KR20200051242A - Apparatus for Controlling File Access and Method thereof - Google Patents

Abstract

The present invention relates to an apparatus of setting file access and a method thereof and, particularly, to a method of setting file access, which controls access to a file by converting a specific field in a target file to be converted based on a structure of a target file to be accessed. According to the present invention, the method of setting file access comprises the following steps of: changing a first extension for identifying a type of a target file to be accessed to a second extension for defining a compression form of the target file to be accessed; extracting a target file to be converted, which represents text attributes of the target file to be accessed from the target file to be accessed, based on the compression form according to the second extension; converting at least one field in the extracted target file to be converted; storing the target file to be converted including the converted at least one field in the target file to be accessed; and changing the second extension defining the compression form of the target file to be accessed to the first extension.

Description

Apparatus for Controlling File Access and Method thereof

The present invention relates to an apparatus and method for controlling file access. More particularly, the present invention relates to a file access setting apparatus and method for maintaining security of a file processed by a word processor.

2. Description of the Related Art Recently, as computer-based working environments have become more common, security incidents in which personal information or confidential information contained in electronic documents related to electronic documents are leaked differently from the intention of the document creator have increased. As the incidence of document security incidents increases, the need for document security is gradually increasing, and in Korea, Digital Right Management (DRM) is leading the document security market. Recently, in addition to DRM, solutions such as a data loss prevention (DLP) method and a document centralization method have been provided.

In the modern society in which e-commerce is activated, the cost of storing and distributing various documents or documents continues to increase, and in particular, there is a limitation in that more costs are required than storing or distributing documents to solve security problems for electronic documents.

For the management of electronic documents containing only confidential information of individuals or companies, it is often used with encryption and decryption techniques, and various algorithms such as disk encryption or file encryption are also used. For example, disk encryption is a technology that encrypts an entire disk or a partial file with a password, and refers to a technology that encrypts a storage device such as an HDD, SSD, or USB memory, or encrypts a file system. There are some aspects that are not suitable for recent trends such as exchange of documents through.

Accordingly, there is a need for a document security technique that effectively controls access to electronic files and is advantageous in terms of cost and performance.

Korean Open Patent No. 10-2010-0043140 A

The present invention has been devised to solve the above problems, and discloses an apparatus and method for setting file access. In particular, based on the structure of a file, there is disclosed a file access setting apparatus and method for setting or releasing access to a file by modifying a specific field in the file.

The present invention has been devised to achieve the above object, and the file access setting apparatus of the present invention changes the first extension identifying the type of the access target file to the second extension defining the compression format of the access target file. A first extension change unit; A file extracting unit extracting a conversion target file indicating a content attribute of the access target file from the access target file based on the compression format according to the second extension; A field converting unit converting at least one field in the extracted conversion target file; A storage unit for storing a conversion target file including the converted at least one field in the access target file; And a second extension changing unit that changes a second extension that defines the compression format of the file to be accessed to the first extension. It includes.

In the present invention, the field conversion unit includes a field detection unit that detects at least one field in the conversion target file using preset field location information; And a field value changing unit changing a field value stored in the detected at least one field. In addition, the at least one field may be converted by storing the changed field value in the at least one field according to the field location information.

The access target file includes a compression flag indicating the compression status of the access target file, and the field converting unit can convert the at least one field while maintaining the compression status of the target file indicated by the compression flag.

In addition, in order to achieve the above object, the file access releasing apparatus of the present invention is a first extension changing unit that changes a first extension identifying a type of a file to be accessed to a second extension defining a compression format of the file to be accessed. ; A file extracting unit extracting a conversion target file indicating a content attribute of the access target file from the access target file based on the compression format according to the second extension; A field recovery unit for recovering at least one field in the extracted conversion target file; A storage unit for storing the converted target file including the recovered at least one field in the access target file; And a second extension changing unit that changes a second extension that defines the compression format of the file to be accessed to the first extension. It includes.

In the present invention, the field recovery unit includes a field detection unit that detects at least one field in the conversion target file using preset field location information; And a field value reduction unit for reducing the field value stored in the detected at least one field. In addition, the at least one field may be recovered by storing the recovered field value in the at least one field according to the field location information.

In addition, in order to achieve the above object, the file access setting method of the present invention includes changing a first extension identifying a type of a file to be accessed to a second extension defining a compression format of the file to be accessed; Extracting a conversion target file indicating a content attribute of the access target file from the access target file based on the compression format according to the second extension; Converting at least one field in the extracted conversion target file; Storing the converted target file including the converted at least one field in the access target file; And changing a second extension defining the compression format of the file to be accessed to the first extension. It includes.

In addition, the access target file includes a compression flag indicating the compression status of the access target file, and the converting step converts the at least one field based on the compression status of the target file indicated by the compression flag. Can be.

In addition, the converting may include detecting at least one field in the conversion target file using preset field location information; And changing a field value stored in the detected at least one field. In addition, the at least one field may be converted by storing the changed field value in the at least one field according to the field location information.

In addition, in order to achieve the above object, the method for releasing access to a file of the present invention includes changing a first extension identifying a type of a file to be accessed to a second extension defining a compression format of the file to be accessed; Extracting a conversion target file indicating a content attribute of the access target file from the access target file based on the compression format according to the second extension; Recovering at least one field in the extracted conversion target file; Storing the converted target file including the recovered at least one field in the access target file; And changing a second extension defining the compression format of the file to be accessed to the first extension. It includes.

