JP5372051B2 - File management apparatus, file management method and program - Google Patents

Description

  The present invention relates to a file management apparatus, a file management method, and a program.

  In recent years, a large number of files are managed in computers. The update date and time may be referred to in determining whether the contents of the file have not been changed. For example, in the system described in Patent Document 1, it is described that the control operation is changed when the update dates and times do not match.

JP 2002-297439 A

  However, the update date and time of a file can be easily updated in a general computer, but verification that the update date and time has not been falsified has been rarely performed.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a file management apparatus, a file management method, and a program capable of easily grasping the falsification of the update date and time of a file.

A main invention of the present invention for solving the above problems is an apparatus for managing a file, a file storage unit for storing the file, an update date acquisition unit for acquiring an update date of the file, and the update date and time. a key storage unit for storing a different second key is the first key and the first key for encrypting the first and encrypts the update time in the first and second key An update date / time encryption processing unit for generating a second encryption update date / time, an update date / time setting unit for setting the first encryption update date / time in the file together with the update date / time, and the second encryption update date / time. And a password setting unit for setting the file as a password for opening the file .

  The setting of the update date / time and encryption update date / time to the file is, for example, attached to the file as a file attribute, written as a property (attribute) included in the file, or another storage area associated with the file (for example, a file This can be realized by writing to another node of the system.

  According to the file management apparatus of the present invention, in addition to the update date and time, the encrypted update date and time can be set in the file. Therefore, it is possible to easily detect falsification of the update date / time by comparing the encrypted update date / time using the same key with the encrypted update date / time set in the file.

Further, the file management apparatus of the present invention includes an attribute acquisition unit that acquires the update date and time and the encryption update date and time set in the file, and a decryption update date and time obtained by decrypting the encryption update date and time with the key. You may make it provide the update date decoding process part to produce | generate and the update date comparison part which compares the said update date and the said decoding update date.
In this case, it is possible to easily detect falsification of the update date and time by decrypting the encrypted update date and comparing it with the update date and time.

  In the file management apparatus of the present invention, the key includes a secret key and a public key by a public key encryption method, and the update date / time encryption processing unit uses the secret key included in the key to perform the encryption update. The update date / time decryption processing unit may generate the decryption update date / time using the public key included in the key.

  The file management apparatus of the present invention includes an attribute acquisition unit that acquires the update date and time and the first encrypted update date and time set in the file, and decrypts the encrypted update date and time with the first key. An update date / time decryption processing unit for generating the decrypted update date / time, a password generation unit for generating the password by encrypting the acquired update date / time with the second key, the acquired update date / time and the first You may make it provide the update date comparison part which compares a decryption update date, and the password output part which outputs the said password.

  The file management apparatus of the present invention may further include a password release unit that opens the file using the password generated by the password generation unit.

  In the file management device of the present invention, the key storage unit further stores a creation date / time key for encrypting the creation date / time of the file, and a creation date / time acquisition unit that acquires the creation date / time; and the creation date / time A creation date / time encryption processing unit that encrypts the file with the creation date / time key to generate an encryption creation date / time, and a creation date / time setting unit that sets the encryption creation date / time in the file together with the creation date / time. May be.

  In the file management apparatus of the present invention, the update date and time and the encrypted update date and time may be set as property information included in the file.

According to another aspect of the present invention, there is provided a method for managing a file, wherein the computer stores the file in a memory, acquires the update date / time of the file, and the update date / time. A first key for encrypting the second key and a second key different from the first key are stored in the memory, and the update date and time are encrypted with the first and second keys, and the first and second keys are encrypted . 2 is generated, and the first encryption update date and time is set in the file together with the update date, and the second encryption update date and time is set as a password for opening the file. Set to .

According to another aspect of the present invention, there is provided a program for managing a file, the step of storing the file in a memory, the step of obtaining the update date / time of the file, and the encryption of the update date / time. storing a different second key in said memory to the first key and the first key to reduction, first and encrypts the update time in the first and second key Generating the second encryption update date and time, setting the first encryption update date and time together with the update date and time, and opening the file with the second encryption update date and time. And setting the password as the password in the file .

