KR102602189B1 - Document sharing service server for managing document sharing service based on cloud, and the operating method thereof - Google Patents

Abstract

A document sharing service server for operating a cloud-based document sharing service and its operating method are disclosed. The present invention proposes a technology for encrypting document files for electronic documents containing personal information, storing them in a document file storage, and allowing only approved members to view the document files in a cloud-based document sharing service. By doing so, you can prevent document files containing personal information from being leaked to others.

Description

Document sharing service server for operating a cloud-based document sharing service and its operating method {DOCUMENT SHARING SERVICE SERVER FOR MANAGING DOCUMENT SHARING SERVICE BASED ON CLOUD, AND THE OPERATING METHOD THEREOF}

The present invention relates to a document sharing service server for operating a cloud-based document sharing service and a method of operating the same.

Recently, as high-speed Internet environments become widespread and the demand for working from home increases, the introduction of cloud-based document sharing services is increasing in various fields such as companies and schools.

The cloud-based document sharing service stores document files in a separate document file storage rather than the electronic terminal of members who subscribe to the document sharing service, allowing members to share document files stored in the document file storage. This refers to the supported service.

Through this document sharing service, members can access the document file storage without physical restrictions, save new document files in the document file storage, or view document files stored in the document file storage.

Meanwhile, electronic documents written by members may contain personal information such as resident registration numbers or phone numbers. If personal information is indiscriminately leaked to others, it can be misused for crimes. Therefore, document files containing personal information Be careful not to leak it to others.

In particular, document files stored in the document file storage may be shared with other members through document sharing services, preventing document files containing personal information from being leaked to others in these document sharing services. It is necessary to introduce technology to do this.

In this regard, before storing a document file in a document file storage, it is checked whether the electronic document according to the document file contains personal information, and if it is confirmed that it contains personal information, the document file is encrypted. If you store it in a document file storage and allow only approved members to view the document file, you can minimize the leakage of document files containing personal information to others.

Therefore, in cloud-based document sharing services, research is needed on technology to encrypt document files containing personal information and store them in document file storage.

The present invention proposes a technology for encrypting document files for electronic documents containing personal information, storing them in a document file storage, and allowing only approved members to view the document files in a cloud-based document sharing service. By doing so, it is possible to prevent document files containing personal information from being leaked to others.

The document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention stores a plurality of different regular expressions that are preset to correspond to the notation format of personal information. a storage unit, a member information storage unit storing member identification information of each of a plurality of members subscribed to the document sharing service and terminal identification information of an electronic terminal held by each of the plurality of members in correspondence with each other; When a first document file is received from a first electronic terminal owned by a first member, which is one of a plurality of members, and a storage request command for the first document file is received, the first document file according to the first document file is received. A string confirmation unit that checks whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document, and an electronic document according to the first document file. If it is confirmed that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the document, the member information storage unit is referred to, and the first member's first string is referred to. 1. A document file storage processing unit that verifies member identification information, encrypts the first document file, stores the encrypted first document file and the first member identification information in a document file storage by matching the encrypted first document file with the first member identification information, and the encrypted first document file. After the first document file and the first member identification information are stored in the document file storage in correspondence with each other, the first document file is received from a second electronic terminal held by a second member, another one of the plurality of members. When a sharing request is received, the first member identification information stored in correspondence with the encrypted first document file is checked on the document file storage, and based on the first member identification information, the member After checking the first terminal identification information stored in correspondence with the first member identification information on the information storage unit, based on the first terminal identification information, the first electronic terminal sends the information to the second member. By transmitting an inquiry message containing a question asking for approval for sharing the first document file, an approval order for sharing the first document file with the second member is received from the first electronic terminal. Once done, it includes a document file transmission unit that extracts the encrypted first document file from the document file storage, decrypts the encrypted first document file, and transmits it to the second electronic terminal.

In addition, the method of operating a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention is a regular expression in which a plurality of different regular expressions preset to correspond to the notation format of personal information are stored. Maintaining an expression storage unit, member information storing member identification information of each of a plurality of members subscribed to the document sharing service and terminal identification information of an electronic terminal held by each of the plurality of members in correspondence with each other. Maintaining a storage unit, when a first document file is received from a first electronic terminal owned by a first member, which is one of the plurality of members, and a storage request command for the first document file is received, Checking whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document according to the first document file, the first When it is confirmed that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the document file, referring to the member information storage unit, Confirming the first member identification information of the first member, encrypting the first document file, and then storing the encrypted first document file and the first member identification information in a document file storage in correspondence with each other, and encrypting the first member identification information. After the first document file and the first member identification information correspond to each other and are stored in the document file storage, from a second electronic terminal held by a second member, which is another one of the plurality of members, the first member identification information is stored in the document file storage. When a sharing request for a document file is received, check the first member identification information stored in correspondence with the encrypted first document file on the document file storage, and based on the first member identification information, After checking the first terminal identification information stored in the member information storage unit corresponding to the first member identification information, based on the first terminal identification information, the second member is transferred to the first electronic terminal. An inquiry message containing a question asking for approval for sharing the first document file is sent to the first electronic terminal, and an order for approval for sharing the first document file is sent from the first electronic terminal to the second member. When received, the method includes extracting the encrypted first document file from the document file storage, decrypting the encrypted first document file, and transmitting the encrypted first document file to the second electronic terminal.

The present invention proposes a technology for encrypting document files for electronic documents containing personal information, storing them in a document file storage, and allowing only approved members to view the document files in a cloud-based document sharing service. By doing so, you can prevent document files containing personal information from being leaked to others.

Figure 1 is a diagram showing the structure of a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention.
Figure 2 is a flowchart showing a method of operating a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings. This description is not intended to limit the present invention to specific embodiments, but should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used for similar components, and unless otherwise defined, all terms used in this specification, including technical or scientific terms, are within the scope of common knowledge in the technical field to which the present invention pertains. It has the same meaning as generally understood by those who have it.

In this document, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary. Additionally, in various embodiments of the present invention, each component, functional block, or means may be composed of one or more subcomponents, and the electrical, electronic, and mechanical functions performed by each component may be electronic. It may be implemented with various known elements or mechanical elements such as circuits, integrated circuits, and ASICs (Application Specific Integrated Circuits), and may be implemented separately or by integrating two or more into one.