In the present invention, the recovering may include detecting at least one field in the conversion target file using preset field location information; And reducing the field value stored in the detected at least one field. Further comprising, the at least one field may be recovered by storing the reduced field value in the at least one field according to the field location information.

The present invention also discloses a computer program stored in a computer-readable recording medium for executing the above-described file access setting method on a computer.

According to the present invention, access to a file can be controlled based on the structure of the file.

In particular, it is possible to effectively maintain the security of the file by using the transform field in the target file.

1 is a block diagram of a file access setting apparatus according to an embodiment of the present invention.
2 is an enlarged block diagram of a field conversion unit in the embodiment of FIG. 1.
3 is a block diagram of an apparatus for releasing file access according to an embodiment of the present invention.
4 is an enlarged block diagram of a field recovery unit in the embodiment of FIG. 3.
5 is a flowchart of a file access setting method according to another embodiment of the present invention.
FIG. 6 is an enlarged flowchart of the step of transforming a field in the embodiment of FIG. 5.
7 is a flowchart of a method for releasing file access according to another embodiment of the present invention.
8 is an enlarged flow diagram of a step of recovering a field in the embodiment of FIG. 7.
9 is a flowchart of a file access setting method according to another embodiment of the present invention.
10 is a diagram for describing a file structure of an access target file, a conversion target file, and a compression flag according to an embodiment.
11 is a flowchart of a file access release method according to another embodiment of the present invention.
12 is a view for explaining the structure of a file access control device corresponding to a file access setting device and a file access release device according to another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the description with reference to the accompanying drawings, the same or corresponding components are assigned the same drawing numbers, and redundant description thereof will be omitted.

In addition, in describing the present invention, when it is determined that detailed descriptions of related well-known configurations or functions may obscure the subject matter of the present invention, detailed descriptions thereof may be omitted.

Terms used in the present application are only used to describe specific embodiments, and are not intended to limit the terms. Singular expressions include plural expressions unless the context clearly indicates otherwise. Each of the steps described below may be provided with one or several software modules or may be implemented with hardware in charge of each function, or a combination of software and hardware.

The specific meaning and examples of each term will be described below in the order of each drawing.

Hereinafter, a configuration of a file access setting apparatus according to an embodiment of the present invention will be described in detail with reference to related drawings.

1 is a block diagram of a file access setting apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the file access setting apparatus 10 according to an embodiment includes a first extension change unit 120, a file extraction unit 140, a field conversion unit 160, a storage unit 180, and a second Extension extension unit 190 may be included. According to another embodiment, the file access setting apparatus 10 may further include a rating determining unit (not shown) and a decompression unit (not shown). However, not all of the illustrated components are required components, and the file access setting apparatus 10 may be implemented by more components than the illustrated components, and the file access setting apparatus 10 may be implemented by fewer components. Can be implemented.

According to an embodiment, the file access setting device 10 obtains an access target file, extracts a conversion target file from the obtained access target file, and converts at least one field in the extracted conversion target file to convert the field It is possible to limit access to the access target file provided with the conversion target file.

The target access file described in this specification may include an electronic document file processed on a computer, and the target access file described in this specification is a document file processed in a word processor, such as Korean or Microsoft Word (MS). word processor software. Hereinafter, a case in which the target access file is processed by Microsoft's word processor software will be described as an example.

According to an embodiment, the first extension changing unit 120 changes the first extension that identifies the type of the file to be accessed to the second extension that defines the compression format of the file to be accessed. For example, the first extension changer 120 may obtain a user right for changing the extension of the target access file, and change the extension of the target access file by using the user right for changing the obtained extension. The extension described in the present specification means a convention defined in an operating system for defining the name and function of the target access file.

According to the present disclosure, the first extension is a basic extension (Basis File Extension) that identifies the type of the file to be accessed, and may include doc, docx, hwp, txt, xls, xlsx, ppt, pptx, pdf, psd , The second extension may include zip, apk, rar, tar, 7z, and the like. Preferably, the first extension may be provided as docx, and the second extension may be provided as zip. For example, the extension docx is a basic extension that identifies a document type processed by an MS word processor, and may be an extension of an opem xml based format.

For example, the access target file identified by the extension docx may include a plurality of parts compressed in a compressed format defined by the extension zip, and each part may include at least one xml file. In addition, the file to be accessed may include media data including images or videos as well as text files. Therefore, the first extension changing unit changes the extension of the access target file identified as docx in which the plurality of xml files are compressed in the zip format to the second extension, so that the file access setting device 10 changes the structure of the target access file. Can analyze

The decompression unit (not shown) decompresses the access target file compressed in a compression format according to the second extension. The decompression unit may decompress the access target file based on the compression format of the access target file whose extension is changed to the second extension. The access target file according to the present disclosure may further include media data including a video image in addition to text data, and the decompressing unit decompresses the access target file to different degrees depending on the properties of the data included in the access target file. Can be. For example, the decompression unit may maintain compression of media data included in the file to be accessed, and decompress only text data.

The file extracting unit 140 according to an embodiment extracts a conversion target file indicating a content attribute of the access target file from the access target file based on a compression format according to the second extension (eg .zip). For example, the file extractor 140 may directly extract a conversion target file from an access target file whose extension is changed to a second extension (for example, compressed in a compressed format defined by the second extension). However, the file extraction unit 140 may extract the conversion target file from the access target file that has been decompressed by the decompression unit.

