Intelligence protection device

Abstract

To provide an information protection device capable of suitably protecting predetermined information contained in a data file even if the data file is leaked. [Solution] The information protection device 300 disclosed herein is a device that protects information by converting an important character string containing predetermined information into a random character string, and includes a processor 303 that executes arithmetic processing, and a storage device 302 that stores data used by the processor 303. The storage device 302 stores a shift pattern for shifting characters included in the important character string, and a conversion table and conversion pattern for randomly changing one digit of the hexadecimal number for a conversion target obtained by converting the character string shifted by the shift processing into a hexadecimal number, and the processor 303 converts the important character string into a random character string by executing a conversion process for the conversion target based on the conversion table and the conversion pattern.

Description

[Technical Field]

[0001] The present invention relates to an information protection device that protects information by converting a sensitive character string containing predetermined information into a random character string. [Background technology]

[0002] Conventionally, organizations such as companies have encrypted data containing confidential information, such as the private information of individuals belonging to the organization and information on customers and business partners, in order to prevent such information from leaking to the outside.

[0003] Furthermore, a technique has been proposed for generating hidden text that does not reveal the fact that it is hiding confidential information.

[0004] For example, Patent Document 1 discloses an information hiding system that converts ASCII characters (search string for replacement) sandwiched between characters related to confidential information into half-width characters, converts ASCII characters (search string for non-replacement) sandwiched between characters not related to confidential information into full-width characters, and generates hidden text for a character string of target text by converting between half-width and full-width characters. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-198816 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the technology described in Patent Document 1, an information hiding device on the sender side can generate hidden text that does not reveal the fact that secret information is being hidden by minimizing changes to the cover text through conversion between half-width characters and full-width characters. By making it impossible to detect the fact that secret information is being hidden, it seems possible to protect the information contained in the electronic data against leakage.

[0007] However, with the technology described in Patent Document 1, if the fact that confidential information is being concealed is discovered, the information can be restored relatively easily, which may result in a security problem against leakage of electronic data.There is still room for improvement in the technology for improving security against leakage of electronic data.

[0008] An object of the present disclosure is to provide an information protection device that can suitably protect a data file containing predetermined information even if the data file is leaked. [Means for solving the problem]

[0009] The information protection device disclosed herein protects information by converting a sensitive character string containing predetermined information into a random character string. The information protection device includes a processor that performs arithmetic processing and a storage device that stores data used by the processor. The storage device stores a shift pattern for shifting characters included in the sensitive character string, and a conversion table and conversion pattern for randomly changing one hexadecimal digit of a conversion target obtained by converting the shifted character string into a hexadecimal number. The processor converts the sensitive character string into the random character string by performing a conversion process on the conversion target based on the conversion table and the conversion pattern.

[0010] According to the information protection device, even if a data file containing sensitive character strings representing private information is leaked, the sensitive character strings are converted into random character strings, making it impossible to identify an individual from the data file. Therefore, private information that could identify an individual is protected. In other words, for a data file containing specified information, the information can be suitably protected even if the data file is leaked.

[0011] In the above information protection device, the processor may, in the conversion process, divide the conversion object into bytes, perform a first conversion on the first four bits of each byte based on the conversion table and the conversion pattern, divide the conversion object converted by the first conversion into bytes, perform a second conversion on the last four bits of each byte based on the conversion table and the conversion pattern, and convert the conversion object converted by the second conversion into characters, thereby converting the important character string into the random character string. This makes it more difficult to restore the random character string converted by the above conversion process to the original important character string, thereby making it possible to suitably protect the original information.

[0012] In this case, the processor may convert the important character string into the random character string by excluding predetermined characters. By doing so, by converting characters within a specific range rather than all characters being converted, it is possible to make it difficult to use the characters as information.

