-book content. It may transmit to the receiving terminal (S29).

Meanwhile, in the above-described configuration, license information may be stored in the receiving terminal, and the repackaging module 200 configured in the transmitting terminal directly requests the license information corresponding to the receiving terminal to the receiving terminal and directly receives the receiving information from the receiving terminal. License information corresponding to the terminal may be received.

FIG. 10 is a flowchart illustrating an e-book content viewing process of the client module 300. As shown in FIG. 10, the client module 300 extracts the received e-book content to extract encryption resources and license information (S31). The client module 300 may determine whether the certificate information exists in the storage of the configured user terminal (S32).

Subsequently, 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 includes the digital signature information included in the license information. Verifying the integrity of the license information, and checks the period of use based on the license information (S33) to stop reading e-book content when the period expires, and if the period is valid from the certificate information stored in the storage unit The encrypted CEK private key may be extracted (S34).

In this case, the client module 300 may decrypt the encrypted CEK private key with preset device information, and decrypt the encrypted CEK included in the license information by using the decrypted CEK private key (S35). .

Next, the client module may decrypt the encryption resource by using the decrypted CEK, thereby generating a plain text resource (S36).

Thereafter, the client module 300 displays the plain text resource through the viewer and provides the user to view the e-book content (S37).

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

Accordingly, when a user uses different user terminals, each terminal may store certificate information in a storage unit, and the client module 300 configured in each terminal receives the e-book content from the cloud server 3. Through the above-described operation process, the plain text resource is generated by decrypting the encryption resource included in the e-book content, and then displayed by the viewer so that the user can read the e-book.

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

In this case, the certificate management server 1 is assigned to each different user terminal when issuing certificate information corresponding to the user and give a unique device key (device key) different from each other to include in the certificate information sent to the user terminal Accordingly, each user terminal may store certificate information including a unique device key corresponding to the user terminal.

The certificate management server 1 and the client module 300 may encrypt and store the CEK private key based on the unique device key.

Accordingly, the certificate management server 1 and the client module 300 decrypt the CEK private key encrypted using the unique device key, and accordingly decrypt the CEK of the e-book content using the decrypted CEK private key. Can be decrypted

Through this, the present invention can be limited so that the same user can view the e-book content in each user terminal only when the corresponding user terminal is issued a certificate.

The above description may be modified and modified by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims

Issuing and storing public key and private key certificate information for use of the e-book content, and the e-book content of the certificate information issued in response to the receiving terminal upon request of the transmitting terminal to deliver the e-book content to the receiving terminal A certificate management server for transmitting the public key certificate related information required for encryption to the transmitting terminal;

A cryptographic resource configured to generate a plain text resource constituting the e-book by using a predetermined content encryption key (CEK) and configured to include the CEK in the public key certificate information. A packaging module for encrypting with a public key for CEK and generating and transmitting license information including encrypted CEK, pre-stored electronic signature information and license information, and e-book content packaged with the encryption resource; And

The e-signature information and the license information included in the license information when the e-book contents are received when the e-book contents are valid, and the encrypted CEK is stored in the stored private key certificate information. After decrypting with the included CEK private key, encrypting with the public key for CEK included in the public key certificate related information received from the certificate management server, and including the new license information received corresponding to the receiving terminal, the e-book content Ebook distribution optimized for a cloud environment including a repackaging module for replacing the existing license information contained in the new license information with the new e-book content generated by repackaging with the encryption resource to the receiving terminal Service system.
The method according to claim 1,

The CEK is configured in a user terminal to decrypt the CEK included in the e-book content by using a CEK private key in a private key certificate stored in a pre-stored private key certificate when the e-book content is received, and then using the corresponding CEK. And a client module for decrypting the encryption resource and generating the plain text resource according to the decryption of the encryption resource so that a user can read the e-book. .
The method according to claim 2,

The CEK private key is encrypted with device information of a terminal corresponding to the CEK private key by at least one of the certificate management server, a repackaging module, and a client module.

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 CEK private key. Distribution service system.
The method according to claim 2,

The certificate information is an e-book distribution service system optimized for a cloud environment comprising a CA certificate, the CEK private key, the CEK public key, digital signature public key, digital signature private key.
The method according to claim 4,

The packaging module and the repackaging module add digital signature verification information for verifying the integrity of the e-book content to the license information,

The repackaging module of the transmitting terminal encrypts the digital signature verification information with the digital signature private key included in the certificate related information, and the repackaging module and the client module of the receiving terminal use the digital signature included in prestored certificate information. E-book distribution service system optimized for a cloud environment, characterized in that for verifying the integrity by decrypting the digital signature verification information using a public key.
The method according to claim 5,

The repackaging module and the client module of the receiving terminal checks the usage period according to the usage permission information at the time of integrity check and decrypts the CEK when the usage period is valid.
The method according to claim 2,

The client module is an e-book distribution service system optimized for a cloud environment, characterized in that for transmitting and storing the e-book content to a predetermined cloud server.
The method according to claim 2,

When the certificate management server requests for issuance of certificates from different user terminals, the certificate management server assigns different unique device keys to each user terminal, and transmits certificate information including unique device keys corresponding to each user terminal to each user terminal. ,

The client module encrypts the CEK private key included in the certificate information using the unique device key, and decrypts the CEK private key encrypted using the unique device key when decrypting the encrypted CEK. E-book distribution service system optimized for a cloud environment, characterized in that for decrypting the encrypted CEK using the decrypted private key for CEK.
The method according to claim 1,

Further comprising a license server corresponding to each different terminal for storing license information including license information,

The repackaging module requests the license information of the receiving terminal to the license server to generate the new e-book content, and receives the license information corresponding to the receiving terminal from the license server. Optimized e-book distribution service system.
Certificate required for encrypting the e-book content among certificate information issued corresponding to the receiving terminal upon issuing and storing certificate information for use of the e-book content and transmitting the e-book contents to the receiving terminal. A certificate management server for transmitting related information to the transmitting terminal, issuing and transmitting certificate information corresponding to each terminal using e-book contents;

The packaging module configured in the terminal generating the e-book content generates an encryption resource by encrypting the plain text resource constituting the e-book with a predetermined content encryption key (CEK), CEK included in the previously stored certificate information Generating license information including an encrypted CEK, pre-stored electronic signature information, and license information and an e-book content packaged with the encryption resource after encrypting with a public key for use; And

The CEK when the use of the e-book content is valid by checking the e-signature information and the license information included in the license information when the repackage module configured in the transmitting terminal receives the e-book content from the packaging module or another terminal. Decrypts the CEK private key included in the previously stored certificate information, encrypts it with the public key for CEK included in the certificate-related information received from the certificate management server, and includes it in the new license information received corresponding to the receiving terminal. And replacing the existing license information included in the e-book content with the new license information and transmitting the new e-book content generated by repackaging together with the encryption resource to the receiving terminal.

E-book distribution service method optimized for a cloud environment including a.