Electronic contract system, electronic contract method, and electronic contract program

Abstract

To enable an information terminal device in an LGWAN (Local Government Wide Area Network) to receive an electronic file transmitted from the outside of the LGWAN without damaging the originality of the electronic file.SOLUTION: A harmless relay server 200 is a relay device for connecting an LGWAN and an external network, a communication part 210 transmits an originality confirmation request to an electronic contract server 100 in the case of receiving a download request to instruct a PDF file to be stored in the electronic contract server 100 from an information terminal device 300, an originality confirmation part 131 of the electronic contract server 100 confirms the originality of the PDF file in response to the originality confirmation request received from the harmless relay server 200, a communication part 110 transmits a confirmation result and the PDF file to the harmless relay server 200, and a harmless rendering part 232 of the harmless relay server 200 renders the PDF file received from the electronic contract server 100 harmless in the case of receiving a confirmation result that the originality can be confirmed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic contract system, an electronic contract method, and an electronic contract program. [Background technology]

[0002] A technology has been disclosed that, when an information terminal device connected to a closed network such as a Local Government Wide Area Network (LGWAN) within a local government imports data from an external computer via the external network, relays the connection request to the external computer to a relay device and converts the data acquired from the external computer into data that can be used in the closed network in the relay device, thereby preventing a decrease in the security level in the local government (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-013399 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 has the problem that the originality of electronic files received from outside is compromised by converting (neutralizing) the data into data that can be used in a closed network, and the electronic signature attached to the electronic file is invalidated, making it impossible to exchange electronic contracts, etc. via an external network.

[0005] The present invention has been made in consideration of the above, and aims to provide an electronic contract system, an electronic contract method, and an electronic contract program that can receive electronic files sent from outside the LGWAN on an information terminal device within the LGWAN without compromising the originality of the electronic files. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides an electronic contract system comprising a sanitization relay server connected to an information terminal device via a LGWAN (general government network), and an electronic contract server connected to the sanitization relay server via an external network, wherein the sanitization relay server is a relay device connecting the LGWAN and the external network, and when a download request specifying a PDF file to be stored in the electronic contract server is received from the information terminal device, it sends a request to confirm the originality of the PDF file to the electronic contract server, and the electronic contract server comprises a document storage means for storing the PDF file, and in response to the request for confirmation of originality received from the sanitization relay server, it confirms the originality of the PDF file and sends the confirmation result and the PDF file to the sanitization relay server, and when the sanitization relay server receives from the electronic contract server a notification that the originality has been confirmed as a confirmation result, it does not sanitize the PDF file received from the electronic contract server. Effect of the Invention

[0007] According to the present invention configured as described above, it is possible to advantageously receive an electronic file transmitted from outside the LGWAN by an information terminal device within the LGWAN without compromising the originality of the electronic file. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of an electronic contract system 10 according to the present embodiment. [Diagram 2] FIG. 2 is a block diagram showing the configurations of an electronic contract server 100 and a harmless relay server 200. [Diagram 3] 13 is a flowchart showing an electronic contract processing procedure executed by the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400. [Figure 4]13 is a flowchart showing an electronic contract processing procedure executed by the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400. [Diagram 5] 1 is an explanatory diagram showing a schematic diagram of the relationship between a PDF contract and a hash value, and the originality verification process. [Figure 6] 13 is a flowchart showing an electronic contract processing procedure executed by the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Below, examples of the electronic contract system, electronic contract method, and electronic contract program according to the present application will be described with reference to the accompanying drawings. The following explanations are examples of the embodiments of the present application, and the electronic contract system, electronic contract method, and electronic contract program according to the present application are not limited to these examples.

[0010] 1 is an explanatory diagram showing a schematic configuration of an electronic contract system 10 according to this embodiment. The electronic contract system 10 executes electronic contract processing between an information terminal device 300 connected to a closed network LGWAN and an information terminal device 400 connected to an external network N. The electronic contract system 10 includes an electronic contract server 100, a harmless relay server 200, information terminal devices 300-1 to 300-n (hereinafter referred to as "information terminal devices 300") connected to the LGWAN, and information terminal devices 400-1 to 400-m (hereinafter referred to as "information terminal devices 400") connected to the external network N.

