JP2009265775A - Mail transmission management server device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mail transmission management server device and a method capable of ensuring the security of mail without placing a burden on a recipient, and reliably deleting or changing erroneously transmitted mail. <P>SOLUTION: In receiving plain text mail created by a transmitter, a cryptography processing part 121 creates cryptographic mail, and stores information for decoding the cryptographic mail in a status management DB 130. A file attaching part 122 attaches an execution file for acquiring the decoding information from the status management DB 130 etc. to the cryptographic mail created by the cryptography processing part 121, and creates outgoing mail. When a recipient who has received the transmitted mail attempts to see the transmitted mail, the execution file is activated. The execution file acquires the decoding information from the status management DB 130 through a management part 123, and decodes the transmitted mail. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for managing transmission / reception of electronic mail at a transmission source.

  When using an e-mail system, there is a problem that the recipient who sent the unrelated mail is not bothered if the wrong address is used, but the content that requires confidentiality is known to others. . There is also a problem in that if an attachment is forgotten or the content is incorrect, it is necessary to send the mail again and ask the other party to delete the previous mail. Therefore, various proposals have been made to prevent erroneous mail transmission that causes these problems.

  Conventionally, in order to prevent leakage of the contents of an electronic mail, an encrypted mail obtained by encrypting the contents of the electronic mail has been used. Encryption includes, for example, a common key encryption method and a public key encryption method, and both require a decryption key to decrypt encrypted mail. Therefore, when a mail is sent to a user who does not have a decryption key, the user cannot decrypt the mail and prevent the contents of the mail from being known.

  Patent Document 1 discloses a system for changing or deleting a transmitted message. In the system described in Patent Document 1, first, a sender mail system creates an action mail for changing or deleting a sent mail designated by a sender, and transmits the action mail to the receiver mail system. Subsequently, when the receiving mail system receives this action mail, the sent mail specified by the sender is changed or deleted based on the action mail.

Patent Document 2 discloses a system for deleting erroneously transmitted mail. The system described in Patent Document 2 sends a deletion mail identifier requesting deletion of an erroneously transmitted mail and a deletion mail assigned a deletion target identifier for identifying the erroneously transmitted mail to the same erroneously transmitted destination. It is a system that deletes outgoing mail.
JP-A-10-55322 Japanese Patent Laid-Open No. 2003-174481

  However, when using encrypted mail, the recipient must obtain the decryption key, and the recipient must manage the decryption key. On the other hand, in the system described in Patent Document 1, dedicated mail receiving software having a function for changing or deleting mail based on action mail is required. Moreover, in the system described in Patent Document 2, a mail to be deleted by the sender must be transmitted to the receiver terminal. Further, in any system, when the receiving mail server is disconnected from the network, the mail cannot be deleted before the recipient reads it.

  Therefore, in view of the above problems, the present invention provides a mail transmission management server device and method for ensuring mail security and steadily deleting and changing an erroneously transmitted mail without imposing a burden on the recipient. With the goal.

  (1) Provided is a mail transmission management server device that receives a mail from a sender terminal, transmits a mail to a receiving system including a destination mail receiving server and a receiver terminal and manages the mail. The mail transmission management server device includes an encryption processing unit, a decryption information storage unit, a file attachment unit, and a communication unit. The encryption processing unit creates an encrypted mail obtained by encrypting the plain text mail created by the mail sender. The decryption information storage unit stores the decryption information for decrypting the encrypted mail to be created while the encryption processing unit creates the encrypted mail. The file attachment unit attaches the executable file to the encrypted mail. Here, the executable file is activated when a recipient tries to view the encrypted mail transmitted from the communication unit to the receiving system, and the receiving system communicates with the mail transmission management server device, The decryption program obtains the decryption information from the decryption information storage unit and decrypts the encrypted mail. The communication unit transmits the encrypted mail with the executable file attached to the receiving system at the file attachment unit.

  According to the configuration of (1), the decryption information can be centrally managed by having the decryption information for decrypting the encrypted mail in the mail transmission management server device on the mail transmission side. Further, by attaching an execution file for automatically decrypting encrypted mail to the encrypted mail, it is not necessary to store and manage the decryption information in the receiving system. As a result, mail security can be ensured. Furthermore, it is possible to use a different encryption for each mail.