The file to be converted according to the present disclosure is a file indicating the content attribute of the file to be accessed, and preferably the attribute of text data included in the file to be accessed. For example, when the file to be accessed is a document processed by the MS word processor identified by the extension docx, the file to be converted may be provided as a document.xml file indicating the text attribute of the target access file. This will be described with reference to FIG. 2.

The rating determining unit (not shown) according to an embodiment may determine the security level of the access target file based on the content attribute of the access target file. For example, the rating determining unit may determine the security level of the access target file based on at least one of attributes of text data and media data included in the access target file. According to another embodiment, the rating determining unit accesses based on at least one of a connection relationship of each part in the file to be accessed, a metadata list of each part and fields, type information of content, and the number of times the text stored in the file to be accessed is viewed. The security level of the target file can be determined. The field converter 160 according to the present disclosure may convert at least one field in a conversion target file differently according to the determined security level.

The field conversion unit 160 according to an embodiment includes a field detection unit 162 and a field value changing unit 164. According to another embodiment, the field conversion unit 160 may further include a correction unit (not shown). However, not all of the illustrated components are required components, and the field converting unit 160 may be implemented by more components than the illustrated components, or the field converting unit 10 may be implemented by fewer components. Can be.

For example, the field converter 160 may convert at least one field in the extracted conversion target file. The file to be converted according to the present disclosure may include a reference field, a file name to be converted, a field in which information about an attribute of text in an access target file is stored, and a waiting field, and the field converting unit 160 includes a reference field and a conversion target At least one field of a file name, a field in which information about an attribute of text in an access target file is stored, and a standby field may be converted. The field conversion unit 160 detects at least one field in the conversion target file using preset field position information that identifies the positions of a plurality of fields in the conversion target file, and retrieves the field values stored in the detected at least one field. You can change it.

According to one embodiment, the field conversion unit 160 is a document to be accessed by the MS word processor identified by the extension docx, and the conversion target file is a document.xml file indicating the text attribute of the target access file Based on the reference field in the document.xml file, the field value of the field corresponding to the address value 0xA15 can be changed. The access target file according to the present disclosure may further include a compression flag indicating the compression state of the access target file, and the field converting unit 160 may generate at least a conversion target file based on the compression state of the target file indicated by the compression flag. One field can be converted.

According to an embodiment, the field converter 160 may convert a field in the conversion target file extracted from the access target file while maintaining the compressed state of the access target file. For example, the access target file of the present disclosure may further include a compression flag indicating the compression state of the access target file, and the field converter 160 converts while maintaining the compression state of the access target file indicated by the compression flag. You can convert the fields in the target file. That is, the file access setting apparatus 10 can reduce the access control cost for the file because the field in the file to be converted can be converted using the compression flag while maintaining the compressed state of the file to be accessed. That is, the field conversion unit 160 may convert at least one field in the conversion target file based on the compression state of the access target file indicated by the compression flag.

According to another embodiment of the present disclosure, the field conversion unit 160 may convert fields in the conversion target file in different ways based on the determined security level. For example, the field conversion unit 160 according to the present disclosure converts a field in a conversion target file in different ways based on the determined security level, the position of a field to be detected in the conversion target file according to the determined security level , The number of fields to be detected and the target field values to be stored in the fields to be detected are set differently, and at least one field in the conversion target file is set using differently set positions of the fields to be detected, the number of fields to be detected, and the target field values It may be to change.

The correction unit (not shown) according to an embodiment may correct the length and offset of the converted conversion target file when the length of the conversion target file including at least one field in which the changed field value is stored is changed. For example, when the field converting unit 160 changes the field value stored in the conversion target file by using a target field value that does not match the length of the field value stored in the conversion target file, the length of the conversion target file Can be different. Accordingly, when the length of the file to be converted is changed, a relative position of fields in the file to be converted is changed, and as a result, a problem may arise that the access restriction setting for the file to be accessed is not made accurately.

That is, when the length of the file to be converted is changed by the correction unit according to the present disclosure, the offset of the file to be converted is adjusted by adjusting the length of the file to be converted or resetting the location information of a plurality of fields in the file based on the reference field. By correcting, the file access setting apparatus 10 can accurately set the access to the access target file. The correction unit according to the present disclosure may be included in the field conversion unit 160, but is included in the file access setting device 10 other than the field conversion unit 160, and the conversion target file including at least one field in which the changed field value is stored. It is possible to detect whether the length of is changed, and if the length of the file to be converted is changed, the length and offset of the converted file to be converted may be corrected.

The storage unit 180 according to an embodiment may store a conversion target file including at least one converted field in the access target file. The file access setting apparatus 10 according to the present disclosure stores the changed field value in at least one field according to the preset field location information, and finally converts the converted target file by storing the converted target file in the access target file Fields in the target file can be converted.

According to another embodiment, the storage unit 180 may further store conversion identification information indicating whether at least one field in the conversion target file has been converted, and a time when the at least one field has been converted, in the access target file.

