JP2004302749A - Contract document guaranteeing system and method for guaranteeing validity of contract document - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To store contract documents while keeping high secrecy and easily browse the content of a contract. <P>SOLUTION: A contract document guaranteeing system 10 is operated by a third party's institution to guarantee the validity of a contract document exchanged between first and second parties of the contract. An encryption process part 30 stores a copy of the contract document in a copy database T1 according to a request to store the contract document, and encrypts the contract document using an encryption key to store it in an encrypted document database T2 as an encrypted document. A copy browsing process part 60 performs predetermined authentication according to a request to browse the copy of the contract document and permits browsing of the copy of the contract document stored in the copy database T1. A collating process part 40 encrypts the copy of the contract document using the encryption key according to a request to authenticate the copy of the contract document, reads the corresponding encrypted document from the encrypted document database T2, collates it, and determines if the copy of the contract document is valid according to the result of collation to guarantee the validity of the contract document. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a contract document guarantee system and a method for guaranteeing the validity of a contract document.
[0002]
[Prior art]
With the advent of the computer society in recent years, paperless processing of digitizing and processing information in various fields has been progressing. However, with respect to contract documents, exchanges on paper media using actual seals are mainstream, and at present, contract documents are stored in paper media. Therefore, both contractors need to hold the contract document, and at least two contract documents must be prepared.
[0003]
Also, if the contractor is an individual, if the contract period is long, such as various insurance contracts such as life insurance and non-life insurance and various loan contracts such as mortgage loans, the contract documents will be lost due to changes in the environment such as relocation. May be done. Even if the contractor is a company, storing contract documents with a large number of customers is costly in terms of space, and the management cost is enormous.
[0004]
For example, Patent Document 1 discloses a system for electronically concluding a contract and holding and storing a contract document. In this system, an electronic document is stored in a state where originality is guaranteed. When issuing a transcript / abstract, the transcript / abstract is checked against the original, signed and authenticated, prepared into a contract form, and transmitted as a transcript / abstract.
[0005]
[Patent Document 1]
JP 2002-99843 A
[0006]
[Problems to be solved by the invention]
The above-mentioned gazette requires collation with the original every time a transcript / abstract is issued, and does not include a mechanism for guaranteeing the validity of the transcript / abstract once issued. Therefore, in order for the contracting party to confirm the contents of the contract, the contractor must keep a copy / abstract of the contract document by himself / herself or request the issuance of a copy / abstract whenever necessary. And the labor required for storage is still not eliminated.
[0007]
The present invention has been made in view of such a problem, and an object of the present invention is to keep a contract document in a highly confidential state. Another object of the present invention is to maintain the contract document in a highly confidential state while allowing the contents of the contract to be easily confirmed, and to guarantee the validity of the contents of the contract as necessary. .
[0008]
[Means for Solving the Problems]
According to the present invention, there is provided a system which is operated by a third party and guarantees the validity of a contract document exchanged between a first and a second contracting party. A processing unit, an encrypted document holding unit that holds a contract document encrypted with an encryption key as an encrypted document, a guarantee request receiving unit that receives a request for guaranteeing the validity of a duplicate of the contract document, A verification processing unit that verifies a plurality of documents, and when the warranty request reception unit receives the warranty request, the encryption processing unit encrypts a duplicate of the contract document using an encryption key, and the verification processing unit Read the encrypted document corresponding to the warranty request from the encrypted document holding unit, collate the encrypted copy of the contract document with the encrypted document, and judge the validity of the copy of the contract document based on the comparison result Guarantees the validity of contract documents Agreement document assurance system which is characterized in that there is provided.
[0009]
A third party is an entity that has some degree of social credibility and has no stake in a contract between the contracting parties. Here, the encryption means making the contents of the contract document invisible by encryption. Further, the duplicate of the contract document has the same contents as the contract document before the encryption process is performed.
[0010]
According to the above configuration, since the contract document is held as an encrypted document, the contract document can be stored in a highly confidential state. In addition, since the copy of the contract document is encrypted in the same manner as the encrypted document and collation with the encrypted document is performed, the legitimacy of the copy of the contract document is determined while maintaining the confidentiality of the encrypted document. Can be performed, whereby the validity of the contract document can be determined. In addition, since the encrypted document is held by a third party, contracts between the company and the individual (B → C (Business), for example, various insurance contracts such as life insurance and non-life insurance, various loan contracts such as mortgage loans, etc. The encrypted contract document can be kept secure even if one side between the contracting parties is weak, such as To Consumer)).
[0011]
The encryption key may be generated based on at least the first and second keys assigned to the first and second contracting parties, respectively, and the verification processing unit may determine whether the first and second contracting parties The encryption processing unit may include a key acquisition unit that receives the first and second keys, respectively, and an encryption key reproduction unit that reproduces an encryption key based on the first and second keys. The copy of the contract document can be encrypted using the encryption key reproduced by the section.
[0012]
Here, the encryption key is used when encrypting a document so that it is invisible. The key can be a value of a constant or a variable in a predetermined logical expression. In this case, an encryption key can be generated by inputting the key to a corresponding part of the predetermined logical expression. Also, the key may itself be independently encryptable. Reproducing the encryption key means reproducing the encryption key used for encrypting the contract document in order to encrypt a duplicate of the contract document. Note that the contract document assurance system can include an encryption key generation unit that generates an encryption key for encrypting the contract document. In this case, the function of the encryption key reproduction unit can be realized by the encryption key generation unit. .
[0013]
According to this configuration, in order to reproduce (generate) the encryption key obtained by encrypting the encrypted document, the first and second keys respectively assigned to the first and second contracting parties are required. An encryption key can be generated only with the consent of both parties. Therefore, the confidentiality of the encrypted document can be further increased. Further, even if one party between contracting parties is weak, such as a contract between a company and an individual, the encrypted contract document can be kept secure.
[0014]
The encryption key may be generated based on at least the first, second and third parties, and the first, second and third keys assigned to the third party, respectively, and the system comprises: The key processing unit may further include a key holding unit that holds a third key assigned to the three-party organization, and the verification processing unit receives the first and second keys from the first and second contracting parties and holds the key. A key acquisition unit that reads a third key from the unit, and an encryption key reproduction unit that reproduces an encryption key based on the first, second, and third keys. Using the encryption key reproduced by the reproducing unit, the duplicate of the contract document can be encrypted.
[0015]
According to this configuration, in order to reproduce (generate) the encryption key obtained by encrypting the encrypted document, the first, second, and third parties assigned to the first and second contracting parties and the third party, respectively. Since three keys are required, an encryption key can be generated only with the consent of both parties and a third party. Therefore, the confidentiality of the encrypted document can be further increased. Further, even if one party between contracting parties is weak, such as a contract between a company and an individual, the encrypted contract document can be kept secure.
[0016]
According to the present invention, there is provided a system operated by a third-party organization for guaranteeing the validity of a contract document exchanged between the first and second contracting parties, wherein at least the first and second contracting parties include: And an encryption processing unit for encrypting the document using an encryption key generated based on the first, second, and third keys respectively assigned to the third party, and the document encrypted with the encryption key A decryption processing unit that decrypts the contract document, an encrypted document storage unit that stores the contract document encrypted using the encryption key by the encryption processing unit as an encrypted document, A key holding unit for holding a third key, a guarantee request receiving unit for receiving a request for guaranteeing the validity of a copy of the contract document, and a key for receiving the first and second keys from the first and second contracting parties Third from holding part A key acquisition unit that reads the key, an encryption key reproduction unit that reproduces the encryption key based on the first, second, and third keys, and a verification processing unit that verifies a plurality of documents. Upon receiving the guarantee request, the decryption processing unit reads the encrypted document corresponding to the guarantee request from the encrypted document holding unit, decrypts the encrypted document using the encryption key, and the verification processing unit decrypts the encrypted document. The contract document assurance system is characterized by collating the encrypted document with a copy of the contract document and judging the validity of the copy of the contract document based on the comparison result, thereby guaranteeing the validity of the contract document. Provided.
[0017]
According to the above configuration, since the contract document is held as an encrypted document, the contract document can be stored in a highly confidential state. In order to reproduce (generate) the encryption key that encrypted the encrypted document, the first and second contracting parties and the first, second and third keys respectively assigned to the third party are required. Therefore, the encryption key can be generated only in a state where the consent of both parties and the third party has been obtained, and the encrypted document can be decrypted only in that case. Therefore, the confidentiality of the encrypted document can be further increased. Further, even if one party between contracting parties is weak, such as a contract between a company and an individual, the encrypted contract document can be kept secure.
[0018]
The contract document assurance system of the present invention further includes an encryption key generation unit that generates an encryption key, and a distribution processing unit that performs processing of distributing the first and second keys to the first and second contract parties, respectively. Can be included. Note that the first and second keys can be destroyed after being distributed to the first and second contracting parties. As a result, since the encryption key cannot be generated without the consent of the first and second contracting parties, the encrypted document can be kept secure.
