KR20220074199A - Computer program for dividing original file into multiple pieces, encrypting divided files and restoring original file by decrypting encrypted files, and method thereof - Google Patents

Abstract

A method of dividing and merging original files of an electronic device is disclosed. The original file division and merging method includes the steps of setting division number information indicating how many original files are to be divided and division size information of each of the files to be divided according to the division number information; Creating divided files by dividing each of the files to be divided according to division size information, encrypting each of the divided files to generate each of the encrypted divided files, and an order for each of the divided files generating each of the headers including information, the divided number information, and division size information for each of the divided files, and each of the encrypted divided files and the final divided files including each of the headers It includes the step of creating

Description

A computer program and method for splitting an original file into several, encrypting the divided files, and decrypting the encrypted files to restore the original file FILES, AND METHOD THEREOF}

An embodiment according to the concept of the present invention relates to a file protection technology. In particular, in order to safely protect an original file, the original file is divided into several pieces according to division number information and division size information, the divided files are encrypted, and the encrypted file is encrypted. It relates to a computer program and method for restoring the original file by decoding divided files.

Encryption is a process of encrypting and delivering information using an encryption algorithm so that it cannot be read by anyone, and decryption restores encrypted information so that it can be read again.

Encryption protects personal information and plays a role of processing so that important information (eg, data) cannot be taken immediately when important information (eg, data) is leaked due to an attack by a malicious attacker.

An encryption algorithm is used to encrypt information, and the encryption algorithm can be largely divided into a symmetric encryption algorithm and an asymmetric encryption algorithm. A symmetric encryption algorithm is an encryption technique in which a key used to encrypt information and a key used to decrypt the information are the same. An example of a symmetric encryption algorithm is the AES algorithm. The asymmetric encryption algorithm is an encryption technique in which a key used to encrypt information and a key used to decrypt the information are different from each other.

Registered Patent Publication: Registration No. 10-1638398 (Announced on July 12, 2016) Registered Patent Publication: Registration No. 10-1582128 (Announced on January 04, 2016) Laid-Open Patent Publication: Publication No. 10-2019-0091762 (published on August 07, 2019)

The technical problem to be achieved by the present invention is to divide the original file into several pieces according to division number information and division size information in order to safely protect the original file from attacks by malicious attackers, encrypt the divided files, and store the encrypted files. It is to provide a computer program and method for restoring original files by decryption.

The method for dividing and merging original files of an electronic device according to the present invention comprises the steps of: setting division number information indicating how many original files are to be divided and division size information of each of the files to be divided according to the division number information; generating divided files by dividing according to the number of division information and division size information of each of the files to be divided, and encrypting each of the divided files to generate each of the encrypted divided files; Generating each of the headers including order information for each of the files, the number of division information, and division size information for each of the divided files, including each of the encrypted divided files and each of the headers and generating each of the final split files.

In combination with the hardware according to the present invention, the computer program stored in the storage medium for dividing and merging the original files is divided into the number of division information indicating how many the original files are divided and the division size of each of the files to be divided according to the division number information. setting information; dividing the original file according to the number of divisions information and division size information of each of the files to be divided to generate divided files; generating each of the headers, each of the headers including order information for each of the divided files, information on the number of divisions, and division size information for each of the divided files; A step of generating each of the final divided files including each of the files and each of the headers is performed.

In combination with the hardware according to the present invention, the computer program stored in the storage medium to divide and merge the original file sets the number of division information indicating how many the original file is divided; generating divided files by dividing the original file by a number corresponding to the divided number information; generating an encrypted first divided file by encrypting a first divided file among the divided files; generating a first hash file by hashing the encrypted first divided file; and encrypting the first file with a first public key for the first divided file to generate an encrypted first hash file.

According to an embodiment of the present invention, a computer program and protection method for safely protecting an original file from an attack (eg, hacking) of a malicious attacker divides the original file into several pieces according to the number of division information and the division size information. and encrypting the divided files, merging the corresponding header for each encrypted divided file to generate final divided files, and decrypting the encrypted divided files to restore the original file.