[0011] The electronic contract server 100 is a computer that manages PDF (Portable Document Format) files such as contracts sent from the information terminal device 300, and verifies the originality of PDF files such as contracts in response to an originality verification request received from the decontamination relay server 200. The electronic contract server 100 is connected to the decontamination relay server 200 and the information terminal device 400 via an external network N.

[0012] The sanitization relay server 200 is a server that relays data transmitted and received via the external network N and the LGWAN, and is a computer that provides the functions of LGWAN-ASP (government-only application service provided via the LGWAN). When the sanitization relay server 200 transmits a PDF file to be stored in the electronic contract server 100 to an information terminal device 300 in the LGWAN, the sanitization relay server 200 transmits a request to confirm the originality of the PDF file to the electronic contract server 100, and if the originality is confirmed, the sanitization process is not performed, and if the originality is not confirmed, the sanitization process is performed.

[0013] The information terminal device 300 is a computer that is located in each local government or administrative agency and is connected to the LGWAN. The LGWAN is a comprehensive administrative network, and is a closed network exclusively for administration that interconnects computers of local governments, administrative agencies, etc.

[0014] The information terminal device 400 is a computer connected to an external network N, and in this embodiment, is described as an information terminal device operated by a business operator who exchanges electronic contracts with a local government. The external network N is any communication network, such as the Internet, an intranet, a LAN (Local Area Network), a VPN (Virtual Private Network), or a mobile communication network, or a combination thereof, and some or all of them may be wired or wireless.

[0015] 2 is a block diagram showing the configuration of the electronic contract server 100 and the detoxification relay server 200. As shown in FIG. 2, the electronic contract server 100 includes a communication unit 110, a storage unit 120, and a control unit .

[0016] The communication unit 110 is connected to other devices via an external network N so that they can communicate with each other, and transmits and receives data between the other devices. The communication unit 110 is connected to the information terminal device 400 and the detoxification relay server 200 via the external network N, and transmits and receives data between the information terminal device 400 and the detoxification relay server 200. The communication unit 110 transmits and receives data to and from the information terminal device 300 via the detoxification relay server 200 connected to the LGWAN.

[0017] The storage unit 120 stores programs for controlling each unit, application programs, various control information, intermediate files, etc. The storage unit 120 includes an originality confirmation information storage unit 121 and a document storage unit 122. The originality confirmation information storage unit 121 stores a local government name, a contract name, and originality confirmation information in association with each other. The local government name and the contract name are information that uniquely identifies a PDF file, and document identification information may be used instead of the local government name and the contract name. One example of the originality confirmation information is a hash value of the PDF file. The document storage unit 122 stores a local government name, a contract name, and a PDF file that is a document in association with each other.

[0018] The control unit 130 controls the operation of each unit of the electronic contract server 100 by deploying and executing various programs and control information stored in the memory unit 120. The control unit 130 includes an originality confirmation unit 131, a hash value calculation unit 132, and a digital signature unit 133.

[0019] The originality confirmation unit 131 executes an originality confirmation process for the target PDF file in response to an originality confirmation request received from the harmless relay server 200. More specifically, the originality confirmation unit 131 calculates a hash value of the PDF file requested to be downloaded by the hash value calculation unit 132. The originality confirmation unit 131 acquires a hash value associated with the local government name and contract name included in the download request from the originality confirmation information storage unit 121. The originality confirmation unit 131 judges whether the calculated hash value matches the acquired hash value. If the hash values ​​match, the originality confirmation unit 131 judges that the originality has been confirmed as a confirmation result, and if the hash values ​​do not match, it judges that the originality cannot be confirmed. Note that if the hash value associated with the local government name and contract name does not exist in the originality confirmation information storage unit 121, it also judges that the originality cannot be confirmed.

[0020] The hash value calculation unit 132 calculates a hash value of the PDF file. More specifically, the hash value calculation unit 132 calculates a hash value of the entire PDF file. The hash value calculation unit 132 calculates a hash value of a portion of the PDF file excluding the digital signature portion (hereinafter referred to as the "original portion").

[0021] When electronic signature unit 133 accepts input of agreement regarding a PDF file displayed on the display screen of information terminal device 300 or information terminal device 400, it affixes an electronic signature to the displayed PDF file in accordance with the agreement accepted by information terminal device 300 or information terminal device 400, respectively.