[0019]
The contract document assurance system of the present invention further includes a key entrustment system for storing first and second keys, and the distribution processing unit identifies the first and second keys with the identification of the first and second contracting parties. A process of distributing the information to the key trust system in association with the information can be performed. The contract document assurance system of the present invention may be managed by a plurality of third parties, and the key trust system may be managed by a third party different from the third party that manages other services of the contract document assurance system. It can also be configured to be managed. In this case, a third-party organization that manages other services of the contract document assurance system can perform processing of associating the third key with its own identification information and delivering it to the key trust system. Can also store a third key. Further, for example, when the first and second contracting parties have a business-to-individual relationship, the key trust system may be configured to store only keys assigned to individuals. By doing so, even if the first or second contracting party or a third party loses the key, the key can be recovered. Since each key is distributed in association with the original owner, the key entrustment system can store each key in association with the original owner as described below. As a result, a process of distributing each key to only the original owner can be performed.
[0020]
In this key trust system, the key trust system includes: a key storage unit that holds the first and second keys in association with the identification information of the first and second contract parties, respectively; Based on a request for recovery of the first or second key from the party, the first or second key is distributed to the first or second contracting party after performing a predetermined matching with reference to the key storage unit. A user authentication unit that performs processing. In this key trust system, the key storage unit can hold the third key in association with the identification information of the third party, and the user authentication unit can store the third key from the third party. Based on the recovery request described above, a process of distributing the third key to a third party can be performed after performing a predetermined collation by referring to the key storage unit.
[0021]
The contract document assurance system of the present invention includes a key recovery information generation unit that generates first and second key recovery information capable of recovering first and second keys, respectively, and a first and second key recovery information. , A key recovery information holding unit that holds the identification information of the first and second contracting parties in association with each other, and the distribution processing unit can The first or second key recovery information stored in the key recovery information holding unit can be distributed to the first or second contracting party.
[0022]
The contract document assurance system of the present invention includes: an application information holding unit that holds a contract period of a contract document; and after the contract period ends, reads an encrypted document from the encrypted document holding unit, and stores the encrypted document in first and second data. A data return processing unit that returns the encrypted document to at least one of the two contracting parties and deletes the encrypted document from the encrypted document holding unit. The application information holding unit can also hold the usage contract period of the contract document assurance system, and the data return processing unit reads the encrypted document from the encrypted document holding unit after the end of the usage contract period, and reads the encrypted document. Can be returned to at least one of the first and second contracting parties, and the encrypted document can be deleted from the encrypted document holding unit.
[0023]
The application information holding unit can also hold information on the time when the validity of the duplicate of the contract document should be guaranteed, and the warranty request receiving unit refers to the application information holding unit and, at the time, Can be performed in the same manner as when the request is received.
[0024]
The contract document assurance system of the present invention includes a duplicate document holding unit that holds a duplicate document of a contract document, and performs a predetermined authentication based on a request to view the duplicate document of the contract document, and then performs the corresponding contract document held by the duplicate document holding unit And a browsing processing unit that permits browsing of the duplicate.
[0025]
According to this configuration, apart from the encrypted document held in a highly confidential state, a copy of the contract document can be held so as to be viewable, so that the contracting party can easily confirm the contents of the contract. Can be.
[0026]
The data return processing unit described above reads out the duplicate of the contract document from the duplicate copy holding unit after the end of the usage contract period, returns the duplicate of the contract document to at least one of the first and second contracting parties, and A duplicate of the document can be deleted from the duplicate holder.
[0027]
The contract document assurance system of the present invention refers to an event information holding unit that holds event information included in a contract document in association with a contractor, a time measuring unit that measures time, an event information holding unit, and a time counting unit. And a notification processing unit that notifies the contractor when an event occurs.
[0028]
According to this configuration, the event information included in the contract document can be stored separately from the encrypted document stored in a highly confidential state, so that the notification processing unit can access the encrypted document. In addition, necessary event information can be notified to the contracting party. Thus, the contract provider can easily manage the customer, while the contractee can enjoy the benefits of the contract.
[0029]
A contract document assurance system according to the present invention includes a template document holding unit that holds a template document, and an encrypted template document holding unit that holds an encrypted template document obtained by encrypting the template document with an encryption key when the encrypted document is held. When the collation processing unit detects that the duplicate of the contract document is not valid, the encryption processing unit reads the template document from the template document holding unit, and reads the template document. Encrypted with the encryption key, the collation processing unit compares the encrypted template document with the corresponding encryption template document held by the encryption template document holding unit, detects whether the encryption key is correct, and checks whether the encryption key is correct. Based on the detection result, the validity of the contract document can be determined.
[0030]
With the above configuration, it is possible to avoid a situation where the validity of the contract document is denied due to an incorrect encryption key, and it is possible to accurately guarantee the validity of the contract document.
[0031]
The contract document assurance system of the present invention may be capable of communicating with first and second contracting parties via a network, and may transmit and receive data to and from the first and second contracting parties via a network. .
[0032]
According to the present invention, a third party can use a device including an encrypted document holding unit, an encryption processing unit, and a collation processing unit to validate a contract document exchanged between the first and second contracting parties. Storing an encrypted document obtained by encrypting a contract document with an encryption key in an encrypted document holding unit, and a collation processing unit accepting a request for assuring the validity of a duplicate of the contract document Step, the encryption processing unit encrypts a duplicate of the contract document using the encryption key, and the collation processing unit reads the encrypted document corresponding to the guarantee request from the encrypted document holding unit, and Collating the duplicate of the contract document with the encrypted document and judging the validity of the duplicate of the contract document based on the collation result, thereby guaranteeing the validity of the contract document. A method for ensuring the validity of the document is provided. It is.
[0033]
According to the above method, the contract document is stored as an encrypted document, so that the contract document can be stored in a highly confidential state. In addition, since the copy of the contract document is encrypted in the same manner as the encrypted document and collation with the encrypted document is performed, the legitimacy of the copy of the contract document is determined while maintaining the confidentiality of the encrypted document. Can be performed, and the validity of the contract document can be determined.
[0034]
Here, the apparatus may further include a key holding unit, and the method further comprises, prior to the step of storing the encrypted document in the encrypted document holding unit, wherein the encryption processing unit transmits the first and second contracts. Generating first, second and third keys respectively assigned to the parties and the third party, and generating an encryption key based on the first, second and third keys by the encryption processing unit Wherein the encryption processing unit encrypts the contract document using the encryption key, storing the third key in the key holding unit, and wherein the encryption processing unit stores the first and second keys Delivering to the first and second contracting parties, respectively. In addition, after the step of distributing the first and second keys, the encryption processing unit may include a step of destroying the first and second keys.
[0035]
The method comprises the steps of: a cryptographic processing unit obtaining keys required to generate a cryptographic key from first and second contracting parties, respectively; and a cryptographic processing unit generating a cryptographic key from the key. And can further include.
[0036]
The method includes the steps of: storing a duplicate of a contract document in a duplicate holder having a lower security level than that of the encrypted document storage unit; and performing a predetermined authentication based on a request to view the duplicate of the contract document. And permitting viewing of a duplicate copy of the corresponding contract document stored in the contract document.
[0037]
Note that any combination of the above-described components and any conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a program, and the like are also effective as embodiments of the present invention.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
(First embodiment)
FIG. 1 is a block diagram showing a network configuration including a contract document assurance system 10 according to the first embodiment of the present invention. The contract document assurance system 10 according to the present embodiment has a function of guaranteeing the validity of a contract document exchanged between the user of the contract provider terminal 12 and the user of the contractor terminal 14. Taking life insurance as an example, the contract provider terminal 12 is a server managed by the insurance company, and the contractor terminal 14 is a terminal used by the insurance subscriber. Here, it is assumed that the insurance company and the insurance subscriber have agreed to store the contract document in the contract document assurance system 10 and make a request for guaranteeing the validity of the duplicate. The contract document assurance system 10 is operated by a third-party organization that has no interest in the user of the contract provider terminal 12 and the user of the contractor terminal 14, receives an application for a usage contract from these users, and Provide services that guarantee legitimacy.
[0039]
The contract document assurance system 10 includes a duplicate database T1 for storing a copy of the contract document, an encrypted document database T2 for storing an encrypted document obtained by encrypting the contract document, and a third key database T3 for storing a third key K3. And The contract provider terminal 12 includes a second key database 13 that holds a second key K2. The contractor terminal 14 includes a first key holding unit 15 that holds a first key K1. The copy of the contract document, the encrypted document, the first key K1, the second key K2, and the third key K3 will be described later.
[0040]
In the present embodiment, the contract provider terminal 12 and the contractor terminal 14 may be of any type as long as they can communicate with the contract document assurance system 10 via the network 16. For example, the subscriber terminal 14 can be a PC, PDA, mobile phone, or any other hardware. Here, in the contract provider terminal 12 and / or the contractor terminal 14, the second key database 13 and / or the first key holding unit 15, respectively, are not essential components. For example, the user of the contractor terminal 14 can write down the first key K1 on a paper medium and input the first key K1 to the contractor terminal 14 as needed.
