JP2010081400A - Electronic mail verification system, transmitting terminal, receiving terminal, electronic mail processing terminal, and electronic mail verifying, transmitting and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic mail verification system in which, when transmitting correction mail generated by correcting transmitted electronic mail, correctness of its transmission source is guaranteed and a user of a receiving source can be surely notified about contents of the correction mail. <P>SOLUTION: An electronic mail verification system includes: a key generation section 132 for generating a public key and a private key paired with the public key at a transmitting terminal 1; an electronic mail transmission section 133 for transmitting electronic mail from the transmitting terminal 1 to a receiving terminal 2 and providing the public key to the receiving terminal 2; a correction mail transmission section 134 for transmitting from the transmitting terminal 1 to the receiving terminal 2 both correction mail generated by correcting the electronic mail and an electronic signature generated on the basis of the electronic mail using the private key; and a verification section 231 for verifying whether or not the electronic signature received from the transmitting terminal 1 together with the correction mail is suited to the electronic mail received from the transmitting terminal 1, at the receiving terminal 2 using the public key. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic mail verification system, a transmission terminal, a reception terminal, an electronic mail processing terminal, an electronic mail verification method, an electronic mail transmission method, an electronic mail reception method, an electronic mail processing terminal, and a program.

  In recent years, with the spread of the Internet, e-mail has been widely used, and has become an indispensable tool that is indispensable as one of communication means such as business requests and conference contacts, particularly in business. When a correction text of a mail content is delivered by mail due to an error or a schedule change, the receiving side must definitely recognize the correction content and ignore the content of the previously sent mail. At this time, there are many mistakes due to human error such as not seeing the correction text and forgetting the correction contents. It is also possible for a malicious third party to pretend to be a sender and send a corrected text with incorrect contents. For this reason, various techniques have been proposed so far in order to guarantee the correctness of the correction text of the e-mail and to notify the correction contents without fail.

  As this type of technology, Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-55932) discloses header information included in each of a sent mail and a correction mail stored in a mail box in a mail server. Interpretation, authenticate the person using the public key, determine whether or not the same person has sent both mails, and execute mail correction or deletion only if it is determined that they are the same person The technology is described.

  Further, in Patent Document 2 (Japanese Patent Laid-Open No. 2004-326278), when an e-mail including a plurality of pieces of information and condition information indicating conditions for permitting display of the plurality of pieces of information is received, the e-mail is included. A terminal device that displays one of a plurality of pieces of information according to condition information is described. This terminal device has a function of rejecting the above processing for an electronic mail from a predetermined mail address.

Further, in Patent Document 3 (Japanese Patent Laid-Open No. 2008-35145), a secure mail distribution device is provided between a distribution source user terminal and a mail server, and the distribution control device of the secure mail distribution device includes a distribution source user terminal and Authenticating the user, creating a different mail body for each destination user based on the advertisement mail input from the distribution source user terminal, creating an electronic signature using the private key, A mail delivery method is described in which is attached to an e-mail and sent to a mail server. This secure mail delivery apparatus can decrypt the signature data attached to the e-mail using the public key acquired from the public key management server.
JP 2002-55932 A JP 2004-326278 A JP 2008-35145 A

  However, the above technique has room for improvement in the following points. In other words, it is assumed that the recipient of the e-mail is in a known state (which source should be obtained) which is the public key of the sender of the e-mail. However, if the recipient does not recognize (cannot obtain) the correct public key, the recipient cannot view the corrected content even if the recipient receives an e-mail containing the corrected content. In such a case, there is a problem that the correction contents are not thoroughly applied to all recipients.

  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to guarantee the validity of the transmission source when sending a correction mail obtained by correcting a transmitted electronic mail, An object of the present invention is to provide an e-mail verification system that can notify a user of the contents of a correction mail without fail.

  According to the present invention, a key generation unit that generates a public key and a secret key that is paired with the public key at the transmission terminal, an electronic mail is transmitted from the transmission terminal to the reception terminal, and the public key is transmitted to the reception terminal. An e-mail transmission unit provided to the e-mail, a correction e-mail generated by correcting the e-mail, and an electronic signature generated based on the e-mail using the secret key, from the transmission terminal to the reception terminal A correction mail transmission unit that transmits to the transmission terminal, and whether the electronic signature received together with the correction mail from the transmission terminal matches the electronic mail received from the transmission terminal, the public key at the reception terminal An e-mail verification system comprising: a verification unit that uses and verifies.