A computer program and protection method for safely protecting an original file from an attack (for example, hacking) of a malicious attacker divides the original file into several pieces according to the division number information and division size information and encrypts it, so the encryption speed is fast, Since the encrypted split files are decrypted, the decryption speed is effective.

In order to more fully understand the drawings recited in the Detailed Description, a detailed description of each drawing is provided.
1 is a block diagram of an electronic device executing a computer program according to an embodiment of the present invention.
FIG. 2 is a view for explaining a process of generating final divided files from an original file using the computer program shown in FIG. 1 .
FIG. 3 is a diagram for explaining a process of encrypting a divided file and decrypting an encrypted divided file using the computer program shown in FIG. 1 .
FIG. 4 is a flowchart for explaining a method of operating the computer program shown in FIG. 1 .

In the present specification, an original file (also referred to as a 'file') means a computer file, and logical information including meaningful information (this is also referred to as 'data') in an electronic device such as a computer. is a unit of Examples of the original file include a text file, a design file, a binary file, an image file, an audio file, an image file, a compressed file, a program file, and/or an operating system (OS) update file.

The computer program 115 described herein is a set of instructions that, when the computer program 115 is executed in the computer 100 , performs a specific task.

A series of files including a file division operation, an encryption operation, a decryption operation, and a file merging operation, which will be described with reference to FIGS. 1 to 4 in combination with hardware (eg, the electronic device 100 or the processor 110 ) The computer program 115 that performs the operations is stored in a storage medium (eg, the storage device 140 accessible by the electronic device 100 or the processor 110) in a program, program code, or binary format. It is stored as a file and when the user executes the computer program 115, it is loaded from the storage medium to a memory device (eg, a memory device accessible by the electronic device 100 or the processor 110). is executed

Examples of storage device 140 include a hard disk, a solid state disk, a removable memory device, and/or a memory device, and the like. The memory device is a generic term for a volatile memory device such as a DRAM and a nonvolatile memory device such as a flash memory device.

The computer program 115 records information (this is also referred to as 'data' or 'file') in each header (HED1 to HED4) to be described herein, and extracts the information recorded in each header (HED1 to HED4). can be read

1 is a block diagram of an electronic device executing a computer program according to an embodiment of the present invention. Referring to FIG. 1 , the electronic device 100 includes a processor 110 that executes a computer program 115 , an input device 120 , a communication device 130 , a storage device 140 , and an output device 150 . include

Examples of the electronic device 100 include a computer, a personal computer (PC), a server, and a mobile device. Server refers to a computer system that provides information or services to client computers through a communication network. Examples of mobile devices include laptop computers, mobile internet devices (MIDs), tablet PCs, personal digital assistants (PDAs), and/or smart phones, and the like.

The computer program 115 executed by the processor 110 is a malicious attacker's attack (eg, hacking) and/or malicious information on an original file (or an original file of various formats; ORF). In order to safely protect the original file (ORF) from leakage, it is divided into several divided files according to the division number information (NOD) and division size information (FSi, i is a natural number greater than or equal to 2), and each of the divided files is It encrypts and creates final split files by attaching a corresponding header to each encrypted split file.

The division number information NOD is information indicating how many original files the ORF is to be divided into, and is a natural number, and the division size information FSi is information indicating the size of the divided file, which is a natural number and may be expressed as a multiple of bytes.

Also, the computer program 115 decrypts each of the final divided files, and restores one original file (ORF) by combining the decrypted divided files.

The input device 120 transmits the division number information NOD and division size information FSi input from the user of the electronic device 100 to the computer program 115 executed by the processor 110 . For example, the original file ORF may be a file to be transmitted from another electronic device communicating with the communication device 130 of the electronic device 100 , and input (or generated) by a user using the input device 120 . It can be a file.

The communication device 130 may receive the original file ORF input from the outside of the electronic device 100 and transmit the original file ORF to the computer program 115 of the processor 110 .