  Other problems and solutions to be disclosed by the present application will be made clear by the embodiments of the invention and the drawings.

  According to the present invention, it is possible to easily grasp the falsification of the update date and time of a file.

3 is a diagram illustrating a configuration example of a file 1. FIG. It is a figure which shows the hardware constitutions of the file management apparatus 20 of this embodiment. It is a figure which shows the software structure of the file management apparatus 20 of this embodiment. 3 is a diagram illustrating a configuration example of a file storage unit 231. FIG. 3 is a diagram illustrating an example of a key stored in a key storage unit 232. FIG. It is a figure which shows the flow of the process performed when the unsealing preservation | save process part 211 preserve | saves the file 1. FIG. It is a figure which shows the flow of a setting process of encryption creation update date. It is a figure which shows the flow of a password setting process. It is a figure which shows the flow of the process performed when the opening preservation | save process part 211 opens the file 1. FIG. It is a figure which shows the flow of a tampering determination process.

  The file management apparatus 20 according to an embodiment of the present invention will be described below. The file management apparatus 20 of this embodiment is a computer such as a personal computer, a workstation, a mobile phone terminal, or a PDA (Personal Digital Assistant), for example, and makes it difficult to falsify the creation date and update date of the file 1. Specifically, the file management apparatus 20 according to the present embodiment sets the encrypted creation date / time and update date / time in the file 1.

  FIG. 1 is a diagram showing a configuration example of the file 1. The file 1 includes a property 11 in which the attribute of the file 1 is set and data 12 that is the contents of the file 1. In the property 11, a creation date 111 and an update date 112 are set by the operating system executed in the file management apparatus 20. The property 11 of the file 1 can be read even if a password is set in the file 1. In a general operating system, the property 11 of the file 1 can often be easily altered. However, since the file management apparatus 20 of the present embodiment encrypts the creation date / time and the update date / time and sets them in the property 11, if the creation date / update date / time encrypted in the property 11 does not exist in the first place, it is determined that the falsification has occurred. The file creation date or update date and time, the encryption creation date and time and the encryption update date and time are read out from the file 1 and the creation date or update date and time encrypted, and the read encryption creation date and time or encryption update date and time. Can be determined whether or not tampering has occurred.

  In this embodiment, in the property 11 of the file 1, in addition to the creation date 111 and the update date 112 set by the operating system, the original creation date 113, the dark creation date 114, the original update date 115 The dark update date 116 is set. The original creation date 113 and the original update date 115 are the date when the file 1 was created and the date when it was updated. Normally, the creation date 111 and the update date 112 set by the operating system coincide with the original creation date 113 and the original update date 115. For example, when the file 1 is copied, the creation date 111 In this embodiment, the time when the user created and updated the file 1 is set as the original creation date 113 and the original update date 115 in the property 11. doing.

== Hardware configuration ==
FIG. 2 is a diagram illustrating a hardware configuration of the file management apparatus 20 according to the present embodiment. The file management apparatus 20 includes a CPU 201, a memory 202, a storage device 203, an input device 204, and an output device 205. The storage device 203 is, for example, a hard disk drive or a flash memory that stores various data and programs. The CPU 201 implements various functions by reading a program stored in the storage device 203 into a memory and executing it. The input device 204 is a keyboard, mouse, touch panel, microphone, or the like that accepts data input. The output device 205 is, for example, a display, a printer, or a speaker that outputs data. Note that the input device 204 and the output device 205 may be configured to connect the file management device 20 to a communication network and to input and output data with other computers connected to the communication network.

== Software configuration ==
FIG. 3 is a diagram illustrating a software configuration of the file management apparatus 20 according to the present embodiment. The file management apparatus 20 includes an unsealing storage processing unit 211, an encryption / decryption processing unit 212, a creation / update date setting unit 213, a password setting unit 214, a tampering determination unit 215, a file storage unit 231, and a key storage unit 232. The unsealing / storing processing unit 211, the encryption / decryption processing unit 212, and the creation / update date setting unit 213 are realized by the CPU 201 reading the program stored in the storage device 203 into the memory 102 and executing it, and the password setting unit 214. The tampering determination unit 215, the file storage unit 231, and the key storage unit 232 are realized as part of a storage area provided by the memory 102 and the storage device 103.

