JP2023122460A - Organizational encryption key storage method and storage system - Google Patents

Abstract

To realize further reduction of information leakage risk by safely storing an encryption key and reducing the risk of information leakage while improving convenience for a recipient and a submitter and reducing transmission and management costs without compromising the effectiveness of information leakage prevention measures when data encrypted with an encryption key is stored in a server connected via a network to one or more submitter terminals that are data submitters and have a submitter ID, and one or more recipient terminals that are recipients of the data and have a recipient ID.SOLUTION: An encryption key is encrypted and stored using a generated submitter's public key and a generated recipient's public key, and is encrypted and stored using a submitter's passphrase generated by a submitter's private key and a recipient's passphrase generated by a recipient's private key, and each of the passphrases is automatically notified to the submitter contact and recipient contact and is not stored in a system.SELECTED DRAWING: Figure 12

Description

The present invention relates to an encryption key storage method and system, and more particularly to an organization encryption key storage method and an organization encryption key storage system suitable for exchanging data between different organizations.

Conventionally, various methods are used for data encryption. In particular, when exchanging data over a network, encryption is essential to prevent information leakage.

For example, in a high school entrance examination, a questionnaire containing highly confidential and confidential personal information is passed from the applicant's school (e.g. junior high school) to the recipient (e.g. high school). There is a need.

Applicant has developed a system that involves submitting research papers in the form of data from a submitter to a recipient over a network (see, for example, Patent Document 1).

When there are multiple or unspecified number of submitters of highly confidential or confidential data, or when there are multiple recipients, or when both submitters and recipients are multiple may temporarily store data on a server connected to the Internet between submission by the submitter and receipt by the recipient.

The applicant shall store the survey report data encrypted with a common key method on the server, and also encrypt the common key used for encryption with the passphrase issued to the submitter and the recipient respectively and store it on the server. We have developed a system that includes the secure submission of survey data from the submitter to the recipient by storing it (see, for example, US Pat.

Japanese Patent No. 6715423 Japanese Patent No. 6752480

In the systems described in Patent Literatures 1 and 2, as well as in general data transmission/reception via networks, higher measures are always required for information leakage prevention measures. On the other hand, simply enhancing measures to prevent information leaks generally makes the business flow more complicated, which may lead to human error and the like.

In Patent Document 2, although a high degree of information leakage prevention is achieved, from the point of view of the recipient, it is necessary to transmit the passphrase from the recipient to the submitter by some means, which poses problems in terms of convenience and transmission costs. was there. In addition, when there are multiple recipients from the submitter's point of view, it is necessary to manage a different passphrase for each recipient, which also poses problems in terms of convenience and management costs.

The present invention has been made in view of such circumstances, and is intended to reduce the risk of information leakage by safely storing encryption keys, while maintaining the convenience of recipients and presenters without impairing the effectiveness of measures to prevent information leakage. The purpose is to further reduce the risk of information leakage by improving communication and reducing transmission and management costs. In the present application, a key used for encryption and a key used for decryption are collectively referred to as "encryption key".

In order to achieve the above object, the inventor of the present application seeks a method for safely storing an encryption key on a server when data is encrypted and stored on a server on the Internet. In order to realize the strict management required for this, after much trial and error, the inventors have invented the present invention, which stores the encryption key so that even the server administrator cannot decrypt and decipher it, thereby reducing the risk of information leakage.

In a first aspect of the present invention, one or more submitter terminals that are submitters of data and have submitter IDs, and one or more recipient terminals that are recipients of the data and have recipient IDs , one or more web servers connected via a network;
one or more database servers interconnected to the web server;
A server group with multiple types of server functions including
A method for separately storing a cryptographic key for encrypting the data by a submitter and a recipient,
The server group receives a recipient public key, a recipient secret key corresponding to the recipient public key, and an encryption key for encrypting the data using the recipient secret key as a box management key. a recipient's encryption key storage box which is encrypted with the recipient's public key, stores the data in association with the submitter's ID of the person who submitted the data, and can be retrieved by decrypting the encryption key with the recipient's private key; a recipient's encryption key storage box generating step for generating each recipient and storing the recipient's encryption key storage box in the database server in association with each recipient's ID;
a recipient passphrase generation step in which the server group automatically generates a recipient passphrase for encrypting the recipient private key;
A recipient whose server group encrypts the recipient's private key with the recipient's passphrase and stores the encrypted recipient's private key and the recipient's public key in the database server a private key encryption step for
a recipient passphrase notification step in which the server group notifies a predetermined recipient notification destination of the recipient passphrase and prevents the database server from storing the recipient passphrase;
and
a presenter login accepting step in which the server group accepts a login from the presenter terminal;
The server group submits the presenter's public key, the presenter's private key corresponding to the presenter's public key, and the encryption key for encrypting the data using the presenter's private key as a box management key. a submitter's encryption key storage box that stores the data in association with the recipient's recipient's ID after being encrypted with the submitter's public key, and that can be retrieved by decrypting the encryption key with the submitter's private key; a submitter's encryption key storage box generating step of generating each submitter's encryption key storage box and storing the submitter's encryption key storage box in the database server in association with each submitter's ID;
a presenter's passphrase generation step in which the server group generates a presenter's passphrase for encrypting the presenter's private key;
The submitter, wherein the server group encrypts the submitter's private key with the submitter's passphrase, and stores the encrypted submitter's private key and the submitter's public key in the database server; a private key encryption step for
a submitter passphrase notification step in which the server group notifies a predetermined submitter notification destination of the submitter passphrase and does not cause the database server to store the submitter passphrase;
To provide an organization-specific encryption key storage method characterized by comprising:

The "server group" includes not only a combination of multiple servers but also one server having multiple types of server functions. Each server may be a physically independent server, a plurality of types of servers may be physically the same server, or one server may be physically composed of a plurality of servers. The database may be in one of the servers, may be in an independent server, or may be distributed in multiple servers.

A "submitter" is treated as one "submitter" in one organization, and a plurality of persons may be included in the "submitters". Similarly, the "recipient" may be treated as one "recipient" in one organization different from the "submitter", and multiple persons may be included in the "recipient".

In the present invention, the data passed from the submitter to the recipient may be data expressed in tabular format such as CSV, Excel (registered trademark), or tab-separated data, or XML or JSON data. is not limited.

According to the first aspect of the present invention, the encryption key encrypted using the submitter public key and the same encryption key encrypted using the recipient public key are stored. The public key/private key pair is not common between the submitter and the recipient, and the encryption key is safely stored to reduce the risk of information leakage, and the recipient and the submitter without impairing the effectiveness of information leakage prevention measures. It is possible to further reduce the risk of information leakage by improving the convenience of communication and reducing transmission and management costs. Furthermore, since the private key corresponding to each public key is encrypted with each passphrase, the encryption key can be stored more safely, and the risk of information leakage is further reduced. Further, the submitter only has to manage the passphrase for the submitter and the recipient only has to manage the passphrase for the recipient, which is highly convenient. Furthermore, neither the submitter's passphrase nor the recipient's passphrase are stored on the server, so neither the submitter's private key nor the recipient's private key can be decrypted by a server attack, and there is a risk of information leakage. is further reduced.

a data reception step in which the server group receives an input of the submitter's passphrase from the submitter's terminal, selects a recipient of the data, and receives an upload of the data;
If there is no encryption key associated with the recipient ID of the selected recipient in the encryption key storage box for the submitter, the server group a submitter's encryption key encryption and storage step of generating a key, encrypting it with the submitter's public key, and storing it in the submitter's encryption key storage box in association with the recipient ID;
The server group encrypts the encryption key generated in the encryption key encryption storage step of the submitter with the recipient's public key of the selected recipient, and encrypts the recipient's encryption of the selected recipient. a recipient's encryption key encryption storage step for storing in a key storage box in association with the submitter ID;
If the server group has an encryption key associated with the recipient ID in the encryption key storage box for the submitter and if it was stored in the encryption key encryption storage step of the submitter, the submitter a presenter's private key decryption step of decrypting the presenter's private key with a passphrase for
a submitter's encryption key decryption step in which the server group decrypts the encryption key associated with the recipient ID from the submitter's encryption key storage box using the submitter's private key;
a data storage step in which the server group encrypts the data with an encryption key decrypted with the submitter private key, and stores the data in the database server in association with the submitter ID and the recipient ID;
is preferably included.

The submitter only needs to enter the passphrase for the submitter and select the recipient, and the data is automatically encrypted at the time of uploading, so security is high and convenience is high. In addition, since data is encrypted for each submitter and each recipient, the risk of data information leakage can be reduced. The cryptographic key is not limited to any cryptographic method, but a common key is preferable from the viewpoint of convenience. Since the encryption key itself used for data encryption is encrypted with separate public keys for the submitter and the recipient, the risk of information leakage is further reduced.

a browsing acceptance step in which the server group selects a recipient of the data from the submitter terminal, accepts input of the passphrase for the submitter, and accepts a browsing request;
The server group decrypts the presenter's private key with the presenter's passphrase, and stores the presenter's encryption key storage box in association with the recipient ID of the selected recipient with the presenter's private key. decrypts the data stored in the database server in association with the recipient ID and the submitter ID with the encryption key decrypted with the submitter private key a data decryption step (submitter);
a data display step in which the server group displays the decrypted data on the submitter terminal;
is preferably included.

The submitter can use the submitter's passphrase to decrypt the data stored on the server and check the contents. Therefore, while realizing high security, troublesome operations are unnecessary and convenience is high. Even if there are a large number of recipients, if the presenter ID is the same, the passphrase for the presenter is common, which facilitates management.

an output reception step in which the server group selects the data submitter from the recipient terminal, receives the input of the recipient's passphrase, and receives an output request;
The server group decrypts the recipient's private key with the recipient's passphrase, and associates the decrypted recipient's private key with the submitter ID of the selected submitter to encrypt the recipient's encryption key. Decrypting the encryption key stored in the storage box, and using the encryption key decrypted with the recipient's private key, the data stored in the database server in association with the recipient ID and the submitter ID a data decryption step (recipient) to decrypt;
a data output step in which the server group outputs the decrypted data to the recipient terminal;
is preferably included.

The recipient can obtain the data by decrypting the data stored in the server using the recipient's passphrase. Therefore, while realizing high security, troublesome operations are unnecessary and convenience is high. Even if there are a large number of submitters, if the recipient ID is the same, the passphrase for the recipient is common, which facilitates management.

