KR20210097294A - Data hiding method and apparatus thereof - Google Patents

Abstract

The present invention relates to a data hiding method in a user terminal, which includes the steps of: monitoring whether a first file is generated in a path predetermined by a terminal user; determining a target file to hide the first file when generation of the first file is detected; hiding the first file in the target file using a bit combination function corresponding to the first file; and generating hiding information for restoring the first file hidden in the target file.

Description

DATA HIDING METHOD AND APPARATUS THEREOF

The present invention relates to information security technology, and more particularly, to a data hiding method and apparatus capable of automatically detecting a file generated in a specific path of a user terminal and hiding it in another file.

The terminal may be divided into a mobile/portable terminal and a stationary terminal according to whether the terminal can be moved. Again, the mobile terminal can be divided into a handheld terminal and a vehicle mounted terminal depending on whether the user can carry it directly.

The functions of mobile terminals are diversifying. For example, there are functions for data and voice communication, photo and video shooting through a camera, voice recording, music file playback through a speaker system, and an image or video output to the display unit. Some terminals add an electronic game play function or perform a multimedia player function. In particular, recent mobile terminals can receive multicast signals that provide broadcast and visual content such as video or television programs. As the functions of such mobile terminals are diversified, they are implemented in the form of multimedia players equipped with complex functions, such as, for example, taking pictures or videos, playing music or video files, playing games, and receiving broadcasts. is becoming

BACKGROUND With the development of mobile communication technology, wireless Internet technology, digital camera technology, and the like, mobile terminals are becoming the most used daily necessities in people's daily lives. Accordingly, data 　 transmission speed, user convenience, product stability, and security technology of the mobile terminal become important indicators for the terminal user to select the mobile terminal. In particular, security indicators become more important when it relates to sensitive user and personal information. As the importance of these security indicators increases, various kinds of privacy protection applications are being launched.

In general, the privacy protection application installed in the mobile terminal is not only the login account and password information of the terminal user, but also various kinds of information such as memos, messages, chatting history, shopping order information, payment information, photo files and video files related to sensitive user personal information. Generate mobile data. Such mobile data is stored in the form of a text file, a database file, a media file, etc. in a local folder of the mobile terminal. Since mobile data stored in a mobile terminal can be easily discovered by a third party, there is a high possibility that sensitive user personal information is leaked to the outside. In order to avoid the possibility of leakage of the user's personal information, the user's personal information generated by the currently running application is automatically encrypted before being stored in the local folder of the mobile terminal.

However, even if the user's personal information is encrypted and stored in the local folder of the mobile terminal, there is a possibility that the encrypted text of the encrypted information will still be exposed to the outside. For example, common third-party tools (database tools such as iTools and Peapod) can decrypt the passphrase to easily retrieve mobile data related to user personal information. As described above, as the possibility that the user 　 personal information stored in the mobile terminal is leaked to the outside increases, there is a problem that the security level of the corresponding terminal gradually decreases.

SUMMARY OF THE INVENTION The present invention aims to solve the above and other problems. Another object of the present invention is to provide a data hiding method and apparatus capable of automatically detecting a file generated in a predetermined path of a user terminal and hiding it in another file.

Another object is to provide a data hiding method and apparatus capable of automatically detecting an image file generated in a predetermined path of a user terminal and easily inserting the detected image file in the middle of a predetermined moving picture file to hide it. there is.

According to an aspect of the present invention to achieve the above or other objects, the method comprising: monitoring whether a first file is created in a path predetermined by a terminal user; determining a target file in which to hide the first file when the generation of the first file is detected; hiding the first file in the target file using a bit combination function corresponding to the first file; and generating secret information for restoring the first file hidden in the target file.

According to another aspect of the present invention, a data generation monitoring unit for monitoring whether the first file is generated in a predetermined path; When the generation of the first file is detected, a target file to hide the first file and a bit combination function corresponding to the first file are determined, and the first file is stored in the target file by using the determined bit combination function. a data hiding unit to be hidden; and a secret information generator generating secret information for restoring the first file hidden in the target file.

