KR20040023092A - Method of digital rights management for the content owner - Google Patents

Abstract

PURPOSE: A DRM(Digital Rights Management) method for a contents holder is provided to reduce an economic burden of the contents holder and strengthen the DRM by making the contents holder encrypts the contents personally even if a license server is operated by a manager of the DRM system. CONSTITUTION: A password key set is generated/stored in a password key set database(401). To make the contents holder encrypt the digital contents personally, a password key set file is generated from the password key set database and obfuscation is performed by changing a key ID of the password key set file(408). A counter file for the contents holder is generated(409). The obfuscated password key set file and the counter file are transmitted to the contents holder(410).

Description

Method of digital rights management for the content owner

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of information protection technology, and in particular, to a content owner without having to establish a license server that issues a license (data including decryption key for decrypting encrypted content and usage rights of the content). It relates to a digital rights protection (DRM) method for copyright-protected content owners and a computer-readable recording medium having recorded thereon a program for realizing the method.

The terms used in the present invention are defined as follows.

Digital Rights Management (DRM) refers to a function that protects and manages the rights of digital content creators.

License refers to data that contains the decryption key used to decrypt the encrypted content and the contents specifying the right (number, duration) of the content.

Digital content, unlike analog content, retains the same quality as the original after several copies. When digital content having such characteristics meets the Internet communication media, copies of the same quality as the original can be propagated infinitely rapidly. That's why content owners (e.g., Hollywood filmmakers) who have invested so much capital and effort are reluctant to digitize their content and commercialize it on the Internet. This climate eventually leads to disadvantages in that content consumers (users) cannot receive high quality content.

When users want to distribute digital contents owned by content owners to paid services or restricted users through the Internet, users who use them illegally due to the copying and distribution function, which is characteristic of digital contents There was a difficulty in not being fully compensated for the cost and time required to produce content.

The digital copyright protection (DRM) technology has emerged as a way to solve this problem. However, it is expensive for content owners to build and operate DRM systems and requires considerable security technology, so many of the companies that operate DRM systems act as copyright protection for the contents.

However, encrypting all the content owners' contents by an administrator operating a digital rights protection (DRM) system also required a lot of cost and time, which eventually passed on to the content owners at a cost. Accordingly, in order to reduce the economic burden, there is a growing demand for content owners to enhance copyright protection of content by encrypting the content before sending it to the DRM system administrator.

Therefore, in the current technical field, the license server operation enables content owners to directly encrypt content even if the DRM system administrator performs it, thereby reducing the burden on the content owner and enhancing the copyright protection of the content. A solution is essential.

The present invention has been proposed to meet the above requirements, and the operation of the license server enables the content owner to directly perform content encryption even if the digital rights protection system administrator performs it, thereby reducing the economic burden on the content owner. It is an object of the present invention to provide a digital rights protection (DRM) method for a content owner who can enhance copyright protection of a content and a computer-readable recording medium that records a program for realizing the method.

1 is an exemplary configuration diagram of a digital rights protection (DRM) system to which the present invention is applied.

2 is a diagram illustrating an embodiment of a process of generating an encryption key set file among digital copyright protection methods used in the present invention.

FIG. 3 is an exemplary explanatory diagram showing a process of retrieving a corresponding encryption key set of an encryption key set file with a pointer of a counter file used in the present invention. FIG.

4 is a flowchart of an embodiment of a digital copyright protection method according to the present invention;

* Explanation of symbols for the main parts of the drawings

11: unencrypted digital content 12: packager

13: encrypted content file 14: web server (or media server)

15: license server 16: database (DB)

According to an aspect of the present invention, there is provided a digital copyright protection method for a content owner in a digital rights protection system, the method comprising: generating a cryptographic key set and storing the cryptographic key set in a database; A second step of generating an encryption key set file from the encryption key set database and changing the key ID of the encryption key set file to obfuscation so that a content owner can encrypt digital content directly with a packager. ; Generating a counter file for the content owner; And a fourth step of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner.

