JP4584196B2 - Information processing system, information processing method, and program - Google Patents

Description

  The present invention relates to an information processing system, an information processing method, and a program that use a self-decryption type encrypted file.

  An example of a system using a self-decryption encryption file is described in Patent Document 1. This system includes a transmitting PC (personal computer) and a receiving PC, and operates as follows. The transmitting-side PC generates a self-decryption file that holds the self-decryption execution program for decrypting the encryption information inseparably from the encrypted data, and transmits the self-decryption file to the receiving PC. In the receiving PC, the use of the self-decryption execution program is permitted by the input of the regular password, and the encrypted data associated with the self-decryption execution program can be decrypted to extract the data. In this way, even if the receiving PC does not have a decryption program, the encrypted data can be decrypted by the self-decryption execution program that is inseparably held from the encrypted data.

JP 2003-76268 A

  However, in the above-described conventional technique, when the receiving PC randomly inputs a password from a person who does not have a normal password, the input password is accidentally changed to a normal password. If they match, there is a security problem that the unauthorized use of the self-decoding execution program cannot be prevented.

  An object of the present invention is to provide an information processing system, an information processing method, and a program for preventing unauthorized use of a self-decoding execution program.

  The first information processing system of the present invention includes an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and the encrypted file by decrypting the encrypted file. A self-decryption-encrypted file creation means for creating a self-decryption-type encrypted file including a decryption program for restoring the file; and a copy-decryption that is a copy of the decryption program according to the execution of the self-decryption-type encrypted file A copy / decryption program creating means for creating a program, wherein the copy / decryption program requests input of a password, determines whether or not the input password is correct, and if the input password is incorrect, the password error The number of password errors updated and the upper limit of password errors Comparing the number, if the password error count reaches said password error limit number of times, deletes the self-decryption file, characterized in that.

  The second information processing system of the present invention is an information processing system in which a first information processing apparatus and a second information processing apparatus are connected to each other via a network, and the first information processing apparatus is an arbitrary information processing system. A self-decryption type including: an encrypted file obtained by encrypting the file with a password; common information including at least a password error count and a password error upper limit count; and a decryption program for decrypting the encrypted file and restoring the file A self-decryption type encrypted file creation unit that creates an encrypted file; and a self-decryption type encrypted file transmission unit that transmits the self-decryption type encrypted file to the second information processing apparatus. The information processing apparatus includes: a self-decryption encrypted file receiving unit that receives the self-decryption encrypted file; and an execution of the self-decryption encrypted file. And a copy decryption program creating means for creating a copy decryption program that is a copy of the decryption program, wherein the copy decryption program requests input of a password, determines whether the input password is correct, When the input password is incorrect, the password error count is incremented, the updated password error count is compared with the password error upper limit count, and the password error count reaches the password error upper limit count. Deletes the self-decryption type encrypted file.

  According to a third information processing system of the present invention, in the first or second information processing system, the common information includes a password hash value that is a hash value of a password. The hash value is calculated and compared with the password hash value to determine whether the input password is correct or incorrect.

  According to a fourth information processing system of the present invention, in any one of the first to third information processing systems, the common information includes a common information hash value that is a hash value for data of each item included in the common information. And the replication decryption program calculates a hash value for each item of data of the common information, compares it with the common information hash value, and deletes the self-decryption encryption file if they do not match It is characterized by.

  The first information processing method of the present invention includes an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and decrypting the encrypted file to A self-decryption-encrypted file creation step for creating a self-decryption-type encrypted file including a decryption program for restoring the file; and a copy-decryption that is a copy of the decryption program according to the execution of the self-decryption-type encrypted file A copy decryption program creating step for creating a program; executing the copy decryption program; requesting input of a password; determining whether the input password is correct; Incremented and updated the password error count and the password error Comparing the number of times, if the password error count reaches said password error limit number of times, characterized in that it comprises a and a replication decoding program execution step of deleting the self-decryption file.

  According to a second information processing method of the present invention, the first information processing apparatus includes an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, A self-decryption-encrypted file creation step for creating a self-decryption-type encrypted file including a decryption program for decrypting the encrypted file and restoring the file; and A self-decryption encrypted file transmission step for transmitting the encrypted file to the second information processing device; and a self-decryption encrypted file reception step for the second information processing device to receive the self-decryption encryption file; The second information processing apparatus is a copy decryption program that is a copy of the decryption program in response to execution of the self-decryption encrypted file. A duplicate decryption program creation step for creating a program; and the second information processing apparatus executes the duplicate decryption program, requests input of a password, determines whether the entered password is correct, and the entered password is If the password error count is incorrect, the password error count is incremented, the updated password error count is compared with the password error upper limit count, and if the password error count reaches the password error upper limit count, the self-decryption is performed. A copy decryption program executing step for deleting the type encrypted file.

