JP6931906B2 - Programs and servers - Google Patents

Description

The present invention relates to programs and servers.

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) the 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 SMTP (Simple Mail Transfer Server Protocol). A server (mail server).

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

For example, according to the first embodiment shown in Patent Document 1, the receiving terminal 24 inquires the attached file encryption device 17 for the password for decrypting the encrypted file and attaches the password. When the file encryption device 17 succeeds in authentication, the password is transmitted to the terminal 24, and the terminal 24 can decrypt the encrypted file by the received password (see FIG. 2 of Patent Document 1).

Further, according to the second embodiment shown in Patent Document 1, the terminal 16 on the transmitting side accesses the designated URL (URL is an abbreviation for Uniform Resource Password; the same applies hereinafter) to encrypt the attached file. The computer 57 is made to transmit the password to the destination terminal 24. Then, the terminal 24 receives a password for decrypting the encrypted file from the attached file encryption device 57, and the terminal 24 can decrypt the encrypted file by the received password (Patent Document). 1)

Japanese Unexamined Patent Publication No. 2008-187280

However, in the first embodiment of the prior art, the sender (sender) sends an e-mail or password with an attachment, and then notices an erroneous transmission or provides the password for given circumstances. If you want to cancel, you could not cancel the provision of the password, and there was a risk that a third party could view the contents of the attached file.

Further, also in the second embodiment of the prior art, the password notification cannot be canceled after the sender (sender) clicks the URL for notifying the destination (receiver) of the password. , There is a risk that a third party will be able to view the contents of the attached file.

The present invention has been made in view of the above-mentioned problems, and when an e-mail with an encrypted file attached is sent to a destination, the password for decrypting the encrypted file is made even more secure. The purpose is to provide manageable programs and servers.

(1) The present invention
A program for a server that sends e-mail with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs a process of encrypting the attached file to generate an encrypted file and a process of generating a password for decrypting the encrypted file when the attached file exists in the e-mail. When,
An encrypted file e-mail to which the encrypted file is attached instead of the attached file, and a transmission unit that transmits password inquiry information associated with the password to the destination.
A password control unit that sets the disclosure or non-disclosure of the password in association with the password.
When the password inquiry information is accepted and the password is set to be public, the computer is made to function as a password providing unit for providing the password.
The password control unit
The present invention relates to a program that sets the password to be public when the sender gives an instruction to disclose the password, and sets the password to be private when the sender gives an instruction to keep the password private.

The present invention also relates to an information storage medium in which the above program is stored. The present invention also relates to a server configured as each of the above parts.

According to the present invention, when the password disclosure instruction is received from the sender, the password is set to public, and when the password non-disclosure instruction is received from the sender, the password is set to private. It is possible to flexibly manage the disclosure and non-disclosure of the password at the will of the sender user.

For example, even if the password is set to public, if the sender is set to private before the sender knows the password to the destination user, the password will be provided even after sending the encrypted file email. It is possible to cancel the password and prevent the contents of the attached file from being viewed by preventing a third party from decrypting the encrypted file.

(2) In addition, the program, information storage medium, and server of this application example are
When the transmission of the encrypted file e-mail is completed, the computer may further function as a transmission completion notification unit for notifying the sender of the transmission completion notification e-mail containing the information regarding the password.

According to the present invention, since the sender receives the transmission completion notification email, the sender user can be aware of the necessity of setting the password to be public or private, and change the password from public to private. Alternatively, you can remember to set the password to change from private to public.

(3) In addition, the program, information storage medium, and server of this application example are
The transmitter
The encrypted file e-mail and the inquiry information e-mail including the password inquiry information may be individually transmitted to the destination.

According to the present invention, since the encrypted file e-mail and the inquiry information e-mail are individually transmitted to the destination, the encrypted file e-mail and the inquiry information e-mail can be separately controlled.

(4) In addition, the program, information storage medium, and server of this application example are
The transmitter
The inquiry information e-mail may be transmitted after a predetermined period from the time when the encrypted file e-mail is transmitted.

According to the present invention, since the inquiry information e-mail is transmitted after a predetermined period from the time when the encrypted file e-mail is transmitted, the sender user sets the password to be public or private until the predetermined period ends. You can have time to review and reset. On the other hand, since the destination user receives the inquiry information e-mail after receiving the encrypted file, the destination user receives the encrypted file e-mail with the encrypted file attached, and then decrypts the encrypted file. You can naturally perform a series of operations to obtain and decrypt the password.