According to another aspect of the present invention, the process of monitoring whether the first file is generated in a path predetermined by the terminal user; determining a target file in which to hide the first file when generation of the first file is detected; hiding the first file in the target file using a bit combination function corresponding to the first file; and a computer program stored in a computer-readable recording medium so that the process of generating secret information for restoring the first file hidden in the target file is executable on the computer.

The effects of the data hiding method and the apparatus according to the embodiments of the present invention will be described as follows.

According to at least one of the embodiments of the present invention, by automatically detecting a file generated in a path specified in advance by the terminal user and hiding it in a predetermined target file, sensitive personal information stored in the user terminal is hacked and leaked to the outside. It has the advantage of being able to effectively prevent it.

In addition, according to at least one of the embodiments of the present invention, by automatically detecting a file generated in a path specified in advance by the terminal user and hiding it in a predetermined target file, even if a third party acquires the user terminal, it is hidden in the target file It has the advantage of not being able to check the existence of the file itself at all.

However, the effects achievable by the data hiding method and the apparatus according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned may be found in the technical field to which the present invention belongs from the description below. It will be clearly understood by those of ordinary skill in the art.

1 is a block diagram showing the configuration of a user terminal according to an embodiment of the present invention;
FIG. 2 is a block diagram showing the configuration of a data hiding device implemented in the user terminal of FIG. 1;
3 is a flowchart illustrating a data hiding and restoration method according to an embodiment of the present invention;
4 is a flowchart illustrating a data hiding algorithm according to an embodiment of the present invention;
5 to 9 are diagrams referenced to explain a data hiding algorithm according to an embodiment of the present invention.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and overlapping descriptions thereof will be omitted. The suffixes "module" and "part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves. That is, the term 'unit' used in the present invention means a hardware component such as software, FPGA, or ASIC, and 'unit' performs certain roles. However, 'part' is not limited to software or hardware. The 'unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, 'part' refers to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. Functions provided within components and 'units' may be combined into a smaller number of components and 'units' or further divided into additional components and 'units'.

In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

On the other hand, the 'user terminal' described in the present specification is a concept including a fixed terminal as well as a mobile terminal, and includes a desktop PC, a laptop computer, a slate PC, a tablet PC, an ultra Book (ultrabook), digital broadcasting terminal, PDA (personal digital assistants), PMP (portable multimedia player), navigation, mobile phone, smart phone (smart phone), wearable device (wearable device, for example, watch-type terminal (smartwatch) , a glass-type terminal (smart glass), a head mounted display (HMD), and the like.

The present invention proposes a data hiding method and apparatus capable of automatically detecting a file generated in a predetermined path of a user terminal and hiding it in another file. In addition, the present invention proposes a data hiding method and apparatus capable of automatically detecting an image file generated in a predetermined path of a user terminal and easily inserting the detected image file in the middle of a predetermined moving picture file to hide it. do.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

1 is a block diagram illustrating a configuration of a user terminal according to an embodiment of the present invention.

Referring to FIG. 1 , a user terminal 100 according to an embodiment of the present invention includes a communication unit 110 , an input unit 120 , an output unit 130 , a memory 140 , and a control unit 150 . The components shown in FIG. 1 are not essential for implementing the user terminal, so the user terminal described in this specification may have more or fewer components than those listed above.

The communication unit 110 includes a wired communication module for supporting a wired network and a wireless communication module for supporting a wireless network. The wired communication module is external on a wired communication network constructed according to technical standards or communication methods (eg, Ethernet, PLC (Power Line Communication), Home PNA, IEEE 1394, etc.) for wired communication. It transmits and receives a wired signal with at least one of the server and other terminals. The wireless communication module is a technology standard or communication method for wireless communication (eg, WLAN (Wireless LAN), Wi-Fi (Wireless-Fidelity), DLNA (Digital Living Network Alliance), GSM (Global System for Mobile communication) , CDMA (Code Division Multi Access), WCDMA (Wideband CDMA), LTE (Long Term Evolution), LTE-A (Long Term Evolution-Advanced), 5G, etc.) It transmits and receives a wireless signal to and from at least one.

The input unit 120 includes a camera for inputting an image signal, a microphone for inputting an audio signal, and a user input unit for receiving information from a user (eg, a keyboard, a mouse, a touch key, a push key) mechanical key), etc.) and the like.