Further, it is preferable that the data is survey report data, the submitter is a graduated school, and the recipient is an examination school. The data to be passed from the submitter to the recipient is highly confidential data, and since the submitter and the recipient are separate organizations, the added value generated by high security is large.

In addition, a second aspect of the present invention includes one or more submitter terminals that are submitters of data and have submitter IDs, and one or more recipient terminals that are recipients of the data and have recipient IDs. and one or more web servers connected via a network;
one or more database servers interconnected to the web server;
A server group with multiple types of server functions including
A system in which an encryption key for encrypting the data is stored separately by a submitter and a recipient,
The server group
a recipient public key, a recipient secret key corresponding to the recipient public key, and an encryption key for encrypting the data using the recipient secret key as a box management key, using the recipient public key An encryption key storage box for recipients, which is encrypted and stored in association with the submitter ID of the person who submitted the data and can be retrieved by decrypting the encryption key with the private key for recipients, is generated for each recipient. recipient encryption key storage box generating means for storing the recipient encryption key storage box in the database server in association with each recipient ID;
Recipient passphrase generation means for automatically generating a recipient passphrase for encrypting the recipient private key;
Recipient's private key encryption for encrypting the recipient's private key with the recipient's passphrase and storing the encrypted recipient's private key and the recipient's public key in the database server means and
a recipient passphrase notifying means for notifying a predetermined recipient notification destination of the recipient passphrase and not allowing the database server to store the recipient passphrase;
Submitter login reception means for accepting login from the submitter terminal;
a submitter's public key, a submitter's private key corresponding to the submitter's public key, and an encryption key for encrypting the data using the submitter's private key as a box management key using the submitter's public key An encryption key storage box for the submitter, which stores the encrypted data in association with the recipient ID of the recipient and can be retrieved by decrypting the encryption key with the private key for the submitter, is generated for each submitter. and encryption key storage box generation means for submitter for storing the encryption key storage box for submitter in the database server in association with each submitter ID;
submitter passphrase generation means for generating a submitter passphrase for encrypting the submitter private key;
Encrypting the submitter's private key with the submitter's passphrase, and storing the encrypted submitter's private key and the submitter's public key in the database server. means and
submitter passphrase notification means for notifying a submitter passphrase to a predetermined submitter notification destination and not allowing the database server to store the submitter passphrase;
To provide an organization-specific encryption key storage system characterized by:

According to the second aspect of the present invention, the encryption key encrypted using the submitter's public key and the same encryption key encrypted using the recipient's public key are stored. The public key/private key pair is not common between the submitter and the recipient, and the encryption key is safely stored to reduce the risk of information leakage, and the recipient and the submitter without impairing the effectiveness of information leakage prevention measures. It is possible to further reduce the risk of information leakage by improving the convenience of communication and reducing transmission and management costs. Furthermore, since the private key corresponding to each public key is encrypted with each passphrase, the encryption key can be stored more safely, and the risk of information leakage is further reduced. Further, the submitter only has to manage the passphrase for the submitter and the recipient only has to manage the passphrase for the recipient, which is highly convenient. Furthermore, neither the submitter's passphrase nor the recipient's passphrase are stored on the server, so neither the submitter's private key nor the recipient's private key can be decrypted by a server attack, and there is a risk of information leakage. is further reduced.

Further, the server group further
data receiving means for receiving an input of the presenter's passphrase from the presenter's terminal, selecting a recipient of the data, and accepting uploading of the data;
if there is no encryption key associated with the recipient ID of the selected recipient in the submitter's encryption key storage box, generating an encryption key associated with the submitter ID and the recipient ID; means for encrypting and storing the submitter's encryption key, which is encrypted with the submitter's public key and stored in the submitter's encryption key storage box in association with the recipient's ID;
The encryption key generated by the encryption key encryption storage means of the submitter is encrypted with the recipient's public key of the selected recipient, and stored in the recipient's encryption key storage box of the selected recipient. a recipient's encryption key encryption storage means for storing in association with the submitter ID;
The submitter who decrypts the submitter's private key with the submitter's passphrase if the submitter's encryption key storage box contains the encryption key associated with the recipient's ID and is stored. private key decryption means for
encryption key decryption means for decrypting the encryption key associated with the recipient ID from the submitter's encryption key storage box with the submitter's private key;
data storage means for encrypting the data with an encryption key decrypted with the submitter private key and storing the data in the database server in association with the submitter ID and the recipient ID;
It is preferred to have

Furthermore, the server group further
a browsing acceptance means for allowing the recipient of the data to be selected from the submitter terminal, accepting the input of the submitter's passphrase, and accepting a browsing request;
Decrypting the presenter's private key with the presenter's passphrase, and using the presenter's private key, the cipher stored in the presenter's encryption key storage box in association with the recipient's ID of the selected recipient data decryption means (submission person) and
data display means for displaying the decrypted data on the submitter terminal;
It is preferred to have

Further, the server group further
output receiving means for selecting a submitter of the data, receiving input of the passphrase for the receiver, and receiving an output request from the receiver terminal;
decrypting the recipient's private key with the recipient's passphrase, and storing the decrypted recipient's private key in the recipient's encryption key storage box in association with the submitter ID of the selected submitter; data decryption means for decrypting the encrypted key, and decrypting the data stored in the database server in association with the recipient ID and the submitter ID with the encryption key decrypted with the recipient's private key; (recipient) and
data output means for outputting the decrypted data to the recipient terminal;
It is preferred to have

Further, it is preferable that the data is survey report data, the submitter is a graduated school, and the recipient is an examination school.

According to the present invention, it is possible to safely store encryption keys and reduce the risk of information leakage, improve convenience for recipients and submitters, and reduce transmission costs and management costs without impairing the effectiveness of information leakage prevention measures. This makes it possible to further reduce the risk of information leakage.

1 is a diagram showing a network configuration of Example 1 of an organization-based encryption key storage system of the present invention; FIG. 1 is a diagram showing a server configuration of Example 1 of an organization-based encryption key storage system of the present invention; FIG. FIG. 4 is an image diagram of the inside of the database server when creating a submitter's encryption key storage box in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 4 is an image diagram of the inside of the database server when a recipient's encryption key storage box is created in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 2 is a diagram showing the flow of generation of a graduated school encryption key storage box in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 3 is a diagram showing an example of a graduated school table in the first embodiment of the organization-based encryption key storage system of the present invention; FIG. 4 is an image diagram of the inside of the database server when uploading data is encrypted and stored in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 2 is a diagram showing the flow of data encryption processing in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 4 is a diagram showing an example of a recipient (entrance school) table in the first embodiment of the organization-specific encryption key storage method of the present invention; It is an example of a report table in the first embodiment of the storage method of the organization-specific encryption key of the present invention. It is a figure which shows an example of the alma mater encryption key table and the examination school encryption key table in Example 1 of the storage method of the encryption key classified by organization of this invention. FIG. 4 is an image diagram showing a key storage state in the database server in the first embodiment of the organization-specific encryption key storage method of the present invention; FIG. 4 is a diagram showing the flow of data retrieval in the first embodiment of the organization-specific encryption key storage method of the present invention;

The processing of the organization-specific encryption key storage system of the present invention is realized on a computer terminal (including a server) having an arithmetic processing unit such as a CPU and a storage device such as a RAM or hard disk. A program for realizing an organization-specific encryption key storage system of this embodiment, which will be described later, is stored in the hard disk of the computer terminal. A function (means) is executed by an arithmetic processing unit, and thus a predetermined process is performed. Information stored as storage means used for such processing is stored in storage devices such as RAM and hard disks in various file storage formats such as databases and data files. Predetermined processing is performed. Further, the processed result is also written to a storage device such as a RAM or a hard disk and stored as appropriate. Each means in the present invention is only logically distinguished in its function, and may constitute the same area physically or practically.

Also, in the organization-specific encryption key storage system of this embodiment, which will be described later, the submitter of the data is the school where the test is taken, and the recipient is the school where the test is taken. There may be. The data submitter and the recipient are different organizations, but in this application, the "organization" is not limited to the school unit, but may be the company or group unit, the department unit, or the individual unit. may be of different dimensions, such as being a company.

Preferred embodiments of the organization-specific encryption key storage method and organization-specific encryption key storage system according to the present invention will now be described in detail with reference to the accompanying drawings. The invention is not limited to these.

This embodiment is a method for safely storing keys used for encryption and keys used for decryption when encrypting and storing highly confidential data in a server. In this embodiment, when one or an unspecified number of data submission sources (submitters) submit data to one or more submission destinations (recipients) via the Internet, management of submission destinations (recipients) is performed. Until the person receives the data, it is necessary to temporarily store the data on a server connected to the Internet, but if the data is highly confidential, it must be encrypted and stored, and It realizes that even the server administrator can decrypt the data so that it cannot be deciphered.

{composition}
In this embodiment, as an example, we will describe the transfer of survey report data in a high school entrance examination in which applications are accepted on the Internet, and the case where "data" is the survey report data of applicants (examinees) will be described. It is not limited to the examination, and may be other entrance examinations such as university entrance examinations, junior high school entrance examinations, or various certification examinations. Applicants may be applicants for entrance examinations as well as for certification examinations. Better suited for high data handling. The school to which the applicant for the examination belongs is the school of origin, and the school to which the applicant applies is the examination school.

FIG. 1 is a diagram showing a network configuration of a first embodiment of an organization-based encryption key storage system according to the present invention. In this embodiment, the organizational encryption key storage system has a server group consisting of one or more servers, and the server group connects one or more Web servers 6 and the Web servers 6 to each other. It has one or more database servers 7 . Each server may be physically composed of one or a plurality of servers and function as one type of server, and functions as a plurality of types of servers may be physically composed of one server. may have been For example, the database server may reside within a web server. In addition, the database may exist within one database server, or may exist distributed among a plurality of database servers. In this embodiment, the Web server and the database server are physically connected to each other, but they may be in the same server, or they may be connected via a network and accessible to each other. good.

In this embodiment, as shown in FIG. 1, one or more submitter terminals 2 (this one or a plurality of recipient terminals 3 (in this embodiment, the administrator's terminal of the school attended), and one or more recipient terminals 3 (in this embodiment, In the example, the terminal of the administrator of the school for examination) and the Web server 6 are connected via the Internet. The server administrator terminal 5 may be directly connected to a server group including the Web server 6 and the database server 7, or may be connected via the Internet as shown in FIG. The submitter logs in with the submitter ID and the recipient logs in with the recipient ID. A known method using a password can be used as a login method. There may be multiple submitter terminals with the same submitter ID within the same organization. Also, there may be a plurality of recipient terminals having the same recipient ID within the same organization as the submitter.

