JP2022087410A - server - Google Patents

Abstract

To provide a server capable of managing an attached file of an E-mail more safely.SOLUTION: A sever stores an encrypted attached file in which an attached file of an E-mail sent from a sender is encrypted in a storage unit and generates inquiry information. Then E-mail in which the attached file is deleted and the inquiry information is inserted is sent to a destination. When receiving the inquiry information, a password associated to the inquiry information is notified to the destination corresponding to the inquiry information. Then, when receiving the inquiry information, an authentication is conducted based on the password, and if the authentication is permitted, the decrypted attached file is controlled to be downloaded to or browsed by a user.SELECTED DRAWING: Figure 2

Description

The present invention relates to a server.

Traditionally, e-mail has been used as a communication tool, and there is an MTA (Mail Transfer Agent) that accepts e-mail from MUA (Mail User Agent) and delivers (delivers, sends, forwards) e-mail. do.

Here, the MUA is a client program used to send and receive e-mails on a terminal on the Internet, and the MTA is a client program that receives and delivers e-mails on a network through a SMTP (Simple Mail Transfer Protocol). A server (mail server).

As a prior art, for example, when an attached file exists in an e-mail, there is also a file management system that encrypts the attached file and delivers the e-mail to which the encrypted file is attached to the destination (Patent Document 1).

For example, according to Patent Document 1, when the server 10 determines that an attached file exists in the received e-mail, the server 10 performs a process of encrypting the attached file and sends the e-mail to the destination. Then, the destination user B decrypts the encrypted file only when the password is set to be public by clicking the URL of the password inquiry information (URL is an abbreviation of Uniform Resource Locator; the same applies hereinafter). You can view the URL to do so, and you can decrypt the encrypted attachment file (see 0061 to 0067 of Patent Document 1).

Japanese Unexamined Patent Publication No. 2017-215744

However, in the prior art shown in Patent Document 1, there is a possibility that another person who is not the destination user B can easily share the attached file. For example, if the destination user B mistakenly forwards an e-mail with an encrypted file to a third-party user X and then forwards the password inquiry information URL, the user X also forwards the password inquiry information if it is in a public state. There is a risk that the password can be easily obtained and the encrypted file can be decrypted.

Further, the conventional technique shown in Patent Document 1 has a problem that the attached file needs to be decoded on the user side, which is troublesome.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a server that manages e-mail attachments more safely and enhances user convenience.

(1) The present invention
A server that manages attachments to e-mails with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs processing for encrypting the attached file of the e-mail, and
A storage processing unit that performs processing to store encrypted attachments in the storage unit,
An inquiry information generation unit that generates inquiry information in which the destination and an encrypted attachment file are associated with each other.
A transmitter that sends the e-mail with the attached file deleted and the inquiry information inserted to the destination, and
When the inquiry information is received, a notification unit for notifying the destination associated with the inquiry information of the password associated with the inquiry information, and a notification unit.
When the inquiry information is received, authentication is performed based on the password received from the user and the password associated with the inquiry information, and when the authentication is permitted, the attached file associated with the inquiry information is performed. The present invention relates to a server including a file control unit that decodes and controls the decrypted attached file so that the user can download or view the decrypted attached file.

The present invention relates to a program characterized in that a computer functions as each part of the server. The present invention also relates to an information storage medium in which the above program is stored.

Here, the "inquiry information" can be, for example, a URL for uniquely designating a web page on the Internet by a protocol such as HTTP (HyperText Markup Language) or HTML (HyperText Markup Language Sequence). The inquiry information may be information on a server capable of transmitting and receiving data by another communication protocol such as FTP (File Transfer Protocol). Further, the "when the inquiry information is accepted" is, for example, the case where the access to the information specified by the URL is accepted.

According to the present invention, the destination user can obtain the password by accessing the inquiry information, but the user other than the destination user cannot obtain the password even if the destination user accesses the inquiry information. Can be done. That is, according to the present invention, since the password is notified to the destination, even if the inquiry information is known to another person, the other person cannot obtain the password.

Further, according to the present invention, even if the inquiry information is known to another person, the attached file is controlled so that the attached file can be downloaded or viewed by the authorized user, so that the other person can obtain the attached file and obtain the attached file. You can prevent it from being viewed. As a result, attachments can be managed safely.

Further, according to the present invention, since the authenticated user can download or view the decrypted attached file, it is possible to save the trouble of decoding on the user's terminal and improve the convenience. ..

(2) Further, the server, program and information storage medium of the present invention are
The inquiry information generation unit is
When there are multiple attachments in one e-mail, one inquiry information that associates the destination with the plurality of encrypted attachments is generated.
The notification unit
When the inquiry information is received, the destination associated with the inquiry information is notified of one password associated with the inquiry information.
The file control unit
When the inquiry information is received, authentication is performed based on the password received from the user and the password associated with the inquiry information, and when the authentication is permitted, a plurality of numbers associated with the inquiry information are performed. The attached file may be decoded, and the decrypted attached file may be controlled to be downloadable or viewable by the user.

According to the present invention, even if there are a plurality of attachments in one e-mail, the user can acquire or view the plurality of decrypted attachments by one password associated with one inquiry information. Therefore, it is possible to improve the convenience for the user.

(3) The present invention
A server that manages attachments to e-mails with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs processing for encrypting the attached file of the e-mail, and
A storage processing unit that performs processing to store encrypted attachments in the storage unit,
An inquiry information generation unit that generates a first inquiry information and a second inquiry information in which the destination and an encrypted attachment file are associated with each other.
A transmission unit that sends the e-mail to the destination by deleting the attached file and inserting the first inquiry information.
A notification unit that notifies the second inquiry information to the destination associated with the first inquiry information when the first inquiry information is received.
When the second inquiry information is received, the attached file associated with the second inquiry information is decoded, and the decoded attached file can be controlled or viewed by the user so that it can be downloaded. The present invention relates to a server including a file control unit for controlling.

The present invention relates to a program characterized in that a computer functions as each part of the server. The present invention also relates to an information storage medium in which the above program is stored.

