JPH11345181A - Method and device for transferring enciphered electronic mail and recording medium with the method recorded therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm at a user terminal connected to the Internet that an electronic mail to be deciphered has been properly deciphered at a mail host terminal inside an internal network connected through the Internet. SOLUTION: An ID to be enciphered is described in electronic mail at a terminal 100 (102), and the electronic mail is enciphered (103) and sent to a terminal 120. That electronic mail is deciphered at the terminal 120 (122), the enciphering ID is collated with an enciphering ID registered previously in a storage part 125 (123), and when they are match, that electronic mail is transmitted to the terminal at the destination (124).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transmits an encrypted e-mail from an external network to a terminal in an internal network and determines whether or not the encrypted e-mail has been correctly decrypted in a terminal in the internal network. The present invention relates to a method, an apparatus, and a recording medium on which the method is recorded.

[0002]

2. Description of the Related Art Conventionally, an encrypted e-mail is transmitted from a terminal comprising a computer connected to an external network to a terminal comprising a computer in an internal network, and the encrypted electronic mail is transmitted from a terminal in the internal network. When decrypting and transmitting an e-mail, it has been difficult to determine whether the decryption has been performed correctly.

[0003]

In the prior art, an encrypted e-mail is transmitted from an external network to a terminal in an internal network, and is decrypted at the terminal.
When sending a decrypted e-mail to a designated destination, it has been difficult to determine whether the decryption was performed correctly.

[0004] Therefore, an object of the present invention is to embed an encrypted ID in a predetermined place in the body of an electronic mail,
It is an object of the present invention to provide a technique for determining whether or not the encrypted ID has been correctly decrypted by checking whether or not the encrypted ID has been correctly extracted.

[0005]

According to the present invention, when a terminal connected to an external network encrypts an e-mail, a predetermined encryption ID is described in the e-mail, and The e-mail is decrypted correctly by encrypting the e-mail, transmitting the e-mail to a terminal in the internal network, and decrypting the e-mail at a terminal in the internal network and checking the encrypted ID described in the e-mail. Make it clear that it was done.

However, the external network is, for example, a wide-area computer network such as the Internet, and the internal network is a closed computer network that passes only a predetermined protocol from the external network through a firewall or the like. is there.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 The present invention is described below. A terminal connected to an external network describes an encryption ID in an e-mail, encrypts the same, transmits the encrypted ID to a mail host terminal in the internal network, The host terminal decrypts the received e-mail, checks the ID registered in the mail host terminal in advance against the encrypted ID described in the e-mail, and confirms that the e-mail has been correctly decrypted. An encrypted e-mail transfer apparatus applied to the first embodiment for transmitting the e-mail to a destination described in the e-mail will be described.

FIG. 1 is a diagram showing a schematic configuration of an encrypted electronic mail transfer device. A user (user) creates an e-mail title, body, and destination in an e-mail creation unit 101 of a user terminal 100 connected to the Internet 110, and inputs an encryption ID in an encryption ID input unit 102. Write it in a predetermined position in the e-mail. At this time, the program may automatically describe the encryption ID input in advance by the user. Next, the e-mail is encrypted by the e-mail encryption unit 103, and the e-mail transmission unit 104 transmits the e-mail to the mail host terminal 120 via the Internet 110 and the firewall 130. Mail host terminal 12
At 0, the encrypted electronic mail received from the user by the electronic mail receiving unit 121 is decrypted by the encrypted electronic mail decryption unit 122. Next, in the encrypted ID collating unit 123, the encrypted ID registered in the ID information storage unit 125 in advance and the encrypted I
D, and if correct, the e-mail transmission unit 124
The e-mail is sent to the destination described in the e-mail. The ID information storage unit 125 stores the encrypted I for each user.
D is registered in advance.

In this embodiment, the user's terminal is directly connected to the Internet, but may be a terminal on another internal network different from the internal network separated by a firewall. In addition, a mail transmission / reception protocol (Simple Mail)
When the transfer is performed without using the Transfer Protocol, it goes without saying that the mail host terminal 120 adds a protocol conversion device.

Further, it goes without saying that an authentication process can be added to determine whether the received electronic mail is an electronic mail from a valid user. FIG. 2 shows a processing procedure in the user terminal 100. The user creates an e-mail including a destination, a title, and a body in step 201, and
To enter the encryption ID. In step 203, the e-mail is encrypted, and in step 204, the e-mail is transmitted to the mail host terminal.

FIG. 3 shows a processing procedure in the mail host terminal 120. In the mail host terminal,
In step 301, an encrypted electronic mail from a user is received, and in step 302, the encrypted electronic mail is decrypted. In step 303, a check is made with the pre-registered encryption ID. In step 304, if the data has been correctly decrypted, the e-mail is transmitted to the destination described in the e-mail. Is not sent.