[0041]
The configuration of the contract document assurance system 10 can be realized by hardware components such as a CPU of a computer, a memory, other elements, and a program having a contract document assurance function loaded with a memory as software. Here, the functional blocks realized by their cooperation are drawn. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.
[0042]
FIG. 2 is a flowchart showing functions of contract document assurance system 10 in the present embodiment. When a contract document is created between the contracting parties (S10) and the contracting parties make a request to save the contract document, the contract document assurance system 10 duplicates the contract document and saves a duplicate of the contract document, It has the function of encrypting the original document and storing it as an encrypted document (S12). Here, for the sake of explanation, the document before duplication is described separately from the original, and the duplicated document is described separately from the duplicate, but since these are acquired as electronic data, the contents are the same.
[0043]
The contract document assurance system 10 has a function of appropriately permitting viewing of a duplicate copy of the contract document in response to a request (S14). In addition, it has a function of guaranteeing the validity of a duplicate of the contract document and notifying the contracting party in response to a request or periodically at predetermined intervals (S16). The contract document assurance system 10 has a function of obtaining an access log such as a record of permission to view a copy of the contract document and a record of guaranteeing the validity of the copy of the contract document. This makes it possible to confirm the presence or absence of unauthorized access when the validity of the duplicate of the contract document is not guaranteed. Further, when an event such as an expiration date, a renewal date, or a privilege grant date occurs, a function is provided for notifying the contracting party of the event (S18). The processing of the contract document assurance system 10 ends when the use contract period of the contract document assurance system 10 ends (S20). After the end of the usage contract period, the contract document is returned to the contracting party and can be deleted from the contract document assurance system 10.
[0044]
FIG. 3 is a block diagram showing the contract document assurance system 10 shown in FIG. 1 in detail. The contract document assurance system 10 includes, in addition to the configuration shown in FIG. 1, an encrypted document storage processing unit 20, a collation processing unit 40, a duplicate copy browsing processing unit 60, an event management unit 70, a customer management unit 90, , An event information database T4, a user authentication information database T5, and an application information database T8.
[0045]
Based on a request from the contract provider terminal 12 or the contractor terminal 14, the encrypted document storage processing unit 20 creates an encrypted document by encrypting the original of the contract document with an encryption key, and encrypts the encrypted document. A process of storing the document in the document database T2 is performed. The encrypted document storage processing unit 20 includes a contract document acquisition unit 22, a copying unit 24, an encryption key (key) generation unit 26, a key distribution unit 28, and an encryption processing unit 30.
[0046]
The contract document acquisition unit 22 acquires the original of the contract document from the contract provider terminal 12 or the contractor terminal 14 in the form of electronic data. The contract document may be prepared by agreement between the contracting parties, and may be prepared in any manner. For example, the contract document may include a signature such as an electronic signature by the user of the contract provider terminal 12 and the contractor terminal 14. Further, the contract document may be encrypted with any encryption key different from the encryption key described in the present invention, and may be made invisible. The format of the electronic data may be any format. The copy unit 24 copies the original copy of the contract document, and stores the copied electronic data in the copy database T1 as a copy of the contract document.
[0047]
The encryption key (key) generation unit 26 generates an encryption key for encrypting the original of the contract document. The encryption processing unit 30 encrypts the original copy of the contract document using the encryption key generated by the encryption key (key) generation unit 26, and stores it as an encrypted document in the encrypted document database T2. The encrypted document is safely backed up in consideration of disasters, system troubles, and the like. The backup data is stored in a location that is systematically and geographically separated from the encrypted document database T2. In addition, the backup data can be stored in a device such as a tamper-resistant device that cannot be falsified by hardware.
[0048]
Although a method of generating an encryption key will be described in detail later, the encryption key (key) generation unit 26 generates at least three keys, a first key K1, a second key K2, and a third key K3 together with the encryption key. The first key K1, the second key K2, and the third key K3 can be used to derive an encryption key. The first key K1, the second key K2, and the third key K3 are assigned to the contractor terminal 14, the contract provider terminal 12, and the contract document assurance system 10, respectively. The encryption key (key) generation unit 26 stores only the third key K3 assigned to the contract document assurance system 10 in the third key database T3. The third key K3 is stored in a form to which encryption, a digital signature, and the like are given, and in which measures such as leakage prevention and falsification detection are taken. In some cases, the third key K3 can be stored in a device that cannot be falsified by hardware, such as a tamper-resistant device.
[0049]
The key distribution unit 28 distributes the first key K1 assigned to the contractor terminal 14 and the second key K2 assigned to the contract provider terminal 12 to the contractor terminal 14 and the contract provider terminal 12, respectively. Note that the distribution may be performed through the network 16 by performing some encryption processing on the first key K1 and the second key K2 themselves so as not to cause leakage or the like. , Or by processing that does not pass through the network 16, such as mailing or facsimile sending.
[0050]
Although not shown, the contract document assurance system 10 may have a key recovery function of the encryption key generated by the encryption key (key) generation unit 26, the first key K1, the second key K2, and the third key K3. it can. For the key recovery function, a known method such as a method using a key trust server or key encapsulation can be used. However, the first key K1 and the second key K2 are not stored in the contract document assurance system 10 except for being stored in a key trust server or the like for key recovery, and are stored in the contractor terminal 14 and the contract provider terminal 12. After distribution, the contract document assurance system 10 discards it. As another example for key recovery, as described later, the first key K1, the second key K2, and the like are entrusted to another organization independent of a third party that manages the contract document assurance system 10. You can also.
[0051]
Based on the browsing request from the contract provider terminal 12 or the contractor terminal 14, the duplicate browsing processing unit 60 permits a user to browse a duplicate of the relevant contract document held in the duplicate database T1 after performing predetermined authentication. Perform processing. In the duplicate copy processing unit 60, the browse request receiving unit 62 receives a request to view a duplicate copy of a contract document from a related party such as the contract provider terminal 12 or the contractor terminal 14. When there is a browsing request for a duplicate of the contract document from the contract provider terminal 12 or the contractor terminal 14, the browsing request receiving unit 62 gives the user of the contract provider terminal 12 or the contractor terminal 14 user authentication information such as a password and ID. Prompt for input. The user authentication information database T5 holds user authentication information associated with each contract document. When the user authentication information is input from the browsing requester, the authentication unit 64 authenticates the input user authentication information with reference to the user authentication information database T5. When the user authentication information is authenticated, the browsing permission unit 66 permits browsing of a duplicate copy of the contract document associated with the user authentication information of the user. Further, the duplicate copy browsing processing unit 60 may have a function of performing a keyword search on the contents of the contract document. With the above configuration, the user can browse the duplicate of the contract document as necessary, and can confirm the contents of the contract.
[0052]
The collation processing unit 40 performs a process of determining the validity of the duplicate of the contract document held in the duplicate database T1 based on a request from the contract provider terminal 12 or the contractor terminal 14. In the matching processing unit 40, the guarantee request receiving unit 42 receives a request for guaranteeing the validity of the duplicate of the contract document from the contract provider terminal 12 or the contractor terminal 14. When the guarantee request receiving unit 42 receives the guarantee request, the duplicate reading unit 44 reads a duplicate of the corresponding contract document from the duplicate database T1.
[0053]
The key acquisition unit 46 acquires a first key K1 and a second key K2 from the contractor terminal 14 and the contract provider terminal 12, respectively. The first key K1 and the second key K2 are transmitted through the network 16 in a state where some encryption processing has been performed so that leakage or the like does not occur. The first key K1 and the second key K2 are acquired by the user of the contractor terminal 14 and the contract provider terminal 12 inputting the first key K1 and the second key K2 on a web page provided by the contract document assurance system 10. In this case, an encryption technique such as SSL (Secure Socket Layer) can be used.
[0054]
The encryption key reproduction unit 48 reads the corresponding third key K3 from the third key database T3, and reproduces the encryption key together with the first key K1 and the second key K2 acquired by the key acquisition unit 46. The encryption processing unit 30 encrypts the duplicate of the contract document read by the duplicate reading unit 44 using the encryption key reproduced by the encryption key reproduction unit 48. Although the encryption key (key) generation unit 26 and the encryption key reproduction unit 48 are described here, the function of the encryption key reproduction unit 48 can be realized by the encryption key (key) generation unit 26. In this case, the contract document assurance system 10 may not have the encryption key reproducing unit 48. The collation unit 50 refers to the encrypted document database T2 and compares the duplicate of the contract document encrypted by the encryption processing unit 30 with the encrypted document stored in the encrypted document database T2. If they match, the collation unit 50 determines that the duplicate of the contract document has not been falsified and is valid, and guarantees the validity of the duplicate of the contract document. On the other hand, if they do not match, the contract provider terminal 12 or the contractor terminal 14 is notified that the copy of the contract document may be falsified.
[0055]
The event management unit 70 includes an event information acquisition unit 71, a notification processing unit 72, and a clock unit 74. The event information acquisition unit 71 acquires event information corresponding to each contract document from the contract provider terminal 12 or the contractor terminal 14. The event information includes, for example, a date and time and an event content associated with the date and time, such as an expiration date, a renewal date, and a privilege grant date of the contract. For the contract provider, for example, management of documents to be collected from the contractor, management of the contract period of the contractor, and the like can be performed by the event management unit 70. Further, the contractor can receive a notice such as an interim payment, a congratulatory money, or a contract end from the event management unit 70. The event information acquisition unit 71 can also extract the event information from the original at the time of acquiring the original of the contract document or from the duplicate of the contract document. The event information acquisition unit 71 stores the acquired event information in the event information database T4.