Meanwhile, the blocks in the attached block diagram or the steps in the flow chart are computer program instructions that are mounted on the processor or memory of equipment capable of data processing, such as general-purpose computers, special-purpose computers, portable laptop computers, and network computers, and perform designated functions. It can be interpreted to mean. Because these computer program instructions can be stored in a memory provided in a computer device or in a computer-readable memory, the functions described in the blocks of a block diagram or the steps of a flow diagram can be produced as a manufactured product containing instruction means to perform them. It could be. In addition, each block or each step may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative embodiments, it is possible for functions mentioned in blocks or steps to be executed in a different order. For example, two blocks or steps shown in succession may be performed substantially simultaneously or in reverse order, and in some cases, some blocks or steps may be omitted.

Figure 1 is a diagram showing the structure of a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention.

Referring to Figure 1, the document sharing service server 110 according to an embodiment of the present invention includes a regular expression storage unit 111, a member information storage unit 112, a string verification unit 113, and a document file storage processing unit ( 114) and a document file transmission unit 115.

The regular expression storage unit 111 stores a plurality of different regular expressions that are preset to correspond to the notation format of personal information.

For example, the regular expression storage unit 111 may store a plurality of different regular expressions that are preset to correspond to the notation format of personal information as shown in Table 1 below.

Format of personal information regular expression Mobile phone number notation format ^\d{3}-\d{3,4}-\d{4}$ Phone number notation format ^\d{2,3}-\d{3,4}-\d{4}$ Resident registration number notation format ^\d{6}-\d{7}$ ... ...

In the member information storage unit 112, member identification information of each of the plurality of members subscribed to the document sharing service and terminal identification information of the electronic terminal held by each of the plurality of members are stored in correspondence with each other.

Here, member identification information refers to information such as ID and resident registration number to identify each member, and terminal identification information refers to identification information pre-assigned to each electronic terminal to identify each electronic terminal. MAC address or IMEI (International Mobile Equipment Identity) may be used.

For example, the member information storage unit 112 includes member identification information for each of the plurality of members subscribed to the document sharing service as shown in Table 2 below, and terminal identification information for the electronic terminal held by each of the plurality of members. may be stored in correspondence with each other.

multiple members Member Identification Information electronic terminal Terminal identification information member 1 Member Identification Information 1 electronic terminal 1 Terminal identification information 1 member 2 Member Identification Information 2 electronic terminal 2 Terminal identification information 2 member 3 Member Identification Information 3 electronic terminal 3 Terminal identification information 3 member 4 Member Identification Information 4 electronic terminal 4 Terminal identification information 4 ... ... ... ..

When the first document file is received from the first electronic terminal 151 owned by the first member 141, which is one of the plurality of members, the string confirmation unit 113 provides information about the first document file. When a storage request command is received, whether there is a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit 111 among the text included in the electronic document according to the first document file. Check whether

The document file storage processing unit 114 determines that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file. Then, the first member identification information of the first member 141 is checked by referring to the member information storage unit 112, the first document file is encrypted, and the encrypted first document file and the first Member identification information is matched to each other and stored in the document file storage 132.

At this time, according to one embodiment of the present invention, the document file storage processing unit 114 includes a table maintenance unit 116, an encryption event generation unit 117, a password setting request unit 118, a serial number extraction unit 119, It may include an operation code generation unit 120, an encryption key generation unit 121, and an encryption storage processing unit 122.

The table maintenance unit 116 is a series of different t (t is a natural number of 2 or more) digits corresponding to each of a plurality of preset document formats that are pre-shared with the electronic terminal held by each of the plurality of members. A serial number table containing numbers is stored and maintained. Here, the document format refers to the file format for each document with an extension such as '.hwp', '.docx', '.pdf', etc.

For example, when t is '4', the table maintenance unit 116 records different '4' digit serial numbers corresponding to each of a plurality of preset document formats, as shown in Table 3 below. You can save and maintain tables.

Multiple document formats Serial Number Format 1 6401 format 2 3286 format 3 5429 format 4 1752 format 5 9367 ... ...

At this time, the serial number table as shown in Table 3 may be pre-stored in the electronic terminal owned by each of the plurality of members.

The encryption event generator 117 determines that the at least one first string is a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file. Once confirmed, the member information storage unit 112 is referred to, the first member identification information of the first member 141 is confirmed, and an encryption event for encrypting the first document file is generated.

When the encryption event is generated by the encryption event generator 117, the password setting request unit 118 requests the first electronic terminal 151 to set a t-digit password for encryption of the first document file. A password setting request message containing the following is sent.

When the serial number extractor 119 receives the first password from the first electronic terminal 151 as the first password is set by the first member 141 in response to the password setting request message, the serial number extractor 119 After confirming the first document format of the first document file, the first serial number corresponding to the first document format is extracted from the serial number table.

The operation code generator 120 generates a t-bit first operation code by configuring the result of performing a modulo-2 operation on each of the t numbers constituting the first password into a bit string. and generate a second operation code of t bits by configuring the result of performing modulo-2 operation on each of the t numbers constituting the first serial number into a bit string.

Here, the modulo-2 operation refers to an operation that performs division by dividing the dividend by 2 and calculates the remainder.

The encryption key generator 121 generates a t-bit seed code by performing an exclusive OR (XOR) operation between the first operation code and the second operation code, and then encrypts the seed code using a preset encryption method. The first encryption key is generated by applying it as an input to the key generation function.

Here, the encryption key generation function may be a preset hash function.

The encryption storage processing unit 122 encrypts the first document file with the first encryption key, then stores the encrypted first document file and the first member identification information in the document file storage 132 in correspondence with each other.

Below, the encryption event generation unit 117, password setting request unit 118, serial number extraction unit 119, operation code generation unit 120, encryption key generation unit 121, and encryption storage processing unit 122. The operation will be explained in detail using an example.

First, when ‘document file 1’ is received from ‘electronic terminal 1 (151)’ owned by ‘member 1 (141)’ on the document sharing service server 110, a storage request command for ‘document file 1’ is sent. Assume this has been received. Afterwards, the string confirmation unit 113 selects, among the text included in the electronic document according to 'document file 1', a plurality of regular expressions corresponding to the plurality of regular expressions stored in the regular expression storage unit 111 as shown in Table 1 above. As a result of checking whether a string with a notation format exists, among the text included in the electronic document according to 'Document File 1', at least one first string is a string with a notation format corresponding to the plurality of regular expressions. Let us assume that it is confirmed to exist.