[0013] In the information protection device of the present disclosure, the processor may select from the plurality of shift patterns, the plurality of conversion tables, and the plurality of conversion patterns stored in the storage device those that correspond to a numerical value calculated based on a predetermined formula, and perform the shift processing and the conversion processing. This makes it possible to perform the conversion more randomly while maintaining a predetermined regularity.

[0014] In addition, the information protection device disclosed herein may further include a network interface board for connecting to a network, and when sending and receiving the information between different terminals, the processor may also send and receive a specified stamp number via the network interface board, thereby enabling the restoration of the information. [Effects of the Invention]

[0015] According to the present disclosure, for a data file containing predetermined information, even if the data file is leaked, the information can be suitably protected. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a schematic configuration of an information protection system according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing in more detail the components of a server included in the information protection system according to the first embodiment, and also showing the components of a user terminal that communicates with the server. [Figure 3] FIG. 2 is a diagram illustrating an example of the flow of operations of the information protection system in the first embodiment. [Figure 4] FIG. 3 is a diagram illustrating an example of a shift pattern in the first embodiment. [Figure 5] 3A to 3C are diagrams illustrating examples of conversion tables and conversion patterns used in the conversion process in the first embodiment. [Figure 6] FIG. 11 is a diagram illustrating restoration of information when predetermined information such as private information or confidential information is transmitted and received between different user terminals in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The configurations of the following embodiments are examples, and the present disclosure is not limited to the configurations of the embodiments.

[0018] First Embodiment An overview of the information protection system according to the first embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram showing a schematic configuration of the information protection system according to this embodiment. The information protection system 100 according to this embodiment includes a network 200, a server 300, and a user terminal 400. The information protection system disclosed herein is a system that protects important character strings containing predetermined information by converting the information into random character strings, and the process for protecting the information is executed by the server 300. The above information is confidential information such as the privacy information of individuals belonging to an organization such as a company, and customer / business partner information.

[0019] Network 200 is, for example, an IP network. As long as network 200 is an IP network, it may be wireless, wired, or a combination of wireless and wired. For example, in the case of wireless communication, user terminal 400 may access a wireless LAN access point (not shown) and communicate with server 300 via a LAN or WAN. Furthermore, network 200 is not limited to these examples and may be, for example, a public switched telephone network, an optical fiber line, an ADSL line, a satellite communication network, etc.

[0020] Server 300 is connected to user terminal 400 via network 200. Here, server 300 and user terminal 400 connected via network 200 constitute an information system in an organization such as a company, and personnel belonging to the organization use user terminal 400, and information input using user terminal 400 can be centrally managed by server 300. Note that, for the sake of simplicity, one server 300 and four user terminals 400 are shown in FIG. 1, but it goes without saying that the number is not limited to this.

[0021] Server 300 may be any electronic device having the processing power for arithmetic and processing operations such as data acquisition, generation, and updating, including personal computers, servers, mainframes, and other electronic devices. That is, server 300 may be configured as a computer having a processor such as a CPU or GPU, a main memory such as RAM or ROM, and an auxiliary memory such as an EPROM, a hard disk drive, or removable media. The removable media may be, for example, a USB memory or a disk recording medium such as a CD or DVD. The auxiliary memory stores an operating system (OS), various programs, various tables, and the like.

[0022] Furthermore, the server 300 may appropriately use SaaS (Software as a Service), Paas (Platform as a Service), or IaaS (Infrastructure as a Service) using a cloud server, without providing software, hardware, an OS, etc., dedicated to the information protection system 100 of this embodiment.

[0023] The user terminal 400 may be any electronic device such as a mobile terminal owned by a user who uses the information protection system 100, and may be, for example, a mobile terminal, a tablet terminal, a smartphone, a wearable terminal, a personal computer, or other terminal device.

[0024] Next, the components of the server 300 will be mainly described in detail with reference to Fig. 2. Fig. 2 shows the components of the server 300 included in the information protection system 100 in more detail in the first embodiment, as well as the components of the user terminal 400 that communicates with the server 300.