[0022] Next, a description will be given of the detoxification relay server 200. The detoxification relay server 200 includes a communication unit 210, a storage unit 220, and a control unit 230.

[0023] The communication unit 210 is communicatively connected to the information terminal device 300 via the LGWAN to transmit and receive data. The communication unit 210 is communicatively connected to the electronic contract server 100 and the information terminal device 400 via the external network N to transmit and receive data. When transmitting and receiving data between the information terminal device 300 and the electronic contract server 100 or the information terminal device 400, the communication unit 210 relays the data and transmits it to the destination.

[0024] The storage unit 220 stores programs for controlling each unit, application programs, various control information, intermediate files, and the like.

[0025] The control unit 230 expands and executes various programs and control information stored in the storage unit 220, thereby controlling the operation of each unit of the detoxification relay server 200. The control unit 230 includes a detoxification determination unit 231 and a detoxification unit 232.

[0026] The sanitization determination unit 231 determines whether to sanitize an electronic file when transmitting or receiving an electronic file between the information terminal device 300 and the electronic contract server 100 or the information terminal device 400. More specifically, the sanitization determination unit 231 determines not to sanitize an electronic file when transmitting an electronic file from the information terminal device 300 to the electronic contract server 100 or the information terminal device 400, that is, when transmitting an electronic file from the LGWAN to the outside.

[0027] The sanitization judgment unit 231 will in principle determine to sanitize an electronic file when it is sent from the electronic contract server 100 or the information terminal device 400 to the information terminal device 300, i.e., when it is sending an electronic file from the outside to the inside of the LGWAN, but will determine not to sanitize the file when it is sent from the electronic contract server 100 to the information terminal device 300 and the originality of the PDF file is confirmed.

[0028] The neutralization unit 232 neutralizes the PDF file. More specifically, the neutralization unit 232 executes a process of removing executable programs and files such as JavaScript embedded in the PDF file, a process of deleting a digital signature added to the PDF file, and the like.

[0029] The electronic contract processing executed in the electronic contract system 10 configured as described above will be described. Figures 3 and 4 are flowcharts showing the electronic contract processing procedure executed by the electronic contract server 100, the harmless relay server 200, the information terminal device 300, and the information terminal device 400. The electronic contract processing using a PDF file contract (hereinafter referred to as a "PDF contract") between a local government and a business operator will be described below.

[0030] The information terminal device 300 receives an instruction to upload a PDF contract (step S301). The PDF contract here is a PDF file that has been confirmed to be harmless, and may be one created by a local government or a business operator. The process of transmitting the PDF contract from the business operator's information terminal device 400 to the information terminal device 300 will be described later. The information terminal device 300 transmits the PDF contract to the electronic contract server 100 (step S302). The PDF contract includes the name of the local government and the contract name. Instead of including the name of the local government and the contract name in the PDF contract, the name of the local government and the contract name may be transmitted together with the PDF contract.

[0031] When a PDF contract is sent from an information terminal device 300 within the LGWAN to an electronic contract server 100 outside the LGWAN, the PDF contract is transmitted via the sanitization relay server 200. The communication unit 210 of the sanitization relay server 200 receives the PDF contract, and the sanitization determination unit 231 determines whether sanitization processing is required (step S303). More specifically, the sanitization determination unit 231 determines that sanitization is not required because the process is to transmit a PDF contract from within the LGWAN to outside the LGWAN. The communication unit 210 transmits the PDF contract to the electronic contract server 100 without performing sanitization processing on the PDF contract (step S304).

[0032] The communication unit 110 of the electronic contract server 100 receives the PDF contract, and the hash value calculation unit 132 calculates a hash value of the received PDF contract (step S305). The hash value calculation unit 132 associates the hash value of the PDF contract with the name of the local government and the contract name, and stores them in the originality confirmation information storage unit 121 (step S306). FIG. 5 is an explanatory diagram that shows the relationship between the PDF contract and the hash value, and the originality confirmation process. As shown in (1) and (2) of FIG. 5, the hash value calculation unit 132 calculates a hash value of the PDF contract (original), associates the calculated hash value with the name of the local government and the contract name, and stores them in the originality confirmation information storage unit 121. Returning to FIG. 3, the communication unit 110 transmits a contract confirmation / agreement screen to the information terminal device 400 of the business operator who will enter into a contract using the PDF contract (step S307).