The storage device 140 may receive and store an original file ORF written by a user or an original file ORF input from the outside under the control of the computer program 115 . When the electronic device 100 is a server, the storage device 140 may be a database storage device that manages a database.

The output device 150 may be a monitor or display device that displays information to be processed or processed information by the computer program 115 .

FIG. 2 is a view for explaining a process of generating final divided files from an original file using the computer program shown in FIG. 1, and FIG. 3 is a diagram for encrypting a divided file using the computer program shown in FIG. It is a diagram explaining the process of decrypting a file.

1 to 3 , the computer program 115 generates an original file ( ORF) is divided into four divided files (DF1 to DF4). Here, it is assumed that the division number information NOD is 4, and division size information FS1 , FS2 , FS3 , and FS4 for each divided file DF1 to DF4 are different from each other.

For example, the size of the original file ORF is 10 bytes, the number of division information NOD is 4, the division size information FS1 of the first divided file DF1 is 4, and the second divided file DF2 ), when the division size information FS2 is 3, the division size information FS3 of the third divided file DF3 is 2, and the division size information FS4 of the fourth divided file DF4 is 1, the computer The program 115 can generate four divided files DF1 to DF4 having a size suitable for the division number information NOD and division size information FS1, FS2, FS3, and FS4 from the original file ORF. have.

According to embodiments, when only the division number information NOD is input and the division size information FSi is not input, the computer program 115 divides the original file ORF by the number corresponding to the division number information NOD. to create split files. In this case, the size of each of the divided files is the same.

However, when the size of the original file ORF is 10 bytes and the number of division information NOD is 3, the computer program 115 generates a first divided file having a size of 4 bytes and a second divided file having a size of 3 bytes. , and a third divided file having a size of 3 bytes may be created. In this case, the computer program 115 may make the size of the first divided file or the last divided file larger than the size of each of the other divided files.

According to embodiments, when the computer program 115 is created as a program that processes only the number of divisions information NOD, the computer program 115 does not process the division size information FSi.

A process in which the computer program 115 processes (eg, encrypts) the first divided file DF1 to generate the first final divided file DATA1 will be described with reference to FIGS. 1 to 3 (a). .

The first final split file DATA1 includes an encrypted first split file EDFi, i=1 and a first header HED1, and the first header HED1 is an encrypted first split file EDF1. information about (CS, PI1, HD1, HI1, and KI1).

The first header (HED1) includes a checksum (CS), first encryption policy information (PI1), a first hash file (HD1), an encrypted first hash file (HI1), and a first public key (KI1), , the first encryption policy information (PI1) includes the encrypted first key (EKi, i=1), the first order information (P1), the number of division information (NOD), the first encryption method information (EM1), and the first Partition size information (FSi, i=1) is included.

The checksum CS commonly included in each header HED1 to HED4 includes a definition value (eg, information about a company that made the computer program 115 ) of each header HED1 to HED4 .

The first order information P1 is a file in which the encrypted first divided file EDF1 and/or the first final divided file DATA1 is related to the first divided file DF1 among the four divided files DF1 to DF4. indicates that For example, the first order information P1 may be 1.

The divided number information NOD indicates the total number (eg, 4) of the divided files DF1 to DF4.

The first encryption method information EM1 indicates information on an encryption method used to generate the encrypted first divided file EDF1.

For example, the first encryption method information EM1 includes an encrypted first divided file EDF1 in the first divided file DF1 with an asymmetric key algorithm (eg, Rivest, Shamir, and Adleman (RSA) algorithm). Whether it is a file created by applying a symmetric key algorithm (eg, AES (Advanced Encryption Standard) algorithm), or a hash algorithm (eg, SHA (Secure Hash Algorithm) or SHA256 algorithm) to indicate whether the file is created.

The first divided size information FS1 indicates size information of the first divided file DF1. For example, the first divided size information FS1 indicates how many bytes the first divided file DF1 is.

Referring to (a) of FIG. 3 , the computer program 115 encrypts the first divided file (DFi, i=1) using the first key (KYi, i=1) and encrypts the first divided file ( EDFi, i = 1) is generated (S110).