  According to a third information processing method of the present invention, in the first or second information processing method, the common information includes a password hash value that is a hash value of a password. The hash value is calculated and compared with the password hash value to determine whether the input password is correct or incorrect.

  According to a fourth information processing method of the present invention, in any one of the first to third information processing methods, the common information includes a common information hash value that is a hash value for each item of data included in the common information. And the replication decryption program calculates a hash value for each item of data of the common information, compares it with the common information hash value, and deletes the self-decryption encryption file if they do not match It is characterized by.

  The first program of the present invention includes an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and decrypting the encrypted file to store the file. A self-decryption encrypted file creation process for creating a self-decryption encrypted file including a decryption program to be restored, and a copy decryption program that is a copy of the decryption program in accordance with the execution of the self-decryption encrypted file. Execute the copy / decryption program creation process to be created, execute the copy / decryption program, request password input, determine whether the input password is correct, and increment the password error count when the input password is incorrect The updated number of password errors and the upper limit number of password errors And compare, if said password error count reaches said password error limit number of times, characterized in that to perform a replication decryption program execution processing for deleting the self-decryption file to the information processing apparatus.

  According to a second program of the present invention, in the first program, the common information includes a password hash value that is a hash value of a password, and the copy decryption program execution process calculates a hash value of the input password. The correctness of the input password is determined by comparing with the password hash value.

  According to a third program of the present invention, in the first or second program, the common information includes a common information hash value that is a hash value for data of each item included in the common information, and the copy decryption program is executed. The process is characterized in that a hash value is calculated for each item of the common information and compared with the common information hash value, and the self-decryption encrypted file is deleted if they do not match.

  According to the present invention, the self-decoding execution program can be prevented from being illegally used. The reason for this is that when a secret key is randomly entered by a person who does not have a regular secret key, if the number of input mistakes for the secret key reaches the upper limit, the decryption process is interrupted and the self-decryption encrypted file This is because of deleting.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 4 is a diagram showing the overall configuration of the present invention.
FIG. 1 is a diagram showing the structure of a self-decoding file.

  Referring to FIG. 4, the best mode for carrying out the present invention is the first information processing apparatus 100, the second information processing apparatus 200, the first information processing apparatus 100, and the second information processing apparatus. 200 is connected to the network 300.

  The first information processing apparatus 100 is an information processing apparatus that operates under program control, such as a personal computer. The first information processing apparatus 100 includes an input unit 101, an encrypted file creation unit 102, a common information creation unit 103, a self-decryption file creation unit 104, a self-decryption file 1, and a self-decryption file transmission unit 105. Is included.

  The input unit 101 inputs a password and the name of a file to be encrypted from a keyboard or the like and stores them in a storage unit (not shown). The input password is used as an encryption key when creating the encrypted file 20.

  The encrypted file creation unit 102 creates an encrypted file by encrypting the file specified by the name of the file to be encrypted with the input password.

  The common information creation unit 103 sets the upper limit allowable value of the password input error count to the password error upper limit count, sets 0 as the number of times the wrong password is input to the password error count, and is input to the password hash value The hash value of the password is calculated and set, and the hash value for the data of each item included in the common information is calculated and set in the common information hash value. Then, common information including a password error upper limit count, a password error count, a password hash value, and a common information hash value is created.

  The self-decryption file creation means 104 creates a self-decryption type encrypted file (hereinafter referred to as a self-decryption file) and stores it in a storage unit (not shown). More specifically, a decryption program stored in a storage unit (not shown) is read in advance, and the decrypted read program, the encrypted file created by the encrypted file creation means 102, and the common information created by the common information creation means 103 are read. Create a self-decrypting file containing information. The decryption program is a program for decrypting the encrypted file and restoring it to the original state.