  (2) The mail transmission management server device also includes a management information storage unit for storing status information indicating whether or not transmission of the encrypted mail is canceled by the mail sender after the encrypted mail is transmitted to the receiving system. The file decryption program also acquires the status information from the management information storage unit. The executable file includes a deletion program that deletes the encrypted mail transmitted from the communication unit to the receiving system when the status information acquired from the management information storage unit is deleted.

  According to the configuration of (2), the sender can delete the transmitted mail without being read by the receiver. As a result, when an address that is not the destination to be sent is specified and sent, the recipient of the unrecognized content is annoying, and the content that requires confidentiality is known to others. This also eliminates the problem and leads to improved security.

  (3) The management information storage unit stores change information indicating whether the encrypted mail has been changed to another encrypted mail by the sender. When the status information acquired from the management information storage unit is changed, the executable file decryption program starts the executable file deletion program in order to delete the encrypted mail, and is changed by the sender. The decryption program for another encrypted mail is started.

  According to the configuration of (3), when the recipient tries to view the email, if the email is replaced by the sender, the email is automatically deleted by the executable file, and the email to be replaced is decrypted. . As a result, only the mail after replacement can be read by the recipient.

  (4) The management information storage unit stores information on the encrypted mail transmitted to the receiving system. The information of the encrypted mail is the opening situation, the opening order of recipients, and the like.

  According to the configuration of (4), the opening state of the encrypted mail transmitted to the receiving system can be centrally managed by the mail transmission management server device, and the opening state of the mail can be grasped by the sender and the recipient. Is possible.

  According to the present invention, in view of the above-mentioned problems, the present invention is a mail transmission management server apparatus and method for ensuring mail security and steadily deleting and changing an erroneously transmitted mail without imposing a burden on the recipient. I will provide a.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an aspect of a mail transmission server device 100A to which the present invention is applied. As shown in the figure, the mail transmission server device 100A of the present embodiment is connected to the mail reception server device 100B via a network communication line represented by the Internet, an intranet, or the like. Here, the mail transmission server device (mail transmission management server device) 100A and the mail reception server device 100B are separate, but the mail transmission server device 100A has a function as a mail reception server, and the mail reception server device 100B has a mail. It is also possible to provide a function as a transmission server device.

  The mail transmission server device 100A is connected to a plurality of sender terminals 200A-1... 200A-n (hereinafter referred to as sender terminals 200A) via a LAN such as an intranet. Similarly, the mail receiving server device 100B is also connected to a plurality of recipient terminals 200B-1... 200B-n (hereinafter referred to as recipient terminals 200B) via a LAN such as an intranet. Note that the mail transmission server device 100A and the mail reception server device 100B in this configuration are not necessarily one, and may be composed of a plurality of devices.

  FIG. 2 is a diagram illustrating a basic system configuration diagram of the mail transmission server device 100A and the mail reception server device 100B according to an embodiment. 100 A of mail transmission server apparatuses are provided with the communication part 110, the control part 120, and the status management database 130 (henceforth, a database is referred to as DB). The control unit 120 includes an encryption processing unit 121, a file attachment unit 122, and a management unit 123. The mail transmission server device 100A includes an SMTP server that supports SMTP, which is the most popular mail transmission protocol at present.

  The mail receiving server device 100B includes a communication unit 140, a control unit 150, and a mail box 160. The mail receiving server device 100B includes a POP3 server that supports POP3, which is the most popular mail receiving protocol at present. The sender terminal 200A and the receiver terminal 200B include e-mail software, for example, mailers such as Outlook Express and Netscape Messenger.

  The functional units of the mail transmission server device 100A and the mail reception server device 100B will be described below. The communication unit 110 transmits and receives mail with the mail receiving server device 100B and the sender terminal 200A. The encryption processing unit 121 creates an encrypted mail obtained by encrypting plain text mail created by the user of the sender terminal 200A, and stores information for decrypting the encrypted mail in the status management DB 130. The file attachment unit 122 attaches an execution file or the like for obtaining decryption information from the status management DB 130 of the mail transmission server device 100A to the encrypted mail in order to decrypt the encrypted mail to the encrypted mail created by the encryption processing unit 121. And create outgoing mail.

  The management unit 123 manages the status management DB 130, specifically, edits the status management DB 130 and extracts information from the status management DB 130 in response to a request. The status management DB 130 stores the decryption information of the encrypted mail and the opened state of the transmitted mail. The communication unit 140 transmits / receives mail to / from the mail transmission server device 100A and the recipient terminal 200B. In response to a request from the recipient terminal 200B, the control unit 150 returns a mail from the mail box 160 or the like. Mailbox 160 stores mail from mail transmission server device 100A.