The computer program 115 encrypts the first key KY1 using the first public key KIi, i=1 and generates an encrypted first key EKi, i=1 (S120).

The computer program 115 hashes (eg, hashes using a hash function) the encrypted first split file EDF1 and generates a first hash file (or first hash data, HDi, i=1) (S130).

The computer program 115 encrypts the first hash file HD1 using the first public key KI1 and generates an encrypted first hash file (or encrypted first hash data, HIi, i=1). (S140).

The computer program 115 generates the first and final divided file DATA1 including the encrypted first divided file EDF1 and the first header HED1.

The second final split file DATA2 includes an encrypted second split file EDF2 and a second header HED2, and the second header HED2 includes information about the encrypted second split file EDF2. do.

The second header (HED2) includes a checksum (CS), second encryption policy information (PI2), a second hash file (HD2), an encrypted second hash file (HI2), and a second public key (KI2). , the second encryption policy information (PI2) includes the encrypted second key (EKi, i=2), the second order information (P2), the number of division information (NOD), the second encryption method information (EM2), and the second Partition size information (FSi, i=2) is included.

The second order information P2 is a file in which the encrypted second divided file EDF2 and/or the second final divided file DATA2 is related to the second divided file DF2 among the four divided files DF1 to DF4. indicates that For example, the second order information P2 may be 2.

The second encryption method information EM2 indicates information on an encryption method used to generate the encrypted second divided file EDF2.

For example, the second encryption method information EM2 includes whether the encrypted second divided file EDF2 is a file generated by applying an asymmetric key algorithm (eg, RSA algorithm) to the second divided file DF2; Indicates whether a file is generated by applying a symmetric key algorithm (eg, AES algorithm) or a file generated by applying a hash algorithm (eg, SHA2 or SHA256 algorithm).

The second divided size information FS2 indicates size information of the second divided file DF2. For example, the second division size information FS2 indicates the number of bytes of the second divided file DF2.

Referring to (a) of FIG. 3 , the computer program 115 encrypts the second divided file (DFi, i=2) using the second key (KYi, i=2) and encrypts the second divided file ( EDFi, i = 2) is generated (S110).

The computer program 115 encrypts the second key KY2 using the second public key KIi, i=2, and generates an encrypted second key EKi, i=2 (S120).

The computer program 115 hashes (eg, hashes using a hash function) the encrypted second split file EDF2 and generates a second hash file (or second hash data, HDi, i=2). (S130).

The computer program 115 encrypts the second hash file HD2 using the second public key KI2 and generates an encrypted second hash file (or encrypted second hash data, HIi, i=2). (S140).

The computer program 115 generates the second final divided file DATA2 including the encrypted second divided file EDF2 and the second header HED2.

The third final split file DATA3 includes an encrypted third split file EDF3 and a third header HED3, and the third header HED3 includes information about the encrypted third split file EDF3. do.

The third header (HED3) includes a checksum (CS), third encryption policy information (PI3), a third hash file (HD3), an encrypted third hash file (HI3), and a third public key (KI3). , the third policy information (PI3) includes the encrypted third key (EKi, i=3), the third order information (P3), the number of partitions information (NOD), the third encryption information (EM3), and the third partition It includes size information (FSi, i=3).

The third order information P3 is the encrypted third divided file EDF3 and/or the third final divided file DATA3 is a file related to the third divided file DF3 among the four divided files DF1 to DF4. indicates that For example, the third order information P3 may be 3.

The third encryption method information EM3 indicates information on an encryption method used to generate the encrypted third divided file EDF3.

For example, the third encryption method information (EM3) is a file generated by applying an asymmetric key algorithm (eg, RSA algorithm) to the third divided file (DF3) that the encrypted third divided file (EDF3) is, Indicates whether a file is generated by applying a symmetric key algorithm (eg, AES algorithm) or a file generated by applying a hash algorithm (eg, SHA2 or SHA256 algorithm).

The third divided size information FS3 indicates size information of the third divided file DF3. For example, the third division size information FS3 indicates the number of bytes of the third divided file DF3.