  The file storage unit 231 stores file 1. The file storage unit 231 can be realized, for example, as a file system provided by an operating system that operates on the file management apparatus 20. FIG. 4 is a diagram illustrating a configuration example of the file storage unit 231. As shown in FIG. 1 described above, the file 1 includes the property 11 and the data 12, and when the file 1 is created in the file storage unit 231, the property 11 of the file 1 contains the creation date and time indicating the time. When 111 and update date 112 are set and the file 1 is updated, the update date 112 set in the property 11 is also updated.

  The key storage unit 232 stores a key used for encryption processing. In this embodiment, it is assumed that the encryption process is a public key encryption method by RSA, and the original creation date 113 and the original update date 115 are set to “YYYYMMDDhhmmss” as will be described later. Since it has a 14-digit format, it is assumed that two prime numbers for creating a secret key and a public key by the RSA method are selected so that a multiplication result becomes a numerical value of 14 digits or more. Note that the above two prime numbers may be any number of digits whose multiplication result is larger than the number of digits of the original creation date 113 and the original update date 115 in consideration of the processing load of the file management device 20. it can. FIG. 5 is a diagram illustrating an example of a key stored in the key storage unit 232. In the present embodiment, the secret key and the public key are used for encrypting the creation date and time, used for encrypting the update date and time, and used for encrypting the password. It is assumed that the pair is stored in advance in the key storage unit 232.

  The unsealing and saving processing unit 211 opens (saves) and saves (saves) the file 1 in accordance with instructions from the user. The unsealing storage processing unit 211 may be realized as a process for executing a user program for reading and writing the file 1, for example, or between the user application program and the file system (file storage unit 231). The file 1 is acquired from the file storage unit 231 in response to the opening request of the file 1 from the user application program, the file 1 is opened, and the file 1 is registered in the file storage unit 231 in response to the storage request from the user application program You may make it do. The details of the file 1 storage processing and the file 1 opening processing by the opening storage processing unit 211 will be described later.

  The encryption / decryption processing unit 212 (corresponding to the “update date / time encryption processing unit”, “update date / time decryption processing unit”, “password generation unit”, and “creation date / time encryption processing unit” of the present invention) encrypts data. Do. In the present embodiment, the encryption / decryption processing unit 212 encrypts the creation date / time using the creation date / time secret key stored in the key storage unit 232 and encrypts the creation date / time using the creation date / time public key. Decrypt date and time. The encryption / decryption processing unit 212 encrypts the update date / time using the update date / time secret key, and decrypts the encrypted update date / time using the update date / time public key. The encryption / decryption processing unit 212 creates a password by encrypting the update date and time using a secret key for password.

  The creation update date setting unit 213 (corresponding to the “update date acquisition unit”, “update date setting unit”, “creation date acquisition unit”, “creation date setting unit” of the present invention) When the file 1 is stored, at least one of the creation date / time and the update date / time and at least one of the encrypted creation date / time and the encrypted update date / time are set in the file 1. In the present embodiment, the creation update date setting unit 213 includes the original creation date 113 that is the creation date and time of the file 1, the dark creation date 114 that is the encryption of the original creation date 113, and the update date and time of the file 1. A certain original renewal date 115 and all of the dark renewal date 116 obtained by encrypting the original renewal date 115 are set in the property 11 as a character string expressing the year, month, day, hour and minute in the format of “YYYYMMDDhhmms”. Shall. Details of the property 11 setting process will be described later.

  The password setting unit 214 sets a password for the file 1 when the unsealing storage processing unit 211 stores the file 1. The password can be set by a general method. The password setting unit 214 sets the password generated by the encryption / decryption processing unit 212 in the file 1.