(5) Further, the program, information storage medium, and server of this application example are
The transmitter
The encrypted file e-mail containing the password inquiry information may be sent to the destination.

According to the present invention, since the password inquiry information is included in the encrypted file email, the destination user can clearly recognize the correspondence between the password inquiry information and the encrypted file email. In addition, the destination user can prevent the password inquiry information from being lost.

(6) Further, the program, information storage medium, and server of this application example are
The password control unit
The number of times the password inquiry information is received may be counted, and when the number of times becomes more than a predetermined number of times, the password may be set to be private.

According to the present invention, when the number of times the password inquiry information is received exceeds a predetermined number of times, the password is set to be private, so that the disclosure of the password can be restricted and unnecessary leakage of the password can be prevented. be able to.

(7) In addition, the program, information storage medium, and server of this application example are
The password control unit
When there are a plurality of recipients of the e-mail, the password may be set to be public or private for each recipient.

According to the present invention, since the password can be set to be public or private for each destination, the password can be managed according to the user.

An example of a functional block of the server of this embodiment. The figure which showed the outline of the processing of the server of this embodiment. The figure which shows an example of the text of the inquiry information e-mail of this embodiment. An example of information stored in the password storage unit 173 of the present embodiment. An example of the mail list screen for password control in this embodiment. An example of the password disclosure / non-disclosure setting screen of this embodiment. An example of the password disclosure / non-disclosure setting screen of this embodiment. 8 (A) and 8 (B) are examples of the password viewing screen of this embodiment. An example of the body of the transmission completion notification email of this embodiment. FIG. 10A shows a schematic diagram of the encrypted file e-mail Ms and the inquiry information e-mail Mp of the present embodiment. Further, FIG. 10B shows a schematic diagram of the encrypted file e-mail Ms of the present 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. The flowchart which shows the flow of the process of this embodiment.

Hereinafter, this embodiment will be described. 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. 1. Configuration FIG. 1 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 password 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 a 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 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 password storage unit 173 stores the password and public or non-public information of the password. The password storage unit 173 may be configured by a DB.

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), an optical magnetic disk (MO), a magnetic disk, a hard disk, and a magnetic tape. Alternatively, it can be realized by a memory (ROM) or the like. The information storage medium 180 is a storage.

Further, the information storage medium 180 can store a program for operating the computer as each part of the present embodiment (a program for causing the computer to execute the processing of each part).

The processing unit 100 performs various processes of the present embodiment based on the programs and data stored in the storage unit 170 and the information storage medium 180.

The processing unit 100 includes an e-mail processing unit (MTA) 110 and a Web processing unit 120.

The e-mail processing unit 110 receives and delivers e-mails on the network through SMTP. The e-mail processing unit 110 of the present embodiment includes a receiving unit 111, a transmitting unit 112, a password control unit 113, a password providing unit 114, a transmission completion notification unit 115, an analysis unit 116, and an encryption processing unit 117.

The receiving unit 111 performs a process of receiving an e-mail transmitted by the MUA 22 of the sending terminal 20 and for which the destination of the envelope is specified.

The transmitting unit 112 performs a process of transmitting (delivering, delivering, forwarding) the e-mail received by the receiving unit 111 to the destination.

In particular, when the e-mail received by the receiving unit 111 includes an attached file, the transmitting unit 112 of the present embodiment includes an encrypted file e-mail to which an encrypted file is attached instead of the attached file, and the encryption. Inquiry information including password inquiry information associated with the password for decrypting the file is sent to the destination.

The transmission unit 112 may individually transmit the encrypted file e-mail and the inquiry information e-mail including the inquiry information to the destination. For example, the transmission unit 112 may transmit the inquiry information e-mail after a predetermined period (for example, 5 minutes) from the time when the encrypted file e-mail is transmitted.

Further, the transmission unit 112 may send an encrypted file e-mail containing the inquiry information to the destination.

The password control unit 113 sets public or private of the password in association with the password for decrypting the encrypted file. For example, the password control unit 113 sets the password to be public when it receives an instruction to disclose the password from the sender. Further, the password control unit 113 sets the password to be private when it receives an instruction to keep the password private from the sender.