The organization-specific encryption key storage system of this embodiment is a system in which the encryption key for encrypting the data described above is stored separately by the submitter and the recipient. , the recipient's private key corresponding to the recipient's public key, and the encryption key for encrypting the data using the recipient's private key as the box management key is encrypted with the recipient's public key and submitted by the data submitter. A recipient's encryption key storage box which is stored in association with a person's ID and can be retrieved by decrypting the encryption key with the recipient's private key is generated for each recipient, and the recipient's encryption key storage box is stored in the database server. and (B) recipient passphrase generation means for automatically generating a recipient passphrase for encrypting the recipient private key. and (C) recipient's private key encryption that encrypts the recipient's private key with the recipient's passphrase and stores the encrypted recipient's private key and the recipient's public key in the database server. (D) recipient passphrase notification means for notifying a recipient passphrase to a predetermined recipient notification destination and not allowing the database server to store the recipient passphrase; E) submitter login reception means for accepting logins from submitter terminals; An encryption key used as a management key for encrypting data is encrypted with a public key for the submitter, stored in association with the recipient ID of the recipient of the data, and submitted by decrypting the encryption key with the private key for the submitter and retrievable. (G and (H) encrypting the submitter's private key with the submitter's passphrase to produce an encrypted submission. (I) a submitter's private key encryption means for storing a submitter's private key and a submitter's public key in a database server; a submitter passphrase notification means for not causing the submitter passphrase to be stored in the submitter passphrase.

In addition, the server group includes (J) data receiving means for receiving an input of a submitter's passphrase from a submitter's terminal, selecting a recipient of data and receiving data upload, and (K) a submitter's encryption If there is no encryption key associated with the recipient ID of the selected recipient in the key storage box, generate an encryption key associated with the submitter ID and the recipient ID of the selected recipient, and submit (L) submitter's encryption key encryption storage means for encrypting with the submitter's public key and storing it in association with the recipient's recipient ID selected in the submitter's encryption key storage box; The encryption key generated by the key encryption storage means is encrypted with the recipient public key of the selected recipient, and is stored in the recipient encryption key storage box of the selected recipient and associated with the submitter ID. Recipient's cryptographic key encryption storage means for storage, and (M) when the cryptographic key associated with the selected recipient's recipient ID is and has been stored in the submitter's encryption key storage box; is the submitter's passphrase to decrypt the submitter's private key; and (O) data is encrypted with the encryption key decrypted with the submitter's private key, and the submitter's ID and the selected data are stored in the database server. and data storage means for storing in association with the recipient's recipient ID.

Further, the server group includes (P) browsing acceptance means for allowing the submitter terminal to select a recipient of the data, accepting the input of the submitter's passphrase, and accepting the browsing request; and (Q) the submitter's pass Decrypt the submitter's private key with the phrase, decrypt the submitter's private key with the submitter's private key, and decrypt the encryption key stored in the submitter's encryption key storage box in association with the recipient ID of the selected recipient. data decryption means (submitter) for decrypting data stored in association with the recipient ID and submitter ID of the recipient selected in the database server with the encryption key decrypted with the private key for ) data display means for displaying the decrypted data on the presenter's terminal;

Further, the server group includes (S) output receiving means for selecting a data submitter from the receiver terminal, receiving input of the receiver's passphrase, and receiving an output request; Decrypt the recipient's private key with the passphrase, and use the decrypted recipient's private key to decrypt the encryption key stored in the recipient's encryption key storage box in association with the submitter ID of the selected submitter. , data decryption means (recipient) for decrypting data stored in the database server in association with the recipient ID and the submitter ID of the selected submitter, with the encryption key decrypted with the recipient's private key; (U) data output means for outputting the decrypted data to a recipient terminal;

In this embodiment, the means (A) to (U) are provided in the Web server 6, but some of the means may be provided in another server within the server group. Since neither the Web server 6 nor the database server 7 is conscious of which server the control unit resides in, the respective front units may be used. Each front part has a program to be executed in each server, and cooperates in processing. In this embodiment, both the Web server 6 and the database server 7 are controlled by their respective front sections.

In this embodiment, the communication means, the input means and the display means are present in the presenter's terminal 2 and the recipient's terminal 3 . The web server 6 includes a memory, a CPU, a storage (hardware) that is secondary storage such as a magnetic disk, an operating system, a device driver, and the like. Storage program for organization-specific encryption keys and various web page contents are stored on a magnetic disk, and the control unit executes various program processes. In order to exchange information between the recipient terminal 2 and the recipient terminal 3 many times, information can be temporarily stored in a non-volatile memory, and input means, display, and other output means may be provided. The database server 7 has a memory, a CPU, a storage (hardware), and local connection means with the Web server 6, but may also have communication means, input means, display, and other output means. The web server 6 and the database server 7 cooperate with each other based on the operation instructions from the web server 6 to perform the encryption key storage processing of the present invention. The Web server 6 and the database server 7 are equipped with a clock function, etc. that a normal server has.

FIG. 2 is a diagram showing the server configuration of the first embodiment of the organization-based encryption key storage system of the present invention. In this embodiment, the Web server 6 is described as an example in which one server has the function of the a-Web server for the submitter and the function of the b-Web server for the recipient. Alternatively, a plurality of Web servers may be provided with a load balancer in order to deal with the concentration of accesses. Also, one or more web servers may be cloud servers on the cloud. A cloud server is virtual, and in practice, multiple servers may be physically used as one cloud server. In that case, memory and CPU (the number of cores) can be expanded/reduced instantaneously.

A single URL (Uniform Resource Locator) is indicated as a connection destination to the submitter terminal 2 or the recipient terminal 3 and accessed, the load balancer receives the access addressed to the URL, and the load balancer connects to a plurality of Web servers connected to the load balancer. 6, it is possible to distribute the load to each Web server. Another method for avoiding concentration of Web access is a system that uses round robin in DNS (Domain Name System). The connection destination URL created by the web server 6 is a web page within the virtual web server. Furthermore, a URL including a virtual directory may be used as the connection destination URL to display a specific web page of the virtual server. When creating a predetermined access web page, an existing access web page may be duplicated.

The server group 5 can exchange information with the submitter terminal 2 and the recipient terminal 3 via communication networks such as the Internet, LAN, and WAN. The submitter terminal 2 and the recipient terminal 3 may be, for example, personal computers (PCs) including notebook PCs and tablet PCs.

In addition, the Web server 6 has respective data for a submitter data submission form screen 68 including a survey form data upload acceptance screen and a recipient data management screen 69 including a survey form data download acceptance screen. The database server 7 stores a submitter ID (login ID) assigned for login for each submitter in association with a password, URL, and submitter identifier, and is assigned for login for each recipient. Recipient IDs (login IDs) are stored in association with passwords, URLs, and recipient identifiers. Submitter passphrases and recipient passphrases are not stored on the servers.

A confidential data management database 71 is stored in the database server 7. In the confidential data management database 71, data for each submitter and for each recipient 31 to 31 which are confidential data encrypted for each submitter and each recipient. 37 are each stored encrypted, ie with decryption locks 311-371, respectively. Each encrypted data is unique data, and known methods can be used for encryption.

FIG. 3 is an image diagram of the inside of the database server when the submitter's encryption key storage box is created in the first embodiment of the organization-specific encryption key storage method of the present invention. The confidential data management database 71 stores encryption key storage boxes 11 to 14 for each submitter and encryption key storage boxes 21 and 22 for each recipient. A cryptographic key storage box is a virtual box in the database server, and is a folder that encrypts and stores one or more cryptographic key data associated with a predetermined relationship.

In FIG. 3, the encryption key storage box 11 for submitter A, the encryption key storage box 12 for submitter B, the encryption key storage box 13 for submitter C, the encryption key storage box 14 for submitter D, and the encryption key storage box for recipient X. Key Storage Box 21, Encryption Key Storage Box 22 for Recipient Y, Submitter A Recipient X Data 31, Submitter B Recipient X Data 32, Submitter C Recipient X Data 33, Submitter A Recipient Y's data 34, submitter B-recipient Y's data 35 and submitter C-recipient Y's data 36 are each encrypted in the confidential data management database 71, i.e., by submitter and by recipient, respectively. Stored under a separate decryption lock. The submission destination X is the recipient X, and the submission destination Y is the recipient Y. Although each box is stored in the confidential data management database 71 in this embodiment, it may be stored in another database within the database server 7 .

The database server 7 also includes a submitter database, a recipient database, and the like. The submitter database stores the alma mater table and the alma mater encryption key table, and session information, the submitter notification destination and the submitter notification destination type for the passphrase, etc. are recorded.The recipient database is the examination school table and the examination school. An encryption key table is stored, and session information, receiver notification destinations and recipient notification destination types for passphrases, and the like are recorded. In this embodiment, the e-mail address is stored as the notification destination of the submitter and the notification destination of the recipient. It may be an identifier. Identifiers indicating whether the notification destination is a mobile number, fax number, or e-mail address are stored in the submitter notification destination type and the recipient notification destination type, and notifications are sent according to the type when the passphrase is automatically notified to each notification destination. conduct.

In this embodiment, the database server 7 is a dedicated server and resides in the data center together with the web server 6, but both may reside in the school. In that case, the terminal of the university to be tested and the Web server will be connected not via the Internet but via the campus LAN. In this embodiment, the database server 7 is a dedicated server, and a physical server is used exclusively (single), so database IO processing is fast. In this embodiment, the database server 7 maintains a mirrored database for system availability, that is, so that even if it goes down, it will not lose important confidential information and can be quickly restored. The original database becomes the master database, and the mirroring side becomes the slave database. Slave databases are not writable, only readable. When the system writes, it writes to the master database. In the slave database, when the master database is written, the data is instantly mirrored and written to the slave database as well.