At this time, the encryption event generator 117 refers to the member information storage unit 112 as shown in Table 2 above, and stores 'member identification information 1', which is the identification information of 'member 1 (141)', as the first member identification information. This can be confirmed with , and an encryption event can be generated to encrypt 'Document File 1'.

Then, the password setting request unit 118 transmits a password setting request message to 'electronic terminal 1 (151)' containing a request to set a '4' digit password for encryption of 'document file 1'. You can.

At this time, 'Member 1 (141)', who confirmed the password setting request message, is said to have set the first password, '1230', as a '4' digit password for encryption of 'Document File 1', and accordingly, the document Let us assume that the first password '1230' is received from 'electronic terminal 1 (151)' at the shared service server 110.

Then, the serial number extraction unit 119 can check the first document format of 'document file 1'.

As a result, when it is confirmed that the first document format of 'document file 1' is 'format 1', the serial number extractor 119 extracts a document corresponding to 'format 1' from the serial number table shown in Table 3 above. The serial number '6401' can be extracted as the first serial number.

Then, the operation code generator 120 configures the result value of performing modulo-2 operation on each of the '4' numbers constituting the first password '1230' into a bit string. A 4'-bit first operation code can be generated such as '1010', and when modulo-2 operation is performed on each of the '4' numbers constituting the first serial number '6401', By organizing the result value into a bit string, a second operation code of '4' bits can be generated, such as '0001'.

Then, the encryption key generator 121 performs an exclusive OR operation between the first operation code '1010' and the second operation code '0001', thereby converting the '4' bit seed code into '1011'. can be created.

Then, the encryption key generator 121 can generate 'encryption key 1' by applying the seed code '1011' as an input to a preset encryption key generation function.

Then, the encryption storage processing unit 122 encrypts 'document file 1' with 'encryption key 1', then matches the encrypted 'document file 1' and 'member identification information 1' to the document file storage 132. You can save it.

In this way, after the encrypted first document file and the first member identification information are stored in the document file storage 132 in correspondence with each other by the document file storage processing unit 114, the first member, who is another one of the plurality of members, 2 When a sharing request for the first document file is received from the second electronic terminal 152 owned by member 142, the document file transmission unit 115 stores the encrypted file on the document file storage 132. The first member identification information stored in correspondence with the first document file is confirmed, and based on the first member identification information, the first member identification information is stored in the member information storage unit 112, corresponding to the first member identification information. After checking the stored first terminal identification information, whether to approve sharing the first document file with the first electronic terminal 151 and the second member 142 based on the first terminal identification information. By transmitting a query message containing inquiry content, when an approval command for sharing the first document file is received from the first electronic terminal 151 to the second member 142, the document file storage 132 ), after extracting the encrypted first document file, the encrypted first document file is decrypted and transmitted to the second electronic terminal 152.

At this time, according to an embodiment of the present invention, the document file transmission unit 115 includes an identification information confirmation unit 123, a query message transmission unit 124, a decryption event generation unit 125, a reply request unit 126, It may include an operation code regeneration unit 127, an encryption key regeneration unit 128, and a decryption transmission processing unit 129.

The identification information confirmation unit 123 stores the encrypted first document file and the first member identification information in correspondence with each other in the document file storage 132 by the document file storage processing unit 114, and then connects the second electronic terminal to the second electronic terminal. When a sharing request for the first document file is received from 152, the first member identification information stored in the document file storage 132 corresponding to the encrypted first document file is checked.

When the first member identification information is confirmed by the identification information confirmation unit 123, the inquiry message transmission unit 124 stores the first member identification information on the member information storage unit 112 based on the first member identification information. After checking the first terminal identification information stored in correspondence with the member identification information, the inquiry message is transmitted to the first electronic terminal 151 based on the first terminal identification information.

When the approval command is received from the first electronic terminal 151 in response to the query message, the decryption event generator 125 extracts the encrypted first document file from the document file storage 132 and then encrypts it. A decryption event is generated to decrypt the first document file.

When the decryption event is generated by the decryption event generator 125, the reply request unit 126 requests the first electronic terminal 151 to enter the password set for encryption of the first document file. At the same time as transmitting the password input request message containing the content, extract the serial number corresponding to the document format of the first document file from the serial number table stored on the first electronic terminal 151 and reply. Send the requested serial number reply command.

The operation code regeneration unit 127 operates on the first electronic terminal 151 as the first password is input by the first member 141 on the first electronic terminal 151 in response to the password input request message. ), and in response to the serial number reply command, the first document is retrieved from the serial number table stored on the first electronic terminal 151 by the first electronic terminal 151. As the first serial number corresponding to the format is extracted, when the first serial number is returned from the first electronic terminal 151, modulo-2 operation is performed on each of the t numbers constituting the first password. The first operation code of t bits is generated by configuring the result value when performing the operation into a bit string, and the modulo-2 operation is performed on each of the t numbers constituting the first serial number. The second operation code of t bits is generated by organizing the result value into a bit string.

The encryption key regeneration unit 128 generates the seed code of t bits by performing an exclusive OR operation between the first operation code and the second operation code, and then inputs the seed code to the encryption key generation function. Authorizes and generates the first encryption key.

The decryption and transmission processing unit 129 restores the first document file by decrypting the encrypted first document file with the first encryption key, and then transmits the restored first document file to the second electronic terminal 152. do.

Hereinafter, the identification information confirmation unit 123, the inquiry message transmission unit 124, the decryption event generation unit 125, the reply request unit 126, the operation code regeneration unit 127, the encryption key regeneration unit 128, and The operation of the decryption and transmission processing unit 129 will be described in detail using an example.

First, according to the above-described example, it is assumed that the encrypted 'document file 1' and 'member identification information 1' are stored in the document file storage 132 in correspondence with each other by the document file storage processing unit 114, and thereafter, Let's assume that a sharing request for 'document file 1' is received from 'electronic terminal 2 (152)' owned by 'member 2 (142)' on the document sharing service server 110.