According to the present invention, the destination user can acquire the second inquiry information by accessing the first inquiry information, but the user other than the destination user accesses the first inquiry information. However, it is possible to prevent the acquisition of the second inquiry information. That is, according to the present invention, the second inquiry information is notified to the destination, so that even if the first inquiry information is known to another person, the other person cannot acquire the second inquiry information. be able to.

That is, according to the present invention, even if the first inquiry information is known to another person, it is possible to prevent the other person from acquiring and viewing the attached file. As a result, attachments can be managed safely.

Further, according to the present invention, the user who has accessed by the second inquiry information can download or view the decrypted attached file, so that the trouble of decoding on the user's terminal can be omitted and the convenience is improved. Can be made to.

(4) Further, the server, program and information storage medium of the present invention are
The inquiry information generation unit is
When a plurality of attachment files exist in one e-mail, the first inquiry information and the second inquiry information in which the destination is associated with the plurality of encrypted attachment files are generated. death,
The file control unit
When the second inquiry information is received, the plurality of attached files associated with the second inquiry information are decoded, and the decoded plurality of attached files are controlled to be downloadable to the user side. Alternatively, it may be controlled so that it can be viewed.

According to the present invention, even if there are a plurality of attachments in one e-mail, the user can collectively acquire or view the plurality of decrypted attachments, which is convenient for the user. Can be improved.

(5) Further, the server, program and information storage medium of the present invention are
The file control unit
Anti-virus processing may be performed on the decrypted attached file before downloading or browsing to the user's terminal. According to the present invention, since the receiving side performs anti-virus processing on the attached file, the security can be further improved.

(6) Further, the server, program and information storage medium of the present invention are
The file control unit
Before downloading to the user's terminal or before browsing, it is determined whether or not the predetermined condition is satisfied, and if the predetermined condition is satisfied, the decrypted attached file is controlled or browsed so that the user can download it. It may be controlled as possible, or it may be controlled to prohibit downloading or prohibiting browsing on the user's terminal. According to the present invention, it is possible to control whether or not the attached file can be downloaded or viewed according to a predetermined condition, so that the security can be further improved.

The figure which shows the outline of management of the attached file of this embodiment. The figure which shows the outline of the password notification of this embodiment. An example of a network diagram of the file management system of this embodiment. The functional block diagram of the server 10 of this embodiment. An example of the password issuance screen of this embodiment. An example of the password input screen of this embodiment. An example of the download screen of this embodiment. An example of the management data storage unit of this embodiment. The flowchart which shows the flow of the process of this embodiment. The flowchart which shows the flow of the process of this embodiment.

Hereinafter, this embodiment will be described. It should be noted that the present embodiment described below does not unreasonably limit the content of the present invention described in the claims. Moreover, not all of the configurations described in the present embodiment are essential constituent requirements of the present invention.

[1] Overview The file management system of the present embodiment relates to a control in which an e-mail relay server manages e-mail attachments. For example, a case where the user A of the sender (A@xxx.com) sends an e-mail containing an attached file to the user B of the destination (B@yy.com) will be described as an example.

For example, as shown in FIG. 1, the server 10 is an e-mail M (e-mail ID = 001) transmitted from a sender (A@xxx.com) and designated as a destination (B@yy.com). To receive. Then, the server 10 determines whether or not the attached file exists. Then, when the attached file exists, the server 10 encrypts the attached file and stores the encrypted attached file (the encrypted attached file is also referred to as an encrypted file; the same applies hereinafter). Remember in.

Then, the server 10 generates inquiry information L (URL) in which the destination (B@yy.com) and the identification information of the attached file are associated with each other. The identification information of the attached file is information that can uniquely identify the attached file. For example, the server 10 generates inquiry information L (URL) based on the destination (B@yy.com) and the identification information of the attached file. That is, the inquiry information L is information that can identify the destination and the attached file. The attached file that can be specified by the inquiry information L is an encrypted attached file.

Then, the server 10 deletes the data portion of the attached file of the e-mail M, and inserts the inquiry information L instead. Then, the e-mail M is transmitted to the destination (B@yy.com).

Then, as shown in FIG. 2, when the server 10 receives the access of the inquiry information L, the server 10 identifies the destination (B@yy.com) from the inquiry information L, and the specified destination (B@yy.com). ) Notify the password. Therefore, when the user B of the legitimate destination (B@yy.com) clicks the inquiry information L, the password can be notified.

Then, when the server 10 accepts the access of the inquiry information L, the password authentication is performed, and when the authentication is permitted, the encrypted attached file can be decrypted and the decrypted attached file can be downloaded. Control so that it can be viewed.

Therefore, even if the user B mistakenly sends (wrongly forwards) the e-mail M to another user X, or if the inquiry information L is illegally known to the user X, the password notification destination is the destination. Since it is limited to the user B, it can be controlled not to notify the user X of the password. That is, according to the present embodiment, even if the inquiry information is known to the user X who is another person, the user X can prevent the user X from acquiring the password and can manage the password safely. As a result, it is possible to control the user X from illegally downloading the attached file or viewing the attached file.

In the following description, a case where the sender user A (A@xxx.com) creates an e-mail with an attached file and the destination of the e-mail M is user B (B@yyy.com). Let's take an example.

[2] Network FIG. 3 shows an example of a network diagram of a file management system. In the file management system of the present embodiment, the server 10 and the user's terminal 20 are connected to each other via a network (Internet, intranet, etc.).

The server 10 is an information processing device capable of providing a mail service by using a terminal 20 which is communicated and connected via the Internet.

The server 10 of the present embodiment has a mail server function (MTA function) of receiving an e-mail consisting of an envelope destination, an envelope sender, and a message, and delivering the e-mail. The server 10 is also referred to as a "relay device" or an "information processing device" that controls the relay of e-mail.

The terminal 20 is a client device, an information processing device such as a smartphone, a mobile phone, a PHS, a computer, a game device, a PDA, and an image generation device, and is connected to a server 10 via a network such as the Internet (WAN) or LAN. It is a possible device.