[0056]
The notification processing unit 72 refers to the event information database T4 and the clock unit 74, and performs a process of notifying the corresponding contract provider terminal 12 and / or contractor terminal 14 when the event occurs. The notification can be made by e-mail or the like via the network 16. Thus, the contractor can enjoy the benefits without missing any. Also, the contract provider can simplify management of many customers.
[0057]
The customer management unit 90 performs an application receiving unit 92 that receives an application for using the contract document assurance system 10 from the contract provider terminal 12 and the contractor terminal 14, and performs processing after the end of the use contract period of the contract document assurance system 10. And a data return processing unit 94. When there is an application to use the contract document assurance system 10 from the contract provider terminal 12 and the contractor terminal 14, the application receiving unit 92 converts the use contract period, that is, the encrypted document obtained by encrypting the original copy of the contract document into an encrypted document The period for storing in the database T2 and the period for receiving a request for guaranteeing the validity of the duplicate from the contract provider terminal 12 and the contractor terminal 14 are stored in the application information database T8. The application receiving unit 92 can also store the contract period in the contract document as a use contract period in the application information database T8.
[0058]
The notification processing unit 72 of the event management unit 70 also refers to the application information database T8 and, for example, when the end of the usage contract period is approaching, provides the contract provider terminal 12 and the contractor terminal 14 with the contract document assurance system 10. Of use contract renewal. For example, one month before the end of the usage contract period, the notification processing unit 72 notifies the contract provider terminal 12 and the contractor terminal 14 "Thank you for using our contract document assurance system. The period is one month left. If there is no notification of suspension by XX days, the update will be performed automatically. " At this time, the notification of the suspension is transmitted to the application receiving unit 92, and the application receiving unit 92 can save the update period in the application information database T8 if there is no notification of the stop by a predetermined date. .
[0059]
After the end of the usage contract period, the data return processing unit 94 reads the duplicate stored in the duplicate database T1 and the encrypted document stored in the encrypted document database T2, and sends the read copy to the contract provider terminal 12 and the contractor terminal 14. In addition to performing the returning process, the process of deleting these data from the duplicate database T1 and the encrypted document database T2 is performed. Further, the data return processing unit 94 can also return the encrypted document to the contract provider terminal 12 and the contractor terminal 14 after decrypting the encrypted document.
[0060]
The application receiving unit 92 determines whether or not to periodically perform a process of assuring the validity of a duplicate copy of a contract document when receiving an application for a contract for using the contract document assurance system 10 from the contract provider terminal 12 and the contractor terminal 14. In addition, when the validity assurance process is performed, it is possible to set how long the process is to be performed, and to store it in the application information database T8 as application information. In this case, the guarantee request receiving unit 42 of the collation processing unit 40 also automatically starts the process of assuring the validity of the duplicate of the contract document every set period with reference to the application information database T8. As a result, the validity assurance process of the duplicate of the contract document stored in the duplicate database T1 can be periodically performed, and the collation unit 50 periodically transmits the collation result to the contract provider terminal 12 and the contractor terminal 14. Can be notified.
[0061]
Next, the processing of each function of the contract document assurance system 10 shown in FIG. 2 will be described in detail with reference to FIGS.
FIG. 4 is a flowchart showing the process of saving the contract document shown in S12 of FIG. When there is a request to save the contract document from the contract provider terminal 12 or the contractor terminal 14 (S20), the contract document acquisition unit 22 acquires the contract document from the contract provider terminal 12 or the contractor terminal 14 in the form of electronic data. (S22). The contract document obtained here is the original. The copying unit 24 copies the contract document, and stores the copied electronic data in the copy database T1 as a copy of the contract document (S24).
[0062]
At the same time, the encryption key (key) generation unit 26 generates an encryption key for encrypting the original of the contract document (S26). In the present embodiment, the encryption key (key) generation unit 26 generates at least three keys, a first key K1, a second key K2, and a third key K3, and an encryption key derived therefrom. The encryption processing unit 30 encrypts the original of the contract document using the encryption key generated by the encryption key (key) generation unit 26 (S28), and stores it in the encrypted document database T2 (S30).
[0063]
The key distribution unit 28 performs a process of distributing the first key K1 and the second key K2 to the contractor terminal 14 and the contract provider terminal 12, respectively (S32). Further, the key distribution unit 28 stores the third key K3 in the third key database T3 (S34). At this time, the first key K1, the second key K2, and the encryption key are not stored in the contract document assurance system 10, but are discarded. As a result, it is impossible to reproduce the encryption key without approval from the contractor terminal 14 and the contract provider terminal 12, and the confidentiality of the encrypted document can be increased.
[0064]
FIG. 5 is a flowchart showing the process of permitting viewing of the duplicate copy of the contract document shown in step 14 of FIG. When there is a browsing request for the duplicate of the contract document from the contractor terminal 14 or the contract provider terminal 12 (S40), the browsing request receiving unit 62 requests the contractor terminal 14 or the contract provider terminal 12 to send the user authentication information. (S42). When the user authentication information is sent from the contractor terminal 14 or the contract provider terminal 12 (S44), the authentication unit 64 performs authentication with reference to the user authentication information database T5 (S46). When the user is authenticated and the browsing is permitted (Yes in S48), the browsing permission unit 66 gives the user of the contractor terminal 14 or the contract provider terminal 12 a duplicate of the corresponding contract document stored in the duplicate database T1. Is displayed (S50). On the other hand, if the user is not authenticated and browsing is not permitted in step 48 (No in S48), the user is notified of that (S52).
[0065]
In this way, the user can always view the duplicate of the contract document by simply sending the user authentication information, and can check the contents of the contract as needed. Further, since only the copy of the contract document is viewed by the user, the original copy of the contract document can be stored in a more secure environment while being encrypted. Therefore, the convenience of the user can be obtained, and the original copy of the contract document can be safely stored.
[0066]
FIG. 6 is a flowchart showing the processing for guaranteeing the validity of the duplicate of the contract document shown in step 16 of FIG. As described above, in order to view the duplicate copy of the contract document, authentication based on user authentication information such as a user ID and a password is performed, so that a certain degree of security is ensured. However, it is necessary to sacrifice the security level somewhat in order to secure the convenience at the time of browsing, and it is undeniable that tampering may be performed. Accordingly, the contracting party seeks assurance that the copy of the contract document has not been tampered with or is appropriate if necessary.
[0067]
Periodically or when there is a request for guarantee of the validity of the duplicate of the contract document from the contractor terminal 14 or the contract provider terminal 12 (S60), the duplicate copy reading unit 44 reads the duplicate of the corresponding contract document from the duplicate database T1. Read (S62). Further, the encryption key reproducing unit 48 reads out the corresponding third key K3 from the third key database T3 (S66). The key acquisition unit 46 requests the contractor terminal 14 and the contract provider terminal 12 to send a key (S68). When the first key K1 and the second key K2 are sent from the contractor terminal 14 and the contract provider terminal 12, respectively (S70 and S71), the encryption key reproducing unit 48 outputs the first key K1, the second key K2, and The encryption key is reproduced from the third key K3 (S72), and the duplicate of the contract document read in step 62 is encrypted with the reproduced encryption key (S74).
[0068]
The collation unit 50 compares the duplicate of the encrypted contract document with the corresponding encrypted document stored in the encrypted document database T2 (S76), and if they match (Yes in S78), the contract A notification that guarantees the validity of the duplicate of the document is issued (S82). In step 78, if they do not match (No in S78), the checking unit 50 determines whether the first key K1 and the second key K2 sent from the contractor terminal 14 and the contract provider terminal 12 are correct, respectively. Is detected (S80), and when the first key K1 and the second key K2 are correct (Yes in S80), the fact that the duplicate of the contract document is not valid is notified (S84).
[0069]
If the first key K1 and / or the second key K2 are not accurate in step 80 (No in S80), if n> 3 is not satisfied in step 81 (No in S81), the process returns to step 68 and the contractor terminal Inform the terminal 14 and / or the contract provider terminal 12 that the first key K1 and / or the second key K2 are incorrect, and request retransmission of the first key K1 and / or the second key K2. Here, n in step 81 indicates the number of times the process returns from step 81 to step 68. If the correct key is not sent even after the retransmission of the first key K1 and / or the second key K2 key is repeated three times (Yes in S81), the collation unit 50 sends the contractor terminal 14 and the contract provider terminal 12 Then, the user is notified that the guarantee process cannot be performed because the transmitted key is incorrect (S84). Although not shown, after this notification, the assurance process may be interrupted with the approval of the contractor terminal 14 and the contract provider terminal 12. Note that the value of n in step 81 can be set as appropriate, and before proceeding from step 81 to step 84, the operator of the contract document assurance system 10 is notified so that the operator interrupts the guarantee processing. May be performed.