  Self-decoding file 1 is created by self-decoding file creation means 104. The self-decryption file 1 includes a decryption program 10 (a program that decrypts an encrypted file and restores the original state is hereinafter referred to as a decryption program), and a single or a plurality of encrypted files 20 (encrypted files). Is hereinafter referred to as an encrypted file) and common information 30. The structure of the self-decoding file 1 is shown in FIG. The self-decryption file 1 can decrypt the stored encrypted file 20 by itself without depending on the computer environment or other programs. The encrypted file 20 stored in the self-decryption file 1 is encrypted with a password. When decrypting the self-decryption file 1, the user inputs a password. At this time, if the user continuously inputs an incorrect password a predetermined number of times, the self-decryption file automatically deletes itself.

  The self-decoding file transmission unit 105 transmits the self-decoding file 1 to the second information processing apparatus 200 via the network 300.

  The second information processing apparatus 200 is an information processing apparatus that operates under program control, and is, for example, a personal computer. The second information processing apparatus 200 includes a self-decoding file receiving unit 201, a self-decoding file 1, a self-decoding file execution unit 202, an input unit 203, and a duplicate decoding program 40.

  The self-decoding file receiving unit 201 receives the self-decoding file 1 from the first information processing apparatus 100 and stores it in a storage unit (not shown).

  The self-decryption file execution unit 202 activates the self-decryption file 1 and decrypts the encrypted file 20.

  The input unit 203 inputs a password from a keyboard or the like.

  The duplicate decryption program 40 is obtained by duplicating itself by the decryption program 10 of the self-decryption file 1. When the encrypted file 20 is decrypted, this copy decryption program 40 is used.

  Next, the configuration of the self-decoding file 1 will be described in more detail with reference to FIG.

  Referring to FIG. 1, the self-decryption file 1 includes a decryption program 10, a single or a plurality of encrypted files 20, and common information 30.

  The decryption program 10 is a program for decrypting the encrypted file 20 and restoring it to the original state. The decryption program 10 duplicates itself and activates the decrypted decryption program (replica decryption program 40). Then, the self-decoding file 1 is terminated.

  The encrypted file 20 includes a file name 21, a file attribute 22, a data size 23, a data hash value 24, and encrypted data 25.

  The file name 21 and the file attribute 22 are values indicating the file name and file attribute (reference only / updatable / executable, etc.) for the original file before encryption (hereinafter referred to as the original file). The file name is defined by the user, and the file attribute is defined by the operating system.

  The data size 23 and the data hash value 24 are the size and hash value of the contents of the original file, respectively.

  The encrypted data 25 is a value obtained by encrypting the contents of the original file with a password.

  The common information 30 includes a decryption program size 31, an encrypted file number 32, a password error upper limit count 33, a password error count 34, a password hash value 35, and a common information hash value 36.

  The decryption program size 31 is the size of the decryption program 10.

  The number of encrypted files 32 is the number of encrypted files 20 stored in the self-decryption file.

  The password error upper limit count 33 is an upper limit allowable value of the password input error count.

  The password error count 34 is a value that records the number of times an incorrect password is input with respect to the password input at the time of decryption of the self-decryption file. When the value of the password error count 34 reaches the password error upper limit count 33, the self-decryption file stops the decryption process and automatically deletes itself.

  The password hash value 35 is a hash value of a password that encrypts a file, and is used when determining whether or not the password input at the time of decrypting the self-decryption file is correct.

  The common information hash value 36 is a hash value for the data of the decryption program size 31 to the password hash value 35, and is used when determining whether the data of the decryption program size 31 to the password hash value 35 has been falsified.

Next, the operation of the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 5 is a diagram showing the flow of the entire operation.

  First, the overall operation will be described with reference to FIG.

  The input unit 101 of the first information processing apparatus 100 inputs the password and the name of the file to be encrypted from a keyboard or the like (step C01).

  The encrypted file creating means 102 creates an encrypted file by encrypting the file designated by the name of the file to be encrypted with the input password (step C02).

  The common information creation unit 103 sets the upper limit allowable value of the password input error count to the password error upper limit count, sets 0 as the number of times the wrong password is input to the password error count, and is input to the password hash value The hash value of the password is calculated and set, and the hash value for the data of each item included in the common information is calculated and set in the common information hash value. Then, common information including a password error upper limit count, a password error count, a password hash value, and a common information hash value is created (step C03).

  The self-decryption file creation unit 104 reads the decryption program stored in the storage unit in advance, and reads the decryption program, the encrypted file created by the encrypted file creation unit 102, the common information created by the common information creation unit 103, Is created (step C04).

  The self-decoding file transmission means 105 transmits the created self-decoding file 1 to the second information processing apparatus 200 via the network 300 (step C05).