Referring to (a) of FIG. 3 , the computer program 115 encrypts the third divided file (DFi, i=3) using the third key (KYi, i=3) and encrypts the third divided file ( EDFi, i = 3) is generated (S110).

The computer program 115 encrypts the third key (KY3) using the third public key (KIi, i=3) and generates an encrypted third key (EKi, i=3) (S120).

The computer program 115 hashes (eg, hashes using a hash function) the encrypted third split file EDF3 and generates a third hash file (or third hash data, HDi, i=3) (S130).

The computer program 115 encrypts the third hash file HD3 using the third public key KI3 and generates an encrypted third hash file (or encrypted third data, HIi, i=3) ( S140).

The computer program 115 generates the third final divided file DATA3 including the encrypted third divided file EDF3 and the third header HED3.

The fourth final divided file DATA4 includes an encrypted fourth divided file EDF4 and a fourth header HED4, and the fourth header HED4 includes information about the encrypted fourth divided file EDF4. do.

The fourth header (HED4) includes a checksum (CS), fourth encryption policy information (PI4), a fourth hash file (HD4), an encrypted fourth hash file (HI4), and a fourth public key (KI4) , the fourth encryption policy information (PI4) includes an encrypted fourth key (EKi, i=4), fourth order information (P4), division number information (NOD), fourth encryption method information (EM4), and a fourth Partition size information (FSi, i=4) is included.

The fourth order information P4 is a file in which the encrypted fourth divided file EDF4 and/or the fourth final divided file DATA4 is related to the fourth divided file DF4 among the four divided files DF1 to DF4. indicates that For example, the fourth order information P4 may be 4.

The fourth encryption method information EM4 indicates information on an encryption method used to generate the encrypted fourth divided file EDF4.

For example, the fourth encryption method information EM4 determines whether the encrypted fourth divided file EDF4 is a file generated by applying an asymmetric key algorithm (eg, RSA algorithm) to the fourth divided file DF4, Indicates whether a file is generated by applying a symmetric key algorithm (eg, AES algorithm) or a file generated by applying a hash algorithm (eg, SHA2 or SHA256 algorithm).

The fourth divided size information FS4 indicates size information of the fourth divided file DF4. For example, the fourth division size information FS4 indicates the number of bytes of the fourth divided file DF4.

Referring to (a) of FIG. 3 , the computer program 115 encrypts the fourth divided file (DFi, i=4) using the fourth key (KYi, i=4) and encrypts the fourth divided file ( EDF4) is generated (S110).

The computer program 115 encrypts the fourth key (KY4) using the fourth public key (KI4) and generates an encrypted fourth key (EKi, i=4) ( S120 ). Each key (KY1 to KY4) is an encryption key.

The computer program 115 hashes (eg, hashes using a hash function) the encrypted fourth split file (EDF4) and generates a fourth hash file (or third hash data, HDi, i=4) (S130).

The computer program 115 encrypts the fourth hash file HD4 using the fourth public key KI4 and generates an encrypted fourth hash file (or an encrypted fourth hash file, HIi, i=4). (S140).

The computer program 115 generates a fourth final divided file DATA4 including an encrypted fourth divided file EDF4 and a fourth header HED4.

According to embodiments, the computer program 115 may sequentially or parallelly generate the final divided files DATA1 to DATA4 from the divided files DF1 to DF4.

According to exemplary embodiments, each of the keys KY1 to KY4 may be different, and at least two of the keys KY1 to KY4 may be the same.

According to embodiments, each of the public keys KI1 to KI4 may be different, and at least two of the public keys KI1 to KI4 may be the same. For example, each of the public keys KI1 to KI4 may be a public key for the RSA algorithm.

According to embodiments, each of the encryption information EM1 to EM4 may be different from or the same as each other.

The process in which the computer program 115 processes (eg, decrypts) each final divided file DATA1 to DATA4 to generate (or restores) each divided file DF1 to DF4 is shown in FIGS. 1, 2, and FIG. It will be described with reference to (b) of 3 .