The output unit (or the display unit, 130 ) displays (outputs) information processed by the user terminal 100 . For example, the output unit 130 may display execution screen information of an application program driven in the user terminal 100 or UI (User Interface) and GUI (Graphic User Interface) information according to the execution screen information. . In particular, in the present embodiment, the output unit may display a user interface screen related to data hiding and restoration.

The memory 140 stores data supporting various functions of the user terminal 100 . The memory 140 may store a plurality of application programs (or applications) driven in the user terminal 100 , data for operation of the user terminal 100 , and commands. In particular, in the present embodiment, the memory 140 may store a data hiding program for hiding and restoring a file generated in a predetermined path.

The memory 140 is a flash memory type, a hard disk type, a solid state disk type, an SDD type, a silicon disk drive type, and a multimedia card micro type. ), card-type memory (such as SD or XD memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read (EEPROM) -only memory), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, and an optical disk may include at least one type of storage medium.

The controller (or processor, 150 ) controls an operation related to an application program stored in the memory 140 and generally an overall operation of the user terminal 100 . Furthermore, in order to implement various embodiments described below on the user terminal 100 according to the present invention, the controller 150 may control by combining at least one of the components described above.

In particular, in this embodiment, the controller 150 may control the overall operation related to data hiding and restoration by driving the data hiding application stored in the memory 140 . For example, the control unit 150 may receive an input from the terminal user through the setting menu of the corresponding application, a path where a file requiring privacy protection (ie, a hidden target file) is generated. In addition, the controller 150 may perform a function of automatically detecting a file generated in a pre-specified path and hiding it in another file when the corresponding application is executed. In addition, the controller 150 may perform a function of restoring a file hidden in a specific file and displaying the restored file to a terminal user when the corresponding application is executed.

Meanwhile, the data hiding apparatus 200 to be described below may be implemented in hardware and/or software through the control unit 150 and the memory 140 constituting the user terminal 100 .

FIG. 2 is a block diagram illustrating a configuration of a data hiding device implemented in the user terminal of FIG. 1 .

Referring to FIG. 2 , the data hiding apparatus 200 according to an embodiment of the present invention includes a data generation monitoring unit 210 , a data hiding unit 220 , a hidden information generation unit 230 , and a data restoration unit 240 . includes The components shown in FIG. 2 are not essential for implementing the data hiding device, so the data hiding device described in this specification may have more or fewer components than those listed above.

The data generation monitoring unit 210 may monitor whether a new file is created in a path previously designated by the terminal user. Here, the file that is the target of data hiding (that is, the hidden target file) is any type of file that can be expressed in binary code, and is a text file, a database (DB) file, a document file, an audio file, an image file, and a moving picture. It may include files and the like.

For example, when a terminal user designates a path where a file requiring privacy protection is generated as a DCIM folder, the data generation monitoring unit 210 monitors whether a new file is created in the DCIM folder in real time.

The data hiding unit 220 is another file to hide a file generated in a predetermined path of the user terminal 100 (hereinafter, for convenience of explanation, referred to as a 'target file' or a 'dummy file'). ) to determine Here, the target file into which the hidden target file is inserted is also any type of file that can be expressed in binary, and may include a text file, a database (DB) file, a document file, an audio file, an image file, and a moving picture file.

The data hiding unit 220 may determine the target file according to the file selection command of the terminal user or randomly select any one of the files previously stored in the memory to determine the target file. Also, according to an embodiment, the data hiding unit 220 may copy the target file and store it in the memory. In this case, a file created in a specific path may be hidden (inserted) in the duplicate target file rather than the original target file.

The data hiding unit 220 may hide the target file generated in a predetermined path by inserting it at a point of the target file. In this case, the data hiding unit 220 may insert a header part and a tail part of the target file to be hidden into the middle part of the target file according to a predetermined rule. This is to make it difficult to decipher the signature information stored in the header or tail of the file to be hidden. The signature information is information indicating the type of the file to be hidden, for example, whether the file is a word file or an image file.

The hidden information generating unit 230 generates various hidden information such as existing path information of the target file to be hidden, hash value information of the corresponding file, and parameter information required for data hiding, when data is hidden, and the generation The hidden information may be stored in a predetermined memory. The secret information stored in the memory may be used to restore a file hidden in the target file later.