Then, the identification information confirmation unit 123 can check 'member identification information 1' stored in correspondence with the encrypted 'document file 1' on the document file storage 132.

After that, the inquiry message transmission unit 124, based on ‘member identification information 1’, stores the ‘terminal information’ stored in correspondence with ‘member identification information 1’ on the member information storage unit 112 as shown in Table 2 above. You can check ‘Identification Information 1’.

Then, the inquiry message transmission unit 124 gives approval to share ‘document file 1’ with ‘electronic terminal 1 (151)’ and ‘member 2 (142)’ based on ‘terminal identification information 1’. You can transmit a query message containing a query about whether or not the device is available.

At this time, it is said that 'member 1 (141)', who confirmed the inquiry message, granted an approval order for sharing 'document file 1' to 'member 2 (142)' on 'electronic terminal 1 (151)'. , Accordingly, let us assume that the approval command is received from 'electronic terminal 1 (151)' at the document sharing service server 110.

Then, the decryption event generator 125 may extract the encrypted 'document file 1' from the document file storage 132 and then generate a decryption event to decrypt the encrypted 'document file 1'.

Then, the reply request unit 126 transmits a password input request message to 'electronic terminal 1 (151)' containing a request to enter the password set for encryption of 'document file 1', and At the same time, a serial number reply command is requested to extract a serial number corresponding to the document format of 'document file 1' from the serial number table shown in Table 3 stored on 'electronic terminal 1 (151)' and request a reply. Can be transmitted.

At this time, it is said that 'Member 1 (141)', who confirmed the password input request message, entered the first password '1230' on 'Electronic Terminal 1 (151)', and accordingly, the document sharing service server 110 Let us assume that the first password '1230' is received from 'electronic terminal 1 (151)'.

At the same time, in response to the serial number reply command, 'electronic terminal 1 (151)' retrieves 'document file 1' from the serial number table as shown in Table 3 stored on 'electronic terminal 1 (151)'. It is said that the first serial number '6401' was extracted as a serial number corresponding to the document format 'Format 1' and returned to the document sharing service server 110. Accordingly, the document sharing service server 110 received '6401'. Let us assume that the first serial number '6401' is received from 'electronic terminal 1 (151)'.

Then, the operation code regeneration unit 127 configures the result of performing modulo-2 operation on each of the '4' numbers constituting the first password '1230' into a bit string, thereby forming '4'. The first operation code of 'bit can be generated as '1010', and when modulo-2 operation is performed on each of the '4' numbers constituting the first serial number '6401' By organizing the result value into a bit string, the second operation code of '4' bits can be generated, such as '0001'.

Then, the encryption key regeneration unit 128 performs an exclusive OR operation between the first operation code '1010' and the second operation code '0001', thereby converting the seed code of '4' bits to '1011'. After generating as follows, 'encryption key 1' can be generated by applying the seed code '1011' as an input to the encryption key generation function.

At this time, according to the above-described example, the encrypted 'document file 1' is a file created by encrypting 'document file 1' with 'encryption key 1', so the decryption and transmission processing unit 129 encodes the encrypted 'document file 1'. By decrypting with 'Encryption Key 1', 'Document File 1' can be restored normally. Then, the decryption and transmission processing unit 129 can transmit the restored 'document file 1' to 'electronic terminal 2 (152)'. Through this, ‘Member 2 (142)’ can view ‘Document File 1’.

According to an embodiment of the present invention, when it is confirmed that the first document file does not contain personal information, the document sharing service server 132 stores the document file in an unencrypted state. By storing it in (132), it is possible to support the plurality of members to share the first document file.

In this regard, according to one embodiment of the present invention, the document file storage processing unit 114 may use the string confirmation unit 113 to select the regular expression storage unit 111 from among the text included in the electronic document according to the first document file. As a result of checking whether a string having a notation format corresponding to the plurality of regular expressions stored in exists, among the text included in the electronic document according to the first document file, there is a string corresponding to the plurality of regular expressions. If it is confirmed that a string with a notation format does not exist, the first document file may not be encrypted, and the first document file and the first member identification information may be matched to each other and stored in the document file storage 132. .

At this time, the document file transmission unit 115 stores the first document file in the document file storage 132 in correspondence with the first document file and the first member identification information, and then sends the second electronic terminal to the second electronic terminal. When a sharing request for the first document file is received from 152, the query message is not transmitted to the first electronic terminal 141, but the first document file is extracted from the document file storage 132 and a second document file is sent to the first electronic terminal 141. It can be transmitted to the electronic terminal 152.

Hereinafter, the operations of the document file storage processing unit 114 and the document file transmission unit 115 will be described in detail using an example.

First, as in the above-mentioned example, let us assume that 'document file 1' is received from 'electronic terminal 1 (151)' at the document sharing service server 110 and a storage request command for 'document file 1' is received. . At this time, the string confirmation unit 113 selects notations corresponding to the plurality of regular expressions stored in the regular expression storage unit 111 as shown in Table 1 among the text included in the electronic document according to 'document file 1'. As a result of checking whether a string with the format exists, let's assume that among the text included in the electronic document according to 'Document File 1', there is no string with the notation format corresponding to the plurality of regular expressions. .

Then, the document file storage processing unit 114 may store 'document file 1' and 'member identification information 1' in the document file storage 132 by matching them without encrypting 'document file 1'.

Afterwards, when the document sharing service server 110 receives a sharing request for 'document file 1' from 'electronic terminal 2 (152)', the document file transmission unit 115 sends 'electronic terminal 1 (151)' )', 'document file 1' can be extracted from the document file storage 132 and transmitted to 'electronic terminal 2 (152)'.

Additionally, according to one embodiment of the present invention, the document sharing service server 110 may further include a sharing history information generating unit 130 and a registration requesting unit 131.

When the first document file is completely transmitted to the second electronic terminal 152 by the document file transmission unit 115, the sharing history information generator 130 refers to the member information storage unit 112 and After confirming the second member identification information of 142 and generating time information about when the first document file was transmitted to the second electronic terminal 152, the second member identification information and the first document Shared history information consisting of the file and the time information is generated.

When the sharing history information is generated by the sharing history information generation unit 130, the registration request unit 131 generates a transaction containing the sharing history information, and then generates a transaction containing the sharing history information, and then Randomly selects a first node device, which is one of the node devices 101, 102, 103, 104, 105, and 106, and transmits the transaction to the first node device, while transmitting the transaction to the blockchain network ( Send a registration request to 100).