The computer program 115 extracts the encrypted first hash file HI1 and the first public key KI1 from the first header HED1 included in the first final split file DATA1, and the encrypted first hash The file (HIi, i=1) is decrypted using the first public key (KIi, i=1), and a decrypted first hash file (HDi, i=1) is generated (or restored) ( S210 ).

The computer program 115 compares the first hash file HD1 extracted from the first header HED1 with the first hash file HD1 decrypted in step 210, and when they match, the computer program 115 hashes the encrypted first split file (EDF, i=1) to re-generate the first hash file (HDi, i=1) (S220).

The computer program 115 compares the first hash file HD1 decrypted in step S210 with the first hash file HD1 generated in step S220. When they match, the computer program 115 decrypts the encrypted first key (EKi, i=1) using the first public key (KIi, i=1) to obtain the first key (KYi, i=1) is created (S230). The computer program 115 decrypts the encrypted first divided file EDF1 with the first key KY1 to restore the first divided file DF, i=1 (S240).

The computer program 115 generates an encrypted second hash file (HIi, i=2) and a second public key (KIi, i=2) from the second header (HED2) included in the second final split file (DATA2). The extracted, encrypted second hash file (HI2) is decrypted with the second public key (KI2), and a decrypted second hash file (HDi, i=2) is generated (or restored) (S210).

The computer program 115 compares the second hash file (HDi, i=2) extracted from the second header (HED2) with the second hash file (HD2) decoded in step 210, and when they match, the computer The program 115 hashes the encrypted second split file (EDFi, i=2) to re-generate the second hash file HD2 (S220).

The computer program 115 compares the second hash file HD2 decrypted in step 210 with the second hash file HD2 generated in step S220. When they match, the computer program 115 decrypts the encrypted second key (EKi, i=2) with the second public key (KI2) to generate the second key (KYi, i=2) ( S230 ). The computer program 115 decrypts the encrypted second divided file EDF2 with the second key KY2 to restore the second divided file DFi, i=2 (S240).

The steps in which the computer program 115 restores the third divided file DF3 and the fourth divided file DF4 from the third and fourth final divided files DATA3 and DATA4, respectively, are the steps of the computer program 115 ), the steps of restoring the first split file DF1 from the first and final split file DATA1 are the same or similar, so a description thereof will be omitted.

The computer program 115 merges the divided files DF1 to DF4 using each order information P1 to P4 included in each encryption policy information PI1 to PI4 of each final divided file DATA1 to DATA4. You can restore the original file (ORF).

According to embodiments, the computer program 115 performs a first operation of comparing the hash file generated in step S130 with the hash file generated in step S210, and the hash file generated in step S210 and step ( At least one of the second operation of comparing the hash files generated in S220) may be performed. After at least one of the first operation and the second operation is performed, the computer program 115 may perform steps S230 and S240.

FIG. 4 is a flowchart for explaining a method of operating the computer program shown in FIG. 1 .

A computer program 115 or a method performed by the computer program 115 is described with reference to FIGS. 1 to 4 .

The computer program 115 provides division size information FSi, i of each of the files DF1 to DF4 to be divided according to division number information NOD indicating how many original files ORF will be divided into division number information NOD and division number information NOD. = 1, 2, 3, and 4) is set (or received) (S310).

The computer program 115 divides the original file ORF according to the division number information NOD and division size information FS1, FS2, FS3, and FS4 of each of the files to be divided (DF1 to DF4) to create divided files. (DF1 to DF4) are generated (S320).

The computer program 115 encrypts each of the divided files DF1 to DF4 to generate each of the encrypted divided files EDF1 to EDF4 ( S330 ).

The computer program 115 includes first order information P1 for the first divided file DF1, number of division information NOD, and first division size information FS1 for the first divided file DF1. A first header HED1 is generated, and a first final divided file DATA1 including an encrypted first divided file EDF1 and a first header HED1 is generated ( S340 ).