For example, the hidden information may include information on the number of hidden files, total size information of the hidden files, hash value information of each hidden file, path information of each hidden file, and the like. In addition, the hidden information includes index information indicating the number of the hidden file for each hidden file, Head_start information indicating the start point of the header part of the corresponding hidden file, and the end point of the header part of the corresponding hidden file. Head_end information indicating , Head_rule information indicating the bit combination method of the header part of the corresponding hidden file, Tail_start information indicating the start point of the tail part of the corresponding hidden file, Tail_end indicating the end point of the tail part of the corresponding hidden file information, and may include Tail_rule information indicating a bit combination method of the tail portion of the corresponding hidden file.

The data restoration unit 240 may restore the hidden file inserted into the target file according to the command of the terminal user. In this case, the data restoration unit 240 may restore the hidden file to its original state by using the hidden information stored in the memory. In addition, the data restoration unit 240 may automatically store the restored hidden file in a folder corresponding to a path previously designated by the terminal user. Accordingly, the terminal user can access the corresponding folder and check the restored hidden file.

As described above, the data hiding device 200 according to the present invention automatically detects a file generated in a predetermined path and hides it in a predetermined target file, thereby hacking and leaking sensitive personal information stored in the user terminal to the outside. can be effectively prevented.

3 is a flowchart illustrating a data hiding and restoration method according to an embodiment of the present invention.

Referring to FIG. 3 , the data hiding apparatus 200 according to an embodiment of the present invention may execute a data hiding application pre-installed in the user terminal in response to a user input.

The data hiding device 200 may display a predefined user interface (UI) screen on the display unit when a corresponding application is executed. The terminal user may use the setting menu of the UI screen to set in advance a path in which a file to be protected by privacy (ie, a file to be hidden) is generated ( S310 ). In addition, the terminal user may preset a target file into which a file to be hidden is to be inserted by using the setting menu of the corresponding UI screen.

When the path setting is completed, the data hiding device 200 may monitor whether a hidden target file is generated in the corresponding path (S320). Here, the hidden target file is any type of file that can be expressed in binary, and may include a text file, a database (DB) file, a document file, an audio file, an image file, and a moving picture file.

As a result of the monitoring, when a new target file to be hidden is generated in the corresponding path (S330), the data hiding device 200 may determine a target file into which the corresponding file is to be hidden (S340). Similarly, the target file is any type of file that can be expressed in binary, and may include a text file, a database (DB) file, a document file, an audio file, an image file, a video file, and the like.

The data hiding device 200 may hide the target file generated in the predetermined path by inserting it at a point of the target file ( S350 ). In this case, the data hiding apparatus 200 may insert the target file to be hidden into the middle part of the target file according to a predetermined rule using a predetermined data hiding algorithm. A more detailed description thereof will be described later with reference to FIGS. 4 to 9 .

The data hiding device 200 generates hidden information including information on the existing path of the file, hash value information of the file, parameter information required for data hiding, etc. when hiding the data of the file to be hidden, and stores it in a predetermined memory. It can be (S360).

Thereafter, when there is a request for restoring the hidden file from the terminal user (S370), the data hiding apparatus 200 may restore the hidden file inserted into the target file to its original state by using the secret information stored in the memory (S380). In addition, the data hiding device 200 may automatically store the restored hidden file in a folder corresponding to a path previously designated by the terminal user.

4 is a flowchart illustrating a data hiding algorithm according to an embodiment of the present invention, and FIGS. 5 to 9 are diagrams referenced to explain the data hiding algorithm according to an embodiment of the present invention. Hereinafter, in the present embodiment, for convenience of explanation, the target file to be hidden is an 'image file' and the target file is a 'video file'.

4 to 9 , the data hiding apparatus 200 according to an embodiment of the present invention may check whether a first file 510, which is a file to be hidden, is generated in a path previously designated by a terminal user. (S405). The first file 510 is an image file and may be expressed as a hexadecimal value or a binary value.

As a result of the check in step 405 , when the first file 510 is generated, the data hiding apparatus 200 may determine a target file 520 into which the first file 510 is to be inserted. Here, the target file 520 is a video file and may be expressed as a hexadecimal value or a binary value.