[0025] The server 300 has, as functional units, a communication unit 301, a storage unit 302, and a control unit 303. The server 300 loads a program stored in an auxiliary storage device into a working area of ​​a main storage device and executes it. The execution of the program controls each functional unit, thereby realizing each function that matches the predetermined purpose of each functional unit. However, some or all of the functions may be realized by hardware circuits such as ASICs and FPGAs.

[0026] Here, the communication unit 301 is a communication interface for connecting the server 300 to the network 200. The communication unit 301 is configured to include, for example, a network interface board and a wireless communication circuit for wireless communication. The server 300 is connected to the user terminal 400 and other external devices via the communication unit 301 so as to be able to communicate with them.

[0027] The storage unit 302 is configured to include a main storage unit and an auxiliary storage unit. The main storage unit is a memory in which programs executed by the control unit 303 and data used by the control programs are developed. The auxiliary storage unit is a device in which programs executed by the control unit 303 and data used by the control programs are stored. The storage unit 302 stores shift patterns, conversion tables, and conversion patterns, which will be described later. The storage unit 302 may also store data transmitted from the user terminal 400 or the like. The server 300 can acquire data transmitted from the user terminal 400 or the like via the communication unit 301.

[0028] The control unit 303 is a functional unit that controls the server 300. The control unit 303 can be realized by an arithmetic processing unit such as a CPU. The control unit 303 further includes three functional units: an acquisition unit 3031, a shift processing unit 3032, and a conversion processing unit 3033. Each functional unit may be realized by the CPU executing a stored program.

[0029] The acquisition unit 3031 acquires a data file including confidential information such as the privacy information of individuals belonging to an organization such as a company, customer business partner information, etc. Here, the acquisition unit 3031 acquires a data file input to the user terminal 400 and transmitted from the user terminal 400, and stores the data file in the storage unit 302.

[0030] Here, the user terminal 400 in this embodiment has, as functional units, a communication unit 401, an input / output unit 402, and a storage unit 403. The communication unit 401 is a communication interface for connecting the user terminal 400 to the network 200, and is configured to include, for example, a network interface board and a wireless communication circuit for wireless communication. The input / output unit 402 is a functional unit for displaying information transmitted from the outside via the communication unit 401, and for inputting information when transmitting the information to the outside via the communication unit 401. The storage unit 403 is configured to include a main storage device and an auxiliary storage device, similar to the storage unit 302 of the server 300.

[0031] The input / output unit 402 further includes a display unit 4021, an operation input unit 4022, and an image / audio input / output unit 4023. The display unit 4021 has a function of displaying various information and is realized, for example, by an LCD (Liquid Crystal Display) display, an LED (Light Emitting Diode) display, an OLED (Organic Light Emitting Diode) display, or the like. The operation input unit 4022 has a function of accepting operation input from a user and is realized, specifically, by soft keys or hard keys on a touch panel or the like. The image / audio input / output unit 4023 has a function of accepting input of images such as still images and videos and is realized, specifically, by a camera using an image sensor such as a Charged-Coupled Device (CCD), a Metal-Oxide-Semiconductor (MOS), or a Complementary Metal-Oxide-Semiconductor (CMOS). The image / audio input / output unit 4023 has a function of accepting input and output of audio and is realized, specifically, by a microphone or speaker.

[0032] Then, a user of the information protection system 100 can create the above-mentioned data file using the user terminal 400 configured in this way and transmit it to the server 300.

[0033] The shift processing unit 3032 executes a shift process to shift characters included in an important character string including predetermined information such as private information, confidential information, etc. Details of the process executed by the shift processing unit 3032 will be described later with reference to FIG.

[0034] The conversion processing unit 3033 performs conversion processing on the conversion target, which is the character string shifted by the shift processing and converted into a hexadecimal number, based on the conversion table and conversion pattern. Details of the processing performed by the conversion processing unit 3033 will be described later with reference to FIG. 3.