In addition, the present invention, after the content owner packager finds the key ID (ID) before the ambiguous from the ambiguous encryption key set file to restore the original encryption key set file, the encryption key set by the pointer of the counter file Searching for and encrypting the digital content using the retrieved encryption key set; A sixth step of the content owner packager incrementing and storing the pointer of the counter file; And a seventh step, wherein the package for the content owner transmits the encrypted digital content to a web server (or a media server) and transmits package information to a license server.

In addition, the present invention, after performing the first step, the eighth step of the package for the copyright manager to download the unencrypted digital content from the content owner; A ninth step of the copyright manager packager searching the encryption key set database to retrieve the corresponding encryption key set, and encrypting the digital content using the retrieved encryption key set; And a tenth step of transmitting the encrypted digital content to a web server (or a media server) and transmitting package information to a license server.

In addition, the present invention is characterized in that the license server further comprises an eleventh step of storing the package information received from the package for the content owner in a database, used for generating and issuing a license.

According to an aspect of the present invention, there is provided a digital copyright protection method for a content owner in a digital rights protection system, the method comprising: generating a cryptographic key set and storing the cryptographic key set in a database; A second step of generating an encryption key set file from the encryption key set database and changing the key ID of the encryption key set file to obfuscation so that a content owner can encrypt digital content directly with a packager. ; Generating a counter file for the content owner; Transmitting the ambiguous encryption key set file and the content owner counter file to a content owner; The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. Encrypting the digital content using an encryption key set; A sixth step of the content owner packager incrementing and storing the pointer of the counter file; And a seventh step of the content owner packager to transmit the encrypted digital content to a web server (or a media server), and to transmit package information to a license server.

In addition, the present invention is characterized in that the license server further comprises an eighth step of storing the package information received from the package for the content owner in a database, used for generating and issuing a license.

The present invention for achieving the above object comprises a first function of generating a cryptographic key set in a digital rights protection system and storing it in a cryptographic key set database; A second function of generating an encryption key set file from the encryption key set database, changing the key ID of the encryption key set file to obfuscation, so that a content owner can encrypt digital content directly with a packager; ; A third function of generating a counter file for the content owner; And a computer-readable recording medium having recorded thereon a program for realizing a fourth function of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner.

In addition, the present invention, after the content owner packager finds the key ID (ID) before the ambiguous from the ambiguous encryption key set file to restore the original encryption key set file, the encryption key set by the pointer of the counter file A fifth function of retrieving and encrypting the digital content using the retrieved encryption key set; A sixth function of storing, by the content owner packager, the pointer of the counter file by incrementing the pointer; And a program for recording a program for the content owner's packager to further transmit the encrypted digital content to a web server (or a media server), and to further realize a seventh function of transmitting the package information to a license server. To provide.

In addition, the present invention includes an eighth function of receiving, after performing the first function, a package for a copyright manager to download unencrypted digital content from a content owner; A ninth function that the copyright manager packager directly searches the encryption key set database to retrieve the corresponding encryption key set, and encrypts the digital content using the retrieved encryption key set; And a computer-readable recording medium having recorded thereon a program for further realizing the tenth function of transmitting the encrypted digital content to a web server (or media server) and transmitting package information to a license server.

The present invention also provides a computer-readable recording medium having stored therein a package information received by the license server from the content owner's packager in a database so as to further realize an eleventh function used for generating and issuing a license. do.

In order to achieve the above object, the present invention provides a digital copyright protection system having a processor, comprising: a first function of generating a cryptographic key set and storing it in a cryptographic key set database; A second function of generating an encryption key set file from the encryption key set database, changing the key ID of the encryption key set file to obfuscation, so that a content owner can encrypt digital content directly with a packager; ; A third function of generating a counter file for the content owner; A fourth function of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner; The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. A fifth function of encrypting digital content using an encryption key set; A sixth function of storing, by the content owner packager, the pointer of the counter file by incrementing the pointer; And a computer-readable recording medium having recorded thereon a program for the content owner packager to transmit the encrypted digital content to a web server (or media server) and to realize a seventh function of transmitting package information to a license server. to provide.