[0033] The information terminal device 400 receives the contract confirmation and agreement screen and displays the received contract confirmation and agreement screen (step S308). The information terminal device 400 accepts input of agreement from the contract confirmation and agreement screen (step S309). If the user does not agree to the contract contents, the information terminal device 400 accepts non-agreement from the contract confirmation and agreement screen and ends the process. If revisions are required, the process returns to step S301 and executes the process using the revised PDF contract. The information terminal device 400 transmits the agreement to the contract contents displayed on the contract confirmation and agreement screen to the electronic contract server 100 (step S310).

[0034] The communication unit 110 of the electronic contract server 100 receives the agreement to the contract contents displayed on the contract confirmation / agreement screen from the information terminal device 400, and the electronic signature unit 133 affixes the business's electronic signature to the PDF contract (step S311). The communication unit 110 transmits the contract confirmation / agreement screen to the information terminal device 300 of the local government that will conclude a contract using the PDF contract (step S312).

[0035] The information terminal device 300 receives the contract confirmation and agreement screen and displays the received contract confirmation and agreement screen (step S313). The information terminal device 300 accepts input of agreement from the contract confirmation and agreement screen (step S314). Note that if the contract contents are not agreed to or revisions are required, the same procedure is followed as for the local government. The information terminal device 300 transmits agreement to the contract contents displayed on the contract confirmation and agreement screen to the electronic contract server 100 (step S315).

[0036] The communication unit 110 of the electronic contract server 100 receives from the information terminal device 300 the agreement to the contract contents displayed on the contract confirmation / agreement screen, and the electronic signature unit 133 affixes the local government's electronic signature to the PDF contract (step S316) and stores the electronically signed PDF contract in the document memory unit 122 in association with the local government name and contract name (step S317).

[0037] The information terminal device 300 receives the instruction to download the PDF contract (step S318). The information terminal device 300 transmits the instruction to download the PDF contract to the electronic contract server 100 (step S319).

[0038] The communication unit 210 of the sanitization relay server 200 receives an instruction to download the PDF contract to the electronic contract server 100, and the sanitization determination unit 231 determines whether or not sanitization processing is required for the target PDF contract (step S320). More specifically, when receiving a PDF contract from the electronic contract server 100 connected to the external network N, and when the originality cannot be confirmed as a result of the originality confirmation request, the sanitization determination unit 231 determines that sanitization is required. The communication unit 210 sends the originality confirmation request to the electronic contract server 100 (step S321).

[0039] The communication unit 110 of the electronic contract server 100 receives the originality confirmation request, and the originality confirmation unit 131 confirms the originality of the PDF contract (step S322). As shown in FIG. 5 (4), the hash value calculation unit 132 calculates a hash value of the original portion of the PDF contract. (5) The originality confirmation unit 131 determines whether the hash value associated with the local government name and contract name stored in the originality confirmation information storage unit 121 matches the hash value of the original portion of the PDF contract. The communication unit 110 transmits the originality confirmation result and the digitally signed PDF contract to the sanitization relay server 200 (step S323).

[0040] The communication unit 210 of the sanitization relay server 200 receives the originality confirmation result and the PDF contract with the electronic signature, and the sanitization determination unit 231 determines whether the originality has been confirmed from the originality confirmation result (step S324). If it is determined that the originality has been confirmed from the originality confirmation result (step S324: Yes), the sanitization process is not performed (FIG. 5(6)). If it is determined that the originality has not been confirmed from the originality confirmation result (step S324: No), the sanitization unit 232 executes the sanitization process (step S325). More specifically, the sanitization unit 232 deletes the executable program, executable file, electronic signature, etc. from the PDF contract to sanitize it (FIG. 5(7)). The communication unit 210 transmits the originality confirmation result and the PDF contract to the information terminal device 300 (step S326).

[0041] The information terminal device 300 receives the originality check result and the PDF contract, and displays the received originality check result (step S327). The information terminal device 300 stores the PDF contract in the storage unit (step S328).

[0042] The information terminal device 400 receives the instruction to download the PDF contract (Step S329). The information terminal device 400 transmits the instruction to download the PDF contract to the electronic contract server 100 (Step S330).