Further, the password control unit 113 may count the number of times the password inquiry information is received, and set the password to be private when the number of times is equal to or more than a predetermined number of times.

Further, when there are a plurality of e-mail destinations, the password control unit 113 may set the password to be public or private for each destination.

The password providing unit 114 provides the password when the password inquiry information is received and the password is set to be public. For example, the password providing unit 114 provides the password to the user when the password inquiry information is received from the user's terminal and the password is set to be public.

Here, the "providing" of the password includes both a method of notifying the password by e-mail and controlling the password so that it can be viewed by a Web server.

When the transmission of the encrypted file e-mail is completed, the transmission completion notification unit 115 notifies the sender of the transmission completion notification e-mail including the information regarding the password.

The analysis unit 116 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 body of 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 117 performs the encryption processing of the attached file, and the encrypted file and the password for decrypting the encrypted file. And generate.

The Web processing unit 120 responds to the request of client software such as the Web browser 21 installed on the terminal 20 through HTTP (Hypertext Transfer Protocol), and HTML (HyperText Markup).
Language) Performs processing for transmitting (providing) data such as documents and images, and processing for receiving data received by the Web browser 21 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 administrator UI unit 121 performs a process of transmitting (providing) management setting data or the like to the administrator terminal 20 in response to an access request from the Web browser 21 of the administrator terminal 20, and information from the terminal 20. Is processed to receive.

That is, the administrator UI unit 121 adds, deletes, updates, and the like to the DB based on the input from the administrator. Only the administrator is authorized to access the Web page (URL) of the administrator UI.

The user UI unit 122 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 21 of the terminal 20.

For example, the user UI unit 122 controls so that the password inquiry information and the Web page for receiving the password disclosure instruction or the non-disclosure instruction can be browsed in response to the request from the Web browser 21 of the terminal 20.

The database processing unit 130 performs a process of registering, updating, and deleting the data stored in the database (DB). For example, the database processing unit 130 performs a process of updating the database in the administrator UI unit 121 and the user UI unit 122 based on the data received from the terminal 20.

The e-mail processing unit 110, the Web processing unit 120, the database processing unit 130, and the storage unit 170 may be executed by one device, or may be distributed to different devices according to the purpose of processing to execute each process. You may do so.

2. Outline FIG. 2 shows an outline of the processing flow of the server (mail server) 10 of the present embodiment. The server of the present embodiment has an 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.

First, the server 10 of the present embodiment receives the e-mail transmitted from the MUA 22 of the terminal 20, analyzes the received e-mail, and determines whether or not there is an attached file.

When the server 10 determines that there is an attached file, the server 10 performs a process of encrypting the attached file and generates an encrypted file. The server 10 also generates a password for decrypting the encrypted file.

Then, the server 10 transmits an encrypted file e-mail to which an encrypted file is attached instead of the attached file, and an inquiry information e-mail including password inquiry information (for example, a URL) associated with the password to the destination.

The sender user A gives an instruction to make the password public or private in association with the password, and the server 10 sets the password to be public or private in association with the password. That is, when the server 10 receives the password disclosure instruction from the user A terminal, which is the sender, the server 10 sets the password to be public, and when the user A terminal receives the password non-disclosure instruction, the server 10 sets the password. Set to private.

Then, the server 10 of the present embodiment provides the password to the terminal of the user B when the password inquiry information is received from the terminal of the user B who is the destination and the password is set to be public. For example, since the server 10 functions as a Web server, the password is controlled to be viewable by the Web browser of the terminal of the user B.

As described above, according to the present embodiment, the attached file can be automatically encrypted by the server 10, so that the user A of the sender can save the trouble of performing the encryption work. In addition, it is possible to prevent falsification of the attached file and information leakage of the attached file.

In addition, the user B can click the URL of the password inquiry information and view the password when the password is set to be public.

In addition, since user A can set the password to be private after setting it to be public, the password can be made private even if the user later learns that the information was not to be shown to user B. can. For example, if the user B is set from public to private before acquiring the password, it is possible to prevent information leakage of the password and the attached file.

The server 10 performs a process of transmitting an e-mail having no attached file as it is.

Here, when an MTA sends an e-mail, it means that the received e-mail is sent to another MTA through SNTP, or is sent locally 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 a distribution agent MDA (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 the following description, the sender, user A (A@xxx.com), creates an e-mail M with an attachment F, and the destination of the e-mail M is user B (B@yyy.com). The case will be described as an example.