The storage unit 180 according to the present disclosure may include an internal memory or an external memory. The internal memory includes, for example, volatile memory (eg, dynamic RAM (DRAM), static RAM (SRAM), or synchronous dynamic RAM (SDRAM)), non-volatile memory (eg, OTPROM (one time programmable ROM (PROM), programmable ROM (PROM), erasable and programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM), mask ROM, flash ROM, flash memory (e.g. NAND flash or NOR flash, etc.), hard drives, Or it may include at least one of a solid state drive (SSD).

In addition, the external memory according to the present disclosure is a flash drive (flash drive), compact flash (CF), secure digital (SD), micro-SD (micro secure digital), mini-SD (mini secure digital), xD (extreme digital) ), MMC (multi-media card) or memory stick (memory stick). The external memory may be functionally and / or physically connected to the file access setting device 10 through various interfaces. Programs stored in the storage unit 180 may be classified into a plurality of modules according to their functions. For example, a first extension change unit, a file extraction unit, a field conversion unit, a second extension change unit, and an access control module It may be classified as, but is not limited to this.

The second extension changing unit 190 according to an embodiment may change the second extension defining the compression format of the file to be accessed to the first extension. For example, if the file to be accessed is a document processed by an MS word processor identified by the extension docx, the first extension may be provided as .docx, the second extension may be provided as .zip, and the second extension is changed. The unit 190 may change the extension .zip to .docx. An access target file having an extension of .docx including at least one field whose field value is converted by the file access setting device 10 cannot be normally executed by the MS word processor.

2 is an enlarged block diagram of a field conversion unit in the embodiment of FIG. 1.

According to an embodiment, the field conversion unit 160 includes a field detection unit 162 and a field value changing unit 164. For example, the field detection unit 162 may detect at least one field in the conversion target file using preset field location information. For example, the file to be converted may include a reference field, a file name to be converted, and a field in which information about an attribute of text in the file to be accessed is stored, and a standby field, which are distinguished according to the set field location information, and the field detection unit 162 ) May detect at least one field according to predetermined field location information.

According to an embodiment, the field value changing unit 164 may change a field value stored in at least one detected field. For example, the fields in the file to be converted may include a preset field value (eg, binary data), and the field value changing unit 164 is determined based on at least one of the compression status and the determined security level indicated by the compression flag. Using the target field value, a field value previously stored in fields in the conversion target file may be changed.

3 is a block diagram of a file access release device 20 according to an embodiment of the present invention.

The file access release device 20 according to an embodiment includes a first extension changer 320, a file extractor 340, a field recovery part 360, a storage part 380, and a second extension changer 390. It may include. According to another embodiment, the file access releasing device 20 may further include a decompression unit (not shown), an identification unit (not shown), and a correction unit (not shown). However, not all of the illustrated components are required components, and the file access releasing apparatus 20 may be implemented by more components than the illustrated components, and the file access releasing apparatus 20 may be implemented by fewer components. Can be implemented.

The first extension change unit 320 according to an embodiment may change the first extension that identifies the type of the file to be accessed to the second extension that defines the compression format of the file to be accessed. Since the first extension changer 320 may correspond to the first extension changer 120 of FIG. 1, a detailed description will be omitted. The file extracting unit 340 according to an embodiment extracts a conversion target file indicating the text attribute of the access target file from the access target file based on the compression format according to the second extension. Since the file extraction unit 340 may correspond to the file extraction unit 140 of FIG. 1, a detailed description will be omitted.

The decompression unit (not shown) decompresses the access target file compressed in a compression format according to the second extension. The decompression unit may decompress the access target file based on the compression format of the access target file whose extension is changed to the second extension. Since the decompression unit may correspond to the decompression unit in the file access setting device 10 of FIG. 1, detailed description will be omitted. This will be described with reference to FIG. 4.

The identification unit according to an embodiment may identify conversion identification information indicating whether at least one field in a conversion target file has been converted. For example, the conversion target file may further include conversion identification information indicating whether at least one field in the conversion target file has been converted (eg, whether a field value in the field has been changed) in the standby field, and the identification unit waits Based on the conversion identification information in the field, it is possible to identify whether the conversion target field has been converted. According to another embodiment, the identification unit is not included in the field recovery unit 360 but is included in the file access release device 20 to identify whether the conversion target field has been converted.

The field recovery unit 360 according to an embodiment includes a field detection unit 362 and a field value reduction unit 364. The above-described identification unit (not shown) may be further included in the field recovery unit 360. For example, the field recovery unit 360 may recover at least one field in the extracted conversion target file. The file to be converted according to the present disclosure may include a reference field, a file name to be converted, a field in which information about an attribute of text in the file to be accessed is stored, and a waiting field, and the field recovery unit 360 includes a reference field and a conversion target Recover at least one field in the file to be converted by reducing the field value in the converted field if at least one of the converted field is present among the file name, the field in which information about the attribute of the text in the file to be accessed is stored, and the standby field. can do.

According to another embodiment, the field recovery unit 360 may recover at least one field in the conversion target file based on the conversion identification information stored in the standby field of the conversion target file. For example, if the conversion identification information in the standby field indicates that the converted field in the conversion target field does not exist, the field recovery unit 360 may not recover at least one field in the conversion target field. That is, the file access releasing device 20 may quickly determine whether to recover the file to be converted using the conversion identification information of the standby field in the file to be converted.

The correction unit (not shown) according to an embodiment may correct the length and offset of the converted conversion target file when the length of the conversion target file including at least one field in which the changed field value is stored is changed. Since the correction unit may correspond to the configuration of the correction unit included in the file access setting device 10 of FIG. 1, a detailed description will be omitted.