  The falsification determination unit 215 (corresponding to the “attribute acquisition unit” of the present invention) determines whether the creation date / time or update date / time of the file 1 has been falsified. In the present embodiment, the falsification determination unit 215 compares the decryption date 114 with the original creation date 113 and compares the decryption date 116 with the original update date. By comparing with the date 115, it is determined whether or not the original creation date 113 and the original update date 115 have been falsified.

== Save and open processing of file 1 ==
FIG. 6 is a diagram illustrating a flow of processing performed when the unsealing / storing processing unit 211 stores the file 1. First, the encryption creation update date and time setting process shown in FIG. 7 is performed (S301), and then the password setting process shown in FIG. 8 is performed (S302).

FIG. 7 is a diagram showing the flow of the encryption creation update date and time setting process.
The creation update date setting unit 213 acquires the creation date and time of the file 1 and sets it as the original creation date (S321). The creation update date setting unit 213 sets the current creation date as the original creation date when the file 1 is newly created, and sets the property 11 as the original creation date when the file 1 is updated. If 113 is set, the original creation date 113 is read from the property 11, and if it is not set, the creation date 111 can be set as the original creation date. The encryption / decryption processing unit 212 reads the creation date / time secret key from the key storage unit 232 (S322), encrypts the original creation date with the read creation date / time secret key, and generates the encryption date / time. (S323).

  The creation update date setting unit 213 sets the update date and time of the file 1 as the original update date (S324). The creation update date setting unit 213 may use the current date and time as the original update date, or may set the date and time when the unsealing save processing unit 211 starts saving the file 1 as the original update date. The encryption / decryption processing unit 212 reads the secret key for the update date / time from the key storage unit 232 (S325), encrypts the original update date with the read secret key for the update date / time, and generates the dark update date / time. (S327). The creation update date setting unit 213 sets the original creation date, the dark creation date, the original update date, and the dark update date in the property 11 of the file 1 (S327).

  FIG. 8 is a diagram showing the flow of password setting processing. The encryption / decryption processing unit 212 reads the secret key for the password from the key storage unit 232 (S341), encrypts the original update date with the read secret key for the password, and generates a password (S342). The password setting unit 214 sets the generated password in the file 1 (S343). It is assumed that the password is set by a general method.

  As described above, when the file 1 is saved, the property 11 of the file 1 includes, in addition to the creation date 111 and the update date 112, the original creation date 113, the dark creation date 114, the original update date. A date 115 and a dark update date 116 are set, and a password created based on the update date is set.

FIG. 9 is a diagram illustrating a flow of processing performed when the unsealing / saving processing unit 211 opens the file 1. First, the falsification determination process shown in FIG. 10 is performed (S401).
The falsification determination unit 215 reads the original creation date 113 and the dark creation date 114 from the property 11 of the file 1 (S421). The encryption / decryption processing unit 212 reads the public key for the creation date from the key storage unit 232 (S422), and decrypts the encryption date 114 with the read public key for the creation date and sets it to X (S423). If the original creation date 113 and X do not match (S424: NO), the falsification determination unit 215 determines that the falsification has occurred (S425).
On the other hand, when the original creation date 113 and X match (S424: YES), the falsification determination unit 215 reads the original update date 115 and the dark update date 116 from the property 11 of the file 1 (S426). ). The encryption / decryption processing unit 212 reads the public key for the update date / time from the key storage unit 232 (S427), and decrypts the dark update date 116 with the read public key for the update date / time to be X (S428). If the original update date 115 and X do not match (S429: NO), the falsification determination unit 215 determines that the original update date 115 and X match the original update date 115 (S429: NO) and proceeds to step S425. : YES), it is determined that there has been no falsification (S430).
Returning to FIG. 9, the encryption / decryption processing unit 212 reads the secret key for the password from the key storage unit 232 (S402), encrypts the original update date 115 with the read secret key for the password, and generates a password. (S403), the opening storage processing unit 211 opens the file 1 using the generated password (S404). The unsealing / storing processing unit 211 can unseal the file 1 in which the password is set by using a general process.