[0070]
A process for detecting whether the first key K1 and the second key K2 sent from the contractor terminal 14 and the contract provider terminal 12 are correct will be described with reference to FIG. 7 and FIG.
[0071]
First, prior to the contract document saving process shown in FIG. _t 1, K _t 2, and K _t 3 is prepared (FIG. 7, S90 and S92). Here, template key K _t 1. Template key K _t 2. Template key K _t Numeral 3 corresponds to the first key K1, the second key K2, and the third key K3 in format. When the encryption key and the first key K1, the second key K2, and the third key K3 are generated in step 26 of FIG. 4, the encryption key reproducing unit 48 outputs the first key K1, the template key K _t 2 and K _t 3 to generate a first template encryption key, encrypt the template document with the encryption key, and store it as a first encrypted template document t1 in a predetermined database (S94). Further, the encryption key reproducing unit 48 includes a second key K2, a template key K _t 1 and K _t 3 to generate a second template encryption key, encrypt the template document with the encryption key, and store it in a predetermined database as a second encrypted template document t2 (S96).
[0072]
In step 78 of FIG. 6, when the encrypted copy of the contract document does not match the encrypted document (No in S78), the collation unit 50 firstly transmits the first key K1 transmitted this time and the template key K _t 2 and K _t 3, a third template encryption key is derived, and the template document is encrypted with the encryption key to create a third encrypted template document t1 ′ (FIG. 8, S100). Further, the collating unit 50 compares the second key K2 transmitted this time with the template key K _t 1 and K _t 3 to derive a fourth template encryption key, and encrypt the template document with the encryption key to create a fourth encrypted template document t2 '(S102).
[0073]
Subsequently, the matching unit 50 compares the first encrypted template document t1 with the third encrypted template document t1 ′ (S104), and determines whether or not they match (S106). Here, if they do not match (No in S106), it is determined that the first key K1 is incorrect in Step 80 of FIG. 6 (No in S80), and a request is made to the contractor terminal 14 to confirm the first key K1. (S68a and S68 in FIG. 6). In step 108, the second encrypted template document t2 and the fourth encrypted template document t2 'are compared (S108), and it is determined whether they match (S110). If they do not match (No in S110), it is determined that the second key K2 is incorrect in Step 80 of FIG. 6 (No in S80), and a request is made to the subscriber terminal 12 to confirm the second key K2. (S68b and S68 in FIG. 6). If there is a match in both Steps 106 and 110 (Yes in S106 and Yes in S110), it is determined in Step 80 of FIG. 6 that the key is correct (S112 and Yes in S80 of FIG. 6), and Step 84 is performed. To notify that the validity of the duplicate of the contract document cannot be guaranteed.
[0074]
As described above, in the present embodiment, since the process of guaranteeing the validity of the duplicate of the contract document can be performed while the original of the contract document is encrypted, the processing procedure can be simplified. In addition, the browsing of the contract document and the notification of the event are performed with reference to the duplicate of the contract document stored in the duplicate database T1 and the event information stored in the event information database T4. Can be stored high. In the present embodiment, the encryption processing unit 30 may have a function of decrypting an encrypted document. The contracting party can also decrypt the original copy of the contract document and confirm the contents as necessary, for example, when the validity of the duplicate copy of the contract document cannot be guaranteed.
[0075]
(Encryption key generation method)
Next, a method for generating an encryption key will be described. Here, a simplified method is illustrated for easy understanding, but the method of generating the encryption key is not limited to the method described below, and any method can be used.
[0076]
(Example 1: factorization)
First, two random numbers C and D are prepared. The numbers C and D are preferably prime numbers and are sufficiently large. Next, a number E obtained by multiplying the numbers C and D is calculated. Subsequently, the number E is divided into two numbers A and B (E = A + B). Division can be performed by random number generation. Here, the number A is assigned to the contractor terminal 14 as the first key K1, the number B is assigned to the contract provider terminal 12 as the second key K2, and the number C is assigned to the contract document assurance system 10 as the third key K3. In this case, the number D can be used as the encryption key.
[0077]
When reproducing the encryption key, the first key K1 is obtained from the contractor terminal 14 and the second key K2 is obtained from the contract provider terminal 12, and the number E is calculated. Thereafter, the encryption key D can be obtained by dividing the number E by the number C which is the third key K3.
[0078]
(Example 2: Cubic function (elliptic function))
Elliptic function Y ² = X ³ Two rational points (X1, A) and (X2, B) are obtained on + aX + b. Here, A is assigned to the contractor terminal 14 as the first key K1, and B is assigned to the contract provider terminal 12 as the second key K2. Note that a and b are assigned to the contract document assurance system 10 as the third key K3. Here, another rational point (X3, D) is used as an encryption key.
[0079]
When reproducing the encryption key, the first key K1 is obtained from the contractor terminal 14 and the second key K2 is obtained from the contract provider terminal 12, and the third key K3 is read from the third key database T3. Since X1 can be calculated from A, a, and b, and X2 can be calculated from B, a, and b, X3 can be calculated from a, X1, and X2 (X3 = a− X1-X2), X3, a, and b can determine the encryption key D. When there are two or more contractors, for example, either a or b can be assigned as a key of another contractor.
[0080]
(Example 3: Triple DES (Data Encryption Standard))
A triple DES technique that performs data encryption standard (DES) encryption three times, which is known as a secret key encryption scheme, can also be applied to the present invention. Three different common keys are assigned as the first key K1, the second key K2, and the third key K3 to the contractor terminal 14, the contract provider terminal 12, and the contract document assurance system 10, respectively. The encryption processing unit 30 performs triple DES encryption using the first key K1, the second key K2, and the third key K3.
The logical expression of the processing described above is a black box, and is not notified to the system administrator.
[0081]
FIG. 13 schematically shows a process in the case where the contract document assurance system 10 receives a contract document storage request in the present embodiment. Hereinafter, description will be made also with reference to FIG. The contract document assurance system 10 assigns a serial number to each contract document requested to be stored by a contracting party. Here, the reference number assigned to the original document 100 of the illustrated contract document is “0001”. When there is a request to save the contract document, the copying unit 24 copies the original document 100 of the contract document to generate a duplicate 102, and stores it in the duplicate database T1 in association with the serial number "0001". At this stage, the duplicate 102 is duplicated electronically. At this stage, the duplicate 102 is the same as the original 100 and cannot be distinguished. However, in order to facilitate understanding, the duplicate 102 is described separately from the original 100 and the duplicate 102. . The duplicate copy of the contract document 102 can be appropriately browsed by performing predetermined authentication.
[0082]
At the same time, the encryption processing unit 30 encrypts the original 100 of the contract document using the encryption key generated from the first key K1, the second key K2, and the third key K3, and generates the encrypted document 104. The encryption processing unit 30 stores the encrypted document 104 in the encrypted document database T2 in association with the serial number “0001”. Further, after the encryption processing of the original document 100 of the contract document, the first key K1 and the second key K2 are distributed to the contractor terminal 14 and the contract provider terminal 12, respectively, and then discarded. On the other hand, the third key K3 is stored in the third key database T3 in association with the reference number "0001". Thus, the saving process is completed. Although not shown here, at this time, event information, user identification information, and the like can also be stored in the event information database T4 and the user authentication information database T5, respectively, in association with the identification number “0001”.
[0083]
FIG. 14 schematically shows processing in the case where the contract document assurance system 10 receives a request for guaranteeing the validity of the contract document in the present embodiment. When the validity request of the contract document is requested together with the designation of the serial number “0001”, the duplicate copy reading unit 44 reads the duplicate document 102 ′ of the contract document associated with the specified serial number “0001” from the duplicate database T1. Is read from the duplicate database T1. Here, the copy of the contract document 102 ′ should be the same as the copy of the contract document 102 shown in FIG. 13 if there is no falsification. explain. The key acquisition unit 46 acquires a first key K1 and a second key K2 from the contractor terminal 14 and the contract provider terminal 12, respectively. Further, the key acquisition unit 46 reads the third key K3 associated with the serial number “0001” from the third key database T3. The encryption processing unit 30 encrypts the copy 102 ′ of the contract document using the encryption key generated from the first key K1, the second key K2, and the third key K3, and generates an encrypted copy 104 ′. . The collation unit 50 determines whether or not the encrypted document 104 and the encrypted duplicate 104 ′ match, and if they match, determines that the duplicate 102 ′ of the contract document matches the original 100 of the contract document, and A notification that guarantees the validity of the duplicate 102 'is issued. If it is determined that the encrypted document 104 and the encrypted duplicate 104 'do not match and the encryption key is also correct, a notification is given to the effect that the duplicate 102' of the contract document is not valid. Here, the notification can be made on a web page provided by the contract document assurance system 10, but can also be made by e-mail.