The organization-specific encryption key storage program installed in the Web server 6 stores (a) the recipient's public key, the recipient's private key corresponding to the recipient's public key, and the recipient's private key in the computer. is a box management key, the encryption key for encrypting data is encrypted with the public key for the recipient, stored in association with the submitter ID of the data submitter, and can be retrieved by decrypting the encryption key with the private key for the recipient a recipient encryption key storage box for each recipient, and a recipient encryption key storage box generation function for causing a database server to store the recipient encryption key storage box in association with each recipient ID; (b) A recipient passphrase generation function that automatically generates a recipient passphrase that encrypts the recipient private key, and (c) encrypts and encrypts the recipient private key with the recipient passphrase. (d) a recipient's private key encryption function for storing the recipient's private key and the recipient's public key in the database server; , a receiver's passphrase notification function that does not store the receiver's passphrase in the database server, (e) a submitter's login reception function that accepts login from the submitter's terminal, and (f) a submitter's public key, The submitter's private key corresponding to the submitter's public key and the encryption key for encrypting data using the submitter's private key as the box management key is encrypted with the submitter's public key to obtain the recipient ID of the data recipient and a submitter's encryption key storage box that can be retrieved by decrypting the encryption key with the submitter's private key. (g) a submitter passphrase generation function that generates a submitter passphrase that encrypts the submitter private key; h) A submitter's private key encryption function that encrypts the submitter's private key with the submitter's passphrase and stores the encrypted submitter's private key and the submitter's public key in the database server. , (i) a submitter passphrase notification function that notifies the submitter passphrase to the specified submitter notification destination and does not store the submitter passphrase in the database server; A data reception function that accepts input of a passphrase, selects a recipient of data, and accepts data upload; If there is no encryption key, generate an encryption key associated with the submitter ID and the selected recipient's recipient ID, encrypt it with the submitter's public key, and store it in the submitter's encryption key storage box. The submitter's encryption key encryption storage function, which is stored in association with the recipient ID of the selected recipient; a recipient's encryption key encryption storage function for encrypting with the recipient's recipient's public key and storing it in the recipient's encryption key storage box of the selected recipient in association with the submitter's ID; If the encryption key associated with the recipient ID of the selected recipient exists in the encryption key storage box for the submitter and if it is stored, decrypt the private key for the submitter with the passphrase for the submitter. Submitter's private key decryption function and (c) submitter's private key to decrypt the encryption key associated with the recipient ID of the recipient selected from the submitter's encryption key storage box (j) a data storage function that encrypts data with the encryption key decrypted with the submitter's private key and stores it in the database server in association with the submitter's ID and the selected recipient's recipient's ID; (2) From the submitter's terminal, the data recipient is selected, the input of the submitter's passphrase is accepted, and the view request is received. (h) The submitter's secret with the submitter's passphrase Decrypt the key, use the submitter's private key to decrypt the encryption key stored in the submitter's encryption key storage box in association with the recipient ID of the selected recipient, and decrypt with the submitter's private key a data decryption function (submitter) that decrypts the data stored in association with the recipient ID and submitter ID of the recipient selected in the database server with the encryption key obtained from the data decryption function (submitter); data display function for displaying data on the terminal of the submitter; ) decrypt the recipient's private key with the recipient's passphrase, and with the decrypted recipient's private key, the encryption stored in the recipient's encryption key storage box in association with the submitter ID of the selected submitter A data decryption function (receipt and (n) a data output function for outputting the decrypted data to the recipient's terminal.

The Web server 6 can store the organization-specific encryption key according to the present invention by loading the organization-specific encryption key storage program of the Web server 6 into the memory of the Web server 6 and executing it by the CPU of the Web server 6. Realize computer functions. The CPUs of the Web server 6 and the database server 7 are arithmetic processing units installed in ordinary computers, and can execute various programs and perform various controls.

In this embodiment, the Web server 6 functions as each means (A) to (U) described above according to the above-described hardware configuration and organization-specific encryption key storage program.

In addition to the storage program for the organization-specific encryption key, the Web server 6 is loaded with related programs and other programs.

The data recipient may distribute to each submitter in advance the submitter screen information describing the URL of the submitter's data submission form screen (web page created for each submitter). Also, the format of the data to be exchanged may be distributed or downloaded. The submitter creates data to be submitted to the recipient and saves (outputs) it on the desktop of the submitter's terminal. The submitter can upload the data (in this embodiment, survey report data) on the submitter's data submission form screen displayed by the organization-specific encryption key storage system of this embodiment on the submitter's terminal.

{Processing process}
The organization-specific encryption key storage method of this embodiment consists of one or more submitter terminals that are submitters of data and have submitter IDs and one or more recipient terminals that are recipients of the data and have recipient IDs. A server group having multiple types of server functions, including one or more web servers connected to terminals via a network and one or more database servers interconnected to the web servers, encrypts data. This is an organization-specific encryption key storage method in which the encryption key to be encrypted is stored separately by the submitter and the recipient. In the storage method of the organization-specific encryption key of this embodiment, (Step 10) the server group manages the recipient's public key, the recipient's private key corresponding to the recipient's public key, and the recipient's private key in a box. A recipient who encrypts an encryption key used as a key and encrypts data with a recipient's public key, stores it in association with the submitter's ID of the person submitting the data, and can retrieve the encryption key by decrypting it with the recipient's private key (Step 20) a recipient encryption key storage box generating step of generating an encryption key storage box for each recipient and storing the recipient encryption key storage box in the database server in association with each recipient ID; (Step 30) a recipient passphrase generation step in which the server group automatically generates a recipient passphrase for encrypting the recipient private key; a recipient's private key encryption step of encrypting and storing the encrypted recipient's private key and the recipient's public key in the database server; a recipient passphrase notification step of notifying a predetermined recipient notification destination and not allowing the database server to store the recipient passphrase; (Step 60) The server group encrypts the data using the presenter's public key, the presenter's private key corresponding to the presenter's public key, and the presenter's private key as box management keys. an encryption key storage box for the submitter which encrypts the encryption key with the public key for the submitter, stores it in association with the recipient ID of the recipient of the data, and can be retrieved by decrypting the encryption key with the private key for the submitter; is generated for each submitter, and the submitter's encryption key storage box is stored in the database server in association with each submitter's ID; (Step 80) A submitter passphrase generation step for generating a submitter passphrase for encrypting the private key for the submitter, and (Step 80) the server group encrypts the submitter private key with the submitter passphrase, and encrypts the encrypted a submitter private key encryption step of storing the submitter private key and the submitter public key in the database server; a submitter passphrase notification step of notifying and not storing the submitter passphrase in the database server.

In this embodiment, (Step 100) a data reception step in which the server group receives an input of the passphrase for the submitter from the submitter terminal, selects the recipient of the data, and receives the upload of the data; Step 110) If there is no encryption key associated with the recipient ID of the selected recipient in the encryption key storage box for the submitter, the server group submitter's encryption key encryption storage for generating an associated encryption key, encrypting it with the submitter's public key, and storing it in the submitter's encryption key storage box in association with the recipient ID of the selected recipient; (Step 120) the server group encrypts the encryption key generated in the submitter's encryption key encryption storage step with the selected recipient's recipient's public key to receive the selected recipient's (Step 130) a process of encrypting and storing the recipient's encryption key, which is stored in the encryption key storage box for the presenter in association with the submitter's ID; If there is an encryption key associated with the recipient ID of and if it is stored, the submitter's private key decryption step for decrypting the submitter's private key with the submitter's passphrase, and (Step 140) the server group , a submitter's encryption key decryption step for decrypting the encryption key associated with the recipient ID of the recipient selected from the submitter's encryption key storage box with the submitter's private key, and (Step 150) a group of servers, and a data storage step of encrypting the data with the encryption key decrypted with the private key for the submitter and storing the data in the database server in association with the submitter ID and the recipient ID of the selected recipient.

In this embodiment, (Step 160) the server group selects the recipient of the data from the submitter terminal, receives the input of the passphrase for the submitter, and receives the view request; Step 170) The server group decrypts the submitter's private key with the submitter's passphrase, and stores it in the submitter's encryption key storage box in association with the recipient's ID of the selected recipient using the submitter's private key. Data for decrypting the encryption key that has been provided, and using the encryption key decrypted with the private key for the submitter to decrypt the data stored in association with the recipient ID and submitter ID of the recipient selected in the database server. (Step 180) A data display step in which the server group displays the decrypted data on the submitter's terminal.

Further, in this embodiment, (Step 190) the server group selects the data submitter from the recipient terminal, receives the input of the recipient's passphrase, and receives the output request. , (Step 200) The server group decrypts the recipient's private key with the recipient's passphrase, and stores the recipient's encryption key with the decrypted recipient's private key in association with the submitter ID of the selected submitter. Decrypt the encryption key stored in the box, and use the encryption key decrypted with the recipient's private key to copy the data stored in the database server in association with the recipient ID and the selected submitter's submitter ID (Step 210) A data output step in which the server group outputs the decrypted data to the recipient terminal.

Among the above steps, Steps 10 to 40 are a series of flow of generation processing of encryption key storage box for recipient (encryption key storage box for examination school), and Steps 50 to 90 are encryption key storage box for submitter ( School encryption key storage box) generation process, Steps 100 to 150 are a series of data (survey document data) encryption process flow, and Steps 160 to 180 are data (survey Document data) is a series of flow of display processing, and Steps 190 to 210 are a series of flow of data (survey report data) extraction processing to the recipient's terminal.

In this embodiment, the organization-specific encryption key storage program causes a computer to execute the steps described above. Each step will be described in detail below.

<Recipient encryption key storage box generation process>
(Step 10: Recipient Encryption Key Storage Box Generation Step)
The Web server 6 of the server group generates a public key for the recipient, a private key for the recipient, and an encryption key storage box for the recipient for each recipient, and receives the encryption key storage box for the recipient. It is stored in the database server 7 in association with the person ID. The receiver's encryption key storage box uses the receiver's private key as a box management key, encrypts the encryption key for encrypting data with the receiver's public key, and stores the data in association with the submitter ID of the data submitter; The encryption key can be decrypted with the recipient's private key and taken out.

For example, when X high school (submission destination X) is the recipient and the recipient ID (entrance school ID) given to X high school is 21, the Web server 6 transmits the public key for the recipient of X high school and X A recipient's private key of X high school corresponding to (paired with) the recipient's public key of high school is generated, and a recipient's encryption key of X high school that can be unlocked with the recipient's private key of X high school An encryption key storage box 21 for recipient X, which is a storage box, is generated and stored in the confidential data management database 71 in association with the recipient ID of X high school. The encryption key storage box 21 for recipient X generated here stores the encryption key for encrypting data and associated with high school X for each submitter, as will be described later. A box that can be encrypted with a key and stored in association with the submitter ID of the data submitter, and decrypts the encryption key encrypted with the recipient's public key of X high school with the recipient's private key of X high school. are available as removable boxes for each submitter. Similarly, when Y high school (submission destination Y) is the recipient and the recipient ID (entrance school ID) given to Y high school is 22, the Web server 6 receives the public key for the recipient of Y high school, A recipient's private key of Y high school corresponding to (paired with) the recipient's public key of Y high school is generated, and the recipient's private key of Y high school is used to unlock the recipient's encryption of high school Y. An encrypted key storage box 22 for recipient Y, which is a key storage box, is generated and stored in the confidential data management database 71 in association with the recipient ID of Y high school.