[0035] Here, the flow of operations of the information protection system 100 in this embodiment will be described. Fig. 3 is a diagram illustrating the flow of operations of the information protection system 100 in this embodiment. Fig. 3 explains the flow of operations between the server 300 and the user terminal 400 in the information protection system 100 in this embodiment, and the processing executed by the server 300 and the user terminal 400.

[0036] In this embodiment, first, a data file is input to the user terminal 400 (S101). The data file in this flow is an Excel file containing private information of individuals belonging to a company. Then, the data file is transmitted from the user terminal 400 to the server 300 by an information system in the company.

[0037] Then, the server 300 acquires the data file transmitted from the user terminal 400 (S102), and extracts important character strings representing private information from the data file (S103).

[0038] Next, the server 300 executes a process of setting variables to be used in the shift process and the conversion process (S104). In this embodiment, the variables are mask variables and character string variables.

[0039] The mask variable may be set based on a predetermined stamp number. Here, the stamp number is determined by a timestamp when the information protection system 100 is installed. For example, if the timestamp at the time of installation is yyyymmddhhmmss (2025 (year) 06 (month) 07 (day) 11 (hour) 02 (minute) 11 (second)), the last two digits of yyyy are defined as YY, mmdd as the total number of days from the first day of the year as DDD, and hhmmss as the total number of seconds from midnight as SSSSS. By defining this, the stamp number is determined as 1582539731, which is obtained by DDD(158)YY(25)SSSSS(39731). Furthermore, the mask variable is set by the last three digits of the calculated value of DDD+YY0+SSSSS. In the above example, the mask variable may be set to 139, which is the last three digits of DDD+YY0+SSSSS=158+250+39731=40139.

[0040] Furthermore, the string variable may be set to the value obtained by converting the second character of the important string (if it is half-width characters) or the first character (if it is full-width characters) into hexadecimal based on Shift-JIS and expressing the last four bits in decimal. For example, if the important string is the name "Tokyo Kazuo," the string variable would be "12," which is the decimal representation of the last four bits "C" of "938C," which is obtained by converting the first character "Higashi" of "Tokyo Kazuo" into hexadecimal based on Shift-JIS.

[0041] Then, the server 300 determines a shift pattern based on the variables set in the process of S104, and executes shift processing based on the shift pattern (S105). Here, the shift pattern used is, for example, a pattern corresponding to the number calculated by (H+M3+0.9) / 2.8, rounded up to the nearest whole number. Note that H above is the value of the string variable, and M3 above is the value of the third digit of the mask variable.

[0042] FIG. 4 is a diagram illustrating shift patterns in this embodiment. As shown in FIG. 4, this embodiment has nine shift patterns, and characters are swapped using each pattern according to the number of characters in the important character string. For example, if the important character string is the name "Tokyo Kazuo," the character string variable H is 12, and the mask variable is 139, the value M3 of the third digit of the mask variable is 9. Therefore, (H+M3+0.9) / 2.8=(12+9+0.9) / 2.8≒8, and the shift pattern is determined to be 8. In this case, according to FIG. 4, the first, second, third, and fourth characters of the pre-shift character string are swapped with the second, fourth, first, and third characters.

[0043] The above shifting process may be performed excluding certain characters. In this embodiment, the excluded character is the second character if the important character string is half-width characters, and the first character if the important character string is full-width characters. For example, if the important character string is a person's name "Tokyo Kazuo," the first character "Higashi" is excluded, and for "Kyo_Kazuo" (_ represents a space), the first, second, third, and fourth characters are swapped to the second, fourth, first, and third characters through the shifting process. In other words, in the shifting process based on the above shift pattern, "Tokyo_Kazuo" is shifted to "Higashi_O Kyoichi."

[0044] 3, the server 300 converts the character string shifted in the process of S105 into a hexadecimal number (S106).The server 300 then executes a conversion process based on the conversion table and conversion pattern for the conversion target converted into a hexadecimal number (S107).