The server 10 includes a storage unit 30 for storing a file. The storage unit 30 functions as a file server that manages files. The storage unit 30 may be provided in a device different from the server 10.

[3] Configuration FIG. 4 is an example of a functional block diagram of the server 10 of the present embodiment. The server 10 of the present embodiment does not need to include all the parts shown in FIG. 1, and a part thereof may be omitted.

The storage unit 170 stores programs and various data for operating the computer as each unit of the processing unit 100, and also functions as a storage area of the processing unit 100.

The storage unit 170 includes a temporary storage area and storage. Storage is a hard disk, optical disk, flash memory, magnetic tape, etc., and refers to a device that permanently stores data. Further, the storage unit 170 may store programs and data stored in the information storage medium 180.

The storage unit 170 of the present embodiment includes a main storage unit 171 used as a work area, a user information storage unit 172, and a management data storage unit 173. It should be noted that a configuration in which some of these may be omitted may be used.

The main storage unit 171 can be realized by RAM or the like. The main storage unit 171 is a storage area used in the processing of the present embodiment. The user information storage unit 172 stores user information (user's account, password, e-mail address, etc.). The user information storage unit 172 may be configured by a DB (DB is an abbreviation for a database, the same applies hereinafter).

The management data storage unit 173 stores at least identifiable and unique inquiry information (URL), destination, and attachment file information (for example, file name) for each attachment file in association with each other. The management data storage unit 173 may be configured by a DB. Further, the management data storage unit 173 may store the generated password, a flag indicating validity or invalidity (1 is valid and 0 is invalid), an expiration date, the number of accesses K, and the like.

Further, the management data storage unit 173 may store an e-mail ID (message ID) for identifying the e-mail containing the attached file.

The information storage medium 180 (a medium that can be read by a computer) stores programs, data, and the like, and its functions are an optical disk (CD, DVD), a magneto-optical disk (MO), a magnetic disk, a hard disk, and a magnetic tape. Or, it can be realized by storage such as memory (ROM).

The communication unit 196 performs various controls for communicating with the outside (for example, a terminal, another server, or another network system), and its function is hardware such as various processors or ASICs for communication. It can be realized by a program or the like.

The processing unit 100 performs various processes of the present embodiment based on the program (data) stored in the storage unit 170 or the information storage medium 180.

The processing unit 100 (processor) performs various processes using the main storage unit 171 in the storage unit 170 as a work area. The function of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.) and a program.

The processing unit 100 includes a receiving unit 111, an analysis unit 112, an encryption processing unit 113, a transmitting unit 114, a notification unit 115, a storage processing unit 116, an inquiry information generation unit 117, a password generation unit 118, a file control unit 119, and Web processing. Including part 120.

The receiving unit 111 receives an e-mail on the network through SMTP. That is, the receiving unit 111 performs a process of receiving an e-mail transmitted by the MUA of the sender terminal 20 and designated as the destination of the envelope.

The analysis unit 112 performs a process of analyzing the received e-mail. For example, the process of analyzing the destination of the envelope, the sender of the envelope, the header of the message, and the body part of the body of the message is performed. For example, the process of extracting the domain from the destination of the envelope, the process of extracting To, Cc, Bcc, Subject, and Message-ID from the header of the message, the process of extracting the text from the body part of the message, and the process of extracting the body of the message. Performs processing such as extracting attached files from the body part.

When the attached file exists in the e-mail received by the receiving unit 111, the encryption processing unit 113 performs a process of encrypting the attached file.

The transmission unit 114 transmits (delivered, delivered, relayed, forwarded) an e-mail on the network through SMTP. That is, the transmitting unit 114 performs a process of transmitting the e-mail received by the receiving unit 111 to the destination.

Here, sending an e-mail means a process of sending the received e-mail to another MTA through SMTP, or a local delivery agent MDA for sending to a user who has an account in the same system in which the server 10 operates. It also includes a process of transmitting to (Mail Delivery Agent) and a case of transmitting to a user who has an account in the same system in which the server 10 operates without going through the MDA.

In particular, the transmission unit 114 of the present embodiment transmits the inquiry information to the destination. The inquiry information is associated with at least the destination and the attached file (encrypted attached file), and the destination and the attached file are identifiable information.

The transmission unit 114 sends an e-mail with the attached file deleted and the inquiry information inserted to the destination.

That is, when the e-mail received by the receiving unit 111 includes an attached file, the transmitting unit 114 of the present embodiment deletes the attached file and inserts (adds) inquiry information in place of the attached file. To the destination. When the first inquiry information and the second inquiry information are generated, the first inquiry information is inserted instead of the attached file.

Further, when the e-mail received by the receiving unit 111 includes an attached file, the transmitting unit 114 of the present embodiment may encrypt the attached file and send it to the destination.

When the inquiry unit 115 receives the inquiry information, the notification unit 115 notifies the destination associated with the inquiry information of the password associated with the inquiry information. Here, the "notification" means that the server 10 transmits to the terminal 20 by e-mail (may be an e-mail newsletter or the like) transmitted / received by SMTP, or is transmitted by a given protocol, not limited to SMTP. , To give a push notification, to present (control to display and view) a predetermined screen (banner display screen, notification screen, pop-up screen, etc.) of a predetermined application, and to notify by the server 10 by a Web page. At least one, indicating that the server 10 actively transmits to the user's terminal 20. In addition, the server 10 may transmit information to the requested terminal 20 in response to a request from the user's terminal 20, or may be an aspect of "notification". Note that push notification is to display a message window in a part of the screen (upper end, etc.) of the screen of the terminal (smartphone).

Further, when the inquiry information is received, the notification unit 115 notifies the destination associated with the inquiry information of one password associated with the inquiry information. That is, there is a one-to-one relationship between the inquiry information and the password.

When the first inquiry information and the second inquiry information are generated, the notification unit 115 sends the first inquiry information to the destination associated with the first inquiry information when the first inquiry information is received. Notify the inquiry information of 2.

The storage processing unit 116 performs a process of storing the encrypted attached file in the storage unit 30 (storage area).