[0043] The communication unit 110 of the electronic contract server 100 receives the instruction to download the PDF contract, and acquires the PDF contract (step S331). The communication unit 110 transmits the originality confirmation result and the PDF contract to the information terminal device 400 (step S332).

[0044] The information terminal device 400 receives the originality check result and the PDF contract, and displays the received originality check result (step S333). The information terminal device 400 stores the PDF contract in the storage unit (step S334).

[0045] In this way, the originality confirmation information of the PDF contract received from the information terminal device 300 is stored in the electronic contract server 100, and when a download request for a PDF contract with an electronic signature is made from the information terminal device 300 in the LGWAN, that is, even when a PDF contract is sent from outside the LGWAN to within the LGWAN, the originality confirmation information is used to confirm the originality, so that the PDF contract with an electronic signature can be received by the information terminal device 300 without sanitizing the PDF contract. This makes it possible to receive a PDF contract with an electronic signature from outside the LGWAN, and to digitize contract processing. Furthermore, by confirming the originality of the PDF contract, a PDF contract with an electronic signature can be used without lowering the security level.

[0046] Furthermore, even if the originality of the PDF contract cannot be confirmed, a sanitized PDF contract can be received and the electronic contract processing can be carried out again between the local government and the business using the received sanitized PDF contract.

[0047] In the above-described embodiment, a process was described in which a PDF contract created, etc. on the information terminal device 300 is sent to the electronic contract server 100, and an electronic signature is added upon confirmation and agreement of the contract by both contracting parties. In addition, an embodiment will be described in which, as shown in Figure 3, before sending the PDF contract from the information terminal device 300 to the electronic contract server 100, a PDF contract created, etc. on the information terminal device 400 is sent to the electronic contract server 100 and stored in the document memory unit 122, and the PDF contract stored in the document memory unit 122 is sent to the information terminal device 300.

[0048] FIG. 6 is a flowchart showing the electronic contract processing procedure executed by the electronic contract server 100, the harmless relay server 200, the information terminal device 300, and the information terminal device 400. As shown in FIG.

[0049] The information terminal device 400 receives an instruction to upload a PDF contract (step S601). The PDF contract to be uploaded has been created or prepared by the business. The information terminal device 400 transmits the PDF contract to the electronic contract server 100 (step S602). The communication unit 110 of the electronic contract server 100 receives the PDF contract, associates the received PDF contract with the local government name and the contract name, and stores the PDF contract in the document storage unit 122 (step S603).

[0050] The information terminal device 300 accepts an instruction to download the PDF contract (step S604). For example, when the information terminal device 300 receives a notification from the information terminal device 400 that the PDF contract has been sent to the electronic contract server 100, the information terminal device 300 accepts the instruction to download by selecting the target PDF contract from the PDF contracts stored in the document storage unit 122 of the electronic contract server 100. The information terminal device 300 transmits a download request for the target PDF contract to the electronic contract server 100 (step S605).

[0051] The communication unit 210 of the sanitization relay server 200 receives the download request for the target PDF contract as a relay device, and the sanitization determination unit 231 determines whether or not the received download request needs to be sanitized (step S606). More specifically, the sanitization determination unit 231 determines that the request is for the information terminal device 300 in the LGWAN to receive an electronic file transmitted from the electronic contract server 100 connected to the external network N, and determines that sanitization is required. The communication unit 210 transmits the download request for the target PDF contract to the electronic contract server 100 (step S607).

[0052] The communication unit 110 of the electronic contract server 100 receives the download request for the target PDF contract document, and the communication unit 110 acquires the PDF contract document from the storage unit 120 (step S608). The communication unit 110 transmits the PDF contract document to the harmless relay server 200 (step S609).

[0053] The communication unit 210 of the decontamination relay server 200 receives the PDF contract, and the decontamination unit 232 decontaminates the received PDF contract (step S610). The communication unit 210 transmits the decontaminated PDF contract to the information terminal device 300 (step S611).

[0054] The information terminal device 300 receives the sanitized PDF contract document and stores the received PDF contract document in the storage unit (step S612). The electronic contract process thereafter executes the processes described with reference to Figures 3 and 4. Step S612 and subsequent steps are the same as the process of step S301 in Figure 3.