  A key generation unit that generates a public key and a secret key that is paired with the public key; an e-mail that transmits the e-mail to the receiving terminal; and the e-mail transmitting unit that provides the public key to the receiving terminal; A correction mail transmitting unit that transmits the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the receiving terminal. A sending terminal is provided.

  Further, the electronic mail is received from the transmission terminal, the electronic mail receiving unit provided with the public key generated at the transmission terminal, and the correction mail generated by correcting the electronic mail at the transmission terminal; A correction mail receiving unit that receives from the transmission terminal together with an electronic signature generated based on the electronic mail using a secret key that is paired with the public key, and the electronic mail that is received together with the correction mail from the transmission terminal There is provided a receiving terminal comprising: a verification unit that verifies, using the public key, whether or not a signature is compatible with the electronic mail received from the transmitting terminal.

  And a key generation step of generating a public key and a secret key that is paired with the public key at the transmission terminal; and sending the e-mail from the transmission terminal to the reception terminal, and providing the public key to the reception terminal An e-mail transmission step, and a correction in which the e-mail generated by correcting the e-mail and the electronic signature generated based on the e-mail using the secret key are transmitted from the transmitting terminal to the receiving terminal. A mail transmission step, and verifying whether the electronic signature received together with the correction mail from the transmission terminal matches the electronic mail received from the transmission terminal using the public key at the reception terminal An e-mail verification method comprising: a verification step.

  A key generation step of generating a public key and a private key that is paired with the public key; and an email transmission step of transmitting the email to the receiving terminal and providing the public key to the receiving terminal; And a correction mail transmission step of transmitting to the receiving terminal both a correction mail generated by correcting the electronic mail and an electronic signature generated based on the electronic mail using the secret key. An email sending method is provided.

  Further, the electronic mail is received from the transmitting terminal, the electronic mail receiving step provided with the public key generated at the transmitting terminal, and the correction mail generated by correcting the electronic mail at the transmitting terminal; A correction mail receiving step of receiving from the transmitting terminal together with an electronic signature generated based on the electronic mail using a secret key paired with the public key, and the electronic mail received together with the correction mail from the transmitting terminal A verification step of verifying, using the public key, whether or not a signature is compatible with the electronic mail received from the transmission terminal.

  An e-mail receiving process for receiving an e-mail from the transmitting terminal and provided with a public key generated at the transmitting terminal; a correction e-mail generated by correcting the e-mail at the transmitting terminal; A correction mail reception process for receiving from the transmission terminal together with an electronic signature generated based on the electronic mail using a secret key paired with a key; and the electronic signature received together with the correction mail from the transmission terminal There is provided a program which causes a computer to execute verification processing for verifying whether or not the electronic mail received from the transmission terminal is compatible with the public key.

  An e-mail receiving process for receiving an e-mail from the transmitting terminal and provided with a public key generated at the transmitting terminal; a correction e-mail generated by correcting the e-mail at the transmitting terminal; A correction mail reception process for receiving from the transmission terminal together with an electronic signature generated based on the electronic mail using a secret key paired with a key; and the electronic signature received together with the correction mail from the transmission terminal A program causing a computer to execute verification processing for verifying whether or not the electronic mail received from the transmission terminal is compatible with the public key.

  A key generation unit that generates a public key and a private key that is paired with the public key; an email that transmits the email to the reception source; and an email transmission unit that provides the public key to the reception source; A correction mail transmission unit that transmits both the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the reception source, and receives the email from the transmission source And an e-mail receiving unit provided with the public key generated at the transmission source, and a secret key paired with the correction mail generated by correcting the e-mail at the transmission source and the public key. A correction mail receiving unit that receives both of the electronic signature generated based on the electronic mail using the transmission source from the transmission source, and before being received together with the correction mail from the transmission source Provided with an e-mail processing terminal, comprising: a verification unit that verifies whether or not an electronic signature matches the e-mail received from the transmission source using the public key at the reception source Is done.

  A key generation process for generating a public key and a private key that is paired with the public key; an e-mail for transmitting to the receiver; and an e-mail transmission process for providing the public key to the receiver; A correction mail transmission process for transmitting a correction mail generated by correcting the electronic mail and an electronic signature generated based on the electronic mail using the secret key to the reception source, and receiving the electronic mail from the transmission source And an e-mail receiving process provided with the public key generated by the transmission source, and a secret key paired with the correction mail generated by correcting the e-mail at the transmission source and the public key. A correction mail reception process for receiving both the electronic signature generated based on the electronic mail using the sender from the sender and the correction mail from the sender together with the correction mail. And verifying whether the received electronic signature matches the electronic mail received from the transmission source using the public key at the reception source. A program is provided.