The inquiry information generation unit 117 generates inquiry information in which the destination and the encrypted attachment file are associated with each other.

Further, when a plurality of attachment files exist in one e-mail, the inquiry information generation unit 117 generates one inquiry information in which the destination is associated with the plurality of encrypted attachment files.

Further, the inquiry information generation unit 117 may generate the first inquiry information and the second inquiry information in which the destination and the encrypted attachment file are associated with each other.

Further, when a plurality of attached files exist in one e-mail, the inquiry information generation unit 117 has one first inquiry information and one that associates the destination with the encrypted plurality of attached files. The second inquiry information may be generated.

Further, when a plurality of attached files exist in one e-mail, the inquiry information generation unit 117 has one first inquiry information and one that associates the destination with the encrypted plurality of attached files. The second inquiry information may be generated.

The password generator 118 generates the password required to download the attached file.

The file control unit 119 decodes the encrypted attachment file and controls the decrypted attachment file so that it can be downloaded or viewed by the user.

For example, when the file control unit 119 receives the inquiry information, the file control unit 119 authenticates based on the password received from the user and the password associated with the inquiry information (password registered and managed on the server side), and the authentication is performed. If is permitted, the attached file associated with the encrypted inquiry information is decrypted, and the decrypted attached file is controlled to be downloadable or viewable by the user.

Further, the file control unit 119 controls as follows when a plurality of attached files exist in one e-mail. That is, when the file control unit 119 receives the inquiry information, the file control unit 119 authenticates based on the password received from the user and the password associated with the inquiry information, and responds to the inquiry information when the authentication is permitted. A plurality of attached attachment files are decoded, and the plurality of decoded attachment files are controlled to be downloadable or viewable by the user.

Further, when the file control unit 119 receives the second inquiry information, the file control unit 119 decodes the attached file associated with the second inquiry information, and the decoded attached file can be downloaded to the user side. It may be controlled or controlled so as to be viewable.

Further, when the file control unit 119 receives the second inquiry information, the file control unit 119 decodes the plurality of attached files associated with the second inquiry information, and the decrypted plurality of attached files are on the user side. It may be controlled so that it can be downloaded or viewed.

Further, the file control unit 119 may perform anti-virus processing on the decrypted attached file before downloading to the user's terminal or viewing the file.

Further, the file control unit 119 determines whether or not the predetermined condition is satisfied before downloading to the user's terminal or before browsing, and if the predetermined condition is satisfied, the decoded attached file is sent to the user side. It may be controlled so that it can be downloaded or viewed, or it may be controlled to prohibit downloading or prohibit viewing on the user's terminal.

The Web processing unit 120 responds to the request of client software such as a Web browser installed in the terminal 20 through HTTP (Hypertext Transfer Protocol), and receives HTML (HyperText Markup).
Language) Performs the process of transmitting (providing) data such as documents and images, and the process of receiving the data received by the Web browser of the terminal. Then, the server performs mail processing, DB update processing, and the like based on the information received from each terminal of the administrator and the user.

The Web processing unit 120 performs a process of transmitting (providing) management setting data or the like to the administrator's terminal 20 in response to an access request from the Web browser of the administrator's terminal 20, and the administrator's terminal 20 sends (provides) data or the like. The process of receiving the information may be performed.

That is, the Web processing unit 120 may add, delete, update, or the like to the DB based on the input from the administrator. Only the administrator is authorized to access the Web page (URL) for the administrator.

Further, the Web processing unit 120 performs a login process and a process of controlling the Web page of information related to the logged-in user to be viewable in response to a request from the Web browser of the terminal 20.

For example, the Web processing unit 120 may control the password input screen and the screen for downloading the attached file to be viewable in response to a request from the Web browser of the terminal 20.

The storage processing unit 116 performs a process of registering, updating, and deleting the data stored in the management data storage unit 173 and the storage unit 30. For example, the storage processing unit 116 may perform a process of updating the database based on the data received from the terminal 20.

A part or all of the processing of the processing unit 100 may be executed by one device, or the storage unit 170 may be executed by one device, or may be distributed to different devices according to the purpose of the processing to execute each processing. You may.

[4] Attachment file encryption processing and storage processing First, when the server 10 of the present embodiment receives an e-mail transmitted from the MUA of the terminal 20, it analyzes the received e-mail and finds an attached file. Judge whether or not.

When the server 10 determines that the e-mail has an attached file, the server 10 performs a process of encrypting the attached file and generates an encrypted attached file.

Then, the server 10 stores the encrypted attached file in the storage area of the storage unit 30. That is, when the attached file is stored in the storage unit 30, it is automatically encrypted. The attached file (encrypted) stored in the storage unit 30 is controlled to be decrypted at the time of download.

Further, the storage unit 30 sequentially stores and stores the encrypted attached file received from the server 10.

The storage unit 30 may be a storage area of the server 10 or a storage area on the cloud. That is, it may be a storage area (storage device) on the Internet that can be connected to the server 10 via the Internet.

According to the present embodiment, the sender user A can save the trouble of performing the encryption work, and the attached file is encrypted and stored in the storage unit 30, so that the attached file is tampered with or the information of the attached file is leaked. Can be prevented.

Further, when a plurality of attachment files exist in the e-mail, the server 10 may generate one encrypted file for the plurality of attachment files, or may generate an individual encryption file for each of the plurality of attachment files. You may generate an attachment file.

In this way, the server 10 performs a process of encrypting the attached file when it is stored in the storage unit 30. As will be described later, when the server 10 receives an instruction to download the attached file to the user's terminal 20, the server 10 decodes the attached file and controls the attachment to be downloadable. Further, when the server 10 receives an instruction to display (view) the attached file on the user's terminal 20, the server 10 performs a process of decoding the attached file and displaying (viewing) the attached file.

[5] E-mail transmission process When the server 10 determines that the e-mail M has an attached file, the server 10 removes the attached file and inserts inquiry information. Then, the e-mail M including the inquiry information is transmitted to the destination. That is, since the server 10 separates the attached file from the e-mail M and stores the attached file in the storage unit 30, it is possible to prevent information leakage of the attached file when it is erroneously transmitted.