FIG. 4 shows the contents of an electronic mail before encryption. The entire e-mail 400 has a destination 401
, Title 402, body 403, and encryption ID 40
Consists of four. The encryption ID can be arbitrarily described as long as it is in the text.
It is also possible to describe within. Mail host terminal 12
It suffices if the encrypted ID can be extracted with 0. Embodiment 2 Hereinafter, after describing the present invention, after describing an encryption ID in an e-mail at a terminal connected to an external network,
Encrypted, transmitted from the terminal to a mail host terminal via a relay server connected to the external network, and decrypted the encrypted e-mail at the mail host terminal; Is compared with an ID registered in the mail host terminal in advance, and it is determined that the data has been correctly decrypted, and then the electronic mail is transmitted to the destination described in the electronic mail. The mail transfer device will be described.

FIG. 5 is a diagram showing a schematic configuration of an encrypted electronic mail transfer device via a relay server. The user
An encrypted electronic mail is transmitted from the user terminal 501 connected to the Internet 507 to the relay server 502. The configuration diagram of the user terminal 501 at this time is the same as that of the user terminal 100 in FIG. 1, and the processing procedure is the same as the user terminal processing procedure shown in FIG. If the user terminal 501 does not have a program for creating an e-mail and encrypting the created e-mail, the relay server 50
2 can be obtained from the program transmission unit 503 in the program 2. Relay server 502 transmits the received e-mail from e-mail transmission unit 505 to mail host terminal 506. User terminal 501 / relay server 5
02, relay server 502, mail host terminal 506
When a different protocol is used on the network between the relay servers, the relay server 502 performs protocol conversion.
The Internet 508 interposed between the relay server 502 and the mail host terminal 506 is connected to the Internet 5
It may be the same as 07. Further, when a firewall 509 is interposed between the Internet 508 and the mail host terminal 506, a protocol that can pass through the firewall 509 is used.

The schematic configuration of the mail host terminal is the same as that of the mail host terminal 120 in FIG. 1, and the processing procedure is the same as the mail host processing procedure in FIG. Further, needless to say, in the encrypted electronic mail transfer device using the relay server, an authentication process can be added in order to permit an encrypted electronic mail transfer service from a valid user.

[0015]

The effects obtained by the method and apparatus for transmitting an encrypted electronic mail transfer service of the present invention and the recording medium on which the method is recorded are as follows. By writing the encrypted ID registered in the mail host terminal in advance in the e-mail at the user terminal, it is possible to determine whether or not the encrypted e-mail has been correctly decrypted at the mail host terminal. It is possible to make a determination. Heretofore, it has been difficult to automatically determine whether decryption has been performed correctly when an electronic mail is transmitted from a mail host terminal to a destination specified by a user. By applying the present invention, it is possible to automatically determine whether or not decoding has been correctly performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic functional configuration of an encrypted electronic mail transfer device of the present invention.

FIG. 2 is a flowchart showing an example of a processing procedure of a user terminal 100 in FIG. 1;

FIG. 3 is a flowchart showing an example of a processing procedure of a mail host terminal 120 in FIG. 1;

FIG. 4 is a diagram showing an example of the content of an electronic mail before encryption.

FIG. 5 is a diagram showing a schematic functional configuration of an encrypted electronic mail transfer device using a relay server according to the present invention.

Claims (5)

[Claims] An encrypted electronic mail from a user terminal capable of transmitting information to an external network by a user is transferred to an internal network via an external network, and the encrypted electronic mail is sent to a mail host terminal in the internal network. In an encrypted e-mail transfer method for decrypting an e-mail and transmitting the e-mail to a destination designated by the user, before the user encrypts the e-mail, an encryption ID is described in a predetermined position of the e-mail. After encrypting and transferring the encrypted e-mail to the mail host terminal on the internal network, and decrypting the encrypted electronic mail at the mail host terminal, the encrypted ID described before being encrypted.
Confirming that the e-mail has been correctly decrypted, and transmitting the e-mail to a destination designated by the user. 2. A terminal connected to an external network, wherein: an ID registration unit for embedding an encryption ID in an electronic mail; an encryption unit for encrypting the electronic mail in which the encryption ID is embedded; Transmitting means for transmitting the e-mail to the mail host terminal in the internal network via the external network. 3. A mail host terminal installed in an internal network, receiving means for receiving an encrypted electronic mail transferred via an external network, and decrypting the received and encrypted electronic mail. Decrypting means, and an encrypted ID embedded in the decrypted e-mail.
A mail host terminal comprising: an encrypted ID checking means for checking whether the data can be read correctly; and an e-mail transmitting means for transmitting the decrypted e-mail. 4. A recording medium recording a program to be executed by a computer operating as a user terminal connected to an external network, the program comprising: a process of embedding an encryption ID in an electronic mail; Causing the computer to execute a process of encrypting an email with an embedded ID, and a process of transmitting the encrypted email to a mail host in an internal network via the external network. Recording medium. 5. A recording medium storing a program to be executed by a computer operating as a mail host terminal installed in an internal network, for receiving an encrypted electronic mail transferred via an external network. Processing, processing for decrypting the encrypted e-mail, and an encryption ID embedded in the decrypted e-mail
A storage medium that causes the computer to execute a process of checking whether the electronic mail can be read correctly and a process of transmitting the electronic mail to a destination specified therein if the check is passed.