The storage unit 380 according to an embodiment may store a conversion target file including the recovered at least one field in the access target file. Since the storage unit 380 may correspond to the storage unit 180 of FIG. 1, detailed description will be omitted. The second extension change unit 390 according to an embodiment may change the second extension defining the compression format of the file to be accessed to the first extension. Since the second extension changer 390 may correspond to the second extension changer 190 of FIG. 1, a detailed description will be omitted.

4 is an enlarged block diagram of a field recovery unit in the embodiment of FIG. 3.

The identification unit according to an embodiment may identify conversion identification information indicating whether at least one field in a conversion target file has been converted. Since the identification part included in the field recovery part may correspond to the identification part in the file access release device of FIG. 3, a detailed description will be omitted.

The field detection unit 360 may detect at least one converted field in the conversion target file using preset field position information or conversion identification information in the conversion target file. For example, when the identified conversion identification information indicates that at least one field converted in the conversion target file exists, the field detection unit 360 converts the at least one conversion in the conversion target file using the preset field position information. Fields can be detected.

The field value reduction unit 364 according to an embodiment may reduce the field value stored in at least one detected field. For example, initial field values of all fields in the conversion target file may be stored in the standby field in the conversion target file, and the field value reduction unit 364 uses the initial values of the fields previously stored in the standby field to convert the target fields. Field values of converted fields in a file may be reduced. For example, the field value reduction unit 364 reducing the field value stored in at least one field detected may be to change the changed field value in the converted field in the conversion target file to an initial value in the corresponding field. . The field value reduction unit 364 may restore the field by storing the recovered field value in at least one field in the conversion target file according to the field location information.

5 is a flowchart of a file access setting method according to another embodiment of the present invention.

The file access setting method includes the following steps performed in time series in the file access setting device 10.

In S520, the first extension changing unit changes the first extension that identifies the type of the file to be accessed to the second extension that defines the compressed format of the file to be accessed. Since the first extension change unit may correspond to the configuration of the first extension change unit 120 of FIG. 1, a detailed description will be omitted.

In S540, the file extracting unit extracts a conversion target file indicating the content attribute of the access target file from the access target file based on the compression format according to the second extension (eg .zip). Since the file extraction unit may correspond to the configuration of the file extraction unit 140 of FIG. 1, a detailed description will be omitted.

In S560, the field conversion unit may convert at least one field in the extracted conversion target file. For example, the field conversion unit detects at least one field in the conversion target file using preset field position information that identifies the positions of a plurality of fields in the conversion target file, and retrieves the field value stored in the detected at least one field. You can change it. Since the field conversion unit may correspond to the configuration of the field conversion unit 160 of FIG. 1, a detailed description will be omitted.

In S580, the storage unit may store a conversion target file including at least one converted field in the access target file. The file access setting apparatus 10 according to the present disclosure stores the changed field value in at least one field according to the preset field location information, and finally converts the converted target file by storing the converted target file in the access target file Fields in the target file can be converted. Since the storage unit may correspond to the configuration of the storage unit 180 of FIG. 1, detailed description will be omitted.

In S590, the second extension changing unit may change the second extension that defines the compression format of the file to be accessed to the first extension. Since the second extension change unit may correspond to the configuration of the second extension change unit 190 of FIG. 1, a detailed description will be omitted.

FIG. 6 is an enlarged flowchart of the step of transforming a field in the embodiment of FIG. 5.

In S562, the field detector may detect at least one field in the file to be converted using the preset field location information. Since the field detection unit may correspond to the field detection unit 162 of FIG. 2, detailed description will be omitted.

In S564, the field value changing unit may change the field value stored in the detected at least one field. Since the field value changing unit may correspond to the field value changing unit 164 of FIG. 2, a detailed description will be omitted.

7 is a flowchart of a method for releasing file access according to another embodiment of the present invention.

The file access release method includes the following steps performed in time series in the file access release device 20.

In S720, the first extension changing unit may change the first extension that identifies the type of the file to be accessed to the second extension that defines the compression format of the file to be accessed. Since the first extension change unit may correspond to the first extension change unit 320 of FIG. 3, a detailed description will be omitted.

In S740, the file extracting unit extracts a conversion target file indicating the text attribute of the access target file from the access target file based on the compression format according to the second extension. Since the file extraction unit may correspond to the file extraction unit 340 of FIG. 3, detailed description will be omitted.

In S760, the field recovery unit may recover at least one field in the conversion target file based on the conversion identification information stored in the standby field of the conversion target file. Since the field recovery unit may correspond to the field recovery unit 360 of FIG. 3, detailed description will be omitted.

In S780, the storage unit may store the converted target file including the recovered at least one field in the access target file. Since the storage unit may correspond to the storage unit 380 of FIG. 3, detailed description will be omitted.

In S790, the second extension changing unit may change the second extension that defines the compression format of the access target file to the first extension. Since the second extension change unit may correspond to the second extension change unit 390 of FIG. 3, a detailed description will be omitted.

8 is an enlarged flow diagram of a step of recovering a field in the embodiment of FIG. 7.

In S762, the field detection unit may detect at least one converted field in the conversion target file using preset field position information or conversion identification information in the conversion target file. Since the field detection unit may correspond to the field detection unit 360 of FIG. 4, detailed description will be omitted.