For example, as shown in FIG. 1, the server 10 inserts the inquiry information into the body of the e-mail M. The server 10 may be inserted as a header of the e-mail M or a new attachment file of the e-mail M. Further, the server 10 may insert not only the inquiry information but also a guide text (for example, click this URL to download the attached file) in the e-mail M.

The server 10 performs a process of transmitting the e-mail as it is for the e-mail without the attached file.

[6] Inquiry Information Generation Method The server 10 generates inquiry information (for example, a URL) as a reference destination for downloading an attached file. The inquiry information is a password required to download the attached file.

The inquiry information is a character string in which at least the destination and the attached file name (for example, the storage destination in the storage unit 30) can be specified according to a predetermined format (URL format). For example, the destination and the attached file name are encoded and described in the parameter part according to the URL format.

When a plurality of attachment files exist for one e-mail, the server 10 generates one inquiry information in which the destination and the plurality of encrypted attachment files are associated with each other.

[7] Password generation The server 10 generates a password based on a given cryptographic algorithm at the timing of receiving the password generation instruction. The generated password is stored in the management data storage unit 173 in association with the inquiry information. The server 10 generates one password associated with the inquiry information even when a plurality of attached files exist in one e-mail. Further, the server 10 may generate a password at the timing when the inquiry information is received, not at the timing when the instruction for password generation is received.

Further, in order to prevent the password character string from being easily analyzed, the password may be a character string having 20 or more digits including symbols, numbers, uppercase letters, and lowercase letters.

The password may be a one-time password that is valid only once. For example, a one-time password generation program that generates a one-time password having the same algorithm as the server 10 is installed in the terminal 20 in advance, and authentication using the one-time password is performed. For example, the one-time password generator installed on the terminal 20 and the one-time password generator installed on the server 10 have the same algorithm and species number, and as a result, the one-time password generated on the terminal side. And the password generated by the server 10 match. For example, in the one-time password generation program, a process of generating a one-time password based on a time and a seed number is performed at a predetermined cycle (for example, every 30 seconds).

[8] Password notification When the server 10 receives inquiry information from a given user, the server 10 notifies the password to the destination associated with the inquiry information. To notify the destination associated with the inquiry information means to specify the destination associated with the inquiry information as the destination of the e-mail for notifying the password and send the e-mail containing the password. Is. Note that notifying the destination associated with the inquiry information may mean that the user of the destination associated with the inquiry information performs login authentication and controls the password to be viewable on the screen dedicated to the user. ..

That is, when the server 10 receives the inquiry information regarding the e-mail M (e-mail ID = 001) from the user B of the destination (B@yy.com), the destination (B @ yyy) associated with the inquiry information. .Com) is notified of the password required to download the attached file attached to the e-mail M (e-mail ID = 001).

For example, as shown in FIG. 5, the server 10 may notify the terminal 20 of the user B of the password issuing screen Sc1. For example, the server 10 displays the password issuance screen Sc1 when the inquiry information is received from the user B of the destination (B@yy.com). Then, when the instruction for issuing a password (password generation) is received from the user B (for example, the instruction by clicking the link L52 from the user B), the destination (B@yy.com) associated with the inquiry information is reached. , You may notify the password.

Further, as shown in FIG. 5, the server 10 may display the destination of the e-mail M (e-mail ID = 001) and the name of the attached file on the password issuing screen Sc1. Although not shown, the header and body of the e-mail M may also be displayed.

Even when the inquiry information is received from the user X who is not related to the destination user B, the password is notified to the destination (B@yyy.com) associated with the inquiry information, so that the destination It is possible to prevent the situation where the password is leaked to anyone other than the user B.

In addition, when a plurality of attached files exist in one e-mail, when the server 10 receives the inquiry information from the user, the server 10 is associated with the inquiry information to the destination associated with the inquiry information. Notify the password.

[9] Attachment file control When the inquiry information is received from the user B, the server 10 controls the attachment file (encrypted attachment file) associated with the inquiry information so that it can be downloaded or viewed.

FIG. 6 shows the password input screen Sc2 displayed on the terminal 20 of the user B. For example, as shown in FIG. 6, the server 10 notifies the password when the inquiry information is received from the user B, and then displays the password input screen Sc2 to the user B.

Then, the user B inputs the notified password in the text box field T61. That is, when the server 10 receives the password input instruction from the user B (for example, the instruction by clicking the link L62 from the user B), the server 10 performs the password authentication process.

For example, the server 10 is a user based on a password received from the user and a password associated with the inquiry information registered in the server 10 (a password corresponding to the inquiry information stored in the management data storage unit 173). Authenticate. For example, if the password received from the user and the password registered in the server 10 match, authentication is permitted.

Then, when the authentication is permitted, the server 10 displays the download screen Sc3 on the terminal 20 of the user B as shown in FIG. 7.

Then, as shown in FIG. 7, when the server 10 receives an instruction to download the attached file from the user B who is authorized to authenticate (for example, an instruction from the user B by clicking the link L72), the server 10 receives the instruction of the user B. The attached file associated with the inquiry information and decrypted is transmitted to the terminal 20. That is, the user B can download the attached file to the terminal 20 of the user B by clicking the link L72.

Although not shown, the server 10 causes the terminal 20 of the user B to receive an instruction to view the attached file (for example, an instruction by clicking the link from the user B) from the user B who is authorized to authenticate. , The decrypted attachment file associated with the inquiry information may be controlled to be viewable. That is, the user B causes the terminal 20 of the user B to display the contents of the attached file by clicking the link for browsing. By doing so, for example, the user B can confirm the contents of the attached file even by using a browser that prohibits downloading (saving to the terminal side).

Further, even when a plurality of attached files exist, the server 10 performs the authentication process with one password received from the user B who has been authenticated, and when the authentication is permitted, the server 10 processes a plurality of attached files corresponding to the inquiry information. , Controlled to be downloadable to the terminal of user B or controlled to be viewable.