  The status management DB 130 and the mailbox 160 are not limited to the DB on the hard disk, but may be an external storage device such as a memory, a magnetic tape, or a flexible disk. The hardware configuration of the server device, the sender terminal 200A, and the receiver terminal 200B will be described later.

  FIG. 3 is a flowchart of mail transmission / reception processing between the mail sender and the mail receiver. In step S30, the user of the sender terminal 200A creates a plain text mail. When creating an e-mail, e-mail software, for example, a mailer such as Outlook Express or Netscape Messenger is used. FIG. 4 shows a schematic diagram of a general mail creation screen. As shown in FIG. 4, the mail creation screen includes a send button 40, a file insertion button 41, a destination field 42, a CC (Carbon Copy) field 43, a BCC (Blind Carbon Copy) field 44, a subject field 45, and a mail text field. 46 and the like. Here, a specific mail creation process of the user will be described.

  The user inputs the mail address of the other party to whom the mail is to be sent in the destination field 42, the subject of the mail in the subject field 45, and the mail text in the mail text field 46. If there is an attached file, the file can be attached to the mail by clicking the file insertion button 41 and specifying the file on the pop-up screen (not shown) that appears. Here, the attached file is a file such as an image or a sound sent along with the body of the e-mail. If it is desired to transfer a mail other than the mail address specified in the destination field 42, the mail address of the other party to which the mail is to be transferred is input to the CC field 43 or the BCC field 44. When all necessary items have been entered, when the send button 40 is clicked, the mail is sent to the mail sending server device 100A by the mailer.

  When the mail transmission server device 100A receives a mail from the sender terminal 200A, in step S31, the encryption processing unit 121 creates an encrypted mail obtained by encrypting the plain text mail. The encryption processing unit 121 also creates decryption information for decrypting the encrypted mail and stores it in the status management DB 130. Here, the object to be encrypted may be a mail text of a plain text mail and an attached file, or may further include a subject name, an address, and the like. In general, the subject of encryption is often the body of an email and an attached file, but it is more secure to encrypt the subject, address, etc. This is because, by encrypting the subject, address, etc., it is possible to prevent the content of the email from being grasped from the subject, leakage of the email address, and the like.

  Examples of the creation of the encrypted mail include a common key encryption method and a public key encryption method. The common key encryption method is an encryption method that uses the same key for data encryption and data decryption. Representative common key encryption includes DES (Data Encryption Standard) and AES (Advanced Encryption Standard).

  The public key encryption method is an encryption method that uses two pairs of keys, a key for encrypting data (public key) and a key for decrypting data (secret key). A typical public key cipher is RSA (Rivest Shamir Adleman). The public key is a key used for data encryption or decryption, and is a publicly disclosed key in the public key cryptosystem. On the other hand, the secret key is a key used for encrypting or decrypting data paired with the public key. The encrypted mail encrypted with the public key can be decrypted only with the private key. Conversely, the data encrypted with the private key can be decrypted only with the public key.

  Subsequently, the file attachment unit 122 attaches the execution file to the encrypted mail created in step S31, and creates a transmission mail to be transmitted to the address specified in the “destination” field 42 of FIG. 4 (step S32). ). The attached execution file includes a decryption execution file for decrypting the encrypted mail created by the encryption processing unit 121 and a deletion execution file for deleting the encrypted mail and the execution file attached to the mail. Consists of Only the decryption execution file may be used. The decryption execution file and the deletion execution file will be described later.

  Subsequently, the transmission mail created in step S32 is transmitted from the mail transmission server apparatus 100A to the mail reception server apparatus 100B. The mail receiving server device 100B is a mail receiving server device 100B having the mail box 160 at the address specified in the destination column 42, the CC column 43, and the BCC column 44 shown in FIG. Note that the mailboxes at the addresses specified in the destination column 42, the CC column 43, and the BCC column 44 may be provided in different mail receiving server devices. The mail received by the mail receiving server device 100B is stored in the corresponding mail box 160 for each address (step S33).