In S764, the field value reduction unit may reduce the field value stored in the detected at least one field. Since the field value reduction unit may correspond to the field value reduction unit 364 of FIG. 4, a detailed description will be omitted.

9 is a flowchart of a file access setting method according to another embodiment of the present invention.

The file access setting method according to another embodiment may include the following steps performed in time series in the file access setting device.

In S910, the file access setting device 10 may obtain an access target file and change the extension .docx of the obtained access target file to an extension .zip.

In S920, the file access setting device 10 may decompress the file to be accessed based on the zip compression format defined by the changed extension .zip. According to another embodiment, the operation of decompressing the file to be accessed by the file access setting device 10 may be omitted.

In S930, the file access setting device 10 may extract the document.xml file from the extracted access target file. The document.xml file described in this specification may indicate text attributes in an access target file.

In S940, the file access setting apparatus 10 may change the field value in the field corresponding to the field location information 0xA15 based on the reference field of the extracted document.xml file.

In S950, the file access setting device 10 may store the document.xml file including the changed field value in a compressed access target file in a zip format.

In S960, the file access setting device 10 may change the extension .zip of the access target file whose extension is changed to the default extension .docx.

10 is a diagram for describing a file structure of an access target file, a conversion target file, and a compression flag according to an embodiment.

Referring to FIG. 10, the access target file 1100 used by the file access setting device 10 or the file access release device 20 includes first connection information 1120, metadata list 1140, and content 1160. , Content type information 1190. For example, the access target file 1100 may include a plurality of parts compressed in a compressed format defined by a zip extension, and may have a package structure including a plurality of parts. In this specification, the first connection information 1120 may indicate a connection relationship between parts of the first layer in the file to be accessed.

According to an embodiment, the first connection information may be information stored in a .rels folder that defines a connection relationship between parts in a .docx file. The metadata list 1140 includes location information of each of the parts included in the access target file, and the content type information 1190 may include MIME information as information related to the type of content included in the access target file. .

Referring to FIG. 10, the content 1160 in the access target file may further include second connection information 1162, media data 1164, text data 1166, and a standby array 1188. For example, the second connection information 1162 may include information defining a connection relationship between sub-parts included in a content 1160 part among a plurality of parts in an access target file. According to an embodiment, the second connection information may be information stored in a .rels folder that defines a connection relationship between parts in a .docx file.

The media data 1164 includes data related to at least one of video and images, not text, and the text data 1166 includes data related to text in the file to be accessed. The standby array 1188 may be a part in which data in an access target file is not stored.

The conversion target file 1168 according to the present disclosure may be included in at least some of the text data 1166 parts, and may indicate attributes for text in the access target file. Further, the compression flag 1176 according to the present disclosure may be included in the standby array 1188 in the file to be accessed to indicate the compressed state of the file to be accessed. As described above, the decompression unit according to the present disclosure can decompress based on the compression state of the access target file indicated by the compression flag 1176. In addition, as described above, the field conversion unit according to the present disclosure can convert at least one field in the conversion target file based on the compression state of the target file indicated by the compression flag.

The conversion target file 1168 according to the present disclosure includes a reference field 1169, a file name 1170, an attribute 1171 of text stored in the access target file, and a waiting field (1172, 1173, 1174) in which a plurality of fields are located. It may include. For example, the reference field 1169 is a field for defining location information of a file to be converted, and may not have a data capacity. However, the correction unit in the file access setting device may increase the data capacity of the reference field 1169 in order to correct the length of the conversion target file when the length of the conversion target file is different from before conversion.

For example, the file name 1170 indicates a file name that identifies the file to be converted, and the text attribute 1171 includes information for defining an attribute of text included in the file to be converted. According to an embodiment, the text attribute 1171 may include information about fonts, line spacing, and margins. The waiting fields 1172, 1173, and 1174 are empty fields in which field values in the conversion target file are not stored, and the file access setting device 10, if necessary, converts the target field values in the waiting field to be converted. You can convert at least one field in the file.

The compression flag 1176 according to the present disclosure includes a reference field 1176, a field in which information 1178 about whether to compress an access target file is stored, a field in which information about a file length 1179 of a conversion target file before compression is stored, Field storing information about the file length of the file to be converted after compression (1180), Field storing information about the file size (1181) of the file to be converted before compression, Information about the file capacity (1182) of the file to be converted after compression May include a stored field and a standby array 1183 field.

For example, the compression status indicated by the compression flag in the file to be converted includes information about whether the file to be accessed is compressed (1178), information about the length of the file before compression (1179), and information about the size of the file before compression (1181). , May vary according to at least one of information about a file length after compression 1180 and information about a file capacity after compression 1182.

The file access setting apparatus 10 according to the present disclosure may convert a field of a conversion target file in the access target file based on the compression state of the access target file indicated by the compression flag. That is, before converting at least one field in the file to be converted, the file access setting device 10 may first check the compressed state of the file to be accessed using a compression flag.

The file access setting apparatus 10 according to the present disclosure may immediately determine the compression state of the access target file by using the information on whether to compress the access target file stored in the compression flag 1176, but before the compression stored in the compression flag The compression state of the access target file may be determined by using at least one of information on the file length of the target conversion target file and information on the size of the target conversion target file before and after compression.