  As described above, when the file 1 is opened, it is determined whether the creation date / time or the update date / time has been tampered with, and the file 1 is opened using the password generated based on the update date / time.

  According to the data management device 20 of the present embodiment, in addition to the original creation date 113 and the original update date 115 indicating the creation date and update date and time of the file 1, a secret creation year obtained by encrypting these with a secret key The date 114 and the dark update date 116 can be set in the property 11 of the file 1. Since the dark creation date 114 and the dark update date 116 cannot be generated without the secret key, the original creation date 113 and the original update date 115 can be prevented from being falsified. In general, the creation date 111 and the update date 112 set in the property 11 can be easily changed. However, in the data management apparatus 20 of this embodiment, the creation date 111, the update date 112, and the original creation year By comparing the date 113 and the original update date 115, it is possible to easily determine whether the creation date 111 and the update date 112 have been changed.

  In addition, according to the data management apparatus 20 of the present embodiment, the property 11 is set to the original update date 115 when the file is saved in accordance with an instruction from the user, in addition to the update date 112 created or changed by the operating system. Can be set to Therefore, the date and time when the user updated the contents of the file 1 can be correctly set in the property 11. Depending on the operating system, when the file 1 is copied, the update date and time 112 may be updated. However, in the data management apparatus 20 of this embodiment, the update date and time intended by the user is displayed as the original update date 115. Therefore, the update date and time can be managed correctly regardless of the behavior of the operating system.

  Further, according to the data management apparatus 20 of the present embodiment, since the update date and time encrypted with the password secret key is the password of the file 1, by decrypting the password with the password public key, You can also check the update date and time from the password.

  In this embodiment, a secret key and a public key are created using two prime numbers whose multiplication result is 14 digits or more, and there are many combinations of such two prime numbers, and the secret key and the public key are estimated. It is thought that there is little fear of being done.

  In the present embodiment, the file management apparatus 20 is a single computer. However, the present invention is not limited to this, and the file management apparatus 20 may be configured by a plurality of computers. For example, the file storage unit 231 may be realized as a file server separate from the file management device 20, or the file server may include an encryption / decryption processing unit 212, a creation update date setting unit 213, a password setting unit 214, and a falsification determination unit. 215, and a file storage unit 231 may be provided. Further, the key storage unit 232 may be provided in another computer so that the key can be read out after being authenticated by the other computer.

  In the present embodiment, the original creation date 113, the dark creation date 114, the original update date 115, and the dark update date 116 are written in the property 11 included in the file 1. For example, the file 1 may be written in a storage area managed by the file system as an attribute of the file 1. In this case, the file 1 may not include the property 11.

  In this embodiment, the original creation date 113 and the original update date 115 are set in the property 11 in addition to the creation date 111 and the update date 112, but the original creation date 113 is used. Alternatively, the original update date 115 may be omitted, the creation date 111 and the update date 112 may be encrypted, and the dark creation date 114 and the dark update date 116 may be set.

  In the present embodiment, the original creation date 113 and the original update date 115 are the creation date and the update date and time of the file 1, but may be the creation date and the update date and time of the data 12, for example. .

  In the present embodiment, the creation date / time and the update date / time are encrypted using the public key encryption method and decrypted using the public key, but are encrypted using the public key and decrypted using the private key. Alternatively, encryption / decryption may be performed with either a secret key or a public key. In addition, the creation date / time and the update date / time may be encrypted and decrypted with a common key based on the common key encryption method regardless of the public key encryption method.

  In the present embodiment, the password is obtained by encrypting the update date and time with a secret key by a public key encryption method. However, the password may be obtained by encrypting the update date and time with a public key, or a secret key or public key. The creation date and time may be encrypted. Further, the update date / time or the creation date / time may be encrypted with a common key using a common key encryption method or a public key encryption method, instead of a public key encryption method.

  In this embodiment, the encryption method is premised on RSA, but various public key encryption methods can be adopted in addition to RSA.