  When the user of the mail recipient terminal 200B activates the mailer and presses a mailer send / receive button (not shown), the mailer makes a request for acquiring the received mail to the mailbox 160 of the mail receiving server apparatus 100B (step S1). S34). When receiving the received mail acquisition request from the mail recipient terminal 200B to the mail box 160, the control unit 150 of the mail receiving server apparatus 100B acquires the mail from the mail box 160. The acquired mail is transmitted to the recipient terminal 200B and stored in a storage unit (not shown) of the recipient terminal 200B.

  Next, the decryption execution file is activated when the user of the mail recipient terminal 200B performs an operation such as opening the encrypted mail stored in the mailer (step S35). The timing at which the decryption execution file is activated can be arbitrarily set by the creator of the decryption execution file. The decryption execution file may be activated by opening the encrypted mail, and the user may execute the execution file consciously. When the decryption execution file is activated, the decryption execution file makes a request for obtaining decryption information from the mail recipient terminal 200B to the mail transmission server device 100A.

  The decryption information acquisition request includes information necessary for acquiring the decryption information from the status management DB 130 storing the decryption information. This information is information for uniquely identifying the mail, for example, information on the sender, the recipient, and the transmission date and time. Further, when an ID is given to the mail when the outgoing mail is created in step S32, the necessary information is only the ID. This is because the mail can be uniquely specified by the ID.

  Upon receiving the decryption information acquisition request, the management unit 123 of the mail transmission server device 100A acquires status, decryption information, and the like from the status management DB 130 using information included in the decryption information acquisition request as a key (step S36). Here, the status management DB 130 will be described. FIG. 5 is a diagram showing the status management DB 130. As shown in FIG. 5, the status management DB 130 has columns of ID, sender, recipient, subject, transmission date / time, status, post-change ID, decryption information, opening status, and reading order in a record.

  In the ID, a symbol uniquely indicating a record is stored. This symbol may be appropriately added when the encryption processing unit 121 registers the decryption information. The sender stores the address and name of the mail sender, and the receiver stores the address and name of the mail receiver. In the receiver column, all recipients specified in the destination column 42, the CC column 43, and the BCC column 44 in FIG. 4 are stored. When storing names and the like, a name list in which addresses and names are registered is required. This is because only the address is set in the mail.

  The subject of the email is stored in the subject. The date and time when the mail is transmitted is stored in the transmission date and time. This date is Japan Standard Time or World Standard Time. The status indicates the state of the mail, and is represented by three states, for example, normal, deleted, and changed. Deletion indicates a state in which the transmission of mail is stopped after the sender transmits the mail. The change indicates a state in which the sender has replaced the mail after sending the mail. Normal indicates a state that is neither deleted nor changed. The decryption information is information for decrypting the encrypted mail created by the encryption processing unit, and stores a password and a decryption key. The post-change ID, mail opening status, and reading order will be described later.

  It should be noted that a record in the status management DB 130 is preferably created for each recipient. This is because the opening status and reading order are managed for each recipient. Further, for improving security, the unsealing status, reading order, and decryption information may be set as separate DBs. As will be described later, the opening status and reading order are used by the sender and the receiver. Therefore, if the same DB is used, the decryption information may be known to the sender and the receiver or may be altered. It is.

  Returning to FIG. 3, when the status is acquired in step S36, the management unit 123 determines the status (step S37), and the subsequent processing is performed according to the status. First, the case where the status is normal will be described. When the status is normal, the management unit 123 transmits the decryption information to the recipient terminal 200B. The decryption execution file that has received the decryption information is decrypted into the encrypted mail plaintext mail using the decryption information, and the plaintext mail is stored (step S38).

  As described above, since the mail is automatically encrypted by the mail transmission server apparatus 100A by using the mail transmission management server apparatus mail transmission server apparatus as the mail transmission server apparatus 100A, the mail is sent without being encrypted. It is possible to improve email security. In addition, since the decryption information is managed by the mail transmission server device 100A, the composite information is not passed to the recipient terminal 200B, and the composite information is not stored in the recipient terminal 200B, thereby ensuring email security. Can do.

  Next, the processing after step S37 when the status is deletion will be described. FIG. 6 is a flowchart of mail deletion processing when the status is deletion. When the status is deletion, the management unit 123 transmits a deletion instruction instead of the decryption information. As described above, the term “deletion” is because it is not necessary to transmit the decryption information because the transmission is stopped after the sender transmits the mail. The deletion instruction is performed using, for example, a flag indicating that the decoding information is deletion such as blank or NULL. As for the method for the sender to change the status of the status management DB 130 from normal to deletion, for example, an interface for the sender to edit the status management DB 130 is prepared, and the sender uses the interface to change the status. There is a way to change.