[0045] 5A and 5B are diagrams illustrating conversion tables and conversion patterns used in the conversion process of this embodiment, with FIG. 5A showing the conversion table and conversion pattern used in the first conversion described later, and FIG. 5B showing the conversion table and conversion pattern used in the second conversion described later. The conversion table is determined, for example, by rounding up the decimal point of the numerical value calculated by (H+M1+0.9) / 2.8. Note that H above is the value of the string variable, and M1 above is the value of the first digit of the mask variable. The conversion pattern is determined, for example, by rounding up the decimal point of the numerical value calculated by (H+M2+0.9) / 2.8. Note that H above is the value of the string variable, and M2 above is the value of the second digit of the mask variable.

[0046] The conversion process using such a conversion table and conversion pattern will be explained using an example in which the important character string is a person's name "Tokyo Kazuo."

[0047] As described above, the shift process shifts the important character string "Tokyo Kazuo" to "Higashi_o Kyoichi," which is converted to hexadecimal as "938C8140926A8B9E88EA." For this conversion object "938C8140926A8B9E88EA," the first conversion separates the conversion object into bytes, and converts the first four bits of each byte based on a conversion table and a conversion pattern. Then, the second conversion separates the conversion object converted by the first conversion into bytes, and converts the last four bits of each byte based on a conversion table and a conversion pattern.

[0048] For example, when the conversion table is 1 and the conversion pattern is 1, that is, when pattern 1 of conversion table 1 in Fig. 5 is used, the conversion target "938C8140926A8B9E88EA" is converted to "939C8140927A8BAE88FA" by the first conversion. Furthermore, "939C8140927A8BAE88FA" is converted to "939C814092798BAD88F9" by the second conversion.

[0049] In this way, in this embodiment, from among a plurality of shift patterns, a plurality of conversion tables, and a plurality of conversion patterns, one that corresponds to a numerical value calculated based on a predetermined formula is selected, and the shift processing and conversion processing are performed.

[0050] Returning to FIG. 3, the server 300 then generates a random character string (S108). In the process of S108, the result of the conversion process in S107 is subjected to character conversion based on Shift-JIS, thereby generating a random character string. In this embodiment, the original important character string "Tokyo Kazuo" is converted into the random character string "Sugar Chi Strong Drink" by converting "939C814092798BAD88F9".

[0051] As a result, even if a data file is leaked from the server 300, it is not possible to identify an individual from the data file, and therefore privacy information that could identify an individual is protected.

[0052] According to the information protection system 100 described above, even if a data file containing privacy information to be protected is leaked, the privacy information can be suitably protected.

[0053] Second Embodiment The second embodiment will be described with reference to Fig. 6. In the first embodiment described above, an example was described in which personnel belonging to an organization such as a company use user terminals 400, and information entered using the user terminals 400 is centrally managed by the server 300. In contrast, in this embodiment, an example will be described in which, when predetermined information such as private information or confidential information is sent and received between different user terminals 400, the stamp number described in the first embodiment is also sent and received, thereby enabling information restoration.

[0054] FIG. 6 is a diagram for explaining restoration of information when predetermined information such as private information or confidential information is transmitted and received between different user terminals 400 in this embodiment.

[0055] In the example shown in Figure 6, an application having the functions of the information protection device of the present disclosure is installed as individual app A on one user terminal 400, and an application having the functions of the information protection device of the present disclosure is installed as individual app B on the other user terminal 400.

[0056] Then, based on the time when individual app A was installed, stamp number "1582539731" is linked to one user terminal 400, and based on the time when individual app B was installed, stamp number "2582639102" is linked to the other user terminal 400.