_{The data hiding apparatus 200 may determine a bit combination function a n} corresponding to the first file 510 when the first file is created ( S410 ). Here, the bit combination function (a _n ) is a function defining a rule for inserting the first file 510 at a point in another file. As the bit combination function (a _n ), a geometrical sequence function, an arithmetic sequence function, a progressive sequence, an exponentiation sequence, a Fibonacci sequence function, etc. may be used, but is not necessarily limited thereto.

The bit combination function may include a first bit combination function corresponding to the header portion of the first file 510 and a second bit combination function corresponding to the tail portion of the first file 510 . Here, the second bit combination function may be set to be the same as or set differently from the first bit combination function. Hereinafter, in this embodiment, the first bit combination function and the second bit combination function will be described by illustrating that they are different functions.

The data hiding device 200 may detect the binary code corresponding to the header part of the first file 510, the binary code corresponding to the tail part, and the binary code corresponding to the middle part between the header part and the tail part, respectively. There is (S415).

The data hiding device 200 may check whether a hidden second file exists in the target file 520 ( S420 ). The second file is the same image file as the first file, and may be expressed as a hexadecimal value or a binary value.

As a result of the check in step 420 , when the second file hidden in the target file 520 does not exist, the data hiding device 200 corresponds to the header portion of the first file 510 using the first bit combination function. binary code may be inserted between bitstreams starting at a predetermined point of the target file 520 ( S425 ). Here, the predetermined point may be a midpoint, a 1/3 point, or a 2/3 point of the target file 520 , but is not limited thereto.

)가

이고, 타겟 파일의 미리 결정된 지점이 P(=1/2) 지점인 경우, 데이터 은닉 장치(200)는 제1 파일(510)의 헤더 부분에 존재하는 비트들을 타겟 파일(520)의 P 지점에서 시작하는 비트스트림(bitstream) 중 n+1번째 비트의 다음 위치에 순차적으로 삽입할 수 있다. 좀 더 구체적으로, 데이터 은닉 장치(200)는 제1 파일(510)의 헤더 부분에 존재하는 첫 번째 비트("0")를 타겟 파일(520)의 P 지점에서 시작하는 비트스트림 중 두 번째 비트("1") 다음 위치에 삽입할 수 있다. 그리고, 데이터 은닉 장치(200)는 제1 파일(510)의 헤더 부분에 존재하는 두 번째 비트("1")를 타겟 파일(520)의 P 지점에서 시작하는 비트스트림 중 세 번째 비트("1") 다음 위치에 삽입할 수 있다. 데이터 은닉 장치(200)는 이와 같은 동작을 반복하여 제1 파일(510)의 헤더 부분에 존재하는 모든 비트들을 타겟 파일(520)의 P 지점에서 시작하는 비트스트림 사이에 순차적으로 삽입하게 된다.For example, as shown in FIGS. 6 and 8, the first bit combination function (

)go

, and when the predetermined point of the target file is the point P (=1/2), the data hiding device 200 converts the bits present in the header part of the first file 510 to the point P of the target file 520 . It can be sequentially inserted at the position following the n+1th bit among the starting bitstreams. More specifically, the data hiding device 200 converts the first bit (“0”) present in the header part of the first file 510 to the second bit of the bitstream starting at the P point of the target file 520 . ("1") can be inserted at the following position. Then, the data hiding device 200 converts the second bit (“1”) present in the header part of the first file 510 to the third bit (“1”) of the bitstream starting at the point P of the target file 520 . ") can be inserted in the following positions. The data hiding device 200 repeats this operation to sequentially insert all bits present in the header portion of the first file 510 between bitstreams starting at the P point of the target file 520 .

Upon completion of bit insertion into the header portion of the first file 510 , the data hiding device 200 converts bits existing in the middle portion of the first file 510 to bits existing in the header portion of the first file 510 . Among them, the last bit may be inserted as it is after the insertion point (S440). For example, as shown in FIG. 8 , the data hiding device 200 converts the bits present in the middle part of the first file 510 to the last bit among the bits present in the first part 520a of the target file 520 . It may be inserted between the bit and the first bit among the bits existing in the second part 520b of the target file 520 as it is.