In addition, the present invention provides a computer-readable recording medium having a program for storing the package information received from the content owner's packager in a database to further realize the eighth function used for license generation and issuance. do.

According to the present invention, a content owner can receive copyright protection for a content without directly establishing a license server. The license server operation can be performed by a content owner to perform content encryption even if a digital rights protection (DRM) system administrator performs the content. Accordingly, the copyright protection of the content can be strengthened while reducing the economic burden of the content owner, so that the content can be used for online paid content services through copyright protection of the digital content.

In the present invention, a package for a content owner having a function different from that of a digital rights protection (DRM) system administrator is separately configured so that the package for the content owner obtains a set of encryption keys from a file. In this case, unlike the conventional method of directly importing the encryption key set from the encryption key set database, the encryption key set file is retrieved with the pointer of the counter file to obtain the encryption key set value from the file.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a digital rights protection (DRM) system to which the present invention is applied. In the drawing, "11" is an unencrypted digital content, "12" is a copyright protection package, and "13" is an encrypted content and package. Information, "14" represents a web server (or media server), "15" represents a license server, and "16" represents a database (DB), respectively.

As shown in FIG. 1, the digital rights protection (DRM) system to which the present invention is applied encrypts the unencrypted digital content 11 using the copyright protection packager 12. At this time, the copyright protection packager 12 is responsible for generating an encryption key, adding additional information to the original content, encrypting the content using the same, and generating related package information. At this time, the encrypted content generated as a result of the package and the encrypted content of the package information 13 is transmitted to the web server (or media server) 14 for download or streaming service, the package information is the license server 15 Is stored in the database 16. Therefore, the license server 15 is responsible for the license issuing function using the package information of the database 16.

In the present invention, a package for a content owner having a function different from that of a digital rights protection (DRM) system administrator is separately configured so that the package for the content owner obtains a set of encryption keys from a file. In this case, unlike the conventional method of directly importing the encryption key set from the encryption key set database, the encryption key set file is retrieved with the pointer of the counter file to obtain the encryption key set value from the file.

Next, a process of generating an encryption key set file will be described with reference to FIG. 2.

FIG. 2 is an exemplary explanatory diagram illustrating a process of generating an encryption key set file among digital copyright protection methods used in the present invention, wherein “21” is an encryption key set generator, “22” is an encryption key set database, and “23”. Is a cryptographic key set file generator, and "24" represents a cryptographic key set file, respectively.

As shown in Figure 2, the encryption key set file generation process, after the DRM system administrator generates the encryption key set with the encryption key set generator 21 and stores it in the encryption key set DB 22, the encryption key set file The generator 23 generates the encryption key set file 24 for the content owner.

Now, a process of retrieving the encryption key set file with the pointer of the counter file and obtaining the encryption key set value from the encryption key set file will be described in more detail with reference to FIG.

FIG. 3 is a diagram illustrating an embodiment of searching for a corresponding encryption key set of an encryption key set file with a pointer of a counter file used in the present invention.

Prior to the process of searching for the corresponding encryption key set of the encryption key set file 32 with the pointer of the counter file 33, the DRM system administrator should send the encryption key set file 30 to the content owner. However, since the security problem occurs when it is transmitted as it is, this problem is solved by generating the ambiguous encryption key set file 31 through an obfuscation process of the encryption key set file 30. Here, the method of ambiguizing by changing the key ID of the encryption key set file 30 is shown in Equation 1 below.

Ambiguity Key ID = (Key ID × 10) + 2

In Equation 1, the key ID is a key ID of the encryption key set file 30 before being sent to the content owner, and the ambiguity key ID is an ambiguous encryption key set generated through Equation 1 above. The ambiguous key ID of the file 31.

The obfuscated cryptographic key set file 31 thus generated is transmitted to the content owner by the DRM system administrator. The package owner of the content owner then uses the following equation (2) to find the key ID before obfuscation.