3. 3. Explanation of Encryption Process First, when the attached file F exists in the e-mail M received from the terminal 20-A of the user A, the server 10 encrypts the attached file F and generates the encrypted file Fs. .. Further, the server 10 generates a password for decrypting the encrypted file Fs.

Then, the server 10 transmits the encrypted file e-mail Ms to which the encrypted file Fs is attached instead of the attached file F.

The server 10 generates a password for decrypting the encrypted file Fs based on a given algorithm. To prevent the password string from being easily parsed, the password may be a string of 20 or more digits including symbols, numbers, upper and lower letters.

Then, the server 10 generates the encrypted file Fs in the ZIP format based on the password. That is, the user B who has received the encrypted file e-mail Ms cannot restore the original file F unless the password is specified.

In this way, since the server 10 automatically encrypts the attached file, it is possible to prevent a situation in which the sender mistakenly sends the attached file F without encrypting it and makes a human operation error. Can be done.

The server 10 may generate encrypted files Fs by various methods, not limited to the ZIP format. Further, when a plurality of attached files F exist in the e-mail M, the server 10 compresses the plurality of attached files F in the ZIP format to generate one encrypted file Fs, but the server 10 generates a plurality of attached files Fs. One encrypted file Fs may be generated for each file F.

4. Explanation of Password Inquiry Information When sending the encrypted file e-mail Ms, the server 10 sends the inquiry information e-mail Mp including the password inquiry information (for example, URL) associated with the password to the destination (B@yyy.com). Send.

The password inquiry information is information for inquiring the password of the encrypted file Fs, and is, for example, the URL of the server 10. The password inquiry information (URL) is a URL associated with the password. The password inquiry information (URL) may be a URL associated with the identification information (for example, message ID) of the encrypted file e-mail Ms.

FIG. 3 shows an example of the text of the inquiry information e-mail Mp received by the destination user B. For example, the body of the inquiry information e-mail Mp includes a subject Ba of the encrypted file e-mail Ms, a date Bb, a descriptive text Bc indicating a method of obtaining a password, and a password inquiry information Bd.

The password inquiry information Bd is associated with the password and indicates the URL of the website where the password can be viewed.

Further, the server 10 may send the inquiry information e-mail Mp to the destination (B@yyy.com) after a predetermined period (for example, 5 minutes) from T1 at the time of transmitting the e-mail Ms. In this way, until the end of the predetermined period, the sender user A can have a grace period to review and reset the public / private setting of the password. The server 10 may set the length of the predetermined period based on the setting instruction of the user A of the sender.

5. Description of password information In the present embodiment, the password is set to be public or private in association with the password. FIG. 4 is an example of information stored in the password storage unit 173 of the server 10. For example, the password storage unit 173 has the sender, destination, password, public flag F, expiration date, and access count K of the encrypted file e-mail associated with the ID for identifying the encrypted file e-mail. It will be remembered.

For example, the ID is identification information that can uniquely identify the encrypted file e-mail, for example, a Message-ID of the e-mail. The sender indicates the envelope From. The destination indicates the envelope To. The password is a password used to decrypt the encrypted file. The public flag F indicates that the password is public or private. For example, the public flag F = 1 means that the password is disclosed, and the password public flag F = 0 means that the password is not disclosed.

In the example of FIG. 4, for the encrypted file e-mail having the ID of 0001, the public flag F = 1, so that the user B of the destination (B@yyy.com) can acquire the password, but the ID Since the public flag F = 0 for the encrypted file e-mail of 0003, the user G of the destination (G@zzz.com) cannot obtain the password.

The expiration date indicates the date and time of the expiration date when the password can be obtained. The access count K is the number of times the password inquiry information is received. In other words, it indicates the number of times the password inquiry information (URL) for obtaining the password has been accessed.

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

6. Explanation of setting public or private password For example, when the server 10 of the present embodiment receives a password public instruction from a sender, the password is set to public and the password private instruction is accepted from the sender. If so, set the password to private.

As an initial state, the server 10 sets the initial value of the public flag F associated with the password to 1. That is, in the initial state, the password is made public. Then, when the "private" instruction (F = 0) from the sender user is received, the value of the public flag F is updated to 0.