Upon completion of bit insertion into the middle portion of the first file 510 , the data hiding device 200 converts the binary code corresponding to the tail of the first file 510 to the target file 520 using the second bit combination function. ) may be inserted between bitstreams starting at a point (S445).

)가

인 경우, 데이터 은닉 장치(200)는 제1 파일(510)의 테일 부분에 존재하는 비트들을 타겟 파일(520)의 Q 지점에서 시작하는 비트스트림(bitstream) 중 2n번째 비트의 다음 위치에 순차적으로 삽입할 수 있다. 여기서, 타겟 파일(520)의 Q 지점은 제1 파일(510)의 중간 부분에 존재하는 비트들 중 마지막 비트 다음에 위치하는 타겟 파일의 일 지점에 대응한다. 좀 더 구체적으로, 데이터 은닉 장치(200)는 제1 파일(510)의 테일 부분에 존재하는 첫 번째 비트("1")를 타겟 파일(520)의 Q 지점에서 시작하는 비트스트림 중 두 번째 비트("1") 다음 위치에 삽입할 수 있다. 그리고, 데이터 은닉 장치(200)는 제1 파일(510)의 테일 부분에 존재하는 두 번째 비트("1")를 타겟 파일(520)의 Q 지점에서 시작하는 비트스트림 중 네 번째 비트("0") 다음 위치에 삽입할 수 있다. 데이터 은닉 장치(200)는 이와 같은 동작을 반복하여 제1 파일(510)의 테일 부분에 존재하는 모든 비트들을 타겟 파일(520)의 Q 지점에서 시작하는 비트스트림 사이에 순차적으로 삽입하게 된다.For example, as shown in FIGS. 7 and 8, the second bit combination function (

)go

In the case of , the data hiding device 200 sequentially transfers bits present in the tail portion of the first file 510 to the position next to the 2n-th bit among the bitstream starting at the Q point of the target file 520 . can be inserted. Here, the Q point of the target file 520 corresponds to a point of the target file located after the last bit among bits existing in the middle of the first file 510 . More specifically, the data hiding device 200 converts the first bit (“1”) present in the tail portion of the first file 510 to the second bit of the bitstream starting at the Q point of the target file 520 . ("1") can be inserted at the following position. In addition, the data hiding device 200 converts the second bit (“1”) present in the tail of the first file 510 to the fourth bit (“0”) of the bitstream starting at the Q point of the target file 520 . ") can be inserted in the following positions. The data hiding device 200 repeats this operation to sequentially insert all bits present in the tail portion of the first file 510 between bitstreams starting at the Q point of the target file 520 .

Meanwhile, as a result of checking in step 420 , if the second file hidden in the target file 520 exists, the data hiding device 200 restores the tail portion of the second file using the hidden information pre-stored in the memory. can be (S430). If there are a plurality of files hidden in the target file 520 , the second file to be bit restored is the last hidden file among the plurality of files hidden in the target file 520 .

)가

인 경우, 데이터 은닉 장치(200)는 제1 파일(510)의 헤더 부분에 존재하는 비트들을 가장 최근에 은닉된 파일(530)의 복원된 테일 부분에 해당하는 비트스트림 중 n+1번째 비트의 다음 위치에 순차적으로 삽입할 수 있다. Upon completion of bit restoration for the tail portion of the second file, the data hiding device 200 converts the binary code corresponding to the header portion of the first file 510 to the restored tail of the second file using the first bit combination function. It can be inserted between bitstreams corresponding to the portions (S435). For example, as shown in FIG. 9, the first bit combination function (

)go

In the case of , the data hiding device 200 converts the bits present in the header part of the first file 510 to the n+1th bit of the bitstream corresponding to the restored tail part of the most recently hidden file 530 . They can be inserted sequentially in the following positions.