The computer program 115 includes second order information P2 for the second divided file DF2, number of division information NOD, and second division size information FS2 for the second divided file DF2. A second header HED2 is generated, and a second final divided file DATA2 including the encrypted second divided file EDF2 and the second header HED2 is generated (S340).

The computer program 115 includes third order information P3 for the third divided file DF3, number of division information NOD, and third division size information FS3 for the third divided file DF3. A third header HED3 is generated, and a third final divided file DATA3 including the encrypted third divided file EDF3 and the third header HED3 is generated (S340).

The computer program 115 includes fourth order information P4 for the fourth divided file DF4, number of division information NOD, and fourth division size information FS4 for the fourth divided file DF4. A fourth header HED4 is generated, and a fourth final divided file DATA4 including an encrypted fourth divided file EDF4 and a fourth header HED4 is generated (S340).

The computer program 115 separates the encrypted first hash file HI1 and the first public key KI1 from the first header HED1, and converts the encrypted first hash file HI1 to the first public key KI1. ) to generate a decrypted first hash file (HD1), and compare the first hash file (HDI) generated in step S130 with the first hash file (HD1) decrypted in step S210, and the comparison objects match When the encrypted first key (EK1) is decrypted with the first public key (KI1), the decrypted first key (KY1) is restored, and the encrypted first divided file (EDF1) is decrypted with the decrypted first key (KY1). ) to generate a decrypted first divided file DF1 (S350).

The computer program 115 separates the encrypted second hash file HI2 and the second public key KI2 from the second header HED2, and converts the encrypted second hash file HI2 to the second public key KI2. ) to generate a decrypted second hash file (HD2), and compare the second hash file (HD2) generated in step S130 with the second hash file (HD2) decrypted in step S210, and the comparison objects match When the encrypted second key (EK2) is decrypted with the second public key (KI2), the decrypted second key (KY2) is restored, and the encrypted second divided file (EDF2) is decrypted with the decrypted second key (KY2). ) to generate a decrypted second divided file DF2 (S350).

The computer program 115 separates the encrypted third hash file (HI3) and the third public key (KI3) from the third header (HED3), and converts the encrypted third hash file (HI3) to the third public key (KI3). ) to generate a decrypted third hash file (HD3), compare the third hash file (HD3) generated in step S130 with the third hash file (HD3) decrypted in step S210, and the comparison targets match When the encrypted third key (EK3) is decrypted with the third public key (KI3), the decrypted third key (KY3) is restored, and the encrypted third divided file (EDF3) is decrypted with the decrypted third key (KY3). ) to generate a decrypted third divided file DF3 (S350).

The computer program 115 separates the encrypted fourth hash file (HI4) and the fourth public key (KI4) from the fourth header (HED4), and converts the encrypted fourth hash file (HI4) to the fourth public key (KI4). ) to generate a decrypted fourth hash file (HD4), compare the fourth hash file (HD4) generated in step S130 with the fourth hash file (HD4) decrypted in step S210, and the comparison targets match When the encrypted fourth key (EK4) is decrypted with the fourth public key (KI4), the decrypted third key (KY4) is restored, and the encrypted fourth divided file (EDF4) is decrypted with the decrypted fourth key (KY4). ) to generate a decrypted fourth divided file DF4 (S350).

The computer program 115 restores the original file ORF by combining the decoded divided files DF1 to DF4 into one using each order information P1 to P4 and the division number information NOD (S360).

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: electronic device
110: processor
115: computer program
120: input device
130: communication device
140: storage device
150: output device
ORF: source file
DF1 to DF4: Split file
EDF1~EDF4: Encrypted Split File
DATA1~DATA4: final split file
KY1~KY4: key
EK1~EK4: encrypted key
PI1~PI4: Password Policy Information
HD1-DH4: Hash file
HI1~HI4: Encrypted hash file
KI1~KI4: public key