Hereinafter, the operations of the sharing history information generating unit 130 and the registration requesting unit 131 will be described in detail using an example.

First, according to the above-described example, let us assume that 'document file 1' has been completely transmitted to 'electronic terminal 2 (152)' by the document file transmission unit 115.

Then, the sharing history information generator 130 refers to the member information storage unit 112 as shown in Table 2 above, and generates 'member identification information 2', which is the member identification information of 'member 2 (142)', as the member identification information of the second member. It can be confirmed with identification information, and 'time information 1', which is time information about the time when 'document file 1' was transmitted to 'electronic terminal 2 (152)', can be generated.

Then, the sharing history information generator 130 may generate sharing history information consisting of 'member identification information 2', 'document file 1', and 'time information 1'.

Then, the registration request unit 131 generates a transaction containing the shared history information and then sends it to a plurality of node devices 101, 102, 103, 104, 105, and 106 constituting the blockchain network 100. The first node device may be randomly selected.

At this time, when the first node device is called the node device 101, the registration request unit 131 transmits the transaction to the node device 101 and requests registration of the transaction to the blockchain network 100. Can be transmitted.

At this time, when the first node device receives the transaction and the registration request from the document sharing service server 110, the first node device based on the previous block chained to the blockchain data stored in the memory of the first node device , After completing storage of the first block by creating a first block containing the transaction and connecting the first block to the blockchain data as a chain, the first block is stored through the blockchain network 100. One block can be propagated to the remaining node devices except the first node device among the plurality of node devices.

For example, as in the example described above, as the registration request unit 131 transmits the transaction to the node device 101 and transmits a request for registration of the transaction to the blockchain network 100, the node device 101 Let us assume that the transaction and the registration request are received.

Then, the node device 101 generates a first block containing the transaction based on the previous block chained to the blockchain data stored in the memory of the node device 101, and creates the first block. After completing the storage of the first block by linking it to the blockchain data with a chain, the first block is stored in a plurality of node devices 101, 102, 103, 104, through the blockchain network 100. It can be propagated to the remaining node devices (102, 103, 104, 105, and 106) except for the node device (101) among 105 and 106.

Specifically, when the node device 101 receives the transaction and the registration request from the document sharing service server 110, the node device 101 refers to the block header of the previous block linked to the blockchain data in a chain to include the transaction. The first block, which is a new block, can be created. Then, the node device 101 connects the first block to the blockchain data in a chain, so that after completing storage of the first block, the node device 101 transfers the first block to the remaining nodes through the blockchain network 100. It can propagate to devices 102, 103, 104, 105, and 106.

In this way, when the first document file is completely transmitted to the second electronic terminal 152, the document sharing service server 110 according to the present invention generates the sharing history information and registers it in the blockchain network 100. , it is possible to support the first member 141 to check the sharing history information and to whom the first document file was shared and when.

Figure 2 is a flowchart showing a method of operating a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention.

In step S210, a regular expression storage unit is maintained in which a plurality of different regular expressions preset to correspond to the notation format of personal information are stored.

In step S220, a member information storage unit in which the member identification information of each of the plurality of members subscribed to the document sharing service and the terminal identification information of the electronic terminal held by each of the plurality of members are stored in correspondence with each other. maintain

In step S230, when a first document file is received from a first electronic terminal owned by a first member, which is one of the plurality of members, and a storage request command for the first document file is received, It is checked whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document according to the first document file.

In step S240, if it is confirmed that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file, Referring to the member information storage unit, the first member identification information of the first member is confirmed, the first document file is encrypted, and the encrypted first document file and the first member identification information are matched to each other to create a document. Save it to file storage.

In step S250, the encrypted first document file and the first member identification information are stored in the document file storage in correspondence with each other, and then a second electronic file held by a second member, another one of the plurality of members, is stored in the document file storage. When a sharing request for the first document file is received from the terminal, the first member identification information stored in correspondence with the encrypted first document file is checked on the document file storage, and the first member Based on the identification information, after checking the first terminal identification information stored in the member information storage unit corresponding to the first member identification information, based on the first terminal identification information, the first electronic terminal By sending an inquiry message containing a question asking whether to approve sharing the first document file to the second member, the first document file is sent from the first electronic terminal to the second member. When an approval command for sharing is received, the encrypted first document file is extracted from the document file storage, and then the encrypted first document file is decrypted and transmitted to the second electronic terminal.

At this time, according to an embodiment of the present invention, in step S240, different t(t is a natural number of 2 or more) storing and maintaining a serial number table in which a serial number of digits is recorded, and notation formats corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file. When it is confirmed that the at least one first string exists, refer to the member information storage unit, confirm the first member identification information of the first member, and encrypt the first document file. Generating an encryption event, when the encryption event occurs, transmitting to the first electronic terminal a password setting request message containing a request to set a password of t digits for encryption of the first document file. Step, in response to the password setting request message, as the first password is set by the first member, when the first password is received from the first electronic terminal, the first document format of the first document file After confirmation, extracting a first serial number corresponding to the first document format from the serial number table, the result of performing modulo-2 operation on each of the t numbers constituting the first password. A first operation code of t bits is generated by configuring the value as a bit string, and the result value when modulo-2 operation is performed on each of the t numbers constituting the first serial number is composed of a bit string. generating a t-bit second operation code by performing an exclusive OR operation between the first operation code and the second operation code, generating a t-bit seed code, and then converting the seed code to a preset encryption key. Generating a first encryption key by applying it as an input to a generating function and encrypting the first document file with the first encryption key, then matching the encrypted first document file with the first member identification information to It may include storing the document in a file storage.