[0055] In this way, even if a PDF contract is sent from outside the LGWAN, it can be neutralized by the neutralization relay server 200, which acts as a relay device, and an electronic signature can be added to the PDF contract in the same way as a PDF contract created or prepared by the information terminal device 300, making it possible to execute electronic contract processing.

[0056] As a modified example, when determining whether or not the download request needs to be sanitized in step S606, an originality confirmation request may be sent to the electronic contract server 100 to confirm the originality (see steps S320 to S324 in FIG. 4). In this case, since the originality confirmation information storage unit 121 does not store a hash value corresponding to the PDF contract, it is determined that the originality cannot be confirmed, and the PDF contract is sanitized by the sanitization relay server 200.

[0057] A PDF contract may include forms in the original portion of the PDF contract. A form refers to an input area that accepts data input by a user's operation on a PDF file, such as a radio button, a check box, a pull-down menu, a text box, a handwritten input area, or an electronic seal area.

[0058] For example, a PDF contract may include forms for the address, name of a local government, company name, representative name, etc., and the address, name of a local government, company name, representative name, etc. of the contractor may be written in advance in these forms. When the address, name of a local government, company name, representative name, etc. are written in the form in advance, the form and the values ​​written in the form are included in the original part of the PDF contract. By writing the address, name of a local government, company name, representative name, etc. of the contractor in the form of the PDF contract, it is possible to easily extract the address, name of a local government, company name, representative name, etc. of the contractor from the PDF contract and link each extracted value with another system. In addition to the address, name of a local government, company name, representative name, etc. of the contractor, the form and values ​​of items to be linked with another system may be written in the PDF contract.

[0059] Also, the PDF contract may include only a form for a signature (handwritten signature) or a seal, etc., and when accepting the input of the agreement in step S309, the signature or seal, etc. on the form may be accepted. In this case, the signature, seal, etc. are not included in the original portion of the PDF contract, but are described as an addendum to the PDF contract.

[0060] In the above embodiment, a PDF contract to which an electronic signature is applied has been described, but this may be performed with a PDF file other than a contract. Even if it is a general PDF file, the PDF file stored in the electronic contract server 100 can be downloaded (transmitted) to the LGWAN without sanitizing it and without compromising its originality by confirming the originality with a hash value or the like. In addition, the electronic file to be targeted may be an electronic file other than a PDF file, such as an image file or other file.

[0061] In the above embodiment, the closed network is described as LGWAN, but it is not limited to LGWAN, and may be other closed networks. Also, the above embodiment is not limited to the transmission and reception of electronic files between a local government, administrative agency, etc. and a business, but may be implemented in the transmission and reception of electronic files between business operators or between a business operator and a general user.

[0062] The hardware configuration of the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400 according to the above-mentioned embodiments is a normal computer including one or more processors such as a CPU (Central Processing Unit), MPU (Micro-Processing Unit) or GPU (Graphics Processing Unit), and equipped with external storage devices such as ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), flash memory, and SSD (Solid State Drive), and a communication control device, etc., and the above-mentioned configuration and functions are realized by the CPU, etc. reading and running programs stored in the ROM, RAM, HDD, etc. The control unit may be an electronic circuit such as an ASIC (Application Specific Integrated Circuit) or PLD (Programmable Logic Device).

[0063] The programs that run on the electronic contract server 100, the harmless relay server 200, the information terminal device 300, and the information terminal device 400 may be stored on a computer connected to a network such as the Internet and provided by downloading via the network, or may be recorded in an installable or executable format on a computer-readable recording medium such as a CD-ROM, DVD, USB memory, or SD card and provided. Furthermore, the programs that realize the above-mentioned functions and processes may be provided in the form of an API (Application Programming Interface), SaaS (Software as a Service), or cloud computing.

[0064] In the above-mentioned embodiment, the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400 have been described as separate devices, but some of the functions of the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400 may be configured as a single device, or the functions of each device may be combined. Also, each of the electronic contract server 100, the detoxification relay server 200, the information terminal device 300, and the information terminal device 400 may be multiple devices.