[10] Effectiveness control In order to improve the information security of the attached file, the server 10 identifies the valid or invalid of the process of generating the password for the attached file, the process of sending the password, and the control enabling the download. The validity of (for example, the value of flag F) is set. That is, the server 10 performs a process of determining the validity of the attached file, and when it is determined to be valid (for example, when the flag F = 1), a process of generating a password, a process of transmitting the password, Control to enable download.

For example, the server 10 sets a flag indicating validity for each attached file (or each inquiry information, each e-mail). For example, flag F = 1 means valid, and flag F = 0 means invalid.

Then, when the flag F = 1, the server 10 controls the process of generating the password, the process of transmitting the password, and the process of downloading the attached file.

On the other hand, when the flag F = 0, the server 10 processes so as not to generate a password, processes so as not to transmit the password, and controls to prohibit the download of the attached file.

In the present embodiment, the server 10 receives a valid or invalid instruction from a predetermined user for each attached file (or for each inquiry information or for each e-mail).

For example, when the server 10 receives a valid instruction from a predetermined user for an attached file of e-mail M (mail ID = 001), the server 10 sets the flag F corresponding to the attached file to 1, and the predetermined user. When an invalid instruction is received from, the flag F corresponding to the attached file is set to 0.

Here, the "predetermined user" is a user of the sender (RCPT FROM, envelope FROM) of the e-mail of the attached file.

The "predetermined user" may be a user other than the sender. For example, in the case of setting a group composed of a plurality of users in advance, a user other than the sender who belongs to the same group as the sender may be a predetermined user. Further, for example, a user who is the superior of the sender may be a predetermined user. Further, when a plurality of destinations are specified in the e-mail, a user who is a user other than the sender and whose domain is the same as the sender among the plurality of recipients may be a predetermined user.

[11] Download restriction and browsing restriction Further, the server 10 counts the number of times K for receiving inquiry information, and prohibits download when the number of times K is more than a predetermined number of times (for example, three times or more). You may want to control at least one of the browsing prohibitions. For example, regardless of the information of the flag F, when the number of times K becomes a predetermined number of times or more (for example, three times or more), at least one of prohibition of download and prohibition of browsing may be controlled.

Further, the server 10 may set an expiration date corresponding to the inquiry information, and if the expiration date has passed, control at least one of prohibition of download and prohibition of browsing regardless of the information of the flag F. good.

[12] Management data FIG. 8 is an example of information stored in the management data storage unit 173 of the server 10. For example, the management data storage unit 173 has a URL (inquiry information), a file name of an attached file, a destination, a generated password, a flag F indicating validity, an expiration date, and a number of times K indicating the number of times of access to the URL. It will be remembered.

For example, the destination indicates the envelope To. The password is a password used to download or view the attached file.

In the example of FIG. 8, since the destination (B@yy.com) has the flag F = 1, the password can be acquired and the attached file can be acquired, but the destination (G@zzz.com) is the flag. Since F = 0, the password cannot be obtained, and the attached file cannot be obtained or viewed.

The expiration date indicates the date and time of the expiration date when the attached file can be acquired. The number of times K is the number of times the inquiry information is received. In other words, it indicates the number of times the query information has been accessed.

The password data stored in the management data storage unit 173 may be not the password itself but a character string (hash value or the like) for obtaining the password.

[13] Flow Chart A flow of processing according to the present embodiment will be described with reference to FIGS. 9A and 9B.

First, as shown in FIG. 9A, the terminal 20-A of the user A (A@xxx.com) on the transmitting side transmits an e-mail with an attached file (step S1). The destination of this e-mail is user B (B@yy.com).

When the server 10 receives the e-mail with the attached file (step S11), the server 10 encrypts the attached file (step S12) and stores the encrypted attached file in the storage unit 30 (step S13).

Then, the inquiry information (URL) is generated (step S14), the attached file is deleted from the received e-mail, and the inquiry information is inserted (step S15). Then, the e-mail is transmitted to the destination (step S16).

Then, the terminal 20-B of the destination user B receives the e-mail (step S100).
).

Subsequently, to explain with reference to FIG. 9B, the terminal 20-B of the destination user B accesses the inquiry information (URL) (step S111).
When the server 10 receives the inquiry information from the terminals 20-B (step S17), the server 10 notifies the password (step S18). When the server 10 receives the password generation instruction from the terminal 20-B, the server 10 may generate a password and notify the password.

Then, the terminal 20-B receives the password (step S112) and inputs the password (step S113). For example, enter the password on the password entry screen. The entered password is transmitted to the server 10.

The server 10 performs an authentication process based on the password (step S19). For example, the server 10 receives the password and performs an authentication process for determining whether or not the password registered in the server 10 and the received password match.

Then, when it is determined to be permitted in the authentication process (Y in step S20), the attached file is decoded and controlled so that it can be downloaded or viewed on the terminal 20-B (step S21). Even if authentication is permitted, the server 10 downloads the attached file to the terminal 20-B when the given condition is not satisfied (for example, when the flag F indicating validity is 0). It may be controlled to prohibit or prohibit viewing.

Then, the terminal 20-B downloads or browses and displays the attached file transmitted from the server 10 (step S114).

On the other hand, when the server 10 determines that the authentication process is not permitted (N in step S20), the server 10 ends the process. This completes the process.

[14] Application example [14.1] Notification of inquiry information When the server 10 determines that the e-mail M has an attached file, the server 10 sends the e-mail M from which the attached file is removed to the destination, and individually sends the inquiry information. May notify the destination user. For example, an e-mail containing inquiry information may be sent to the destination.

[14.2] Regarding a plurality of attachment files When a plurality of attachment files exist in one e-mail, the server 10 may generate a password for each attachment file. Then, the server 10 may control the attached file to be downloadable or viewable when authentication based on the password is permitted.

Further, the server 10 may generate inquiry information corresponding to each of the plurality of attached files, or may generate inquiry information in which a plurality of attached files are collectively collected.

[14.3] First and Second Inquiry Information The server 10 of the present embodiment may enable the download of the attached file by the inquiry information (URL) instead of the password.