At this time, according to one embodiment of the present invention, in step S250, after the encrypted first document file and the first member identification information are stored in the document file storage in correspondence with each other, from the second electronic terminal, the When a sharing request for a first document file is received, checking the first member identification information stored in correspondence with the encrypted first document file on the document file storage, the first member identification information Once confirmed, based on the first member identification information, the first terminal identification information stored in correspondence with the first member identification information is confirmed on the member information storage unit, and then the first terminal identification information is stored. As a basis, transmitting the query message to the first electronic terminal, in response to the query message, when the approval command is received from the first electronic terminal, the encrypted first document file is retrieved from the document file storage. After extracting, generating a decryption event to decrypt the encrypted first document file. When the decryption event occurs, inputting the password set for encryption of the first document file to the first electronic terminal. At the same time as transmitting a password input request message containing a request to enter a password, a serial number corresponding to the document format of the first document file is extracted from the serial number table stored on the first electronic terminal and a reply is sent. transmitting a serial number reply command requesting that the first password be entered by the first member on the first electronic terminal in response to the password input request message; The first password is received from, and in response to the serial number reply command, the first electronic terminal selects the first document format from the serial number table stored on the first electronic terminal. As the first serial number is extracted, when the first serial number is returned from the first electronic terminal, the result value when modulo-2 operation is performed on each of the t numbers constituting the first password The first operation code of t bits is generated by configuring the first serial number as a bit string, and the result value when modulo-2 operation is performed on each of the t numbers constituting the first serial number is composed of a bit string. generating the second operation code of t bits by performing an exclusive OR operation between the first operation code and the second operation code, generating the seed code of t bits, and then encrypting the seed code. An encryption key regeneration unit that generates the first encryption key by applying it as an input to a key generation function and decrypting the encrypted first document file with the first encryption key, thereby restoring the first document file, and then restoring the restored first document file. It may include transmitting a first document file to the second electronic terminal.

In addition, according to an embodiment of the present invention, in step S240, notations corresponding to the plurality of regular expressions stored in the regular expression storage unit are displayed among the text included in the electronic document according to the first document file. As a result of checking whether a string with a format exists, when it is confirmed that a string with a notation format corresponding to the plurality of regular expressions does not exist among the text included in the electronic document according to the first document file, Without encrypting the first document file, the first document file and the first member identification information can be matched to each other and stored in the document file storage, and in step S250, the first document file is not encrypted, After the first document file and the first member identification information correspond to each other and are stored in the document file storage, when a sharing request for the first document file is received from the second electronic terminal, the first document file is sent to the first electronic terminal. Without transmitting a query message, the first document file can be extracted from the document file storage and transmitted to the second electronic terminal.

In addition, according to one embodiment of the present invention, the method of operating the document sharing service server includes, when the first document file is completely transmitted to the second electronic terminal, referring to the member information storage unit, 2 After confirming the member identification information and generating time information about the time when the first document file was transmitted to the second electronic terminal, a message consisting of the second member identification information, the first document file, and the time information A step of generating shared history information, and when the shared history information is generated, a transaction including the shared history information is created, and then a first node device, which is one of a plurality of node devices constituting the blockchain network, is connected to the shared history information. It may further include randomly selecting and transmitting, to the first node device, a request for registration of the transaction to the blockchain network while transmitting the transaction, wherein the first node device transmits the document When the transaction and the registration request are received from the shared service server, a first block containing the transaction is generated based on a previous block chained to the blockchain data stored in the memory of the first node device, and , By connecting the first block to the blockchain data in a chain, after completing storage of the first block, the first block is transferred to the first block among the plurality of node devices through the blockchain network. It can be propagated to all node devices except the node device.

Above, with reference to FIG. 2, a method of operating a document sharing service server for operating a cloud-based document sharing service according to an embodiment of the present invention has been described. Here, the operation method of the document sharing service server according to an embodiment of the present invention may correspond to the configuration of the operation of the document sharing service server 110 described using FIG. 1, so a detailed description thereof will be omitted. Do this.

The method of operating a document sharing service server according to an embodiment of the present invention may be implemented as a computer program stored in a storage medium to be executed through combination with a computer.

Additionally, the method of operating a document sharing service server according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on the medium may be specially designed and constructed for the present invention or may be known and usable by those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

As described above, the present invention has been described with specific details such as specific components and limited embodiments and drawings, but this is only provided to facilitate a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , those skilled in the art can make various modifications and variations from this description.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and the scope of the patent claims described below as well as all modifications that are equivalent or equivalent to the scope of this patent claim shall fall within the scope of the spirit of the present invention. .

110: Document sharing service server for operating a cloud-based document sharing service
111: regular expression storage unit 112: member information storage unit
113: String confirmation unit 114: Document file storage processing unit
115: document file transmission unit 116: table maintenance unit
117: Encryption event occurrence unit 118: Password setting request unit
119: Serial number extraction unit 120: Operation code generation unit
121: Encryption key generation unit 122: Encryption storage processing unit
123: Identification information confirmation unit 124: Inquiry message transmission unit
125: Decryption event generation unit 126: Reply request unit
127: Operation code regeneration unit 128: Encryption key regeneration unit
129: Decryption transmission processing unit 130: Shared history information generation unit
131: Registration request unit 132: Document file storage
100: Blockchain network
101, 102, 103, 104, 105, 106: multiple node devices
141: 1st member 142: 2nd member
151: first electronic terminal 152: second electronic terminal

Claims (12)