Key ID = (Animation Key ID-2) / 10 Shares

The key ID generated in [Equation 2] is generated by the package owner of the content owner using [Equation 2], and the encryption key set file 32 for the content owner is an encryption key set file generated by the DRM system administrator. Same as (24,30).

4 is a flowchart illustrating an embodiment of a digital copyright protection method according to the present invention.

As shown in FIG. 4, in the digital copyright protection method according to the present invention, a digital rights protection (DRM) system administrator first generates a cryptographic key set and stores it in a DB (401).

Then, if the content owner wants to encrypt the digital content directly with the packager (402), the DRM system administrator generates an encryption key set file from the encryption key set database and ambiguously using [Equation 1] ( 408, create a counter file for the content owner (409). Subsequently, the DRM manager transmits the ambiguous encryption key set file and the counter file to the content owner (410), and the package owner of the content owner sends the equation [Equation 2] from the ambiguous encryption key set file among the two files. ] To restore the encryption key set file and retrieve the encryption key set with the pointer of the counter file (411) to encrypt the content using the retrieved encryption key set (412). The pointer is then incremented and the counter file is stored 413 with the incremented pointer. The package process then ends, the content owner uploads the encrypted content to the web server (or media server) for download or streaming service (414), and the DRM system administrator stores the package information received from the content owner's database on the license server. Stored in (415) will be used for license generation and issuance.

On the other hand, if the content owner wants to encrypt the content using the packager of the DRM system manager (402), after the content owner uploads the unencrypted digital content to the package server (403), the manager packager Retrieves the cryptographic key set directly from the cryptographic key set database (404), encrypts the content using the cryptographic key set retrieved through the packager for the DRM system administrator (405), and the DRM administrator directly encrypts the encrypted content. After sending to the web server (or media server) (406), the package information is stored in the database of the license server (407).

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

According to the present invention as described above, even if the license server operation is performed by the digital copyright protection system administrator, the content owner can directly perform content encryption, thereby reducing the economic burden on the content owner and enhancing the copyright protection of the content. There is an effect that can promote content distribution and monetization.

Claims (16)