  According to these inventions, a public key and a secret key are created at the transmission source (transmission terminal), and the public key is provided to the reception source (reception terminal) together with the electronic mail. When sending a correction mail to a sent e-mail, the sender (sending terminal) generates an electronic signature based on the e-mail, sends the correction mail, and publishes it at the receiving source (receiving terminal) Verification using a key encryption method can be performed on a received electronic mail.

  According to the present invention, when sending a correction mail obtained by correcting a transmitted electronic mail, the electronic mail that guarantees the legitimacy of the transmission source and can reliably notify the content of the correction mail to the user of the reception source. An email verification system can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

  FIG. 1 is a configuration diagram of an e-mail verification system according to an embodiment of the present invention. The e-mail verification system includes a transmission terminal 1, a reception terminal 2, and a network 3. The sending terminal 1 can send an e-mail to the receiving terminal 2 via the network 3. The network 3 is the Internet or the like, and although not shown, devices other than the transmission terminal 1 and the reception terminal 2 may be connected to the network 3.

  The transmission terminal 1 includes a display unit 11, an operation input unit 12, an e-mail processing unit 13, a storage unit 14, and a communication unit 15. The display unit 11 can display an e-mail, an operation screen, and the like, and can be specifically configured by a display device or the like. The operation input unit 12 can accept an operation from a transmission user using the transmission terminal 1, and can be specifically configured with a keyboard, a mouse, or the like. The storage unit 14 can store transmitted e-mails and the like. The communication unit 15 can communicate via the network 3. The e-mail processing unit 13 includes an e-mail generation unit 131 that generates an e-mail based on an operation by the transmission user received by the operation input unit 12, and stores the generated e-mail in the storage unit 14. Then, it is possible to execute processing related to transmission of e-mail, such as transmission to the communication unit 15 or display on the display unit 11.

  The receiving terminal 2 includes a display unit 21, an operation input unit 22, an e-mail processing unit 23, a storage unit 24, and a communication unit 25. The display unit 21 can display an e-mail, an operation screen, and the like, and can be specifically configured by a display device or the like. The operation input unit 22 can accept an operation from a receiving user who uses the receiving terminal 2, and can be specifically configured with a keyboard, a mouse, or the like. The storage unit 24 can store received e-mails and the like. The communication unit 25 can communicate via the network 3. The e-mail processing unit 23 receives an e-mail via the communication unit 25, stores the received e-mail in the storage unit 24, causes the display unit 21 to display an e-mail, a list thereof, etc. Processing related to reception of electronic mail can be executed.

  Here, the e-mail verification system according to the present embodiment transmits an e-mail from the transmission terminal 1 to the reception terminal 2 and a key generation unit 132 that generates a public key and a secret key that is paired with the public key in the transmission terminal 1. At the same time, an e-mail transmission unit 133 that provides a public key to the receiving terminal 2 and a correction e-mail generated by correcting the e-mail and an e-signature generated based on the e-mail using the private key The correction mail transmission unit 134 that transmits from the transmission terminal 1 to the reception terminal 2, and whether or not the electronic signature received together with the correction mail from the transmission terminal 1 matches the electronic mail received from the transmission terminal 1. And a verification unit 231 that verifies using the public key.

  In order to configure the above e-mail verification system, the e-mail processing unit 13 of the transmitting terminal 1 sends a e-mail to the receiving terminal, a key generation unit 132 that generates a public key and a secret key that is paired with the public key. An electronic mail transmission unit 133 that transmits a public key to the receiving terminal and transmits an electronic mail that is generated by correcting the electronic mail and an electronic signature that is generated based on the electronic mail using the private key And a correction mail transmission unit 134 that transmits to the reception terminal 2.