[0084]
The contract document assurance system 10 assigns a customer number to each contracting party, and can use the customer number as a key to manage a request to save a plurality of contract documents for each customer. Thus, for example, a customer who has stored a plurality of contract documents of an insurance contract in the contract document assurance system 10 can view duplicate copies of the plurality of contract documents at once using the customer number as a key, Can be requested at once. Further, when the contract is renewed at any time, for example, as in the case of advanced repayment in a mortgage loan, the contract document assurance system 10 can perform processing for saving the contract document every time the contract document is renewed. It can be stored in association with one contract number.
[0085]
Further, the encryption key and key generation processing in step 26 shown in FIG. 4 can be performed by the processing shown in FIG. Hereinafter, description will be made also with reference to FIGS. When generating the encryption key, the encryption key (key) generation unit 26 gives the user of the contractor terminal 14 and the contract provider terminal 12 that the user already obtains the first key K1 and the second key K2 related to another contract document. It is inquired whether or not each of them is performed (S140). If the user of the contractor terminal 14 and / or the contract provider terminal 12 already has the first key K1 and the second key K2 (Yes in S140), the contractor terminal 14 and / or the contract provider terminal 12 Then, the first key K1 and / or the second key K2 are obtained from (step S142). On the other hand, when the contractor terminal 14 and / or the contract provider terminal 12 do not have the first key K1 and the second key K2 (No in S140), the first key K1 and / or the second key K2 are generated. (S144).
[0086]
The encryption key (key) generation unit 26 generates an encryption key from the first key K1, the second key K2 obtained or generated as described above, and the third key K3 separately generated (S146). When the already generated first key K1 and / or second key K2 have been obtained from the contractor terminal 14 and / or the contract provider terminal 12, the original document of the contract document is encrypted (S28 in FIG. 4). ), The first key K1 and / or the second key K2 are discarded without distribution to the contractor terminal 14 and / or the contract provider terminal 12. By doing so, even the same user who uses the contract document assurance system 10 for a plurality of contract documents can perform processing on a plurality of contract documents by holding only one key, User convenience can be achieved. Also, in the contract document assurance system 10, it is not necessary to generate more keys than necessary, so that management of keys and encryption keys can be simplified. Even in the above processing, since the encryption key is generated from the first key K1, the second key K2, and the third key, a different encryption key is generated if the combination between contractors is different. That is, the encrypted document can be kept in a highly confidential state.
[0087]
(Second embodiment)
FIG. 9 is a block diagram showing a network configuration including the contract document assurance system 10 according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that the contract document assurance system 10 does not have the duplicate database T1. Here, for example, the contract provider terminal 12 can include the duplicate copy database T1, and the user of the contract provider terminal 14 makes a browsing request to the contract provider terminal 12 as necessary. In other words, in the present embodiment, the contract document assurance system 10 does not know about the process of browsing the duplicate of the contract document, and holds an encrypted document obtained by encrypting the original copy of the contract document. Or periodically performs only processing to guarantee the validity of the duplicate of the contract document. In the present embodiment, the same components as those described in the first embodiment with reference to FIGS. 1 to 8 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
[0088]
FIG. 10 is a block diagram showing the contract document assurance system 10 in the present embodiment in detail. In the present embodiment, the contract document assurance system 10 does not have the duplicate document browsing processing unit 60, the duplicate document database T1, and the user authentication information database T5, and the encrypted document storage processing unit 20 does not have the copying unit 24. This is different from the first embodiment shown in FIG. Further, the collation processing unit 40 is different from the first embodiment shown in FIG. 3 in that a duplicate copy obtaining unit 45 is provided instead of the duplicate copy reading unit 44. Although not shown, also in the present embodiment, the contract document assurance system 10 can have a customer management unit 90 and an application information database T8.
[0089]
In this embodiment, the contract document is stored in the same manner as described in the first embodiment with reference to FIG. However, in the present embodiment, the process of copying the contract document and storing the duplicate copy in step 24 are not performed. In addition, the process of guaranteeing the validity of the duplicate of the contract document is performed in the same manner as described in the first embodiment with reference to FIG. However, in the present embodiment, a process of acquiring a duplicate via the network 16 is performed instead of the process of reading the duplicate in step 62. As a result, even in the present embodiment, it is impossible to reproduce the encryption key without approval from the contractor terminal 14 and the contract provider terminal 12, so that the encrypted document is held in a state of increased confidentiality. It is possible to accurately evaluate the validity of the duplicate of the contract document.
[0090]
Further, in the present embodiment, the contract document acquisition unit 22 acquires the original copy of the contract document in the form of electronic data that is encrypted in advance by the contract provider terminal 12 or the contractor terminal 14 and whose contents are invisible. You can also. In this way, the user of the contract provider terminal 12 and the contractor terminal 14 can save the contents of the contract document in the contract document assurance system 10 without being informed of the third party, By transmitting a duplicate copy of the contract document to the contract document assurance system 10 in the same manner as when transmitting the original copy of the contract document, it is possible to request the validity evaluation of the copy of the contract document. As a result, even for a contract document whose contents are not desired to be disclosed to a third party, the validity of the contract document can be evaluated using the contract document assurance system 10.
[0091]
(Third embodiment)
FIG. 11 is a block diagram showing a contract document assurance system 10 according to the third embodiment of the present invention. In the present embodiment, the contract document assurance system 10 obtains a pre-encrypted original that has been independently encrypted at the contract provider terminal 12 and the contractor terminal 14, and further converts the pre-encrypted original into a pre-encrypted original. After performing the encryption process, a process of storing the encrypted document in the encrypted document database T2 is performed.
[0092]
In the present embodiment, the contract document assurance system 10 includes an encrypted document storage processing unit 20, a collation processing unit 40, an encrypted document database T2, a third key database T3, a template document holding unit T6, and an encrypted template document database. Includes T7. Although not shown, also in the present embodiment, the contract document assurance system 10 can include an event management unit 70, a customer management unit 90, an event information database T4, and an application information database T8. Note that, in the present embodiment, the same components as those described with reference to FIGS. 1 to 8 regarding the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
[0093]
The encrypted document storage processing unit 20 includes a pre-encrypted original copy acquisition unit 80, an encryption key (key) generation unit 26, an encryption processing unit 30, and a template document transmission / reception unit 82. Here, the pre-encrypted original copy obtaining unit 80 obtains, in the contract provider terminal 12 and the contractor terminal 14, the original copy of the contract document, which has been respectively encrypted, as the pre-encrypted original copy in the form of electronic data. I do. In the present embodiment, the encryption key (key) generation unit 26 generates only the third key K3 assigned to the contract document assurance system 10 as an encryption key. The encryption processing unit 30 encrypts the pre-encrypted original with the third key K3, and stores it in the encrypted document database T2 as an encrypted document.
[0094]
The template document holding unit T6 holds a predetermined template document. The template document transmitting / receiving unit 82 transmits the template document held in the template document holding unit T6 to the contract provider terminal 12 and the contractor terminal 14, and encrypts the original of the contract document in the contract provider terminal 12 and the contractor terminal 14. You are prompted to encrypt the template document with the same encryption key that was encrypted. The template document transmitting / receiving section 82 receives the encrypted template document and stores it in the encrypted template document database T7.
[0095]
The verification processing unit 40 includes a guarantee request receiving unit 42, a pre-encrypted duplicate copy obtaining unit 84, an encryption key reading unit 86, and a verification unit 50. The pre-encrypted duplicate acquisition unit 84, like the pre-encrypted original acquisition unit 80, converts the pre-encrypted duplicate of the contract document, which has been encrypted at the contract provider terminal 12 and the contractor terminal 14, respectively, into a pre-encrypted duplicate In the form of electronic data. The encryption key reading unit 86 reads the third key K3 from the third key database T3. The encryption processing unit 30 encrypts the pre-encrypted duplicate with the third key K3. The collation unit 50 collates the duplicate of the contract document encrypted by the encryption processing unit 30 with the corresponding encrypted document stored in the encrypted document database T2, and guarantees the validity of the pre-encrypted duplicate. .
[0096]
When the collation unit 50 determines that the pre-encrypted duplicate copied by the encryption processing unit 30 does not match the corresponding encrypted document held in the encrypted document database T2, the contract It is checked whether the keys used by the users of the provider terminal 12 and the contractor terminal 14 are correct. The collating unit 50 transmits the template document held in the template document holding unit T6 to the contract provider terminal 12 and the contractor terminal 14 via the template document transmitting / receiving unit 82, and outputs the contract provider terminal 12 and the contractor terminal At 14, the user is prompted to encrypt the template document with the same encryption key as used to encrypt the duplicate of the contract document. This template document is the same as the template document used when the pre-encrypted original is obtained. The collating unit 50 receives the template document encrypted at the contract provider terminal 12 and the contractor terminal 14 via the template document transmitting / receiving unit 82. The collation unit 50 compares the encrypted template document received here with the encrypted template document stored in the template document database T7. If they match, it is confirmed that the keys used by the users of the contract provider terminal 12 and the contractor terminal 14 are correct. Thereby, the collation unit 50 can determine that the pre-encrypted duplicate that has received the guarantee request is not valid. In this case, the matching unit 50 notifies the contract provider terminal 12 and the contractor terminal 14 that the validity of the pre-encrypted duplicate cannot be guaranteed. If the encrypted template documents do not match, it is possible to judge that the key is not accurate. Therefore, the user is notified of the fact and a process of requesting retransmission of the pre-encrypted duplicate is performed.