A digital copyright protection method for content owners in a digital rights protection system, Generating a cryptographic key set and storing it in a cryptographic key set database; A second step of generating an encryption key set file from the encryption key set database and changing the key ID of the encryption key set file to obfuscation so that a content owner can encrypt digital content directly with a packager. ; Generating a counter file for the content owner; And A fourth step of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner; Digital copyright protection method for the content owner comprising a. The method of claim 1, The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. Encrypting the digital content using an encryption key set; A sixth step of a content owner packager incrementing and storing a pointer of the counter file; And A seventh step in which the package for the content owner transmits the encrypted digital content to a web server (or a media server) and transmits package information to a license server; Digital copyright protection method for the content owner further comprising. The method of claim 1, A fifth step of, after performing the first step, a package for a copyright manager to download unencrypted digital content from a content owner; A sixth step of the copyright manager packager searching the encryption key set database to retrieve the corresponding encryption key set, and encrypting the digital content using the retrieved encryption key set; And A seventh step of transmitting the encrypted digital content to a web server (or a media server) and transmitting package information to a license server; Digital copyright protection method for the content owner further comprising. The method of claim 2 or 3, An eighth step in which the license server stores the package information received from the package for the content owner in a database, and uses the license server to generate and issue a license; Digital copyright protection method for the content owner further comprising. The method according to claim 1 or 2, The second step, To encrypt digital content with the content owner packager, an encryption key set file is generated from the encryption key set database, and the key ID (ID) of the encryption key set file is changed by the following equation to be ambiguous ( digital copyright protection method for a content owner, characterized by obfuscation. Ambiguity Key ID = (Key ID × 10) + 2 (However, the key ID is the key ID of the cryptographic key set file before it is sent to the content owner, and the ambiguous key ID is the ambiguous key ID of the ambiguous encryption key set file generated through the above equation.) The method of claim 5, wherein The fifth step, The content owner's packager finds a key ID before the ambigulation from the ambiguous encryption key set file by using the following equation, restores the original encryption key set file, and then encrypts it with the pointer of the counter file. And retrieving a key set to encrypt digital content using the retrieved cryptographic key set. Key ID = (Animation Key ID-2) / 10 Shares The method of claim 6, The content owner packager, And retrieving an encryption key set file with a pointer of the counter file to obtain an encryption key set value from the encryption key set file. A digital copyright protection method for content owners in a digital rights protection system, Generating a cryptographic key set and storing it in a cryptographic key set database; A second step of generating an encryption key set file from the encryption key set database and changing the key ID of the encryption key set file to obfuscation so that a content owner can encrypt digital content directly with a packager. ; Generating a counter file for the content owner; Transmitting the ambiguous encryption key set file and the content owner counter file to a content owner; The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. Encrypting the digital content using an encryption key set; A sixth step of the content owner packager incrementing and storing the pointer of the counter file; And A seventh step in which the package for the content owner transmits the encrypted digital content to a web server (or a media server) and transmits package information to a license server; Digital copyright protection method for the content owner comprising a. The method of claim 8, An eighth step in which the license server stores the package information received from the package for the content owner in a database, and uses the license server to generate and issue a license; Digital copyright protection method for the content owner further comprising. The method according to claim 8 or 9, Obfuscating the encryption key set file by Equation 1 below, and restoring the original file from the encrypted key set file by Equation 2 below. Digital copyright protection method. (Equation 1) Ambiguity Key ID = (Key ID × 10) + 2 (However, the key ID is the key ID of the cryptographic key set file before it is sent to the content owner, and the ambiguous key ID is the ambiguous key ID of the ambiguous encryption key set file generated through the above equation.) (Equation 2) Key ID = (Animation Key ID-2) / 10 Shares Processor into a digital copyright protection system, A first function of generating a cryptographic key set and storing it in a cryptographic key set database; A second function of generating an encryption key set file from the encryption key set database, changing the key ID of the encryption key set file to obfuscation, so that a content owner can encrypt digital content directly with a packager; ; A third function of generating a counter file for the content owner; And A fourth function of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 11, The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. A fifth function of encrypting digital content using an encryption key set; A sixth function of storing, by the content owner packager, the pointer of the counter file by incrementing the pointer; And A seventh function, wherein the package for the content owner transmits the encrypted digital content to a web server (or a media server) and transmits package information to a license server; A computer-readable recording medium that records a program for further realization. The method of claim 11, A fifth function of, after performing the first function, a copyright manager packager to download unencrypted digital content from a content owner; A sixth function, wherein the copyright manager packager directly searches the encryption key set database to retrieve the corresponding encryption key set, and encrypts the digital content using the retrieved encryption key set; And A seventh function of transmitting the encrypted digital content to a web server (or a media server) and transmitting package information to a license server A computer-readable recording medium that records a program for further realization. The method according to claim 12 or 13, An eighth function that the license server stores in the database package information received from the content owner's packager and uses the license server to generate and issue a license; A computer-readable recording medium that records a program for further realization. In a digital copyright protection system with a processor, A first function of generating a cryptographic key set and storing it in a cryptographic key set database; A second function of generating an encryption key set file from the encryption key set database, changing the key ID of the encryption key set file to obfuscation, so that a content owner can encrypt digital content directly with a packager; ; A third function of generating a counter file for the content owner; A fourth function of transmitting the ambiguous encryption key set file and the content owner counter file to a content owner; The content owner's packager finds the pre-ambiguization key ID from the ambiguous encryption key set file, restores the original encryption key set file, and retrieves the encryption key set with the pointer of the counter file. A fifth function of encrypting digital content using an encryption key set; A sixth function of storing, by the content owner packager, the pointer of the counter file by incrementing the pointer; And A seventh function, wherein the package for the content owner transmits the encrypted digital content to a web server (or a media server) and transmits package information to a license server; A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 15, An eighth function that the license server stores in the database package information received from the content owner's packager and uses the license server to generate and issue a license; A computer-readable recording medium that records a program for further realization.