  In step S60, the decryption execution file that has received the deletion instruction starts the deletion execution file. The deletion execution file deletes the target mail stored in the storage unit of the recipient terminal by the mailer (step S61). The deletion execution file deletes itself after deleting the target mail.

  As described above, when the status is deletion, the sender can delete the mail of the mail receiver terminal by setting the status in the status management DB 130 to “delete”. Further, the encrypted mail can be deleted without being decrypted, that is, without being read by the recipient. For this reason, if an address that is not the destination to be sent is specified and sent, the other party to whom an unrelated content is sent may be annoying, and the content that requires confidentiality will be known to others. Problems will not occur and security will be improved.

  Finally, the processing after step S37 when the status is changed will be described. FIG. 7 is a flowchart of the mail replacement process when the status is changed. When the status is changed, the management unit 123 searches the status management DB 130 using the changed ID acquired in step S37 of FIG. 3 as a key, and acquires the information of the replaced mail (step S70). Here, the post-change ID in the status management DB 130 is an ID indicating the post-replacement mail when the mail sender replaces the mail. The post-change ID may be specified by the sender through an interface for the sender to edit the status management DB 130, or may be automatically specified by the mail transmission server device 100A.

  In addition, in order to change the status, there is a method of using the interface for editing the status management DB 130 as described above, but in addition, the replaced mail is the same recipient and the same as the mail to be replaced. There is a method in which the status management DB 130 is automatically updated when the control unit 120 of the mail transmission server device 100A receives the replaced mail.

  Subsequently, a change instruction is transmitted from the mail transmission server device 100A to the recipient terminal 200B. Here, when the status of the encrypted mail after replacement is “normal”, the change instruction is a flag indicating the change, the subject of the mail after replacement, the transmission date and time, and the decryption information. The decryption execution file that has received the change instruction activates the deletion execution file and deletes the encrypted mail to be replaced (step S71). Also, the decryption execution file specifies the replacement encrypted mail from the subject and the transmission date / time of the replaced encrypted mail, activates the decryption execution file, and passes the decryption information (step S72). The encrypted mail is decrypted in the decrypted execution file of the encrypted mail after the replacement (step S73).

  On the other hand, when the status of the mail after replacement is “deleted”, the change instruction includes a deletion instruction in addition to the flag indicating the change, the subject of the encrypted mail after replacement, and the transmission date and time. Mail after replacement is deleted according to the deletion instruction. Furthermore, when the status of the mail after replacement is “changed”, the management unit 123 acquires the changed ID of the replacement mail again using the changed ID acquired in step S70 as a key.

  As described above, the replaced mail is automatically deleted, and the replaced mail is stored in the recipient terminal 200B to replace the mail. The replaced mail is processed by the user of the mail recipient terminal 200B by opening the mail stored in the mailer or the like after step S34 in FIG. 3, and the user can read the replaced mail. it can. As a result, when the content is changed for the same topic, the recipient is not notified of the incorrect content. In addition, when the content of the same topic is changed many times, it can be prevented that the content of the mail is not correct, and the burden on the recipient can be reduced.

  As described above, in the present invention, since the decryption information is managed by the mail transmission server device 100A, the mail recipient always requests the mail transmission server device 100A to acquire the decryption information before reading the mail. Utilizing this fact, the status management DB 130 can manage the mail opening status. That is, the fact that a request for obtaining decryption information is made to the mail transmission server device 100A means that the user is trying to read the mail, so that the opening status can be determined without a request for obtaining decryption information.

  As shown in FIG. 5, the status management DB 130 has an opening status column. In the opened state, either opened or unopened is stored. As described above, it is unopened until there is a request for obtaining decryption information from the recipient terminal 200B, and it is already opened when there is a request for obtaining decryption information. In FIG. 5, as an example, the unsealing situation is represented using 0 and 1 flags. It is arbitrary how 0 and 1 are assigned to opened and unopened.

  Further, the sender can determine the reading order of the recipients in the destination column of the mail by using the fact that the mail receiver always makes a request for obtaining the decryption information to the mail transmission server device 100A before reading the mail. The status management DB shown in FIG. 5 has a reading order column. The reading order of the recipients in the mail address column is set in reading order, and a number is stored.