  The self-decoding file receiving unit 201 of the second information processing apparatus 200 receives the self-decoding file 1 from the first information processing apparatus 100 (step C06).

  The self-decoding file execution unit 202 activates the self-decoding file 1 (step C07).

  The self-decryption file 1 decrypts the encrypted file 20 (step C08). Details of the operation of the self-decryption file 1 will be described later.

Next, the operation at the time of decoding the self-decoding file 1 will be described with reference to FIGS.
FIG. 2 is a diagram illustrating an operation when the self-decryption file is normally decrypted.
FIG. 3 is a diagram showing an operation when the decoding of the self-decoding file fails.

  First, referring to FIG. 2, an operation when the self-decrypting file is normally decrypted will be described.

  The user executes the self-decryption file 1 (step A01).

  The decryption program 10 of the self-decryption file 1 duplicates itself and executes the duplicated decryption program (hereinafter referred to as a duplicate decryption program) 40 (step A02). Then, the self-decoding file 1 is terminated.

  The copy decryption program 40 reads the common information 30 stored in the self-decryption file 1 and verifies the common information hash value 36, thereby confirming that the common information 30 has not been tampered with (step A03). More specifically, a common information hash value is calculated from the common information 30, and the calculated common information hash value is compared with the common information hash value 36 of the common information 30. If the comparison results are equal, it is determined that the common information 30 has not been tampered with.

  The copy decryption program 40 requests the user to input a password (step A04).

  The user inputs a correct password for the copy decryption program 40 (step A05).

  The copy decryption program 40 verifies the password input by the user using the password hash value 35 of the common information 30 (step A06). More specifically, a password hash value is calculated from the input password, and the calculated password hash value is compared with the password hash value 35 of the common information 30. If the comparison results are equal, it is determined that the entered password is correct.

  The copy decryption program 40 decrypts all the encrypted files 20 stored in the self-decryption file 1 using the password input by the user and restores them to the original file (step A07).

  The copy decryption program 40 deletes itself (step A08).

  Next, with reference to FIG. 3, an operation in the case where the decryption of the self-decryption file fails due to the user continuously inputting the wrong password a predetermined number of times will be described.

  The user executes the self-decryption file 1 (step B01).

  The decryption program 10 of the self-decryption file 1 duplicates itself and executes the decrypted decryption program (hereinafter referred to as a duplicate decryption program) 40 (step B02). Then, the self-decoding file 1 is terminated.

  The copy decryption program 40 reads the common information 30 stored in the self-decryption file 1 and verifies the common information hash value 36, thereby confirming that the common information 30 has not been tampered with (step B03).

  The copy decryption program 40 requests the user to input a password (step B04).

  The user inputs an incorrect password to the copy decryption program 40 (step B05).

  The copy decryption program 40 verifies the password input by the user using the password hash value 35 of the common information 30 (step B06).

  The copy decryption program 40 detects that the password entered by the user is incorrect, and records the password error count 34 of the common information 30 stored in the self-decryption file 1 by adding 1 (step B07). At this time, the hash value for the data of the decryption program size 31 to the password hash value 35 is recalculated and reset to the common information hash value 36.

  The copy decryption program 40 compares the password error count 34 of the common information 30 stored in the self-decryption file 1 with the password error upper limit count 33. If the password error count 34 has not reached the password error upper limit count 33, steps B4 to B7 are executed again (step B08).

  When the password error count 34 reaches the password error upper limit count 33, the copy decryption program 40 deletes the self-decryption file 1 (step B09).

  The copy decryption program 40 deletes itself (step B10).

  In step B07, by recording the password error count 34 in the self-decryption file 1, even if the user forcibly terminates the replication decryption program 40 in the middle, the password error count 34 is executed the next time the self-decryption file 1 is executed. Can be counted continuously.

In step B06, when the user inputs the correct password, the password error count 34 is recorded as zero.
In step B03, if the common information 30 has been tampered with, the duplicate decryption program 40 deletes the self-decryption file 1 and deletes itself.

  Next, effects of the embodiment of the present invention will be described.

  First, by providing the password error upper limit count 33, it is possible to improve security.

  The reason is that a random password entry attack by a third party who does not know the password becomes difficult. When a random password is input a plurality of times, if the password error count 34 reaches the upper limit, the decryption process is interrupted and the self-decryption file is deleted, making it impossible to perform an attack thereafter.

  Second, it is possible to provide a reliable management mechanism for the password error count 34. There are two reasons for this.