  Further, in order to configure the above-described e-mail verification system, the e-mail processing unit 23 of the receiving terminal 2 receives the e-mail from the transmitting terminal 1 and is provided with the public key generated at the transmitting terminal. Correction in which the receiving unit 233 and the correction mail generated by correcting the electronic mail at the transmission terminal and the electronic signature generated based on the electronic mail using the private key paired with the public key are received from the transmission terminal A mail receiving unit 234, and a verification unit 231 for verifying whether the electronic signature received together with the correction mail from the transmitting terminal is compatible with the electronic mail received from the transmitting terminal using the public key You may prepare. Note that the e-mail generated by the e-mail transmitting unit 133 of the transmitting terminal 1 and the corrected e-mail transmitted by the corrected e-mail transmitting unit 134 are generated by the e-mail generating unit 131 based on the operation of the transmitting user input from the operation input unit 12. It may be generated.

  Note that all or part of the configuration of the transmission terminal 1 and the reception terminal 2 according to the present embodiment may be realized by hardware, or realized by a program (or program code) that causes a processor to execute processing. May be. The processor reads and executes the program from a recording medium such as a nonvolatile memory. In the present embodiment, the processor may be included in each of the email processing unit 13 and the email processing unit 23, and the program may be stored in each of the storage unit 14 and the storage unit 24.

  When the function included in the transmission terminal 1 is realized by a program, the program transmits a key generation process for generating a public key and a secret key that is paired with the public key, and sends an e-mail to the reception terminal 2 and makes it public. An e-mail transmission process for providing a key to the receiving terminal 2 and a correction e-mail generated by correcting the e-mail and an e-signature generated based on the e-mail using the private key are transmitted to the receiving terminal 2 together. The correction mail transmission process to be performed can be executed by the transmission terminal 1 (computer).

  When the functions included in the receiving terminal 2 are realized by a program, the program receives an e-mail from the transmitting terminal 1 and is provided with an e-mail receiving process provided with a public key generated by the transmitting terminal 1 And a correction mail received from the transmission terminal 1 together with a correction mail generated by correcting the electronic mail at the transmission terminal 1 and an electronic signature generated based on the electronic mail using a secret key paired with the public key The receiving terminal 2 (computer) includes a receiving process and a verification process for verifying whether the electronic signature received together with the correction mail from the transmitting terminal 1 matches the electronic mail received from the transmitting terminal 1 using a public key. ) Can be executed.

  Thus, since the public key is provided to the receiving terminal 2 together with the electronic mail, the receiving terminal 2 specifies the public key to be used and reliably receives the correction mail even if the receiving user does not know the public key. Can do. In addition, since the electronic signature is generated and verified based on the electronic mail, the receiving user does not make a mistake in associating the received electronic mail with the correction mail. Further, since the verification by the public key cryptosystem is performed, the correctness of the sender of the correction mail is clear, and no malicious correction mail from a third party is accepted. Therefore, it is possible to reliably notify the content of the correction mail to the receiving user.

  Verification by the public key cryptosystem is realized on the premise that only a user having a secret key can create an electronic signature. Since verification is performed using a public key that is paired with a private key, the public key must be guaranteed to be valid. A typical verification method using a public key cryptosystem is the RSA signature method. A case where the RSA signature method is used in this embodiment will be described. The RSA signature method has a case where the entire message is signed and a case where the hash value of the message is signed. In the present embodiment, an e-mail that is a source of the correction mail is used as a message.

  When signing the entire message, the correction mail transmission unit 134 divides the message (e-mail) into a plurality of blocks, generates a plurality of electronic signatures using a secret key for each block, and generates the generated plurality of electronic signatures. It is transmitted to the receiving terminal 2 together with the correction mail. By generating a plurality of electronic signatures, verification accuracy can be further increased. The verification unit 231 decrypts each electronic signature using the acquired public key. The decrypted message (e-mail) is compared with the e-mail stored in the storage unit 24, and the matching e-mail is determined to be an e-mail that matches the electronic signature.

  When signing a hash value of a message, the hash value of the message is calculated by hashing the message (e-mail), an electronic signature is generated using the private key for the hash value, and the generated electronic signature is It is transmitted to the receiving terminal 2 together with the correction mail. In this case, sufficient verification accuracy can be achieved without dividing the message into a plurality of blocks and generating a plurality of electronic signatures. The verification unit 231 decrypts the electronic signature using the acquired public key. The hash value after decryption is compared with the hash value of the email stored in the storage unit 24, and an email having the same hash value is determined as an email matching the electronic signature.

  In the present embodiment, the key generation unit 132 may generate a public key and a secret key together with the e-mail generation unit 131 when generating an e-mail, and send the generated public key and secret key to the e-mail transmission unit 133. The key generation unit 132 may generate a public key and a secret key in advance and store them in the storage unit 14, and may acquire the public key from the storage unit 14 when the email transmission unit 133 transmits an email. . As a method of providing a public key from the transmission terminal 1 (e-mail transmission unit 133) to the reception terminal 2, there is a method of attaching a public key to an e-mail to be transmitted.