  In the present embodiment, the original creation date 113 is compared with the decryption of the dark creation date 114, or the original update date 115 and the dark update date 116 are decrypted. It is assumed that the creation date / time or the falsification of the update date / time is detected by comparing with the thing. Furthermore, the creation date / time 111 and the original creation date / time 113 are compared, the update date / time 112 and the original update date / time 115 may be compared to determine whether the creation date 111 and the update date 112 have been tampered with.

  In this embodiment, when the file 1 is opened, the password is automatically generated and the password is used. However, the password is displayed, and the password is entered by the user referring to the displayed password. An output unit may be provided.

  Although the present embodiment has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 1 File 11 Property 12 Data 20 File management apparatus 111 Creation date 112 Update date 113 Original creation date 114 Dark creation date 115 Original update date 116 Dark update date 211 Opening storage processing unit 212 Encryption / decryption processing unit 213 Creation update date setting unit 214 Password setting unit 215 Tampering determination unit 231 File storage unit 232 Key storage unit

Claims (9)

A device for managing files,
A file storage unit for storing the file;
An update date and time acquisition unit for acquiring the update date and time of the file;
A key storage unit for storing a different second key is the first key and the first key for encrypting the update date,
An update date and time encryption processing unit that encrypts the update date and time with the first and second keys to generate first and second encrypted update dates and times;
An update date and time setting unit that sets the first encrypted update date and time together with the update date and time,
A password setting unit for setting the second encryption update date and time in the file as a password for opening the file;
A file management apparatus comprising: The file management apparatus according to claim 1,
An attribute acquisition unit for acquiring the update date and time and the encryption update date and time set in the file;
An update date / time decryption processing unit for generating a decryption update date / time by decrypting the encryption update date / time with the key;
An update date and time comparison unit for comparing the update date and time and the decryption update date and time;
A file management apparatus comprising: The file management device according to claim 2,
The key includes a secret key and a public key by a public key encryption method,
The update date / time encryption processing unit generates the encryption update date / time using the secret key included in the key,
The update date and time decryption processing unit generates the decryption update date and time using the public key included in the key;
A file management device characterized by the above. The file management device according to any one of claims 1 to 3 ,
An attribute acquisition unit that acquires the update date and time and the first encrypted update date and time set in the file;
An update date / time decryption processing unit for generating a decryption update date / time obtained by decrypting the encryption update date / time with the first key;
A password generation unit that generates the password by encrypting the obtained update date and time with the second key;
An update date and time comparison unit for comparing the acquired update date and time and the first decryption update date and time;
A password output unit for outputting the password;
A file management apparatus comprising: The file management apparatus according to any one of claims 1 to 4 ,
Comprising an opening processing unit for opening the file using the password generated by the password generation unit;
A file management device characterized by the above. A file management apparatus according to any one of claims 1 to 5 ,
The key storage unit further stores a creation date key for encrypting the creation date of the file,
A creation date acquisition unit for acquiring the creation date;
A creation date / time encryption processing unit that encrypts the creation date / time with the creation date / time key to generate an encryption creation date / time;
A creation date and time setting unit that sets the encryption creation date and time together with the creation date and time,
A file management apparatus comprising: The file management device according to any one of claims 1 to 6 ,
The update date and time and the encryption update date and time are set as property information included in the file;
A file management device characterized by the above. A method of managing files,
Computer
Storing the file in memory;
Get the update date of the file,
Storing a first key for encrypting the update date and time and a second key different from the first key in the memory;
Encrypting the update date and time with the first and second keys to generate first and second encrypted update dates and times,
Along with the update date and time, the first encryption update date and time is set in the file,
Setting the second encryption update date and time in the file as a password for opening the file;
File management method characterized by the above. A program for managing files,
On the computer,
Storing the file in memory;
Obtaining an update date and time of the file;
Storing a different second key in said memory to the first key and the first key for encrypting the update date,
Encrypting the update date with the first and second keys to generate first and second encrypted update dates;
Setting the first encrypted update date and time together with the update date and time in the file;
Setting the second encryption update date and time in the file as a password for opening the file;
A program for running

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