Claims (11)

receiving division number information indicating how many original files are to be divided and division size information of each of the files to be divided according to the division number information;
generating divided files by dividing the original file according to the division number information and division size information of each of the files to be divided;
encrypting each of the divided files to generate each of the encrypted divided files;
generating each of the headers including order information for each of the divided files, information on the number of divisions, and division size information for each of the divided files; and
and generating each of the encrypted split files and each of the final split files including each of the headers. According to claim 1,
The step of generating each of the encrypted split files comprises:
generating each of the encrypted divided files by encrypting each of the divided files with a key for each of the divided files;
generating each of the encrypted keys by encrypting a key for each of the divided files with a public key for each of the divided files; and
and storing each of the encrypted keys and a public key for each of the divided files in each of the headers. 3. The method of claim 2,
generating each of the first hash files by hashing each of the encrypted split files;
generating each of the first hash files by encrypting each of the first hash files with a public key for each of the divided files; and
Splitting and merging the original file of the electronic device further comprising the step of storing each of the first hash files, each of the encrypted first hash files, and a public key for each of the split files in each of the headers Way. 4. The method of claim 3,
separating each of the encrypted first hash files and a public key for each of the divided files from each of the headers;
generating each of the decrypted hash files by decrypting each of the encrypted first hash files with a public key for each of the divided files;
comparing each of the first hash files with each of the decrypted hash files;
restoring the decrypted keys by decrypting each of the encrypted keys with a public key for each of the divided files when the comparison objects match;
generating each of the decrypted divided files by decrypting each of the encrypted divided files with each of the decrypted keys; and
and restoring the original file by combining each of the decoded divided files using order information on each of the divided files and information on the number of divisions. 4. The method of claim 3,
separating each of the encrypted first hash files and a public key for each of the divided files from each of the headers;
generating each of the decrypted hash files by decrypting each of the encrypted first hash files with a public key for each of the divided files;
generating each of the second hash files by hashing each of the encrypted split files;
comparing each of the second hash files with each of the decrypted hash files;
restoring the decrypted keys by decrypting each of the encrypted keys with a public key for each of the divided files when the comparison objects match;
generating each of the decrypted divided files by decrypting each of the encrypted divided files with each of the decrypted keys; and
and restoring the original file by combining each of the decoded divided files using order information on each of the divided files and information on the number of divisions. According to claim 1,
Wherein the original file is a text file, a design file, a binary file, an image file, an audio file, an image file, a compressed file, a program file, or an operating system (OS) update file. In a computer program combined with hardware and stored in a storage medium to divide and merge original files,
The computer program is
receiving division number information indicating how many of the original file is to be divided and division size information of each of the files to be divided according to the division number information;
generating divided files by dividing the original file according to the division number information and division size information of each of the files to be divided;
encrypting each of the divided files to generate each of the encrypted divided files;
generating each of the headers including order information for each of the divided files, information on the number of divisions, and division size information for each of the divided files; and
and generating each of the encrypted divided files and each of the final divided files including each of the headers. 8. The method of claim 7,
generating each of the hash files by hashing each of the encrypted split files;
generating each of the encrypted hash files by encrypting each of the hash files with a public key for each of the divided files; and
The computer program stored in the storage medium further performing the step of storing each of the hash files, each of the encrypted hash files, and a public key for each of the divided files in each of the headers. In a computer program combined with hardware and stored in a storage medium to divide and merge original files,
The computer program is
setting information on the number of divisions indicating the number of divisions of the original file;
generating divided files by dividing the original file by a number corresponding to the divided number information;
generating an encrypted first divided file by encrypting a first divided file among the divided files;
generating a first hash file by hashing the encrypted first divided file; and
A computer program stored in a storage medium for generating an encrypted first hash file by encrypting the first hash file with a first public key for the first divided file. 10. The method of claim 9,
generating a first header including order information of the first divided file, information on the number of divisions, the first hash file, the encrypted first hash file, and the first public key; and
The computer program stored in the storage medium further performs the step of generating a first final divided file including the encrypted first divided file and the first header. 10. The method of claim 9,
setting first divided size information for determining the size of the first divided file;
determining a size of the first divided file to be divided according to the divided number information and the first divided size information; and
The computer program stored in the storage medium further performing the step of generating the first header further including the first division size information.

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