  A specific example will be described using the status management DB 130 shown in FIG. An email is sent from the sender “xyz@mmm.jp” to “ppp@mmm.jp”, “efg@yyy.jp”, and “rst@ttt.jp”, and the sender “xyz@mmm.jp”. The reading order is set in the order of “efg@yyy.jp”, “ppp@mmm.jp”, and “rst@ttt.jp”. For example, the management unit 123 may automatically set the reading order in the status management DB 130 as the order of addresses in the mail address field, or prepare an interface for editing the status management DB 130 for the sender. The sender may set the reading order in the status management DB 130.

  In the status management DB 130 shown in FIG. 5, 1 is stored in the reading order of “efg@yyy.jp”, 2 is stored in the reading order of “ppp@mmm.jp”, and 3 is stored in the reading order of “rst@ttt.jp”. When the recipient “ppp@mmm.jp” tries to read the mail and requests the mail transmission server device 100A to obtain the decryption information, the opening status of the recipient “efg@yyy.jp” whose reading order is 1 is When it is unopened, the management unit 123 replies to the receiver terminal of the receiver “ppp@mmm.jp” that it cannot be opened. Therefore, the recipient “ppp@mmm.jp” cannot decrypt the mail and cannot read the mail. At this time, a message such as “cannot be opened yet” may be displayed on the display of the recipient terminal of the recipient “ppp@mmm.jp”.

  When the decryption information is acquired because the recipient “efg@yyy.jp” whose reading order is 1 tries to read the mail, the unsealing status is unsealed. Thereafter, when the receiver “ppp@mmm.jp” tries to read the mail and requests the mail transmission server device 100A to acquire the decryption information, the management unit 123 receives the receiver “ppp@mmm.jp”. Returns the decryption information to “Rst@ttt.jp” in reading order 3 cannot read the mail unless the opening status of both the recipient “efg@yyy.jp” and the recipient “ppp@mmm.jp” is opened.

  In this way, priority can be set for recipients, so that mail can be read in order from the person who wants to convey information. You can also prioritize emails. As a result, when a plurality of mails are sent to a single recipient, the recipients can be read first by setting the reading order for those emails.

  Further, the sender can acquire the opening status of the mail transmitted from the status management DB 130, and the receiver can acquire the mail opening status of the recipient who has received the same mail from the status management DB 130. You can also As a result, it is possible for the sender and the receiver to grasp the opening status of the mail and to manage the mail.

  FIG. 8 is a diagram illustrating a hardware configuration of the information processing device 30 of the mail transmission server device 100A, the mail reception server device 100B, the sender terminal 200A, and the recipient terminal 200B according to the embodiment of the present invention. In the following, an overall configuration of an information processing apparatus typified by a computer will be described. Needless to say, in the case of a dedicated machine or an embedded apparatus, the minimum required configuration can be selected according to the environment.

  The information processing apparatus 30 includes a central processing unit (CPU) 310 (a plurality of CPUs such as a CPU 320 may be added in a multiprocessor configuration), a bus line 200, a communication I / F (I / F: An interface) 330, a main memory 340, a BIOS (Basic Input Output System) 350, a display device 360, an I / O controller 370, an input device 380 such as a keyboard and a mouse, a hard disk 390, an optical disk drive 400, and a semiconductor memory 420. The hard disk 390, the optical disk drive 400, and the semiconductor memory 420 are collectively referred to as a storage device 430.

  The control unit 300 is a part that controls the information processing apparatus 30 in an integrated manner, and appropriately reads and executes various programs stored in the hard disk 390 (described later), thereby cooperating with the above-described hardware. Various functions related to are realized.

  The communication I / F 330 is a network adapter when the information processing apparatus 30 transmits / receives information to / from another information processing apparatus 30 via a communication network. The communication I / F 330 may include a modem, a cable modem, and an Ethernet (registered trademark) adapter.

  The BIOS 350 records a boot program executed by the CPU 310 when the information processing apparatus 30 is started up, a program depending on the hardware of the information processing apparatus 30, and the like.

  The display device 360 includes a display device such as a cathode ray tube display device (CRT) or a liquid crystal display device (LCD).

  A storage device 430 such as a hard disk 390, an optical disk drive 400, and a semiconductor memory 420 can be connected to the I / O controller 370.

  The input device 380 accepts input by the user of the information processing device 30.