FIG. 4 is an image diagram of the inside of the database server when the recipient's encryption key storage box is created in the first embodiment of the organization-specific encryption key storage method of the present invention. FIG. 4 shows a state in which the encryption key storage box 23 for recipient Z, which is the recipient encryption key storage box for Z high school, is generated. The Web server 6 generates the recipient public key of Z high school and the recipient private key of Z high school corresponding to (pairing with) the recipient public key of Z high school. An encryption key storage box 23 for recipient Z that can be unlocked with a secret key is generated and stored in the confidential data management database 71 in association with the recipient ID of Z high school.

(Step 20: Recipient passphrase generation step)
Next, the Web server 6 automatically generates a recipient's passphrase for encrypting the recipient's private key. For example, the recipient passphrase for X high school that encrypts the recipient private key for X high school is a unique passphrase that is different from the recipient passphrases that encrypt the recipient private keys for other high schools. be.

(Step 30: Recipient private key encryption step)
Next, the Web server 6 encrypts the recipient's private key with the recipient's passphrase, and stores the encrypted recipient's private key and the recipient's public key in the database server. A box management key (recipient's private key) is protected by a recipient's passphrase.

For example, encrypt the recipient's private key for X high school with the recipient's passphrase for X high school. Then, the recipient ID of X high school, the school name of X high school, the recipient public key of X high school, and the encrypted recipient private key of X high school are associated with each other to create a recipient database (entrance school database). ) is stored in the examination school table, which is the recipient table in the table. The recipient's private key of X High School is not stored in the database server.

In the encryption key storage box 21 for recipient X, using the public key for the recipient of X high school stored in association with the recipient ID of X high school, the submitter and X high school are associated as described later. Since the encryption key is encrypted and stored in the box, the recipient's public key of X High School serves as the entry point for the encryption key in the box. On the other hand, since the recipient's private key of X high school is used to decrypt the encryption key stored in the box, the recipient's private key of X high school serves as a box management key in the box. Since the Recipient's Private Key for High School X is encrypted, if not decrypted, retrieve the encryption key associated with the Submitter and High School X from Recipient X's Encryption Key Vault 21, i.e. The encryption key cannot be decrypted. Therefore, according to this embodiment, the encryption key storage security level is high. Therefore, the risk of information leakage due to leakage of the encryption key is extremely low.

(Step 40: Recipient passphrase notification step)
Next, the Web server 6 notifies the recipient's passphrase to a predetermined recipient notification destination, and does not store the recipient's passphrase in the database server. Since neither the recipient's private key nor the recipient's passphrase is stored in the database server, encrypted Recipient's private key cannot be decrypted. Therefore, the storage security level of the encryption key is further increased, and the risk of information leakage due to leakage of the encryption key is further reduced. In this embodiment, notification of the recipient's passphrase is sent by e-mail, but it may be automatically notified using another notification means. For example, there are SMS, push notification of smart phone, FAX transmission, and the like. Alternatively, by sending an authentication code and entering the authentication code, the passphrase for the recipient may be displayed on the screen. Alternatively, the passphrase may be displayed using an application downloaded to a smartphone or the like. For example, in the case of notification by SMS to the mobile phone number of a smart phone, when the passphrase for the recipient is automatically generated, the Web server 6 sends SMS to the mobile phone number stored as the recipient notification destination in the database server. Notify passphrase for This enables the recipient to enter the recipient's passphrase into the recipient's terminal. The automatically generated passphrase for the recipient remains in memory until notification, but is not stored anywhere in the server group after notification is completed. The same applies to the notification of the submitter's passphrase, which will be described later.

For example, the recipient's passphrase for X high school is sent from X high school to the pre-registered email address for administrator of X high school. Since the database server 7 does not store the recipient's passphrase for X high school, the possibility that the encryption key stored in recipient X's encryption key storage box 21 will be decrypted is extremely small. The possibility that the data (investigation report data) for each submitter will be decrypted with the encryption key decrypted with the private key for the person who submitted the questionnaire is further reduced.

<Cryptographic key storage box generation process for submitter>
(Step 50: submitter login reception process)
The web server 6 accepts logins from submitter terminals. The login is accepted with the login ID and password previously notified to each submitter. FIG. 5 is a diagram showing the flow of generation of the encryption key storage box for the school attended in the first embodiment of the organization-specific encryption key storage method of the present invention. The encryption key storage box for the alma mater, that is, the encryption key storage box for the submitter is generated according to the flow shown in FIG. In this embodiment, when the login from the submitter's terminal is the first login, registration of an e-mail address that can be received by the device owned by the submitter is accepted as the submitter's notification destination. The Web server 6 generates a submitter ID, sets the mail address as the submitter's communication destination, sets the communication destination as mail, associates it with the submitter's ID, and stores it in the database server 7 .

(Step 60: Encryption key storage box generation step for submitter)
The Web server 6 generates a submitter public key, a submitter private key, and a submitter encryption key storage box for each submitter, and assigns the submitter encryption key storage box to each submitter ID. It is associated and stored in the database server 7 . The submitter's encryption key storage box uses the submitter's private key as a box management key, encrypts the encryption key for encrypting data with the submitter's public key, and stores the data in association with the recipient ID of the recipient of the data; The encryption key can be decrypted with the submitter's private key and taken out.

For example, if A junior high school is the submitter and the submitter ID (alma mater ID) given to A junior high school is 11, the Web server 6 stores the public key for the submitter of A junior high school and the public key for the submitter of A junior high school. Submission, which is an encryption key storage box for the submitter of A junior high school, which generates a private key for the submitter of A junior high school corresponding to (paired with) the public key, and can be unlocked with the private key for the submitter of A junior high school. The encryption key storage box 11 for person A is generated and stored in the confidential data management database 71 in association with the submitter ID of A junior high school. The encryption key storage box 11 for submitter A generated here encrypts the encryption key for submitter of junior high school A for each recipient whose data is to be encrypted with the public key for submitter of junior high school A, as will be described later. , and can be stored in association with the submitter ID of Junior High School A, and can be retrieved by decrypting the encryption key for submitter of Junior High School A for each recipient with the private key for recipient of Junior High School A. Similarly, when B junior high school is the submitter and the submitter ID (alma mater ID) given to B junior high school is 12, the Web server 6 receives the public key for the submitter of B junior high school and the submitter of B junior high school. A private key for submitter of B junior high school corresponding to (paired with) the public key for B is generated, and the encryption key storage box for submitter of B junior high school is unlockable with the private key for submitter of B junior high school. The encryption key storage box 12 for submitter B is generated and stored in the confidential data management database 71 in association with the submitter ID of B junior high school.

(Step 70: Passphrase generation step for submitter)
Next, the Web server 6 automatically generates a submitter's passphrase for encrypting the submitter's private key. For example, the submitter passphrase for middle school A that encrypts the submitter private key for middle school A is a unique passphrase that is different from the submitter passphrase that encrypts the submitter private keys for other middle schools. be.

(Step 80: private key encryption step for submitter)
Next, the Web server 6 encrypts the submitter's private key with the submitter's passphrase, and stores the encrypted submitter's private key and the submitter's public key in the database server. The box management key (private key for submitter) is protected by a passphrase for submitter.

For example, the submitter's private key for A's middle school is encrypted with the submitter's passphrase for A's middle school. Then, the submitter ID of junior high school A, the school name of junior high school A, the public key for submitter of junior high school A, and the encrypted private key for submitter of junior high school A are associated with each other to create a submitter database (alma mater database). ) is stored in the alma mater table, which is the submitter table. The private key for the submitter of Junior High School A is not stored in the database server.

FIG. 6 is a diagram showing an example of an alma mater table in the first embodiment of the organization-based encryption key storage system of the present invention. As shown in FIG. 6, A junior high school, B junior high school, and C junior high school are assigned school IDs 11, 12, and 13, which are submitter IDs, in the alma mater table, and are stored in association with each other. In addition, for each junior high school, an encrypted submitter's private key obtained by encrypting the submitter's private key with a submitter's passphrase as an encrypted private key, and a submitter's public key (public key A, B, and C) are respectively stored in association with the submitter ID (school ID) and submitter (school name). The public key A is dedicated to A middle school, the public key B is dedicated to B junior high school, and the public key C is dedicated to C junior high school. The reason why the column for C junior high school is blank is that the submitter's public key and private key pair for C junior high school have not yet been created because the submitter's terminal has not been logged in for the first time. , Therefore, the encrypted submitter private key of C Junior High School has not been created either. In this state, the submitter's encryption key storage box for C junior high school has not yet been created. In FIG. 5, for a junior high school with a submitter ID of 14 (D junior high school), a submitter public key and submitter private key pair is generated, and an encrypted submitter private key is generated. This is the state in which the encryption key storage box 14 for submitter D, which is the encryption key storage box for the submitter of D, has been generated. In FIG. 5, the encryption key for encrypting the data is not yet stored in the encryption key storage box 14 for submitter D.

In addition, in the alma mater table, the submitter ID of A junior high school is stored in association with the submitter communication destination and communication destination type of A junior high school.

In the encryption key storage box 11 for submitter A, using the public key for submitter of junior high school A stored in association with the submitter ID of junior high school A, it is associated with junior high school A and the recipient as will be described later. Since the encryption key is encrypted and stored in the box, the submitter's public key of A Junior High School serves as the entry point for the encryption key in the box. On the other hand, since the submitter's private key of Junior High School A is used to decrypt the encryption key stored in the box, the submitter's private key of Junior High School A serves as a box management key in the box. Since the submitter private key of A middle school is encrypted, if not decrypted, retrieve the encryption key associated with A middle school and the recipient from the submitter A encryption key storage box 11, i.e. The encryption key associated with A Middle School and the recipient cannot be decrypted. Therefore, according to this embodiment, the encryption key storage security level is high. Therefore, the risk of information leakage due to leakage of the encryption key is extremely low.