  One is to create and use a copy of the decryption program 10. The reason why the duplicate decoding program is used will be described below. First, as a premise, depending on the operating system, if the execution file is being executed, the contents of the execution file may not be changed. Since the self-decryption file is one execution file including the decryption program 10, the encrypted file 20, and the common information 30, the common information 30 recorded in the self-decryption file is executed while the self-decryption file is being executed. The password error count 34 cannot be updated. In this case, the self-decryption file is intentionally terminated immediately after the user makes a mistake in the password, thereby making it possible to keep the password error count 34 set to zero forever. A copy decoding program is used as means for preventing this. When the self-decryption file 1 is executed, a duplicate decryption program is first created and the process itself ends immediately. By doing so, it becomes possible to change the contents of the self-decryption file at any time from the duplicate decryption program, and the password error count 34 can be recorded in the common information 30 of the self-decryption file at the moment when the user mistakes the password. It becomes. In addition, since the duplicate decryption program locks the self-decryption file to prohibit changes from other programs, it is guaranteed that the self-decryption file is changed only from the duplicate decryption program.

  The other is that the common information hash value 36 is verified. By performing this verification, even if the user falsifies the password error count 34 and the password error upper limit count 33 of the common information 30 before executing the self-decryption file, the alteration is detected and the self-decryption file is invalidated. Is possible.

  Next, another embodiment of the present invention will be described.

  In another embodiment of the present invention, a function for verifying the validity of a decrypted file is added to the above-described embodiment. Note that the function of verifying the validity of the decrypted file is incorporated in the decryption program 10 in advance.

  As shown in step A07 of FIG. 2, the copy / decryption program 40 decrypts the encrypted file 20 stored in the self-decryption file 1 using the password input by the user and restores it to the original file.

  After this, the validity of the decrypted file is verified.

  That is, the copy decryption program 40 calculates the data hash value of the decrypted file, and compares the calculated data hash value with the data hash value 24 stored in the self-decryption file.

  If the comparison results are equal, it is determined that the decrypted file is valid.

  If the comparison results are not equal, it is determined that the decrypted file is not legitimate, and the copy decryption program 40 deletes the decrypted file, deletes the self-decryption file 1, and deletes itself.

  Next, the effect of another embodiment of the present invention will be described.

  Another embodiment of the present invention has the effect of ensuring the validity of the decrypted file.

  The reason is that a function for verifying the validity of the decrypted file is provided, and if the decrypted file is not valid, the decrypted file is deleted and the decryption process is interrupted.

It is a figure which shows the structure of a self-decryption file. It is a figure which shows operation | movement when a self-decryption file is decoded normally. It is a figure which shows operation | movement when the decoding of a self-decryption file fails. It is a figure which shows the whole structure of this invention. It is a figure which shows the flow of the whole operation | movement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Self-decryption file 10 Decryption program 20 Encrypted file 21 File name 22 File attribute 23 Data size 24 Data hash value 25 Encrypted data 30 Common information 31 Decryption program size 32 Number of encrypted files 33 Password error upper limit number 34 Password error number 35 Password hash value 36 Common information hash value 40 Replication decryption program 100 First information processing apparatus 101 Input means 102 Encrypted file creation means 103 Common information creation means 104 Self-decryption file creation means 105 Self-decryption file transmission means 200 Second information Processing device 201 Self-decoding file receiving means 202 Self-decoding file execution means 203 Input means 300 Network

Claims (11)