According to another embodiment, the file access setting apparatus 10 does not read information about the file length of the files to be converted before and after compression stored in the compression flag 1176 and information about the capacity of the files to be converted before and after compression. If not, the compression status of the access target file may be determined by summing the information of parts in the access target file except for the compression flag.

11 is a flowchart of a file access release method according to another embodiment of the present invention.

The method for releasing file access according to another embodiment may include the following steps performed in time series in the file access releasing device.

In S1110, the file access release device 20 may acquire an access target file and change the extension .docx of the obtained access target file to an extension .zip.

In S1120, the file access release device 20 may decompress the file to be accessed based on the zip compression format defined by the changed extension .zip. According to another embodiment, the operation of decompressing the file to be accessed by the file access releasing device 20 may be omitted.

In S1130, the file access release device 20 may extract the document.xml file from the extracted access target file. The document.xml file described in this specification may indicate text attributes in an access target file.

In S1140, the file access release device 20 may reduce the field value in the field corresponding to the field location information 0xA15 based on the reference field of the extracted document.xml file.

In S1150, the file access release device 20 may store the document.xml file including the reduced field value in a compressed access target file in a zip format.

In S1160, the file access release device 20 may change the extension .zip of the access target file whose extension is changed to the default extension .docx.

12 is a view for explaining the structure of a file access control device corresponding to a file access setting device and a file access release device according to another embodiment of the present invention.

The file access control device 1200 according to the present disclosure may correspond to the file access setting device 10 of FIG. 1 and the file access release device 20 of FIG. 3. For example, the file access setting apparatus 10 according to the present disclosure may include a processor 1300 and a memory 1400. For example, the memory 1400 according to the present disclosure may correspond to the storage unit 180 of FIG. 1. The processor 1300 according to the present disclosure typically controls the overall operation of the file access setting apparatus 1200 by executing one or more instructions stored in the memory 1400. For example, the processor 1300 executes one or more instructions stored in the memory 1400, so that the first extension change unit 120, the file extraction unit 140, the field conversion unit 160, and the storage unit 180 , The second extension change unit 190, the field detection unit 162, and the field value change unit 164 may be generally controlled, or the same function as each module may be performed.

According to another embodiment, the first extension change unit 120, the file extraction unit 140, the field conversion unit 160, the storage unit 180, the second extension change unit 190, the field detection unit 162 And the function of the field value changing unit 164 may be performed on a single processor, but may be divided through a plurality of processors. According to another embodiment, the first extension change unit 120, the file extraction unit 140, the field conversion unit 160, the storage unit 180, the second extension change unit 190, the field detection unit 162 And the field value changing unit 164 may each include at least one processor, and the first extension changing unit 120, the file extracting unit 140, and the field converting unit (using a processor included in each module) 160), the storage unit 180, the second extension changing unit 190, the field detection unit 162 and the field value changing unit 164 may perform each function.

The file access release device 20 according to the present disclosure may include a processor 1300 and a memory 1400. For example, the memory 1400 according to the present disclosure may correspond to the storage unit 380 of FIG. 3. The processor 1300 according to the present disclosure typically controls the overall operation of the file access release device 1200 by executing one or more instructions stored in the memory 1400. For example, the processor 1300 executes one or more instructions stored in the memory 1400, so that the first extension change unit 320, the file extraction unit 340, the field recovery unit 360, and the storage unit 380 , The second extension change unit 390, the field detection unit 362, and the field value reduction unit 364 may be generally controlled, or the same function as each module may be performed.

According to another embodiment, the first extension change unit 320, the file extraction unit 340, the field recovery unit 360, the storage unit 380, the second extension change unit 390, the field detection unit 362 And the function of the field value reduction unit 364 may be performed on a single processor, but may be divided through a plurality of processors. According to another embodiment, the first extension change unit 320, the file extraction unit 340, the field recovery unit 360, the storage unit 380, the second extension change unit 390, the field detection unit 362 And the field value reduction unit 364 may include at least one processor, and each of the first extension change unit 320, the file extraction unit 340, and the field recovery unit using processors included in each module. 360), the storage unit 380, the second extension change unit 390, the field detection unit 362 and the field value reduction unit 364 may perform each function.

According to an embodiment, the file access setting device 10 and the file access release device 20 may constitute a file access control system. The file access control system, the file access setting device 10 and the file access release device 20 according to the present disclosure may be implemented in various types of electronic devices. For example, the file access control system, the file access setting device 10 and the file access release device 20 include a desktop, mobile terminal, laptop computer, tablet PC, electronic book terminal, digital broadcasting terminal, PDA (Personal Digital Assistants), PMP (Portable Multimedia), but is not limited thereto.

All or part of the method of an embodiment of the present invention described above may be embodied in the form of a computer-executable recording medium, such as a program module, being executed by a computer. Here, the computer readable medium can be any available medium that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. In addition, computer readable media may include computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.

Further, all or part of a method according to an embodiment of the present invention includes instructions executable by a computer and may be embodied as a computer program (or computer program product) recorded on a medium. The computer program includes programmable machine instructions processed by a processor and may be implemented in a high-level programming language, object-oriented programming language, assembly language, or machine language. . In addition, the computer program may be recorded on a tangible computer-readable recording medium (eg, memory, hard disk, magnetic / optical medium, or solid-state drive (SSD), etc.).