(Step 90: Passphrase notification process for submitter)
Next, the Web server 6 of the server group notifies the submitter's passphrase to a predetermined submitter notification destination, and does not store the submitter's passphrase in the database server. Since neither the submitter's private key nor the submitter's passphrase is stored in the database server, even if the server is attacked, neither the recipient terminal 3 nor the server administrator terminal 5 can access encrypted data. The submitter's private key cannot be decrypted. Therefore, the storage security level of the encryption key is further increased, and the risk of information leakage due to leakage of the encryption key is further reduced. In this embodiment, the submitter's passphrase is notified by e-mail, but it may be automatically notified using another notification means. For example, there are SMS, push notification of smart phone, FAX transmission, and the like. Alternatively, by sending an authorization code and entering the authorization code, the passphrase for the submitter may be displayed on the screen. Alternatively, the passphrase may be displayed using an application downloaded to a smartphone or the like.

For example, the submitter's passphrase for Junior High School A is sent to the email address of the submitter of Junior High School A. In this embodiment, the submitter's notification destination is the e-mail address of the administrator of the graduated school. Since the database server 7 does not store the submitter's passphrase for A junior high school, the possibility that the encryption key stored in the submitter's encryption key storage box 11 for A junior high school will be decrypted is extremely small. The possibility that the data (report data) for each recipient will be decrypted with the encryption key decrypted with the private key for the submitter of the junior high school is further reduced.

<Data encryption processing>
(Step 100: data reception process)
FIG. 7 is an image diagram of the inside of the database server when the uploaded data is encrypted and stored in the first embodiment of the organization-specific encryption key storage method of the present invention. FIG. 7 shows the state when school report data is submitted by the system of this embodiment from Junior High School D (submitter D) with a submitter ID of 14 to High School Y (submission destination Y) with a recipient ID of 22. indicates

The Web server 6 accepts the input of the submitter's passphrase from the submitter's terminal, allows the recipient of the data to select an examination school, and receives the upload of the data. FIG. 8 is a diagram showing the flow of data encryption processing in the first embodiment of the organization-specific encryption key storage method of the present invention. Survey report encryption processing, ie, data encryption processing, is executed according to the flow shown in FIG.

For example, the encryption processing of the report data to be submitted from D junior high school to Y high school is executed as shown in FIGS. 7 and 8. FIG. The submitter data submission form screen displayed from the Web server 6 is displayed on the administrator terminal of D junior high school who accessed the system of this embodiment with the login ID and password, and the administrator terminal of D junior high school notified Accepts the input of the submitter's passphrase for D junior high school.

(Step 110: Encryption key encryption storage step)
Next, if there is no encryption key associated with the selected recipient's recipient ID in the submitter's encryption key storage box, the Web server 6 stores the submitter's ID and the selected recipient's recipient. An encryption key associated with the ID is generated, encrypted with the submitter's public key, and stored in the submitter's encryption key storage box in association with the selected recipient's recipient ID. In FIG. 7, D junior high school and Y high school (submission destination Y ) has not yet been entered, i.e., if the encryption key 424 for submitter D and recipient Y has not been generated, Y An encryption key 424 for submitter D and recipient Y, which is an encryption key for the report data to be submitted from D junior high school to Y high school, is generated for the high school, and the generated encryption key 424 for submitter D and recipient Y is sent to D junior high school. is encrypted with the presenter's public key, that is, it is stored in the presenter's D encryption key storage box 14 in association with the recipient's ID of Y high school. FIG. 7 shows a state in which the encryption key 424 for submitter D and recipient Y is stored in the submitter D encryption key storage box 14, that is, encrypted and stored. In FIG. 7, encryption keys for each submitter and each recipient are stored in the encryption key storage box 11 for submitter A, the encryption key storage box 12 for submitter B, and the encryption key storage box 13 for submitter C. It is That is, an encryption key for each recipient is encrypted for each submitter and stored in the database for each submitter.

(Step 120: Recipient's encryption key encryption storage step)
The Web server 6 encrypts the encryption key generated in Step 110 with the recipient's public key of the selected recipient, and stores it in the recipient's encryption key storage box of the selected recipient and associates it with the submitter's ID. store it. In FIG. 7, for example, when Junior High School D selects High School Y, the encryption key 424 for Submitter D Recipient Y generated in Step 110 is encrypted with the Public Key for Recipient of High School Y, and It is stored in the encryption key storage box 22 for recipient Y, which is the encryption key storage box for the recipient, in association with the submitter ID of D junior high school.

(Step 130: private key decryption step for submitter)
If the encryption key associated with the recipient ID of the selected recipient exists in the encryption key storage box for the submitter and if the encryption key is stored, the Web server 6 stores the secret for the submitter with the passphrase for the submitter. Decrypt the key. As shown in FIG. 7, if the encryption key 424 for the submitter D recipient Y is stored in the submitter D encryption key storage box 14, the passphrase for the submitter D junior high school is used to enter the secret for the submitter D junior high school. Decrypt the key. If stored in Step 120, then the private key for submitter of D junior high school is decrypted with the passphrase for submitter of D junior high school. Through this process, the presenter's private key of D junior high school for presenter's D encryption key storage box 14, that is, the box management key is obtained.

(Step 140: Submitter's Encryption Key Decryption Step)
The Web server 6 uses the submitter's private key to decrypt the encryption key associated with the recipient ID of the recipient selected from the submitter's encryption key storage box. In FIG. 7, using the box management key of the encryption key storage box 14 for submitter D, the encryption key 424 for submitter D recipient Y is decrypted, that is, taken out from the encryption key storage box 14 for submitter D. In FIG.

According to this embodiment, even if the server is attacked, the submitter's private key cannot be decrypted because the server does not have the submitter's passphrase, and therefore the possibility of leakage of the survey data, which is confidential data, can be reduced. .

(Step 150: Data storage process)
The Web server 6 encrypts the data with the encryption key and stores it in the database server 7 in association with the submitter ID and the recipient ID of the selected recipient. However, the encryption key itself is not stored in the data server 7 . In FIG. 7, using the encryption key 424 for the submitter D and the recipient Y, which is taken out from the encryption key storage box 14 for the submitter D, D junior high school uploads from the submitter terminal 2 of D junior high school to Y high school. The data 37 of the submitter D and the recipient Y, which is the research report data, is encrypted, ie, the decryption lock 371 of the submitter D and the recipient Y is locked, and stored in the database server 71 . The encrypted submitter D recipient Y data 37 is associated with the submitter ID of D middle school and the recipient ID of Y high school.

As for the recipients, an examination school table, which is a table of recipients similar to that shown in FIG. 6, is created. FIG. 9 is a diagram showing an example of a recipient (entrance school) table in the first embodiment of the organization-specific encryption key storage method of the present invention. In the examination school table, 21, 22, and 23 are assigned as examination school IDs, which are recipient IDs, to X high school, Y high school, and Z high school, respectively, and stored in association with each other. In addition, for each high school, an encrypted recipient's private key obtained by encrypting the recipient's private key with a recipient's passphrase as an encrypted private key, and a recipient's public key (public key) as a public key Keys X, Y, Z) are stored in association with the recipient ID (entrance school ID) and the recipient (school name). The public key X is dedicated to X high school, the public key Y is dedicated to Y high school, and the public key Z is dedicated to Z high school.

Up to this point, the recipient's encryption key storage box and the submitter's encryption key storage box are generated, and the uploaded data is encrypted. According to this embodiment, the encryption key for encrypting the data can be separately encrypted and stored by the submitter and the recipient.

FIG. 10 is an example of a report table in the first embodiment of the organization-specific encryption key storage method of the present invention. The uploaded questionnaire data is encrypted and stored in the database server 7. The questionnaire ID (ID of data to be encrypted), graduated school ID (submitter ID), and examination school ID (recipient ID) are stored in the database server 7. ) and survey report data (encrypted data) in which the examinee ID is encrypted are stored in association with each other. In FIG. 10, for example, data with a questionnaire ID of 1001 is encrypted with an encryption key AX (encryption key for submitter A recipient X), and has an ID of junior high school A of 11, an examination school ID of X high school of 21, The data stored in association with the examinee ID 2101 and having the questionnaire ID of 1004 is encrypted with the encryption key BX (encryption key for submitter B recipient X), and the school ID 12 of B junior high school and X High school examination school ID 21 and examinee ID 2103 are associated with each other and stored.

FIG. 11 is a diagram showing an example of an alma mater encryption key table and an examination school encryption key table in the first embodiment of the storage method of the organization-based encryption key of the present invention. The encryption key of the uploaded survey data is encrypted and stored. The ID (recipient ID) is stored in association with the submitter's encrypted encryption key (the encryption key in the submitter's encryption key storage box).

In FIG. 11, for example, the encryption key whose alma mater encryption key ID is 101 is the encryption key for the school report data in the combination of the alma mater is junior high school A and the examination school is high school X, and the encryption key AX (submitter A recipient X encryption key 411). The cryptographic key AX is in the submitter A's cryptographic key storage box 11 . That is, the encryption key AX is encrypted with the public key A. The encryption key AX encrypted with the public key A is an encrypted encryption key consisting of the alma mater ID of junior high school A (submitter A), the entrance examination school ID of high school X (recipient X), and the alma mater encryption key It is stored in association with the ID.

In FIG. 11, for example, the encryption key whose entrance school encryption key ID is 201 is the encryption key of the school report data in the combination of the alma mater A junior high school and the examination school X high school, and the encryption key AX (submitter A recipient X encryption key 411). The encryption key AX is in the recipient X encryption key storage box 21 . That is, the encryption key AX is encrypted with the public key X. The encryption key AX encrypted with the public key X is an encrypted encryption key consisting of the graduated school ID of A junior high school (submitter A), the examination school ID of X high school (recipient X), and the examination school encryption key It is stored in association with the ID.

FIG. 12 is an image diagram showing a key storage state in the database server in the first embodiment of the organization-specific encryption key storage method of the present invention. The encryption key with the alma mater encryption key ID of 101 is the encryption key 411 for submitter A recipient X stored in the encryption key storage box 11 for submitter A, and the encryption key with the entrance school encryption key ID of 201 The key is the encryption key 411 for submitter A recipient X stored in recipient X encryption key storage box 21, both of which are the same encryption key, but which are encrypted with separate public keys to create separate encryption keys. stored in a box. The encryption key 411 for the submitter A recipient X unlocks the decryption lock 311 of the submitter A recipient X that has been applied to the data 31 of the submitter A recipient X. This is a key for decrypting the data 31 of the submitter A recipient X encrypted and stored by the decryption lock 311 .