For example, if the attached file exists in the e-mail M (e-mail ID = 001) sent from the sender (A@xxx.com), the server 10 encrypts and encrypts the attached file. The attached file is stored in the storage unit 30.

Then, the server 10 has the first inquiry information L1 (first URL) and the second inquiry information L2 (second URL) based on the destination (B@yy.com) and the identification information of the attached file. ) And.

The first inquiry information L1 is associated with the destination (B@yy.com) and the identification information of the attached file. Further, the second inquiry information L2 is also associated with the destination (B@yy.com) and the identification information of the attached file.

That is, the first inquiry information L1 and the second inquiry information L2 are information that can identify the destination and the attached file. The attached file that can be specified by the first inquiry information L1 and the second inquiry information L2 is an encrypted attached file.

Further, the second inquiry information L2 is information (URL) different from that of the first inquiry information L1. The server 10 stores the first inquiry information L1 and the second inquiry information L2 in association with each other.

Then, the server 10 deletes the data portion of the attached file of the e-mail M, inserts the inquiry information L1 instead, and sends the e-mail M to the destination (B@yyy.com).

When the server 10 determines that the e-mail M has an attached file, the server 10 may send the e-mail M from which the attached file has been removed to the destination and individually notify the destination user of the inquiry information L1. For example, an e-mail containing the inquiry information L1 may be sent to the destination.

After that, when the server 10 receives the access of the inquiry information L1, the server 10 identifies the destination (B@yy.com) from the inquiry information L1 and notifies the specified destination (B@yy.com) of the inquiry information L2. do. That is, the inquiry information L2 corresponding to the inquiry information L1 is notified.

Then, when the server 10 receives the access of the inquiry information L2, the server 10 identifies the attached file based on the inquiry information L2, decodes the attached file, and controls so that the decoded attached file can be downloaded. .. That is, the destination user B can display the download screen Sc3 as shown in FIG. 7 on the terminal simply by clicking the inquiry information L2, and can save the trouble of inputting the password.

According to the present embodiment, the notification destination of the inquiry information L2 is limited to the destination user B, so that when the user B mistakenly sends (wrongly forwards) the e-mail M to another user X, the inquiry information Even when L1 is illegally known to the user X, it is possible to control so that the inquiry information L2 is not notified to the user X. That is, it is possible to control the user X from illegally downloading the attached file or viewing the attached file.

When the server 10 receives the access of the inquiry information L2, the server 10 may internally issue a password, perform authentication based on the issued password, and display the download screen to the destination user B.

Further, when a plurality of attachment files exist in one e-mail, the server 10 has one first inquiry information and one second inquiry information in which the destination and the plurality of encrypted attachment files are associated with each other. Generate query information. Then, when the server 10 receives the second inquiry information, the server 10 decodes the plurality of attached files associated with the second inquiry information and downloads the decoded plurality of attached files to the user side. Control as possible or control as viewable.

[14.4] The anti-virus processing server 10 may perform anti-virus processing on the decrypted attached file before downloading or browsing to the user's terminal. Anti-virus processing means performing processing to remove computer viruses from attached files. For example, the server 10 records a pattern of specific code contained in a predefined known virus, checks for a match in the attachment of interest, and removes the code if it matches. Perform processing.

The server 10 may perform anti-virus processing on the attached file before storing the attached file in the storage unit 30.

[14.5] The filtering processing server 10 determines whether or not a predetermined condition is satisfied before downloading to the user's terminal or before browsing, and if the predetermined condition is satisfied, the decrypted attached file is subjected to the said. It may be controlled so that it can be downloaded or viewed by the user. Alternatively, the server 10 may control the decrypted attached file to prohibit download or prohibit viewing to the terminal of the user when the predetermined condition is satisfied.

The predetermined condition is a predetermined rule condition. The server 10 may define predetermined conditions in advance, or may set predetermined conditions based on input information from an administrator or a user. The server 10 may set a plurality of predetermined conditions.

For example, the server 10 makes it possible to download the decrypted attached file to the user side when the predetermined domain A that the destination domain of the header information is a specific domain (for example, "yy.com" is satisfied. Control or control to be viewable.

Further, for example, when the server 10 satisfies the predetermined condition B that the subject (Subject) of the header information contains the word "secret", the server 10 controls the decrypted attached file to be prohibited from being downloaded to the terminal of the user. Or control to prohibit viewing.

Further, the server 10 determines whether or not the predetermined condition is satisfied before storing the attached file in the storage unit 30, and if the predetermined condition is satisfied, the server 10 stores the attached file in the storage unit 30. May be good. Alternatively, the server 10 may control the attached file to be prohibited from being stored in the storage unit 30 when the predetermined condition is satisfied.

[14.6] The authentication token server 10 may notify the authentication token instead of the password. That is, when the server 10 receives the access of the inquiry information L, the server 10 identifies the destination (B@yy.com) from the inquiry information L and notifies the specified destination (B@yy.com) of the authentication token. ..

The authentication token is a program or URL for generating a password (for example, a one-time password) for accessing the file server, and may be paraphrased as a security token. For example, the server 10 can decrypt the encrypted attachment file and download the decrypted attachment file when the authentication is permitted based on the password generated by using the authentication token according to the instruction from the user. Or control it so that it can be viewed. Further, once the authentication based on the authentication token from the user is permitted, the server 10 may maintain the authentication permission of the user for a predetermined period (for example, 10 minutes after the authentication is permitted). ..

[14.7] E-mail reception control The server 10 may manage the attached file by the above-mentioned method even when it functions as a receiving server for taking in the received e-mail to the user side. In addition, as a server function for fetching received e-mail to the user side, for example, there are POP (Post Office Protocol), IMAP (Internet Message Access Protocol) and the like.

Hereinafter, the case of functioning as a receiving server will be described. First, the server 10 receives an e-mail Mr (e-mail ID = 002) transmitted from the sender (A@xxx.com) and to which the destination (B@yy.com) is designated. Then, the server 10 determines whether or not an attached file exists for the received e-mail Mr (hereinafter referred to as "received e-mail"). Then, if the attached file exists, the server 10 encrypts the attached file and stores the encrypted attached file in the attached file storage unit 40.