[0057] In this case, assuming that the important character string, telephone number "03-6665-0221", is converted into the random character string "ODEED--OAA" by the process described in the first embodiment above on a user terminal 400 on which individual application A is installed, the same stamp number "1582539731" is held on the same user terminal 400. In other words, the variables used in the shift process and conversion process described in the first embodiment above are the same when the important character string is converted and restored. Therefore, the random character string "ODEED--OAA" is successfully restored to "03-6665-0221" on the same user terminal 400.

[0058] On the other hand, in user terminal 400 on which individual app B is installed, the stamp number "2582639102" linked to that user terminal 400 is different from the stamp number "1582539731" used when the important character string was converted. Therefore, if the random character string "ODEED--OAA" is restored using stamp number "2582639102," the result will be "96-333h-4970," which will not be restored correctly.

[0059] In contrast, when specific information such as private information or confidential information is sent and received between different user terminals 400, the stamp number used during conversion is also sent and received. This makes it possible to restore the important character string correctly even on a user terminal 400 on which individual app B is installed, by restoring it using the stamp number "1582539731."

[0060] As a result of the above, even if a data file containing privacy information to be protected is leaked, the privacy information can be protected in an appropriate manner.

[0061] <Other variations> The above-described embodiment is merely an example, and the present disclosure may be modified as appropriate within the scope of the present disclosure. For example, the processes and means described in the present disclosure may be freely combined and implemented as long as no technical contradiction occurs.

[0062] Furthermore, a process described as being performed by one device may be shared and executed by multiple devices. In this case, these arithmetic processing devices are configured to be able to cooperate with each other. Furthermore, a process described as being performed by different devices may be executed by a single device. In a computer system, the hardware configuration (server configuration) by which each function is realized can be flexibly changed.

[0063] The present disclosure can also be realized by providing a computer program implementing the functions described in the above embodiments to a computer, and having one or more processors in the computer read and execute the program. Such a computer program may be provided to the computer via a non-transitory computer-readable storage medium connectable to the computer's system bus or via a network. Non-transitory computer-readable storage media include, for example, any type of disk, such as a magnetic disk (e.g., a floppy disk, a hard disk drive (HDD), etc.), an optical disk (e.g., a CD-ROM, a DVD disk, a Blu-ray disk), a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic card, a flash memory, an optical card, or any type of medium suitable for storing electronic instructions. [Explanation of symbols]

[0064] 100···Information Protection System 200···Network 300 Server 301···Communications Department 302...Storage section 303 Control section 400 User terminal

Claims

1. An information protection device that protects information by converting a sensitive character string containing predetermined information into a random character string, A processor that executes arithmetic processing and a storage device that stores data used by the processor, the storage device stores a shift pattern for shifting characters included in the important character string, and a conversion table and a conversion pattern for randomly changing one digit of a hexadecimal number for a conversion target obtained by converting the character string shifted by the shift process into a hexadecimal number; the processor converts the important character string into the random character string by executing a conversion process on the conversion target based on the conversion table and the conversion pattern; Information protection equipment.

2. In the conversion process, the processor Dividing the conversion object into bytes, and performing a first conversion on the first four bits of each byte based on the conversion table and the conversion pattern; The conversion object converted by the first conversion is divided into byte units, and the last 4 bits of each byte are subjected to a second conversion based on the conversion table and the conversion pattern; converting the conversion target converted by the second conversion into a character string to convert the important character string into the random character string; The information protection device according to claim 1 .

3. The processor: When converting the important character string into the random character string, predetermined characters are excluded from the conversion. The information protection device according to claim 2 .

4. The processor: selecting, from among the plurality of shift patterns, the plurality of conversion tables, and the plurality of conversion patterns stored in the storage device, those that correspond to a numerical value calculated based on a predetermined mathematical formula, and executing the shift processing and the conversion processing; The information protection device according to claim 1 .

5. a network interface board for connecting to a network; When transmitting and receiving the information between different terminals, the processor also transmits and receives a predetermined stamp number via the network interface board, thereby enabling the information to be restored. The information protection device according to claim 1 .

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