Similarly, the decryption lock 321 of the submitter B recipient X attached to the data 32 of the submitter B recipient X is the encryption key 412 for the submitter B recipient X, and the data 33 of the submitter C recipient X is The decryption lock 331 of submitter C, recipient X that has been applied is the encryption key 413 for submitter C, recipient X, and the decryption lock of submitter A, recipient Y that has been applied to the data 34 of submitter A, recipient Y. 341 is the encryption key 421 for the submitter A and the recipient Y, and the decryption lock 351 for the submitter B and the recipient Y that has been multiplied by the data 35 of the submitter B and the recipient Y is the encryption key 422 for the submitter B and the recipient Y. , and the decryption lock 361 of the presenter C and the recipient Y, which is applied to the data 36 of the presenter C and the recipient Y, is unlocked by the encryption key 423 for the presenter C and the recipient Y. In FIGS. 3, 7, 4, and 12, keys with the same shading/pattern are used to represent the same key, and data encrypted with each key is given a lock with the same shading/pattern. It means that there is a corresponding relationship.

According to this embodiment, the questionnaire data is encrypted, i.e., it is locked for decryption, and the encryption key that matches the lock is one if the combination of the submitter and the recipient is the same. Since the submitter and recipient are encrypted separately, the possibility of leakage can be reduced.

<Data display processing>
(Step 160: Browsing reception process)
The Web server 6 allows the submitter terminal 2 to select the recipient of the data, accepts the input of the submitter's passphrase, and accepts the browsing request. In FIG. 12, for example, the input of the passphrase of Junior High School A is accepted from the submitter terminal 2 of Junior High School A, the selection of High School Y is accepted as the recipient, and the survey form encrypted and stored in the database server 7 Receives a request to browse data (data 34 of submitter A and recipient Y). For security, it is desirable to limit the IP address and the retrieval period. Furthermore, it is desirable to perform two-step authentication, such as sending an automatically issued authentication code to the registered e-mail address and confirming the input.

(Step 170: Data decryption step (submitter))
The web server 6 decrypts the presenter's private key with the presenter's passphrase, and stores the presenter's private key in the presenter's encryption key storage box in association with the recipient ID of the selected recipient. The data stored in association with the recipient ID and the submitter ID of the recipient selected in the database server 7 is decrypted with the encryption key decrypted with the private key for the submitter. In FIG. 12, in Step 170, if the input of the passphrase of Junior High School A is received from the submitter terminal of Junior High School A and High School Y is selected as the recipient, the submitter in encryption key storage box 11 for Submitter A The encryption key 421 for A recipient Y is decrypted with the passphrase of A junior high school, and the data 34 of submitter A recipient Y is decrypted using the secret key for A junior high school. Unlock 341 and take it out.

(Step 180: data display step)
The web server 6 displays the decrypted data on the presenter's terminal 2 . If the data decrypted in Step 180 is the data 34 of the submitter A and the recipient Y, the Web server 6 displays the data 34 of the submitter A and the recipient Y on the submitter's terminal of the A junior high school.

According to this embodiment, the submitter does not require complicated operations, and can view only the data for some of the data uploaded by the submitter for one or more recipients. Therefore, the convenience is high and information leakage can be reduced.

<Data retrieval processing>
(Step 190: output reception process)
FIG. 13 is a diagram showing the flow of data retrieval in the first embodiment of the organization-specific encryption key storage method of the present invention. The Web server 6 selects a data submitter from the recipient's terminal, receives input of the recipient's passphrase, and receives an output request. One or more data submitters can be selected. In this embodiment, when the submitter is not selected, it is assumed that all the submitters who have already submitted the report data have been selected.

(Step 200: Data decryption step (recipient))
The Web server 6 decrypts the recipient's private key with the recipient's passphrase, and stores the decrypted recipient's private key in the recipient's encryption key storage box in association with the submitter ID of the selected submitter. The stored encryption key is decrypted, and with the encryption key decrypted with the recipient's private key, data stored in the database server in association with the recipient ID and the submitter ID of the selected submitter is decrypted.

For example, when the recipient terminal is the terminal of X high school and the questionnaire data uploaded and submitted by A junior high school and the questionnaire data uploaded and submitted by B junior high school are to be output, first, the passphrase for the recipient is The receiver's private key is decrypted, that is, the box management key of the receiver's X encryption key storage box 21 is obtained.

The Web server 6 stores in the database server, one of the selected submitters (in this case, junior high school A) submitted to X high school and encrypted (figuratively with a decryption lock in the figure) submission It is determined whether or not there is survey report data 31 for person A recipient X. If there is encrypted survey report data 31 of submitter A and recipient X in the database, the Web server 6 uses the decrypted private key for recipient to send the selected submission from the encryption key storage box 21 for recipient X. The encryption key stored in association with the submitter ID of the person (A junior high school in this case) is retrieved. That is, first, submitter A is stored in encryption key storage box 21 for recipient X, which is the encryption key storage box for recipient, in association with the submitter ID of selected junior high school A (alma mater ID is 11). The encryption key 411 of person X is decrypted.

Next, with the encryption key 411 of submitter A and recipient X decrypted with the recipient's private key, the database server associates the recipient ID (entrance school ID is 21) and the submitter ID (school ID is 11) with each other. Decrypt the data 31 of the submitter A recipient X, which is the data stored in the

The data of submitter A and recipient X may be single data for all applicants, or may be individual data for each applicant. If there is a plurality of data of submitter A recipient X, decryption is repeated with the same encryption key 411 until there is no undecrypted encrypted survey report data.

The Web server 6 stores in the database server the files submitted by other selected submitters (in this case, junior high school B) to high school X and encrypted (figuratively with a decryption lock in the figure). Determine the presence or absence of the questionnaire data 32 of the recipient B of the recipient X, and if there is, associate it with the submitter ID of the selected junior high school B (alma mater ID is 12) in the same way as the case of junior high school A described above. decrypts the encryption key 412 of the submitter B recipient X stored in the encryption key storage box 21 for the recipient X, which is the encryption key storage box for the recipient, and uses the encryption key 412 of the submitter B recipient X to The data 32 of the submitter B and the recipient X, which are data stored in the database server in association with the recipient ID (entrance school ID is 21) and the submitter ID (already attended school ID is 12), are decoded.

The Web server 6 repeats decryption until there is no undecrypted study report data with recipient X as the recipient for all selected submitters in the database server.

(Step 210: data output step)
The web server 6 outputs the decrypted data to the recipient's terminal. For example, if the data are data 31 of submitter A, recipient X and data 32 of submitter B, recipient X, the Web server 6 submits data 31 of submitter A, recipient X and data 31 of submitter A, recipient X to the recipient terminal of X high school. Party B outputs the data 32 of the recipient X. The output may be displayed, printed, or downloaded. If there are multiple pieces of data, they may be grouped and displayed as a list.

According to this embodiment, the receiver can safely output only the data of the selected submitter from among the data uploaded by one or an unspecified number of submitters without requiring complicated operations. It is highly convenient and can reduce information leakage.

In this embodiment, the case where there is one submitter ID and one recipient ID has been illustrated and explained, but there may be multiple IDs on both the submitter side and the recipient side. In that case, it is preferable that the submitter notification destination, recipient notification destination, and encryption key storage box are set for each ID. The encryption key generated when uploading data for the first time as a submitter to a recipient with one submitter ID is automatically stored in the submitter's encryption key storage box associated with that ID. In addition, it is preferable that the encryption key is automatically stored in the submitter's cryptographic key storage box associated with another ID on the submitter's side. Also, if the recipient has multiple IDs, it is preferable that the encryption key is automatically stored in the recipient's encryption key storage box for each recipient's ID. Storing the same encryption key for the submitter/recipient in each encryption key storage box means encrypting the same encryption key for the submitter/recipient with a public key/private key pair that differs for each ID. Both the submitter side and the recipient side are highly convenient because even if one person in charge has a problem, another person in charge can carry out the work safely and promptly.

{effect}
According to this embodiment, the submitter will use the submitter's public key and the recipient will use the recipient's public key. Further reduce the risk of information leakage by improving convenience for recipients and submitters and reducing transmission and management costs without impairing the effectiveness of information leakage prevention measures while reducing the risk of information leakage. be able to. Furthermore, since the private key corresponding to each public key is encrypted with each passphrase, the encryption key can be stored more safely, and the risk of information leakage is further reduced. Further, the submitter only has to manage the passphrase for the submitter and the recipient only has to manage the passphrase for the recipient, which is highly convenient. Furthermore, neither the submitter's passphrase nor the recipient's passphrase are stored on the server, so neither the submitter's private key nor the recipient's private key can be decrypted by a server attack, and there is a risk of information leakage. is further reduced.

According to this embodiment, the submitter only needs to enter the passphrase for the submitter and select the recipient, and the data is automatically encrypted at the time of uploading, so security is high and convenience is high. In addition, since data is encrypted for each submitter and each recipient, the risk of data information leakage can be reduced. The encryption key is not limited, but a common key is preferable from the viewpoint of convenience. Since the encryption key itself used for data encryption is encrypted with separate public keys for the submitter and the recipient, the risk of information leakage is further reduced.

According to the present embodiment, even if a common key is used as the encryption key for decrypting the questionnaire data, different passphrases are used for decryption at the school from which the student graduated and the school for which he/she is taking the exam, so security is superior. The data to be passed from the submitter to the recipient is highly confidential data, and since the submitter and the recipient are separate organizations, the added value generated by high security is large.

According to this embodiment, the submitter can decrypt the data stored in the server by using the submitter's passphrase to check the contents. Therefore, while realizing high security, troublesome operations are unnecessary and convenience is high. Even if there are many recipients, the submitter's passphrase is common, which facilitates management.

According to this embodiment, the recipient can obtain the data by decrypting the data stored in the server using the recipient's passphrase. Therefore, while realizing high security, troublesome operations are unnecessary and convenience is high. In addition, since the common key for decrypting the data is different from that of the submitter, it is highly effective in preventing information leakage.

This embodiment is also suitable when the data to be passed from the submitter to the recipient is highly confidential data and the submitter and the recipient are different organizations.

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the gist of the invention. Also, the constituent elements of the above-described embodiments can be arbitrarily combined without departing from the scope of the invention.

For example, submitters and recipients could be medical institutions instead of schools, and data could be medical charts or other sensitive data instead of dossier data.