Then, the server 10 generates inquiry information L (URL) in which the destination (B@yy.com) and the identification information of the attached file are associated with each other. The identification information of the attached file is information that can uniquely identify the attached file. For example, the server 10 generates inquiry information L (URL) based on the destination (B@yy.com) and the identification information of the attached file.

Then, the server 10 deletes the data portion of the attached file of the e-mail Mr, and instead stores the e-mail Mr in which the inquiry information L is inserted in the received mail storage unit 50.

Then, for example, the e-mail Mr stored in the received mail storage unit 50 is taken in as the received mail of the user B based on the reception instruction of the user B of the destination (B@yy.com).

Then, when the user B accesses the inquiry information L included in the e-mail Mr, the server 10 accepts the access of the inquiry information L, identifies the destination (B@yyy.com) from the inquiry information L, and identifies the destination. Notify (B@yy.com) of the password.

Then, when the server 10 accepts the access of the inquiry information L, the password authentication is performed, and when the authentication is permitted, the attached file stored in the attached file storage unit 40 is decoded and decrypted. Control the attachments so that they can be downloaded or viewed.

Even when the server 10 functions as a receiving server, the server 10 may perform the processing described in the above-mentioned application example.

The received mail storage unit 50 and the attached file storage unit 40 may be a storage area of the server 10 or a storage area on the cloud (for example, a storage area on the Internet that can be connected to the server 10 and the terminal 20 via the Internet). good.

[14.8] Download Destination In the present embodiment, the download destination of the attached file or the like may be not only the user's terminal 20 but also a storage area on the cloud.

That is, controlling the attachment file to be downloadable to the user means not only making the attachment file downloadable to the user's terminal 20, but also to a storage area on the Internet that can be connected to the terminal 20 via the Internet. It also includes controlling the attached file to be memorable in association with the user ID of the user (accessible to the user).

[15] Others The e-mail of the present embodiment is not limited to SMTP, and may be transmitted / received by a given protocol.

Further, the data of the present embodiment, for example, the data of e-mail may be stored in the storage unit 30 or a storage area on the Internet.

Further, the server 10 of the present embodiment may encrypt all the attachment files of the received e-mails, or encrypt the attachment files of the e-mails for the e-mails satisfying a given rule condition. You may control it. For example, the server 10 may set rule conditions in advance based on input information from an administrator or a user.

Further, in the present embodiment, the control that enables downloading may be a concept including a control that enables printing. Further, the control for prohibiting download may be a concept including the control for prohibiting printing.

10 servers, 20 terminals, 30 storage units,
100 Processing unit, 111 Reception unit, 112 Analysis unit, 113 Encryption processing unit, 114 Transmission unit, 115 Notification unit, 116 Storage processing unit, 117 Inquiry information generation unit, 118 Password generation unit, 119 File control unit, 120 Web processing Department, 170 Memory Department, 171
Main storage unit, 172 user information storage unit, 173 management data storage unit, 180 information storage unit

Claims (6)

A server that manages attachments to e-mails with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs processing for encrypting the attached file of the e-mail, and
A storage processing unit that performs processing to store encrypted attachments in the storage unit,
An inquiry information generation unit that generates inquiry information in which the destination and an encrypted attachment file are associated with each other.
A transmitter that sends the e-mail with the attached file deleted and the inquiry information inserted to the destination, and
When the inquiry information is received, a notification unit for notifying the destination associated with the inquiry information of the password associated with the inquiry information, and a notification unit.
When the inquiry information is received, authentication is performed based on the password received from the user and the password associated with the inquiry information, and when the authentication is permitted, the attached file associated with the inquiry information is performed. A server comprising a file control unit that decodes the data and controls the decrypted attached file so that the user can download or view the decrypted attached file. In claim 1,
The inquiry information generation unit is
When there are multiple attachments in one e-mail, one inquiry information that associates the destination with the plurality of encrypted attachments is generated.
The notification unit
When the inquiry information is received, the destination associated with the inquiry information is notified of one password associated with the inquiry information.
The file control unit
When the inquiry information is received, authentication is performed based on the password received from the user and the password associated with the inquiry information, and when the authentication is permitted, a plurality of numbers associated with the inquiry information are performed. A server that decodes an attached file and controls the decrypted attached file so that it can be downloaded or viewed by the user. A server that manages attachments to e-mails with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs processing for encrypting the attached file of the e-mail, and
A storage processing unit that performs processing to store encrypted attachments in the storage unit,
An inquiry information generation unit that generates a first inquiry information and a second inquiry information in which the destination and an encrypted attachment file are associated with each other.
A transmission unit that sends the e-mail to the destination by deleting the attached file and inserting the first inquiry information.
A notification unit that notifies the second inquiry information to the destination associated with the first inquiry information when the first inquiry information is received.
When the second inquiry information is received, the attached file associated with the second inquiry information is decoded, and the decoded attached file can be controlled or viewed by the user so that it can be downloaded. A server characterized by including a file control unit to control. In claim 3,
The inquiry information generation unit is
When a plurality of attachment files exist in one e-mail, the first inquiry information and the second inquiry information in which the destination is associated with the plurality of encrypted attachment files are generated. death,
The file control unit
When the second inquiry information is received, the plurality of attached files associated with the second inquiry information are decoded, and the decoded plurality of attached files are controlled to be downloadable to the user side. Or a server characterized by being controllable so that it can be viewed. In any of claims 1 to 4,
The file control unit
A server characterized by performing antivirus processing on a decrypted attached file before downloading or browsing to the user's terminal. In any of claims 1 to 5,
The file control unit
Before downloading to the user's terminal or before browsing, it is determined whether or not the predetermined condition is satisfied, and if the predetermined condition is satisfied, the decrypted attached file is controlled or browsed so that the user can download it. A server characterized in that it is controlled to be possible, or is controlled to prohibit download or browse to the terminal of the user.

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