Accordingly, a method according to an embodiment of the present invention may be implemented by executing a computer program as described above by a computing device. The computing device may include at least some of a processor, a memory, a storage device, a high-speed interface connected to the memory and a high-speed expansion port, and a low-speed interface connected to the low-speed bus and the storage device. Each of these components is connected to each other using various buses, and can be mounted on a common motherboard or mounted in other suitable ways.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains may make various modifications, changes, and substitutions without departing from the essential characteristics of the present invention. will be. Therefore, the embodiments and the accompanying drawings disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain the scope of the technical spirit of the present invention. . The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (19)

Changing a first extension identifying the type of the file to be accessed to a second extension defining a compression format of the file to be accessed;
Extracting a conversion target file indicating a text attribute of the access target file from the access target file, based on the compression format according to the second extension;
Converting at least one field in the extracted conversion target file;
Storing the converted target file including the converted at least one field in the access target file; And
Changing a second extension defining a compression format of the file to be accessed to the first extension; How to set up file access, including. According to claim 1,
Decompressing the file to be accessed compressed in a compressed format according to the second extension; Further comprising,
The extracting step extracts the file to be converted from the decompressed access target file. According to claim 2,
The access target file includes a compression flag indicating the compression status of the access target file,
And the converting step converts the at least one field based on a compression state of the target file indicated by the compression flag. According to claim 1,
The access target file includes a compression flag indicating the compression status of the access target file,
And the converting step converts the at least one field while maintaining a compressed state of the target file indicated by the compression flag. The method of claim 1, wherein the converting step
Detecting at least one field in the conversion target file using preset field location information; And
Changing a field value stored in the detected at least one field; Further comprising,
And changing the at least one field by storing the changed field value in the at least one field according to the field location information. According to claim 3,
The compression flag may include at least one of information on whether the file to be accessed is compressed, information about a file length before compression, information on a file size before compression, information on a file length after compression, and information on a file size after compression. Including,
The compression status of the target file is among information on whether the access target file is compressed, information on the file length before compression, information on the file size before compression, information on the file length after compression, and information on the file size after compression. Method of setting file access, characterized in that it depends on at least one. According to claim 1,
Determining a security level of the file to be accessed; Further comprising,
The converting of the fields may include converting at least one field in the target file differently according to the determined security level. The method of claim 1, wherein the storing step
A method for setting file access, characterized by further storing conversion identification information indicating whether at least one field in the conversion target file has been converted and information on the time at which the at least one field has been converted in the access target file. According to claim 1,
The access target file identified by the first extension includes a plurality of xml files compressed in a compressed format defined by the second extension. The method of claim 5,
And the file to be accessed includes at least one of an image file and a video file, and is processed in a word processor for editing the file to be accessed. The method of claim 5,
The first extension includes the extension docx, the second extension includes the extension zip, the conversion target file is a document.xml file, and the preset field location information indicates the location of a reference field in the conversion target file. File access setting method characterized in that the field address value determined based on. Changing a first extension identifying the type of the file to be accessed to a second extension defining a compression format of the file to be accessed;
Extracting a conversion target file indicating a text attribute of the access target file from the access target file, based on the compression format according to the second extension;
Recovering at least one field in the extracted conversion target file;
Storing the converted target file including the recovered at least one field in the access target file; And
Changing a second extension defining a compression format of the file to be accessed to the first extension; How to disable file access, including. The method of claim 12,
Identifying conversion identification information indicating whether at least one field in the conversion target file has been converted; Further comprising,
The recovering may include restoring the at least one field based on the conversion identification information in the conversion target file. The method of claim 13, wherein the recovering step
Detecting at least one field in the conversion target file using preset field location information; And
Reducing field values stored in the detected at least one field; Further comprising,
And recovering the at least one field by storing the reduced field value in the at least one field according to the field location information. A first extension changing unit that changes a first extension that identifies the type of the file to be accessed to a second extension that defines a compressed format of the file to be accessed;
A file extraction unit for extracting a conversion target file indicating a text attribute of the access target file from the access target file based on a compression format according to the second extension;
A field converting unit converting at least one field in the extracted conversion target file;
A storage unit for storing a conversion target file including the converted at least one field in the access target file; And
A second extension changing unit that changes a second extension defining the compression format of the file to be accessed to the first extension; File access setting device comprising a. The method of claim 15, wherein the field conversion unit
A field detection unit detecting at least one field in the conversion target file using preset field location information; And
A field value changing unit for changing a field value stored in the detected at least one field; Further comprising,
And converting the at least one field by storing the changed field value in the at least one field according to the field location information. A first extension changing unit that changes a first extension that identifies the type of the file to be accessed to a second extension that defines a compressed format of the file to be accessed;
A file extraction unit for extracting a conversion target file indicating a text attribute of the access target file from the access target file based on a compression format according to the second extension;
A field recovery unit for recovering at least one field in the extracted conversion target file;
A storage unit for storing the converted target file including the recovered at least one field in the access target file; And
A second extension changing unit that changes a second extension defining the compression format of the file to be accessed to the first extension; File access release device comprising a. The method of claim 17, wherein the field recovery unit
A field detection unit detecting at least one field in the conversion target file using preset field location information; And
A field value recovery unit for recovering field values stored in the detected at least one field; Further comprising,
And recovering the at least one field by storing the recovered field value in the at least one field according to the field location information. A program stored in a computer-readable recording medium that realizes the file access setting method according to any one of claims 1 to 11 through being executed by a processor.

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