  The hard disk 390 stores various programs and various data. The information processing apparatus 30 can also use an external hard disk (not shown) as an external storage device.

  As the optical disk drive 400, for example, a DVD-ROM drive, a CD-ROM drive, a DVD-RAM drive, or a CD-RAM drive can be used. In this case, the optical disk 410 corresponding to each drive is used. A program or data may be read from the optical disk 410 by the optical disk drive 400 and provided to the main memory 340 or the hard disk 390 via the I / O controller 370.

It is a figure which shows the aspect of the mail transmission server apparatus to which this invention is applied. It is a figure which shows the basic system block diagram of the mail transmission server apparatus and mail reception server apparatus in one Embodiment. It is a flowchart of a mail transmission / reception process. A schematic diagram of a general mail creation screen is shown. It is a figure which shows status management DB. It is a flowchart of a mail deletion process when a status is deletion. It is a flowchart of the mail replacement | exchange process in case a status is change. It is a figure which shows the hardware constitutions of the information processing apparatus of the mail transmission server apparatus which concerns on embodiment of this invention, a mail reception server apparatus, a mail transmission client terminal, and a receiver terminal.

Explanation of symbols

100A Mail sending server device 100B Mail receiving server device 110, 140 Communication unit 120, 150 Control unit 121 Encryption processing unit 122 File attachment unit 123 Management unit 130 Status management DB
160 Mailbox

Claims (8)

A mail transmission management server device that receives a mail from a sender terminal, performs mail transmission to a receiving system composed of a destination mail receiving server and a receiver terminal, and manages the mail,
An encryption processing unit for creating an encrypted mail obtained by encrypting a plain text mail created by the sender;
The encryption processing unit creates the encrypted mail and a decryption information storage unit that stores decryption information for decrypting the encrypted mail to be created;
A file attachment unit for attaching an executable file to the encrypted mail;
A communication unit for transmitting the encrypted mail with the executable file attached to the file attachment unit to a receiving system;
With
The executable file is activated when a recipient tries to view the encrypted mail transmitted from the communication unit to the receiving system, and the decryption is performed when the receiving system communicates with the mail transmission management server device. A mail transmission management server device, which is a decryption program for obtaining the decryption information from an information storage unit and decrypting the encrypted mail. Furthermore, after the encrypted mail is transmitted to the receiving system, a management information storage unit that stores status information indicating whether or not the transmission of the encrypted mail has been stopped by the sender,
The decryption program acquires the status information from the management information storage unit,
The execution file includes a deletion program for deleting the encrypted mail transmitted from the communication unit to the receiving system when the status information acquired from the management information storage unit is deleted. Mail transmission management server device. The management information storage unit stores change information as to whether or not the encrypted mail has been changed to another encrypted mail by the sender,
When the status information acquired from the management information storage unit is changed, the decryption program activates the deletion program to delete the encrypted mail, and the other encrypted mail changed by the sender The mail transmission management server device according to claim 2, which starts a decryption program.   4. The mail transmission management server device according to claim 2, wherein the management information storage unit stores information regarding the encrypted mail transmitted to the reception system. 5. A mail transmission management method between a sender terminal, a sender mail server, and a receiving system composed of a recipient mail server and a receiver terminal,
Creating encrypted emails that are encrypted plain text emails created by the sender;
Storing decryption information for decrypting the encrypted mail to be created together with creating the encrypted mail;
Attaching an executable file to the encrypted mail;
Sending the encrypted mail with the executable file attached thereto to a receiving system;
Including
The executable file is activated when a recipient tries to view the encrypted mail sent to the receiving system, and the receiving system communicates with the sender mail server to obtain the decryption information, A mail transmission management method which is a decryption program for decrypting the encrypted mail. Further, after the encrypted mail is transmitted to the receiving system, the method further includes the step of storing status information indicating whether the transmission of the encrypted mail has been stopped by the sender.
The decryption program obtains the status information,
The mail transmission management method according to claim 5, further comprising: a deletion program for deleting the encrypted mail transmitted to the receiving system when the acquired status information is deletion. The status information includes change information as to whether or not the encrypted mail has been changed to another encrypted mail by the sender,
The decryption program activates the deletion program to delete the encrypted mail when the status information is changed, and activates the decryption program of another encrypted mail changed by the sender. Email transmission management method described in.   The mail transmission management method according to any one of claims 6 and 7, wherein the status information stores information related to the encrypted mail transmitted to the receiving system.

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