[0097]
In the present embodiment, the contract document assurance system 10 does not know what encryption key the user of the contract provider terminal 12 and the contractor terminal 14 uses to encrypt the original of the contract document. However, the contract document assurance system 10 determines whether or not the user of the contract provider terminal 12 and the contractor terminal 14 has encrypted the copy of the contract document using the correct key when requesting the guarantee of the validity of the copy of the contract document. The processing for detecting is performed.
[0098]
FIG. 12 is a flowchart showing the process of storing the original copy of the contract document. When there is a request to save the original from the contract provider terminal 12 and the contractor terminal 14 (S120), the contract document assurance system 10 requests the contract provider terminal 12 and the contractor terminal 14 to transmit the pre-encrypted original. At the same time, a template document is transmitted to each of the contract provider terminal 12 and the contractor terminal 14, and a request is made to encrypt and transmit the template document using the same encryption key as used for encrypting the original of the contract document (S122). .
[0099]
When the contract provider terminal 12 and the contractor terminal 14 transmit the pre-encrypted original and the encrypted template document (S124), the template document transmitting / receiving unit 82 stores the encrypted template document in the encrypted template document database T7. (S126). Also, the encryption key (key) generation unit 26 generates a third key K3 as an encryption key (S128), and encrypts the pre-encrypted original with the third key K3 (S130). The encryption processing unit 30 stores the encrypted pre-encrypted original as an encrypted document in the encrypted document database T2, and stores the third key K3 in the third key database T3 (S132).
[0100]
In the present embodiment, the contract document assurance system 10 does not involve the user of the contract provider terminal 12 and the contractor terminal 14 in encrypting the contract document using what kind of encryption key. The user of the contract document terminal 12 and the contractor terminal 14 can receive the validity evaluation of the duplicate of the contract document by the contract document assurance system 10 while protecting the contents of the contract document by himself.
[0101]
The present invention has been described based on the embodiments. It should be understood by those skilled in the art that the embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. . Hereinafter, such a modified example will be described.
[0102]
In the first embodiment, when permitting the user to view the duplicate of the contract document, the duplicate reading processing unit 60 displays the advertisement information and the link information to other web pages on the copy of the contract document screen. Display processing can be performed. For example, when receiving a request to view a copy of a contract document from the contractor terminal 14, the duplicate copy browsing processing unit 60 displays an advertisement for another service provided by the contract provider terminal 12 on the browsing screen. Can be. Further, link information of a web page for asset management of the user of the contractor terminal 14 can be displayed.
[0103]
Also, as shown in FIG. 16, the contract document assurance system 10 is different from the third party institution that manages the contract document assurance system 10 in that the key recovery system 200 is managed by an independent third party. The key K1 and the second key K2 can be entrusted. Hereinafter, this example will be described.
[0104]
The key distribution unit 28 shown in FIG. 3 or FIG. 10 transmits the first key K1 and the second key K2 to the contractor terminal 14 and the contract provider terminal 12, respectively. , And the third key K3 are also distributed to the key recovery system 200. At this time, the key distribution unit 28 associates the first key K1, the second key K2, and the third key K3 with the identification information of the contractor terminal 14, the contract provider terminal 12, and the contract document assurance system 10, respectively. It is delivered to the recovery system 200. The key recovery system 200 associates the first key K1, the second key K2, and the third key K3 with the identification information of the contractor terminal 14, the contract provider terminal 12, and the contract document assurance system 10, respectively, in the key storage unit. 201. The key recovery system 200 has a user authentication unit 202, and receives a first key K1, a second key K2, or a third key K3 from any of the contractor terminal 14, the contract provider terminal 12, and the contract document assurance system 10. When a recovery request is issued, identification information is obtained from the requester. The key recovery system 200 refers to the key storage unit 201 and sends the corresponding first key K1, second key K2, or third key K3 to the requester only when the identification information is verified. Accordingly, even if the first key K1, the second key K2, or the third key K3 is lost in the contractor terminal 14, the contract provider terminal 12, or the contract document assurance system 10, the first key K1, the second key K2, or the third key K3 is lost. The key K1, the second key K2, or the third key K3 can be recovered. Also, the key recovery system 200 sends the first key K1, the second key K2, or the third key K3 to a user having valid authority only when the identification information of the user is verified, so that The possibility that the first key K1, the second key K2, or the third key K3 is obtained can be reduced.
[0105]
Further, as another example, the contract document assurance system 10 generates a first key recovery information and a second key recovery information that can recover the first key K1 and the second key K2, and a key recovery information generation unit ( (Not shown), and a key recovery information holding unit (not shown) for holding the first key recovery information and the second key recovery information in association with the identification information of the contractor terminal 14 and the contract provider terminal 12, respectively. Can be included. In this case, the key recovery system 200 may not have the key storage unit 201.
[0106]
The first key recovery information and the second key recovery information include, for example, information obtained by encapsulating the first key K1 and the second key K2 with another key, and data necessary for recovering another key used for the encapsulation. It is. As an example, a random number is created, and a key for encapsulation is created from the random number using a one-way function. At this time, the created random number is encrypted with a public key published by the key recovery system 200. The first key recovery information and the second key recovery information include a first key K1 and a second key K2 encapsulated with a key for encapsulation, a random number encrypted with a public key, and the like. Further, the key recovery information generation unit also encrypts the identification information with the public key of the key recovery system 200, and stores the identification information in the key recovery information holding unit as first key recovery information and second key recovery information.
[0107]
When the first key K1 or the second key K2 is lost in the contractor terminal 14 or the contract provider terminal 12, the key distribution unit 28 shown in FIG. , The first key recovery information or the second key recovery information stored in the key recovery information holding unit is distributed to the contractor terminal 14 or the contract provider terminal 12. The contractor terminal 14 or the contract provider terminal 12 transmits the received first key recovery information or second key recovery information to the key recovery system 200. The key recovery system 200 decrypts the identification information included in the first key recovery information or the second key recovery information with its own secret key, and checks the requester. As a result, only when it is determined that the requester has a proper authority, the key recovery system 200 determines whether the requester has the first key K1 or the second key based on the first key recovery information or the second key recovery information. Restore K2. Specifically, a random number included in the first key recovery information or the second key recovery information is decrypted with its own secret key, and a key for encapsulation is created from this random number. Using this key, the encapsulated first key K1 or second key K2 can be recovered. The key recovery system 200 sends the recovered first key K1 or second key K2 to the requester. By using this method, the first key recovery information or the second key recovery information can be transmitted to the key recovery system 200 only when necessary, and the first key K1 or the second key K2 can be recovered. It is possible to prepare for loss of the first key K1 and the second key K2 while keeping the confidentiality of the key K1 and the second key K2 high.
[0108]
Note that, for example, a logical expression for reproducing an encryption key from the first key K1, the second key K2, or the third key K3 is defined as a third logical expression different from that of a third party managing the key recovery system 200. Can be entrusted to a third party organization.
[0109]
Further, in the embodiment, the encrypted copy of the contract document is compared with the encrypted document stored in the encrypted document database T2 in advance. And a form of collating with the duplicate.
[0110]
Further, the contract document assurance system 10 described in the embodiment can be used for a contract between three or more contracting parties. In this case, a key is assigned to each contracting party and a third party, respectively, and an encryption key is generated based on these keys.
[0111]
Further, the contract document guarantee system 10 described in the embodiment can be applied not only to a contract between a company and an individual but also to a contract between individuals whose will is a will, for example. The contract document assurance system 10 described in the embodiment can also be applied to a contract between companies (B → B (Business To Business)). The above modifications can be used in appropriate combinations.
[0112]
【The invention's effect】
According to the present invention, a contract document can be held in a highly confidential state. Further, according to the present invention, it is possible to easily confirm the contents of the contract while keeping the contract document in a highly confidential state. In addition, if necessary, it is possible to obtain a guarantee of the validity of the contents of the contract.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a network configuration including a contract document assurance system according to a first embodiment of the present invention.
FIG. 2 is a flowchart illustrating functions of a contract document assurance system according to the present embodiment.
FIG. 3 is a block diagram showing a contract document assurance system shown in FIG. 1 in detail.
FIG. 4 is a flowchart showing a contract document saving process shown in step 12 of FIG. 2;
FIG. 5 is a flowchart showing a process of permitting viewing of a duplicate copy of a contract document shown in step 14 of FIG. 2;
FIG. 6 is a flowchart showing a process of guaranteeing the validity of a duplicate of the contract document shown in step 16 of FIG. 2;
FIG. 7 is a flowchart showing a process for detecting whether the first key K1 and the second key K2 are correct.
FIG. 8 is a flowchart showing a process for detecting whether the first key K1 and the second key K2 are correct.
FIG. 9 is a block diagram showing a network configuration including a contract document assurance system according to a second embodiment of the present invention.
FIG. 10 is a block diagram showing the contract document assurance system in the present embodiment in detail.