When the terminal of the sender user A logs in based on the input of the user A, as shown in FIG. 5, the list screen GA for setting the disclosure / non-disclosure of the password is displayed by the Web browser.

On the list screen GA, a list of encrypted file e-mails from which user A (A@xxx.com) is the sender is displayed. For example, when the user A clicks on the subject, the user A can refer to the contents (header, body, attached file, etc.) of the encrypted file e-mail that has been transmitted and is the sender.

For example, when the detail button Ea is clicked on the list screen GA, the password disclosure / non-disclosure setting screen GB is displayed.

FIG. 6 shows an example of the password disclosure / non-disclosure setting screen GB. For example, on the password public / private setting screen GB, the outline Ca of the encrypted file e-mail Ms, the public check box Cb, and the confirmation button Cc are displayed. In FIG. 6, since the box Cb of the public check box of the encrypted file e-mail is checked, it is shown to be “public”.

For example, when the user A unchecks the public check box Cb and clicks the confirm button Cc, the terminal 20 of the user A sends a private instruction (F = 0) to the server 10 in association with the password "df8godfsioh". do. When the server 10 receives the private instruction (F = 0) associated with the password "df8godfsioh" from the terminal 20 of the user A, the server 10 sets the value of the public flag F associated with the password "df8godfsioh" to 0. (Update.

On the other hand, if the current state of the encrypted file e-mail is "private", that is, if the public check box Cb is not checked, if the check box is checked and the confirmation button Cc is clicked, the user A's The terminal 20 transmits a public instruction (F = 1) to the server 10 in association with the password “df8godfsioh”. When the server 10 receives the password disclosure instruction (F = 1) associated with the password "df8godfsioh" from the terminal 20 of the user A, the value of the public flag F associated with the password "df8godfsioh" is set to 1. Set (update).

Further, the server 10 may set the initial value of the public flag F associated with the password "df8godfsioh" to 0 as the initial state. That is, in the initial state, the password "df8godfsioh" is kept private. Then, when the instruction (F = 1) to set the password "df8godfsioh" of the sender user A to "public" is received, the value of the public flag F may be updated to 1.

When the initial state of public / private password is set to public state, that is, when the initial value of the public flag F is set to 1, the time and effort for the sender user A to instruct public from private is reduced. Can be done. However, when the sender user A wants to change from the public state to the private state, the destination user B may be able to obtain the password before the change.

On the other hand, when the initial state of public / private password is made private, that is, when the initial value of the public flag F is set to 0, it takes time and effort for the sender user A to instruct from public to private. However, the sender user A can surely control the disclosure / non-disclosure of the password. That is, if the user A wants to cancel the disclosure of the attached file after sending the encrypted file e-mail Ms to the destination user B, at least the password is kept private and attached to the user B. You can prevent the contents of the file from being viewed.

When there are a plurality of e-mail destinations, the server 10 may set the password to be public or private for each destination.

For example, as shown in FIG. 7, when there are two destinations, B@yyy.com and C@yyy.com, public checks Cb1 and Cb2 are provided for each destination, and the sender user A has a password. To be able to give public / private instructions. In this way, password management suitable for the destination user can be performed.

7. Explanation of password provision The server 10 provides the password when the password inquiry information is received and the password is set to be public.

For example, when the public / private state of the password for the encrypted file e-mail Ms with ID 0001 is public (when the public flag F = 1), the destination (B@yyy.com)
User B can obtain a password. That is, the destination user B can access the password viewing screen GC as shown in FIG. 8 (A) by clicking the password inquiry information Bd (for example, URL) in FIG. 3, and browses the password "df8godfsioh". be able to.

As shown in FIG. 8A, in addition to the password of the encrypted file e-mail Ms, various information such as the subject Da and the date Db related to the encrypted file e-mail Ms may be displayed on the password screen GC.

On the other hand, when the public / private state of the password for the encrypted file e-mail Ms with ID 0001 is private (when the public flag F = 0), the destination (B@yyy.com)
User B cannot view the password. That is, when the destination user B clicks the password inquiry information Bd (for example, URL) in FIG. 3, as shown in FIG. 8 (B), as shown in the password screen GD, the password cannot be viewed at present. The information Dd to be shown is displayed.