In the document sharing service server for operating a cloud-based document sharing service,
a regular expression storage unit storing a plurality of different regular expressions preset to correspond to the notation format of personal information;
a member information storage unit storing member identification information of each of a plurality of members subscribed to the document sharing service and terminal identification information of an electronic terminal held by each of the plurality of members in correspondence with each other;
When a first document file is received from a first electronic terminal owned by a first member, which is one of the plurality of members, and a storage request command for the first document file is received, the first document file is stored in the first document file. a string confirmation unit that checks whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document;
If it is confirmed that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file, refer to the member information storage unit. Thus, confirming the first member identification information of the first member, encrypting the first document file, and then storing the encrypted first document file and the first member identification information in a document file storage in correspondence with each other. Document file storage processing unit; and
After the encrypted first document file and the first member identification information correspond to each other and are stored in the document file storage, the second electronic terminal held by a second member, another one of the plurality of members, 1 When a sharing request for a document file is received, the first member identification information stored corresponding to the encrypted first document file is checked on the document file storage, and based on the first member identification information, , After confirming the first terminal identification information stored in correspondence with the first member identification information on the member information storage unit, based on the first terminal identification information, to the first electronic terminal, the second By transmitting an inquiry message containing a question asking the member for approval for sharing the first document file, approval for sharing the first document file is sent from the first electronic terminal to the second member. When a command is received, a document file transmission unit extracts the encrypted first document file from the document file storage, decrypts the encrypted first document file, and transmits it to the second electronic terminal.
A document sharing service server containing. According to paragraph 1,
The document file storage processing unit
A serial number table in which serial numbers of different t (t is a natural number of 2 or more) digits corresponding to each of a plurality of preset document formats that are pre-shared with the electronic terminal owned by each of the plurality of members are recorded. a table maintenance unit that stores and maintains;
If it is confirmed that the at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file, the member information storage unit For reference, an encryption event generator that verifies the first member identification information of the first member and generates an encryption event to encrypt the first document file;
When the encryption event occurs, a password setting request unit that transmits, to the first electronic terminal, a password setting request message containing a request to set a t-digit password for encryption of the first document file;
In response to the password setting request message, the first password is set by the first member, and when the first password is received from the first electronic terminal, the first document format of the first document file is confirmed, and then , a serial number extractor that extracts a first serial number corresponding to the first document format from the serial number table;
A first operation code of t bits is generated by configuring the result value of performing a modulo-2 operation on each of the t numbers constituting the first password into a bit string, and the first series of an operation code generator that generates a second operation code of t bits by configuring the result of performing a modulo-2 operation on each of the t numbers constituting the number into a bit string;
By performing an exclusive OR (XOR) operation between the first operation code and the second operation code, a t-bit seed code is generated, and then the seed code is applied as an input to a preset encryption key generation function. an encryption key generator that generates a first encryption key; and
An encryption storage processing unit that encrypts the first document file with the first encryption key, then stores the encrypted first document file and the first member identification information in correspondence with each other in the document file storage.
A document sharing service server containing. According to paragraph 2,
The document file transmission unit
After the encrypted first document file and the first member identification information are stored in the document file storage in correspondence with each other, when a sharing request for the first document file is received from the second electronic terminal, the document file storage On top, an identification information confirmation unit that verifies the first member identification information stored in correspondence with the encrypted first document file;
When the first member identification information is confirmed, based on the first member identification information, the first terminal identification information stored in correspondence with the first member identification information is confirmed on the member information storage unit, a query message transmission unit that transmits the query message to the first electronic terminal based on the first terminal identification information;
In response to the inquiry message, when the approval command is received from the first electronic terminal, the encrypted first document file is extracted from the document file storage, and then a decryption event is performed to decrypt the encrypted first document file. A decryption event generator that generates;
When the decryption event occurs, a password input request message containing a request to enter the password set for encryption of the first document file is transmitted to the first electronic terminal, and at the same time, the first electronic terminal a reply request unit that extracts a serial number corresponding to the document format of the first document file from the serial number table stored on the terminal and transmits a serial number reply command requesting a reply;
In response to the password input request message, the first password is input by the first member on the first electronic terminal, the first password is received from the first electronic terminal, and the serial number is returned. In response to the command, the first serial number corresponding to the first document format is extracted by the first electronic terminal from the serial number table stored on the first electronic terminal, so that the first electronic terminal When the first serial number is returned from the terminal, the result of performing the modulo-2 operation on each of the t numbers constituting the first password is configured as a bit string to perform the first operation of t bits. An operation for generating the second operation code of t bits by generating a code and configuring the result of performing modulo-2 operation on each of the t numbers constituting the first serial number into a bit string. Code regeneration unit;
By performing an exclusive OR operation between the first operation code and the second operation code, the seed code of t bits is generated, and then the seed code is applied as an input to the encryption key generation function to generate the first encryption key. An encryption key regeneration unit that generates; and
A decryption and transmission processing unit that restores the first document file by decrypting the encrypted first document file with the first encryption key and then transmits the restored first document file to the second electronic terminal.
A document sharing service server containing. According to paragraph 1,
The document file storage processing unit
As a result of the string confirmation unit checking whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document according to the first document file, When it is confirmed that a string having a notation format corresponding to the plurality of regular expressions does not exist among the text included in the electronic document according to the first document file, the first document file is not encrypted, and the first document file is not encrypted. 1. Correspond the document file and the first member identification information and store them in the document file storage,
The document file transmission unit
After the first document file is not encrypted and the first document file and the first member identification information correspond to each other and are stored in the document file storage, a sharing request for the first document file is received from the second electronic terminal. When received, the document sharing service server extracts the first document file from the document file storage and transmits it to the second electronic terminal, without transmitting the query message to the first electronic terminal. According to paragraph 1,
When the first document file is completely transmitted to the second electronic terminal, the member information storage is referred to, the second member identification information of the second member is checked, and the first document file is sent to the second electronic terminal. a sharing history information generator that generates time information about the point of transmission and then generates sharing history information consisting of the second member identification information, the first document file, and the time information; and
When the sharing history information is generated, a transaction including the sharing history information is created, and then a first node device, which is one of a plurality of node devices constituting the blockchain network, is randomly selected, and the first node device is randomly selected. A registration request unit that transmits, to a node device, a request for registration of the transaction to the blockchain network while transmitting the transaction.
It further includes,
The first node device is
When the transaction and the registration request are received from the document sharing service server, a first block containing the transaction is created based on the previous block chained to the blockchain data stored in the memory of the first node device. After completing storage of the first block by creating and linking the first block to the blockchain data as a chain, the first block is transferred to the first block among the plurality of node devices through the blockchain network. A document sharing service server characterized in that it propagates to the remaining node devices except the first node device. In the method of operating a document sharing service server for operating a cloud-based document sharing service,
maintaining a regular expression storage unit in which a plurality of different regular expressions preset to correspond to the notation format of personal information are stored;