[0065] The present invention is not limited to the above-described embodiment, and does not necessarily have to be physically configured as illustrated. The present invention can be configured by functionally or physically dividing, integrating, replacing, modifying, or deleting all or part of the components described in the embodiment in any unit according to various loads, usage conditions, etc. [Explanation of symbols]

[0066] 100...electronic contract server, 110...communication unit, 120...storage unit, 121...originality confirmation information storage unit, 122...document storage unit, 130...control unit, 131...originality confirmation unit, 132...hash value calculation unit, 133...electronic signature unit, 200...sanitization relay server, 210...communication unit, 220...storage unit, 230...control unit, 231...sanitization determination unit, 232...sanitization unit, 300...information terminal device, 400...information terminal device

Claims

1. An electronic contract system comprising: a detoxification relay server connected to an information terminal device via a local government wide area network (LGWAN); and an electronic contract server connected to the detoxification relay server via an external network, The harmless relay server includes: a relay device that connects the LGWAN and the external network, an originality confirmation sending means for sending an originality confirmation request for the PDF file to the electronic contract server when a download request specifying a PDF file to be stored in the electronic contract server is received from the information terminal device, The electronic contract server includes: A document storage means for storing the PDF file; an originality confirmation means for confirming the originality of the PDF file in response to the originality confirmation request received from the harmless relay server; a confirmation result transmission means for transmitting the confirmation result confirmed by the originality confirmation means and the PDF file to the harmless relay server, The harmless relay server includes: a sanitization means for not sanitizing the PDF file received from the electronic contract server when a notification that the originality has been confirmed as a result of the confirmation is received from the electronic contract server; a PDF file transmission means for transmitting the PDF file received from the electronic contract server to the information terminal device; An electronic contract system comprising:

2. When receiving a message indicating that the originality cannot be confirmed as the verification result, the sanitization means sanitizes the PDF file, 2. The electronic contract system according to claim 1, wherein the PDF file transmission means transmits the PDF file that has been rendered harmless by the harmless rendering means to the information terminal device.

3. The electronic contract server includes: An originality confirmation information storage means for storing a hash value of the PDF file, An electronic contract system as described in claim 1 or claim 2, wherein the originality confirmation means calculates a hash value of the PDF file to be stored in the document storage means for which downloading is requested, and confirms the originality by determining whether the calculated hash value matches the hash value stored in the originality confirmation information storage means.

4. The PDF file is a PDF file to which a digital signature has been added, the hash value stored in the originality confirmation information storage means is a hash value of a portion of the PDF file excluding a portion to which a digital signature has been added, The electronic contract system of claim 3, wherein the originality verification means calculates a hash value of a portion of the PDF file excluding the portion to which an electronic signature has been applied, and verifies the originality by determining whether the calculated hash value matches a hash value associated with the originality verification information storage means.

5. The electronic contract server includes: The electronic contract system of claim 3, further comprising a hash value calculation means that, when a PDF file is received from the information terminal device, calculates a hash value of the PDF file and stores the calculated hash value in the originality confirmation information storage means.

6. The electronic contract system according to claim 1 or 2, wherein the PDF file includes a form.

7. A method executed by a detoxification relay server connected to an information terminal device via a Lightweight Global Wide Area Network (LGWAN) and an electronic contract server connected to the detoxification relay server via an external network, comprising: The harmless relay server includes: a relay device that connects the LGWAN and the external network, an originality confirmation sending step of sending an originality confirmation request for the PDF file to the electronic contract server when a download request specifying a PDF file to be stored in the electronic contract server is received from the information terminal device, The electronic contract server includes: A document storage means for storing the PDF file, an originality confirmation step of confirming the originality of the PDF file in response to the originality confirmation request received from the harmless relay server; a confirmation result transmission step of transmitting the confirmation result confirmed by the originality confirmation step and the PDF file to the harmless relay server, The harmless relay server includes: a sanitization step of not sanitizing the PDF file received from the electronic contract server when a notification that the originality has been confirmed as a result of the confirmation is received from the electronic contract server; a PDF file transmission step of transmitting the PDF file received from the electronic contract server to the information terminal device; An electronic contract method including:

8. The sanitizing step sanitizes the PDF file when a notification that the originality cannot be confirmed is received as the confirmation result, 8. The electronic contract method according to claim 7, wherein the PDF file transmission step transmits the PDF file that has been rendered harmless by the rendering harmless step to the information terminal device.

9. An electronic contract program for causing a computer to execute the electronic contract method according to claim 7 or 8.

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