In the present embodiment, a user other than the destination user B (for example, user C, user D, etc.) can access the password inquiry information (URL). For example, when the password is open to the public, the user C can browse the password inquiry information (URL) by teaching the password inquiry information (URL) to the user C. Further, the server 10 may notify the access code for accessing the password inquiry information (URL) by the inquiry information e-mail, and authenticate with the access code when accessing the password inquiry information (URL). .. In this way, only a user who knows the access code in addition to the password inquiry information (URL) can access it.

8. Explanation of delivery completion notification mail In the present embodiment, when the transmission of the encrypted file e-mail Ms is completed, the transmission completion notification mail Me including the information about the password is notified to the terminal 20 of the user A who is the sender. You may. User A can be alerted to the public and private settings of the password, and user A again about changing the password from public to private or changing the password from private to public. This is because it can be recognized and set again.

FIG. 9 shows an example of the text of the transmission completion notification mail Me. The transmission completion notification mail Me includes information such as the subject Fa of the encrypted file e-mail Ms and the transmission date Fb.

Further, as shown in FIG. 9, a password such as information Fc indicating the state of the password (public or private) and information Fd of the URL of the website for changing the password from public to private or private to public. Display information about.

For example, when the user A clicks the information Fd regarding the password, the screen shifts to the password disclosure / non-disclosure setting screen GB shown in FIG. In this way, the user A can quickly set the password to be public or private.

9. Example of Encrypted File E-mail Ms As shown in FIG. 10A, the server 10 of the present embodiment individually separates the encrypted file e-mail Ms and the inquiry information e-mail Mp including the password inquiry information Bd. Although the example of transmitting to the terminal of the user B who is the destination has been described, the encrypted file e-mail Ms including the password inquiry information Bd may be transmitted to the terminal of the user B who is the destination.

For example, as shown in FIG. 10B, the server 10 attaches the encrypted file Fs and the password inquiry information file Fp including the password inquiry information Bd to the encrypted file e-mail Ms. In this way, the destination user B can clearly recognize the correspondence between the password inquiry information Bd and the encrypted file Fs, so that the user B can obtain the password for decrypting the encrypted file Fs. It is possible to prevent the trouble of finding the password inquiry information Bd. The server 10 may describe the password inquiry information Bd in the header or body of the encrypted file e-mail Ms without attaching the password inquiry information file Fp.

10. Control based on the number of times the password inquiry information is received The server 10 of the present embodiment sets the initial value of the number of times K for which the password inquiry information is received to 0, and counts the number of times K each time the password inquiry information is received. When the number of times K becomes more than a predetermined number of times, the password may be set to be private.

For example, the server 10 automatically sets the password to private when the number of times K of receiving the password inquiry information becomes one or more times (K ≧ 1). By doing so, it is possible to set a limit on the number of times of access to the password inquiry information (URL), and it is possible to reduce the chance of password information leakage as much as possible.

In addition, the sender user A notices that the encrypted file e-mail has been sent to an unintended party, and when he / she tries to keep the password private, he / she can easily check the security status by referring to the number of times K. It can be determined. That is, the sender user A can determine that when the number of times K is 0, it is possible to prevent information leakage about the contents of the encrypted file and it is in time for ensuring security, and when the number of times K is 1 or more. In a certain case (when the number of times K is not 0), it can be determined that it is too late because the information leakage cannot be prevented.

That is, if the number of times K is 0, the sender user A can determine that the password has not yet been referenced by anyone and cannot decrypt the encrypted file, and if the number of times K is 1 or more, it can be determined. , It can be determined that the password has already been referenced by a user such as the destination user B and may have been decrypted.

11. Flowchart The processing flow of the present embodiment will be described with reference to FIGS. 11A, 11B, and 11C.

First, as shown in FIG. 11A, the terminal 20-A of the sending user A (A@xxx.com) transmits the attached file e-mail (step S1). The destination of the attached file e-mail is user B (B@yyy.com).

When the server 10 receives the attached file e-mail (step S11), the server 10 encrypts the attached file (step S12) and generates an encrypted file e-mail (step S13).

Further, the server 10 transmits the encrypted file e-mail to the destination (step S14). Then, the terminal 20-B of the destination user B receives the encrypted file e-mail (step S100).
In addition, the server sends a transmission completion notification email to the sender (step S15). The terminal 20-A of the sender user A receives the transmission completion notification mail (step S2).