maintaining a member information storage unit in which member identification information of each of a plurality of members subscribed to the document sharing service and terminal identification information of an electronic terminal held by each of the plurality of members are stored in correspondence with each other;
When a first document file is received from a first electronic terminal owned by a first member, which is one of the plurality of members, and a storage request command for the first document file is received, the first document file is stored in the first document file. Checking whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document according to the following;
If it is confirmed that at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file, refer to the member information storage unit. Thus, confirming the first member identification information of the first member, encrypting the first document file, and then storing the encrypted first document file and the first member identification information in a document file storage in correspondence with each other. step; and
After the encrypted first document file and the first member identification information correspond to each other and are stored in the document file storage, the second electronic terminal held by a second member, another one of the plurality of members, 1 When a sharing request for a document file is received, the first member identification information stored corresponding to the encrypted first document file is checked on the document file storage, and based on the first member identification information, , After confirming the first terminal identification information stored in correspondence with the first member identification information on the member information storage unit, based on the first terminal identification information, to the first electronic terminal, the second By transmitting an inquiry message containing a question asking the member for approval for sharing the first document file, approval for sharing the first document file is sent from the first electronic terminal to the second member. When a command is received, extracting the encrypted first document file from the document file storage, then decrypting the encrypted first document file and transmitting it to the second electronic terminal.
A method of operation of a document sharing service server including. According to clause 6,
The step of matching the encrypted first document file and the first member identification information to each other and storing them in a document file storage.
A serial number table in which serial numbers of different t (t is a natural number of 2 or more) digits corresponding to each of a plurality of preset document formats that are pre-shared with the electronic terminal owned by each of the plurality of members are recorded. storing and maintaining;
If it is confirmed that the at least one first string exists as a string having a notation format corresponding to the plurality of regular expressions among the text included in the electronic document according to the first document file, the member information storage unit For reference, confirming the first member identification information of the first member and generating an encryption event to encrypt the first document file;
When the encryption event occurs, transmitting, to the first electronic terminal, a password setting request message containing a request to set a t-digit password for encryption of the first document file;
In response to the password setting request message, the first password is set by the first member, and when the first password is received from the first electronic terminal, the first document format of the first document file is confirmed, and then , extracting a first serial number corresponding to the first document format from the serial number table;
A first operation code of t bits is generated by configuring the result value of performing a modulo-2 operation on each of the t numbers constituting the first password into a bit string, and the first series of generating a second operation code of t bits by configuring the result of performing a modulo-2 operation on each of the t numbers constituting the number into a bit string;
By performing an exclusive OR (XOR) operation between the first operation code and the second operation code, a t-bit seed code is generated, and then the seed code is applied as an input to a preset encryption key generation function. generating a first encryption key; and
After encrypting the first document file with the first encryption key, storing the encrypted first document file and the first member identification information in correspondence with each other in the document file storage.
A method of operation of a document sharing service server including. In clause 7,
The step of decrypting the encrypted first document file and transmitting it to the second electronic terminal
After the encrypted first document file and the first member identification information are stored in the document file storage in correspondence with each other, when a sharing request for the first document file is received from the second electronic terminal, the document file storage On top, checking the first member identification information stored in correspondence with the encrypted first document file;
When the first member identification information is confirmed, based on the first member identification information, the first terminal identification information stored in correspondence with the first member identification information is confirmed on the member information storage unit, transmitting the inquiry message to the first electronic terminal based on the first terminal identification information;
In response to the inquiry message, when the approval command is received from the first electronic terminal, the encrypted first document file is extracted from the document file storage, and then a decryption event is performed to decrypt the encrypted first document file. generating a;
When the decryption event occurs, a password input request message containing a request to enter the password set for encryption of the first document file is transmitted to the first electronic terminal, and at the same time, the first electronic terminal Extracting a serial number corresponding to the document format of the first document file from the serial number table stored on the terminal and transmitting a serial number reply command requesting a response;
In response to the password input request message, the first password is input by the first member on the first electronic terminal, the first password is received from the first electronic terminal, and the serial number is returned. In response to the command, the first serial number corresponding to the first document format is extracted by the first electronic terminal from the serial number table stored on the first electronic terminal, so that the first electronic terminal When the first serial number is returned from the terminal, the result of performing the modulo-2 operation on each of the t numbers constituting the first password is configured as a bit string to perform the first operation of t bits. Generating the second operation code of t bits by generating a code and configuring the result of performing modulo-2 operation on each of the t numbers constituting the first serial number into a bit string. ;
By performing an exclusive OR operation between the first operation code and the second operation code, the seed code of t bits is generated, and then the seed code is applied as an input to the encryption key generation function to generate the first encryption key. An encryption key regeneration unit that generates; and
Decrypting the encrypted first document file with the first encryption key, restoring the first document file, and then transmitting the restored first document file to the second electronic terminal.
A method of operation of a document sharing service server including. According to clause 6,
The step of matching the encrypted first document file and the first member identification information to each other and storing them in a document file storage.
As a result of checking whether a string having a notation format corresponding to the plurality of regular expressions stored in the regular expression storage unit exists among the text included in the electronic document according to the first document file, the first document If it is confirmed that a string having a notation format corresponding to the plurality of regular expressions does not exist among the text included in the electronic document according to the file, the first document file is not encrypted, and the first document file and Corresponding the first member identification information and storing it in the document file storage,
The step of decrypting the encrypted first document file and transmitting it to the second electronic terminal
After the first document file is not encrypted and the first document file and the first member identification information correspond to each other and are stored in the document file storage, a sharing request for the first document file is received from the second electronic terminal. When received, a method of operating a document sharing service server, characterized in that the first document file is extracted from the document file storage and transmitted to the second electronic terminal, without transmitting the query message to the first electronic terminal. According to clause 6,
When the first document file is completely transmitted to the second electronic terminal, the member information storage is referred to, the second member identification information of the second member is checked, and the first document file is sent to the second electronic terminal. After generating time information about the point of transmission, generating sharing history information consisting of the second member identification information, the first document file, and the time information; and
When the sharing history information is generated, a transaction including the sharing history information is created, and then a first node device, which is one of a plurality of node devices constituting the blockchain network, is randomly selected, and the first node device is randomly selected. Transmitting, to a node device, a request for registration of the transaction into the blockchain network while transmitting the transaction.
It further includes,
The first node device is
When the transaction and the registration request are received from the document sharing service server, a first block containing the transaction is created based on the previous block chained to the blockchain data stored in the memory of the first node device. After completing storage of the first block by creating and linking the first block to the blockchain data as a chain, the first block is transferred to the first block among the plurality of node devices through the blockchain network. A method of operating a document sharing service server, characterized in that it propagates to the remaining node devices except the first node device. A computer-readable recording medium recording a computer program for executing the method of any one of claims 6 to 10 through combination with a computer. A computer program stored in a storage medium for executing the method of any one of claims 6 to 10 through combination with a computer.

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