Self-decryption including an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and a decryption program for decrypting the encrypted file and restoring the file Self-decryption type encryption file creation means for creating a type encryption file;
A copy decryption program creating means for creating a copy decryption program that is a copy of the decryption program in response to execution of the self-decryption type encrypted file;
The copy decoding program is
Apply lock to the self-decryption encrypted file to prohibit changes from other programs,
Requests the input of a password, determines whether the input password is correct, increments the password error count when the input password is incorrect, and compares the updated password error count with the password error upper limit count When the password error count reaches the password error upper limit count, the self-decryption type encrypted file is deleted.
An information processing system characterized by this. An information processing system in which a first information processing apparatus and a second information processing apparatus are connected to each other via a network,
The first information processing apparatus includes:
Self-decryption including an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and a decryption program for decrypting the encrypted file and restoring the file Self-decryption type encryption file creation means for creating a type encryption file;
Self-decrypting encrypted file transmitting means for transmitting the self-decrypting encrypted file to the second information processing apparatus,
The second information processing apparatus
Self-decryption encrypted file receiving means for receiving the self-decryption encrypted file;
A copy decryption program creating means for creating a copy decryption program that is a copy of the decryption program in response to execution of the self-decryption type encrypted file;
The copy decoding program is
Apply lock to the self-decryption encrypted file to prohibit changes from other programs,
Requests the input of a password, determines whether the input password is correct, increments the password error count when the input password is incorrect, and compares the updated password error count with the password error upper limit count When the password error count reaches the password error upper limit count, the self-decryption type encrypted file is deleted.
An information processing system characterized by this. The common information includes a password hash value that is a hash value of a password,
The copy decryption program calculates the hash value of the input password and compares it with the password hash value, thereby determining the correctness of the input password.
The information processing system according to claim 1 or 2. The common information includes a common information hash value that is a hash value for data of each item included in the common information,
The copy decryption program calculates a hash value for each item of data of the common information and compares it with the common information hash value, and if it does not match, deletes the self-decryption type encrypted file.
The information processing system according to any one of claims 1 to 3. An information processing device encrypts an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and a decryption program for decrypting the encrypted file and restoring the file and in response to the execution of the self-decryption file, replication decoding program generating step of generating a replica decoding program is a copy of the decryption program comprising bets,
The information processing apparatus executes the copy decryption program, locks the self-decryption encrypted file to prohibit changes from other programs , requests input of a password, When the entered password is incorrect, the password error count is incremented, the updated password error count is compared with the password error upper limit count, and the password error count is the password error upper limit count. When the process reaches the copy decryption program execution step of deleting the self-decryption encrypted file,
An information processing method comprising: The first information processing apparatus decrypts the encrypted file by decrypting the encrypted file, encrypted information obtained by encrypting an arbitrary file with a password, common information including at least the password error count and the password error upper limit count, and restoring the file A self-decryption type encryption file creation step for creating a self-decryption type encryption file including a decryption program
A self-decryption encrypted file transmission step in which the first information processing apparatus transmits the self-decryption encrypted file to the second information processing apparatus;
A second information processing apparatus receiving a self-decryption type encrypted file for receiving the self-decryption type encrypted file;
A duplicate decryption program creating step in which the second information processing apparatus creates a duplicate decryption program that is a duplicate of the decryption program in response to execution of the self-decryption encrypted file;
The second information processing apparatus executes the copy / decryption program, locks the self-decryption type encrypted file to prohibit changes from other programs , requests input of a password, and is input The password error count is incremented when the entered password is incorrect, the updated password error count is compared with the password error upper limit count, and the password error count is When the upper limit number of errors is reached, a copy decryption program execution step for deleting the self-decryption encrypted file;
An information processing method comprising: The common information includes a password hash value that is a hash value of a password,
The duplicate decryption program determines whether the input password is correct by calculating a hash value of the input password and comparing the hash value with the password hash value.
The information processing method according to claim 5 or 6. The common information includes a common information hash value that is a hash value for data of each item included in the common information,
The copy decryption program calculates a hash value for the data of each item of the common information, compares the hash value with the common information hash value, and deletes the self-decryption encrypted file if they do not match.
The information processing method according to claim 5, wherein the information processing method is an information processing method. Self-decryption including an encrypted file obtained by encrypting an arbitrary file with a password, common information including at least a password error count and a password error upper limit count, and a decryption program for decrypting the encrypted file and restoring the file Self-decryption type encryption file creation processing to create a type encryption file,
A copy decryption program creating process for creating a copy decryption program that is a copy of the decryption program in accordance with the execution of the self-decryption file;
Execute the copy decryption program, lock the self-decryption type encrypted file to prohibit changes from other programs , request input of a password, determine whether the input password is correct, and input The password error count is incremented when the password is incorrect, the updated password error count is compared with the password error upper limit count, and if the password error count reaches the password error upper limit count, , A copy decryption program execution process for deleting the self-decryption file,
A program characterized by causing an information processing apparatus to perform the above. The common information includes a password hash value that is a hash value of a password,
The copy decryption program execution process determines the correctness of the input password by calculating the hash value of the input password and comparing it with the password hash value.
The program according to claim 9. The common information includes a common information hash value that is a hash value for data of each item included in the common information,
The copy decryption program execution process calculates a hash value for each item of the common information and compares it with the common information hash value, and if it does not match, deletes the self-decryption type encrypted file.
The program according to claim 9 or 10, characterized in that:

Images