Then, the server sends the inquiry information e-mail to the destination (step S16). The terminal 20-B of the destination user B receives the inquiry information e-mail (step S101).

Subsequently, to explain with reference to FIG. 11B, the terminal 20-B of the destination user B accesses the password inquiry information (URL) (step S102).

When the server 10 receives the password inquiry information (step S17), the server 10 determines whether or not the password is open to the public (step S18).

When the password is open to the public (Y in step S18), the password is made viewable and a Web page is generated (step S19). On the other hand, when the password is not disclosed (N in step S18), the password is disabled to be viewed and a Web page is generated (step S20). For example, a Web page without a password is generated.

When the password can be browsed, the terminal 20-B of the destination user B browses the password (step S103), and performs a process of decrypting the encrypted file by the password (step S104). If the password cannot be viewed, the terminal 20-B cannot decrypt the encrypted file.

The terminal 20-A of the sender user A can give an instruction to disclose or not disclose the password after step S2. As shown in FIG. 11C, when there is a password disclosure instruction (Y in step S3), the terminal 20-A transmits the password disclosure instruction to the server 10 (step S4).

When the server 10 receives the password disclosure instruction (step S21), the server 10 sets the password to be public (step S22).

Further, when the terminal 20-A is instructed to keep the password private (Y in step S5), the terminal 20-A transmits the password private instruction to the server 10 (step S6).

When the server 10 receives the password non-disclosure instruction (step S23), the server 10 sets the password private (step S24). This completes the process.

12. Application example (1) Application example of password disclosure or non-disclosure control In this embodiment, an example in which the sender user A sets the password disclosure or non-disclosure has been described, but a user other than the sender is public or private. You may set it to be private.

For example, the server 10 sets in advance a group composed of a plurality of users. For example, it is assumed that the sender user A, the user E, and the group G1 to which the user F belongs are defined. Then, when the server 10 receives the password disclosure instruction from the user E and the user F in the same group G1 as the sender user A, the server 10 sets the password to be public and the user in the same group G1 as the sender user A. When the instruction to keep the password private is received from E and the user F, the password may be set to be private.

In this way, if users E and F of the same group G1 as the sender user A notice that they are sending an encrypted file that should not be sent to the destination, the password of the encrypted file to the destination is sent. Can be prevented from being published.

Further, in the server 10, when the superior of the sender user A (“supervisor” is also referred to as “auditor” or “specific user”) is set in advance, the password is disclosed or disclosed by the superior. Private instructions may be accepted. That is, the server 10 may set the password to be public when it receives the password disclosure instruction from the superior, and may set the password to be private when it receives the password non-disclosure instruction from the superior. ..

Further, in the server 10, the sender user A (A@xxx.com) specifies a plurality of destinations (for example, user B (B@yyy.com) and user J (J@xxx.com)). When sending an e-mail, user J, who owns an e-mail address that includes the same domain name (xxx.com) as the sender (A@xxx.com) included in the e-mail, gives an instruction to disclose or not disclose the password. You may accept it. That is, the server 10 may set the password to be public when receiving the disclosure instruction from the user J, and may set the password to be private when the user J receives the instruction to keep the password private.

Further, the server 10 is a case where, for example, user B (B@yyy.com) and user K (k@xxx.com) are registered on the mailing list (ML@xxx.com), and the sender When user A sends an e-mail with the mailing list (ML@xxx.com) as the destination, the user A is registered on the mailing list and has the same domain name (xxx.com) as the sender (A@xxx.com). You may accept the instruction of disclosure or non-disclosure of the password from the user K who owns the e-mail address (k@xxx.com) including. That is, the server 10 may set the password to be public when it receives the password disclosure instruction from the user K, and may set the password to be private when it receives the password non-disclosure instruction from the user K. ..

Note that the server 10 does not accept password disclosure instructions from users other than the sender (for example, users E, E, superiors, user J, user K, etc.), and only password non-disclosure instructions from users other than the sender. May be accepted.

(2) 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, e-mail data, attached file data, and encrypted file data may be stored in a storage area on the Internet called a cloud.

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 the given rule conditions. 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.