2 Presenter terminal 3 Recipient terminal 4 Network 5 Server administrator terminal 6 Web server 68 Data submission form screen for submitter 69 Data submission form screen for recipient 7 Database server 71 Confidential data management database 11 Encryption key storage for submitter A Box 12 Encryption key storage box 13 for submitter B Encryption key storage box 14 for submitter C Encryption key storage box 21 for submitter D Encryption key storage box 22 for recipient X Encryption key storage box 23 for recipient Y Recipient Z Encryption key storage box 31 Submitter A recipient X data 311 Submitter A recipient X decryption lock 32 Submitter B recipient X data 321 Submitter B recipient X decryption lock 33 Submitter C receipt Party X data 331 Submitter C Recipient X decryption lock 34 Submitter A recipient Y data 341 Submitter A recipient Y decryption lock 35 Submitter B recipient Y data 351 Submitter B recipient Decryption lock 36 for Y Submitter C Recipient Y data 361 Submitter C Recipient Y decryption lock 37 Submitter D Recipient Y data 371 Submitter D Recipient Y decryption lock 411 Submitter A receipt Encryption key 412 for submitter X Encryption key 413 for recipient B Submitter C Encryption key for recipient X 421 Encryption key for submitter A recipient Y 422 Encryption key for submitter B recipient Y Encryption key for party Y 424 Encryption key for sender D recipient Y

Claims (10)

1 connected via a network to one or more submitter terminals that are data submitters and have submitter IDs and one or more recipient terminals that are recipients of the data and have recipient IDs or a plurality of web servers;
one or more database servers interconnected to the web server;
A server group with multiple types of server functions including
A method for separately storing a cryptographic key for encrypting the data by a submitter and a recipient,
The server group receives a recipient public key, a recipient secret key corresponding to the recipient public key, and an encryption key for encrypting the data using the recipient secret key as a box management key. a recipient's encryption key storage box which is encrypted with the recipient's public key, stores the data in association with the submitter's ID of the person who submitted the data, and can be retrieved by decrypting the encryption key with the recipient's private key; a recipient's encryption key storage box generating step for generating each recipient and storing the recipient's encryption key storage box in the database server in association with each recipient's ID;
a recipient passphrase generation step in which the server group automatically generates a recipient passphrase for encrypting the recipient private key;
A recipient whose server group encrypts the recipient's private key with the recipient's passphrase and stores the encrypted recipient's private key and the recipient's public key in the database server a private key encryption step for
a recipient passphrase notification step in which the server group notifies a predetermined recipient notification destination of the recipient passphrase and prevents the database server from storing the recipient passphrase;
and
a presenter login accepting step in which the server group accepts a login from the presenter terminal;
The server group submits the presenter's public key, the presenter's private key corresponding to the presenter's public key, and the encryption key for encrypting the data using the presenter's private key as a box management key. a submitter's encryption key storage box that stores the data in association with the recipient's recipient's ID after being encrypted with the submitter's public key, and that can be retrieved by decrypting the encryption key with the submitter's private key; a submitter's encryption key storage box generating step of generating each submitter's encryption key storage box and storing the submitter's encryption key storage box in the database server in association with each submitter's ID;
a presenter's passphrase generation step in which the server group generates a presenter's passphrase for encrypting the presenter's private key;
The submitter, wherein the server group encrypts the submitter's private key with the submitter's passphrase, and stores the encrypted submitter's private key and the submitter's public key in the database server; a private key encryption step for
a submitter passphrase notification step in which the server group notifies a predetermined submitter notification destination of the submitter passphrase and does not cause the database server to store the submitter passphrase;
A storage method for an organization-specific encryption key, characterized by comprising a data reception step in which the server group receives an input of the submitter's passphrase from the submitter's terminal, selects a recipient of the data, and receives an upload of the data;
If there is no encryption key associated with the recipient ID of the selected recipient in the encryption key storage box for the submitter, the server group a submitter's encryption key encryption and storage step of generating a key, encrypting it with the submitter's public key, and storing it in the submitter's encryption key storage box in association with the recipient ID;
The server group encrypts the encryption key generated in the encryption key encryption storage step of the submitter with the recipient's public key of the selected recipient, and encrypts the recipient's encryption of the selected recipient. a recipient's encryption key encryption storage step for storing in a key storage box in association with the submitter ID;
If the server group has an encryption key associated with the recipient ID in the encryption key storage box for the submitter and if it was stored in the encryption key encryption storage step of the submitter, the submitter a presenter's private key decryption step of decrypting the presenter's private key with a passphrase for
a submitter's encryption key decryption step in which the server group decrypts the encryption key associated with the recipient ID from the submitter's encryption key storage box using the submitter's private key;
a data storage step in which the server group encrypts the data with an encryption key decrypted with the submitter private key, and stores the data in the database server in association with the submitter ID and the recipient ID;
2. The storage method of an organization-specific encryption key according to claim 1, characterized by comprising: a viewing acceptance step in which the server group selects a recipient of the data from the submitter terminal, receives the input of the passphrase for the submitter, and receives a viewing request;
The server group decrypts the presenter's private key with the presenter's passphrase, and stores the presenter's encryption key storage box in association with the recipient ID of the selected recipient with the presenter's private key. decrypts the data stored in the database server in association with the recipient ID and the submitter ID with the encryption key decrypted with the submitter private key a data decryption step (submitter);
a data display step in which the server group displays the decrypted data on the submitter terminal;
3. The method of storing an organization-specific encryption key according to claim 2, characterized by comprising: an output reception step in which the server group selects the data submitter from the recipient terminal, receives the input of the recipient's passphrase, and receives an output request;
The server group decrypts the recipient's private key with the recipient's passphrase, and associates the decrypted recipient's private key with the submitter ID of the selected submitter to encrypt the recipient's encryption key. Decrypting the encryption key stored in the storage box, and using the encryption key decrypted with the recipient's private key, the data stored in the database server in association with the recipient ID and the submitter ID a data decryption step (recipient) to decrypt;
a data output step in which the server group outputs the decrypted data to the recipient terminal;
3. The storage method of an organization-specific encryption key according to claim 2, characterized by comprising: 5. The method of storing an organization-specific encryption key according to claim 1, wherein said data is survey report data, said submitter is a graduated school, and said recipient is an examination school. 1 connected via a network to one or more submitter terminals that are data submitters and have submitter IDs and one or more recipient terminals that are recipients of the data and have recipient IDs or a plurality of web servers;
one or more database servers interconnected to the web server;
A server group with multiple types of server functions including
A system in which an encryption key for encrypting the data is stored separately by a submitter and a recipient,
The server group
a recipient public key, a recipient secret key corresponding to the recipient public key, and an encryption key for encrypting the data using the recipient secret key as a box management key, using the recipient public key An encryption key storage box for recipients, which is encrypted and stored in association with the submitter ID of the person who submitted the data and can be retrieved by decrypting the encryption key with the private key for recipients, is generated for each recipient. recipient encryption key storage box generating means for storing the recipient encryption key storage box in the database server in association with each recipient ID;
Recipient passphrase generation means for automatically generating a recipient passphrase for encrypting the recipient private key;
Recipient's private key encryption for encrypting the recipient's private key with the recipient's passphrase and storing the encrypted recipient's private key and the recipient's public key in the database server means and
a recipient passphrase notifying means for notifying a predetermined recipient notification destination of the recipient passphrase and not allowing the database server to store the recipient passphrase;
Submitter login reception means for accepting login from the submitter terminal;
a submitter's public key, a submitter's private key corresponding to the submitter's public key, and an encryption key for encrypting the data using the submitter's private key as a box management key using the submitter's public key An encryption key storage box for the submitter, which stores the encrypted data in association with the recipient ID of the recipient and can be retrieved by decrypting the encryption key with the private key for the submitter, is generated for each submitter. and encryption key storage box generation means for submitter for storing the encryption key storage box for submitter in the database server in association with each submitter ID;
submitter passphrase generation means for generating a submitter passphrase for encrypting the submitter private key;
Encrypting the submitter's private key with the submitter's passphrase, and storing the encrypted submitter's private key and the submitter's public key in the database server. means and
submitter passphrase notification means for notifying a submitter passphrase to a predetermined submitter notification destination and not allowing the database server to store the submitter passphrase;
An organization-specific cryptographic key storage system characterized by comprising: The server group further
data receiving means for receiving an input of the presenter's passphrase from the presenter's terminal, selecting a recipient of the data, and accepting uploading of the data;
if there is no encryption key associated with the recipient ID of the selected recipient in the submitter's encryption key storage box, generating an encryption key associated with the submitter ID and the recipient ID; means for encrypting and storing the submitter's encryption key, which is encrypted with the submitter's public key and stored in the submitter's encryption key storage box in association with the recipient's ID;
The encryption key generated by the encryption key encryption storage means of the submitter is encrypted with the recipient's public key of the selected recipient, and stored in the recipient's encryption key storage box of the selected recipient. a recipient's encryption key encryption storage means for storing in association with the submitter ID;
The submitter who decrypts the submitter's private key with the submitter's passphrase if the submitter's encryption key storage box contains the encryption key associated with the recipient's ID and is stored. private key decryption means for
encryption key decryption means for decrypting the encryption key associated with the recipient ID from the submitter's encryption key storage box with the submitter's private key;
data storage means for encrypting the data with an encryption key decrypted with the submitter private key and storing the data in the database server in association with the submitter ID and the recipient ID;
7. The organization-based encryption key storage system according to claim 6, characterized by comprising: The server group further
a browsing acceptance means for allowing the recipient of the data to be selected from the submitter terminal, accepting the input of the submitter's passphrase, and accepting a browsing request;
Decrypting the presenter's private key with the presenter's passphrase, and using the presenter's private key, the cipher stored in the presenter's encryption key storage box in association with the recipient's ID of the selected recipient data decryption means (submission person) and
data display means for displaying the decrypted data on the submitter terminal;
8. The organization-based encryption key storage system according to claim 7, characterized by comprising: The server group further
output receiving means for selecting a submitter of the data, receiving input of the passphrase for the receiver, and receiving an output request from the receiver terminal;
decrypting the recipient's private key with the recipient's passphrase, and storing the decrypted recipient's private key in the recipient's encryption key storage box in association with the submitter ID of the selected submitter; data decryption means for decrypting the encrypted key, and decrypting the data stored in the database server in association with the recipient ID and the submitter ID with the encryption key decrypted with the recipient's private key; (recipient) and
data output means for outputting the decrypted data to the recipient terminal;
8. The organization-based encryption key storage system according to claim 7, characterized by comprising: 10. The organization-based encryption key storage system according to any one of claims 6 to 9, wherein said data is survey report data, said submitter is a graduated school, and said recipient is an examination school.

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