FIG. 11 is a block diagram showing a contract document guarantee system according to a third embodiment of the present invention.
FIG. 12 is a flowchart illustrating a process of storing a contract document original.
FIG. 13 is a diagram schematically illustrating processing when the contract document assurance system receives a request to save a contract document in the first embodiment.
FIG. 14 is a diagram schematically illustrating processing when the contract document assurance system receives a request for guaranteeing the validity of the contract document in the first embodiment.
FIG. 15 is a flowchart showing another example of the encryption key and key generation processing in step 26 of FIG. 4 in detail in the first embodiment.
FIG. 16 is a diagram showing a network configuration including a key recovery system.
[Explanation of symbols]
10 Contract document guarantee system
12 Contract provider terminal
13 Second key database
14 Contractor terminal
15 First key holder
16 Network
20 Encrypted document storage processing unit
22 Contract Document Acquisition Department
24 duplication section
26 Encryption key (key) generation unit
28 Key Distribution Department
30 Encryption unit
40 collation processing section
42 Warranty request reception section
44 duplicate copy reading unit
45 Duplicate Acquisition Department
46 Key acquisition unit
48 encryption key playback unit
50 collation unit
60 Duplicate Reading Processing Unit
62 Browsing request reception unit
64 Authentication Department
66 Permission to view
70 Event Management Department
71 Event information acquisition unit
72 Notification processing unit
74 Clock section
80 Pre-encrypted original copy acquisition unit
82 Template Document Transmitter / Receiver
84 Pre-encrypted duplicate copy acquisition unit
86 Encryption key reading unit
90 Customer Management Department
92 Application reception desk
94 Data return processing unit
100 original
102 copy
102 'duplicate
104 Encrypted document
104 'Encrypted duplicate
200 key recovery system
201 Key storage
202 User authentication unit
T1 duplicate database
T2 Encrypted document database
T3 Third Key Database
T4 event information database
T5 user authentication information database
T6 template document storage
T7 Encrypted template document database
T8 application information database

Claims (16)

A system operated by a third party to ensure the validity of contract documents exchanged between the first and second contracting parties,
An encryption processing unit for encrypting the document with an encryption key;
An encrypted document holding unit that holds the contract document encrypted with the encryption key as an encrypted document,
An assurance request receiving unit that receives an assurance request for the validity of a duplicate of the contract document;
A collation processing unit for collating a plurality of encrypted documents,
When the warranty request receiving unit receives the warranty request,
The encryption processing unit encrypts a duplicate of the contract document using the encryption key,
The collation processing unit reads the encrypted document corresponding to the guarantee request from the encrypted document holding unit, collates the encrypted duplicate of the contract document with the encrypted document, and, based on the collation result, describes the contract. A contract document assurance system for assuring the validity of the contract document by judging the validity of a duplicate document. The encryption key is generated based on at least first and second keys respectively assigned to the first and second contracting parties,
The collation processing unit includes a key acquisition unit that receives the first and second keys from the first and second contractors, respectively, and an encryption key that reproduces the encryption key based on the first and second keys. A playback unit;
The contract document assurance system according to claim 1, wherein the encryption processing unit encrypts a duplicate of the contract document using the encryption key reproduced by the encryption key reproduction unit. The encryption key is generated based on at least the first and second contracting parties, and the first, second and third keys respectively assigned to the third party,
The system further includes a key holding unit that holds the third key assigned to the third party,
A key acquisition unit that receives the first and second keys from the first and second contracting parties and reads the third key from the key holding unit; And an encryption key reproducing unit that reproduces the encryption key based on a third key,
The contract document assurance system according to claim 1, wherein the encryption processing unit encrypts a duplicate of the contract document using the encryption key reproduced by the encryption key reproduction unit. A system operated by a third party to ensure the validity of contract documents exchanged between the first and second contracting parties,
An encryption for encrypting a document using at least an encryption key generated based on first, second and third keys respectively assigned to the first and second contracting parties and the third party; A processing unit;
A decryption processing unit for decrypting the document encrypted by the encryption key,
An encrypted document holding unit that holds the contract document encrypted with the encryption key by the encryption processing unit as an encrypted document,
A key holding unit that holds the third key assigned to the third party,
An assurance request receiving unit that receives an assurance request for the validity of a duplicate of the contract document;
A key acquisition unit that receives the first and second keys from the first and second contract parties and reads the third key from the key holding unit,
An encryption key reproducing unit that reproduces the encryption key based on the first, second, and third keys;
A collation processing unit for collating a plurality of documents,
When the warranty request receiving unit receives the warranty request,
The decryption processing unit reads the encrypted document corresponding to the guarantee request from the encrypted document holding unit, and decrypts the encrypted document using the encryption key,
The collation processing unit collates the decrypted encrypted document with a duplicate of the contract document, and determines the validity of the duplicate of the contract document based on the collation result. Contract document guarantee system characterized by guarantee. An encryption key generation unit that generates the encryption key;
A distribution processing unit that performs processing for distributing the first and second keys to the first and second contract parties, respectively;
The contract document assurance system according to any one of claims 2 to 4, further comprising: A key trust system for storing the first and second keys,
The distribution processing unit performs a process of distributing the first and second keys to the key trust system in association with the identification information of the first and second contract parties, respectively. The contract document guarantee system according to claim 5. The key entrustment system, a key storage unit that holds the first and second keys in association with the identification information of the first and second contractors, respectively,
Based on a request for recovery of the first or second key from the first or second contracting party, after performing a predetermined collation with reference to the key storage, the first or second key A user authentication unit that performs a process of delivering to the first or second contracting party,
7. The contract document guarantee system according to claim 6, comprising: An application information holding unit that holds a contract period of the contract document,
After the end of the contract period, the encrypted document is read from the encrypted document holding unit, and the encrypted document is returned to at least one of the first and second contracting parties. A data return processing unit to be deleted from the encrypted document holding unit;
The contract document assurance system according to any one of claims 1 to 7, further comprising: A duplicate holder for holding a duplicate of the contract document;
Based on a request to view a duplicate of the contract document, after performing a predetermined authentication, a browsing processing unit that permits browsing of a corresponding duplicate of the contract document held in the duplicate holding unit,
The contract document assurance system according to any one of claims 1 to 8, further comprising: An event information holding unit that holds the event information included in the contract document in association with the contractor;
A timing unit for measuring time,
A notification processing unit that notifies the contractor when an event occurs with reference to the event information holding unit and the timing unit;
The contract document assurance system according to any one of claims 1 to 9, further comprising: A template document holding unit for holding a template document,
When holding the encrypted document, an encrypted template document holding unit that holds an encrypted template document obtained by encrypting the template document with the encryption key,
Further comprising
When the matching processing unit detects that the duplicate of the contract document is not valid, the encryption processing unit reads the template document from the template document holding unit and encrypts the template document with the encryption key. And
The collation processing unit compares the encrypted template document with the corresponding encrypted template document held by the encrypted template document holding unit, detects whether the encryption key is correct, and checks whether the encryption key is correct. 11. The contract document assurance system according to claim 1, wherein the validity of the contract document is determined based on the detection result of the contract document. The contract document assurance system is capable of communicating with the first and second contracting parties via a network, and transmits and receives data to and from the first and second contracting parties via the network. The contract document assurance system according to any one of claims 1 to 11. A third party uses a device including an encrypted document holding unit, an encryption processing unit, and a collation processing unit to guarantee the validity of a contract document exchanged between the first and second contracting parties. So,
Storing an encrypted document obtained by encrypting the contract document with an encryption key in the encrypted document holding unit;
The collation processing unit accepts a request for guarantee of the validity of a duplicate of the contract document;
The encryption processing unit encrypts a duplicate of the contract document using the encryption key,
The collation processing unit reads the encrypted document corresponding to the guarantee request from the encrypted document holding unit, collates the encrypted duplicate of the contract document with the encrypted document, and, based on the collation result, describes the contract. Assuring the validity of the contract document by determining the validity of the duplicate of the document;
A method for guaranteeing the validity of a contract document, characterized by including: The apparatus further includes a key holding unit,
Prior to storing the encrypted document in the encrypted document holding unit,
Wherein the encryption processing unit generates first, second, and third keys respectively assigned to the first and second contracting parties, and the third party,
The encryption processing unit, the step of generating the encryption key based on the first, second and third keys,
The encryption processing unit encrypts the contract document using the encryption key,
Storing the third key in the key holding unit;
Wherein the encryption processing unit distributes the first and second keys to the first and second contract parties, respectively;
14. The method according to claim 13, further comprising the step of: The encryption processing unit, the step of obtaining a key required to generate the encryption key from the first and second contract parties, respectively,
Wherein the encryption processing unit generates the encryption key from the key;
The method of claim 14, further comprising the step of: Storing a duplicate of the contract document in a duplicate holding unit having a lower security level than the encrypted document holding unit;
Based on a request for viewing a duplicate of the contract document, after performing a predetermined authentication, permitting viewing of a duplicate of the corresponding contract document stored in the duplicate holding unit,
16. The method for assuring the validity of a contract document according to claim 13, further comprising:

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