When the second file hidden in the target file 520 exists, the bit insertion process for the middle part and the tail part of the first file 510 is the same as the above-described steps 440 and 445 , so a detailed description thereof will be omitted. let it do

Upon completion of data hiding of the first file, the data hiding apparatus 200 may update secret information previously stored in the memory or may generate secret information related to the first file. For example, the hidden information includes information on the number of hidden files inserted into the target file, total size information of the hidden files, hash value information of each hidden file, path information of each hidden file, and the number of hidden files in each hidden file. Index information indicating recognition, Head_start information indicating the start point of the header part of each hidden file, Head_end information indicating the end point of the header part of each hidden file, bit combination method of the header part of each hidden file (that is, Head_rule information indicating the bit combination function), Tail_start information indicating the start point of the tail part of each hidden file, Tail_end information indicating the end point of the tail part of each hidden file, bit combination method of the tail part of each hidden file may include Tail_rule information indicating

Meanwhile, in the present embodiment, it is exemplified that the header and tail parts of the target file to be hidden are inserted into the target file according to a predetermined bit combination method, but the present invention is not limited thereto. Accordingly, it will be apparent to those skilled in the art that only one of the header and the tail portion of the file to be hidden can be inserted into the target file according to a predetermined bit combination method. In addition, it will be apparent to those skilled in the art that not only the header and tail parts of the hidden target file but also the middle part may be inserted into the target file according to a predetermined bit combination method.

The present invention described above can be implemented as computer-readable code on a medium in which a program is recorded. The computer-readable medium may continuously store a computer-executable program, or may be temporarily stored for execution or download. In addition, the medium may be various recording means or storage means in the form of a single or several hardware combined, it is not limited to a medium directly connected to any computer system, and may exist distributed on a network. Examples of the medium include a hard disk, a magnetic medium such as a floppy disk and a magnetic tape, an optical recording medium such as CD-ROM and DVD, a magneto-optical medium such as a floppy disk, and those configured to store program instructions, including ROM, RAM, flash memory, and the like. In addition, examples of other media may include recording media or storage media managed by an app store that distributes applications, sites that supply or distribute various other software, and servers. Accordingly, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

200: data hiding device 210: data generation monitoring unit
220: data hiding unit 230: hidden information generating unit
240: data restoration unit

Claims (10)

monitoring whether a first file is generated in a path predetermined by a terminal user;
determining a target file in which to hide the first file when the generation of the first file is detected;
hiding the first file in the target file using a bit combination function corresponding to the first file; and
Data hiding method in a user terminal comprising the step of generating secret information for restoring the first file hidden in the target file. According to claim 1,
The data hiding method in a user terminal, characterized in that the first file and the target file are any one of a text file, a database (DB) file, a document file, an audio file, an image file, and a video file. According to claim 1,
The hidden information includes at least one of existing path information, hash value information, index information, Head_start information, Head_end information, Head_rule information, Tail_start information, Tail_end information, and Tail_rule information of the first file User terminal, characterized in that it includes data hiding methods in According to claim 1,
The data hiding method in the user terminal, characterized in that the bit combination function is a function defining a rule for inserting the first file in the middle of the target file. 5. The method of claim 4,
The bit combination function is a data hiding method in a user terminal, characterized in that any one of a geometric sequence function, an arithmetic sequence function, a progressive sequence function, an exponentiation sequence function, and a Fibonacci sequence function. According to claim 1,
The bit combination function includes a first bit combination function corresponding to a header portion of the first file and a second bit combination function corresponding to a tail portion of the first file. Data hiding method in the terminal. According to claim 6, wherein the hiding step,
sequentially inserting bits existing in a header portion of the first file between bitstreams starting at a first point of the target file using the first bit combination function; and
and sequentially inserting bits existing in the tail portion of the first file between bitstreams starting at a second point of the target file by using the second bit combination function. data hiding method. According to claim 6, wherein the hiding step,
restoring a tail portion of the second file when the second file is hidden in the target file; and
and sequentially inserting bits existing in the header part of the first file between bitstreams corresponding to the restored tail part of the second file using the first bit combination function. Data hiding method in the terminal. A computer program stored in a computer-readable recording medium so that the method according to any one of claims 1 to 9 is executed on a computer. a data generation monitoring unit for monitoring whether the first file is generated in a predetermined path;
When the generation of the first file is detected, a target file to hide the first file and a bit combination function corresponding to the first file are determined, and the first file is stored in the target file by using the determined bit combination function. a data hiding unit to be hidden; and
and a secret information generator for generating secret information for restoring the first file hidden in the target file.

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