10 servers, 20 terminals,
100 processing unit, 110 e-mail processing unit (MTA), 111 receiving unit, 112 transmitting unit, 113 password control unit, 114 password providing unit, 115 transmission completion notification unit, 116 analysis unit, 117 encryption processing unit, 120 Web processing Unit, 121 Administrator UI unit, 122 User UI unit, 130 Database processing unit, 170 storage unit, 171 main storage unit, 172 user information storage unit, 173 password storage unit, 180 information storage medium, 21 Web browser, 22 MUA

Claims (12)

A program for a server that sends e-mail with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs a process of encrypting the attached file to generate an encrypted file and a process of generating a password for decrypting the encrypted file when the attached file exists in the e-mail. When,
A transmitter that transmits password inquiry information associated with the password to the destination, and
A password control unit that sets the disclosure or non-disclosure of the password in association with the password.
When the password inquiry information is accepted and the password is set to be public, the computer is made to function as a password providing unit for providing the password.
The password control unit
When the password disclosure instruction is received from a predetermined user other than the sender, the password is set to public, and when the password non-disclosure instruction is received from the predetermined user, the password is not disclosed. A program characterized by being set to. A program for a server that sends e-mail with a specified destination.
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs a process of encrypting the attached file to generate an encrypted file and a process of generating a password for decrypting the encrypted file when the attached file exists in the e-mail. When,
A transmitter that transmits password inquiry information associated with the password to the destination, and
A password control unit that sets the disclosure or non-disclosure of the password in association with the password.
When the password inquiry information is accepted and the password is set to be public, the computer is made to function as a password providing unit for providing the password.
The password control unit
When the password disclosure instruction is not accepted from a predetermined user other than the sender, the password non-disclosure instruction is received from the predetermined user, and the password non-disclosure instruction is received from the predetermined user. , A program characterized by setting the password to be private. In claim 1 or 2,
The computer is further functioned as a setting unit for setting a group composed of multiple users in advance.
The password control unit
A program characterized in that a user other than the sender, which belongs to the same group as the sender, is designated as the predetermined user. In claim 1 or 2,
The password control unit
A program characterized in that a user who is the superior of the sender is the predetermined user. In claim 1 or 2,
The password control unit
When a plurality of recipients are specified in the e-mail, a user other than the sender and having the same domain as the sender among the plurality of recipients shall be the predetermined user. A program featuring. In claim 1 or 2,
The password control unit
When the destination of the e-mail is a mailing list, a user who is a user other than the sender and whose domain is the same as the sender among the e-mail addresses registered in the mailing list is referred to as the predetermined user. A program characterized by doing. In any of claims 1 to 6,
The password control unit
A program characterized in that the number of times the password inquiry information is received is counted, and when the number of times is equal to or greater than a predetermined number of times, the password is set to be private. In any of claims 1 to 7,
The password control unit
When the sender gives an instruction to disclose the password, the password is set to be public, and when the sender gives an instruction to keep the password private, the password is set to be private. Program to be. In any of claims 1 to 8,
A program characterized by further functioning a computer as a storage processing unit that stores the data of the encrypted file in a storage area on the Internet. In any of claims 1 to 9,
The password provider
A program characterized by providing the password by notifying the password by e-mail. A server that sends e-mail with a specified destination
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs a process of encrypting the attached file to generate an encrypted file and a process of generating a password for decrypting the encrypted file when the attached file exists in the e-mail. When,
A transmitter that transmits password inquiry information associated with the password to the destination, and
A password control unit that sets the disclosure or non-disclosure of the password in association with the password.
Including the password providing unit that provides the password when the password inquiry information is received and the password is set to be public.
The password control unit
When the password disclosure instruction is received from a predetermined user other than the sender, the password is set to public, and when the password non-disclosure instruction is received from the predetermined user, the password is not disclosed. A server characterized by being set to. A server that sends e-mail with a specified destination
A receiver that receives e-mail sent from the sender, and
An encryption processing unit that performs a process of encrypting the attached file to generate an encrypted file and a process of generating a password for decrypting the encrypted file when the attached file exists in the e-mail. When,
A transmitter that transmits password inquiry information associated with the password to the destination, and
A password control unit that sets the disclosure or non-disclosure of the password in association with the password.
Including the password providing unit that provides the password when the password inquiry information is received and the password is set to be public.
The password control unit
When the password disclosure instruction is not accepted from a predetermined user other than the sender, the password non-disclosure instruction is received from the predetermined user, and the password non-disclosure instruction is received from the predetermined user. , A server characterized in that the password is set to private.

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