  The correction mail includes unique correction mail information, and the e-mail processing unit 23 of the receiving terminal 2 extracts the correction mail from the e-mail received by the receiving terminal 2 based on the correction mail information. An extraction unit 232 may be provided. As a result, the verification unit 231 of the receiving terminal 2 only needs to verify the email extracted by the corrected email extracting unit 232, so that the processing load on the receiving terminal 2 is reduced. The correction mail information unique to the correction mail can be realized, for example, by adding unique information to the header information of the correction mail.

  Further, when transmitting the e-mail, the e-mail transmission unit 133 gives a mail identifier for identifying the e-mail to the e-mail (the e-mail receiving unit 233 adds the mail identifier for identifying the e-mail). The correction email transmission unit 134 transmits the correction email generated by correcting the email and the email identifier assigned to the email (the correction email reception unit 234 receives the email). The verification unit 231 receives the e-mail corresponding to the correction e-mail from the e-mail received from the transmission terminal 1 as the e-mail identifier, and receives the correction e-mail generated by correcting the e-mail and the e-mail identifier assigned to the e-mail. May be identified and verified against the identified email. Thereby, the received electronic mail corresponding to the corrected mail can be identified by the mail identifier, so that the processing load of the receiving terminal 2 (verification unit 231) is further reduced.

  Further, the e-mail transmission unit 133 stores the e-mail identifier and the public key in association with each other in a public server (not shown) connected via the network 3, and when the correction e-mail is extracted by the correction e-mail extraction unit 232. The verification unit 231 may acquire the public key associated with the acquired mail identifier from the public server. As a result, the e-mail receiving unit 233 does not have a public key attached to the received e-mail, so the processing load on the receiving terminal 2 (e-mail receiving unit 233) is reduced.

  Further, the receiving terminal 2 obtains a correction mail together with an electronic mail that matches the electronic signature from the storage section 24 that stores the electronic mail that matches the electronic signature and the correction mail that is attached with the electronic signature in association with each other. And a display unit 21 for displaying the content of the correction mail instead of the content of the electronic mail. As a result, the content of the e-mail displayed on the display unit 21 is automatically replaced with the correction mail, so that the receiving user who uses the receiving terminal 2 does not mistake the content of the e-mail and the content of the correction mail. .

  Since the electronic mail that matches the electronic signature and the correction mail to which the electronic signature is attached are stored in the storage unit 24 in association with each other, the display unit 21 can also operate as follows. That is, the display unit 21 can allow the receiving user using the receiving terminal 2 to select which of the contents of the electronic mail that matches the electronic signature and the contents of the correction mail is displayed. Alternatively, the display unit 21 can also highlight and display the difference between the content of the electronic mail that matches the electronic signature and the content of the corrected mail when displaying the corrected mail.

  FIG. 2 is a flowchart of the e-mail verification method of this embodiment. The e-mail verification method of the present embodiment includes a key generation step (step S101) for generating a public key and a secret key that is paired with the public key at the transmission terminal 1, and transmission of the e-mail from the transmission terminal 1 to the reception terminal 2. In addition, an electronic mail transmission step (step S102) for providing the public key to the receiving terminal 2, and an electronic signature generated based on the electronic mail using the correction mail generated by correcting the electronic mail and the private key And a correction mail transmission step (step S103) for transmitting both of them from the transmission terminal 1 to the reception terminal 2, and whether or not the electronic signature received together with the correction mail from the transmission terminal 1 matches the electronic mail received from the transmission terminal 1. A verification step (step S204) for verifying the above using the public key at the receiving terminal 2.

  Further, in the e-mail verification method of this embodiment, the correction e-mail includes unique correction e-mail information, and the correction e-mail is extracted from the e-mail received by the receiving terminal 2 based on the correction e-mail information. A step (step S203) may be provided.

  Further, the e-mail transmission step (step S102) gives a mail identifier for identifying the e-mail to the e-mail when the e-mail is transmitted, and the correction e-mail transmission step (step S103) corrects the e-mail. Then, the mail identifier assigned to the e-mail is added to the correction mail generated by the above process, and the verification step (step S204) uses the e-mail corresponding to the correction mail from the e-mails received from the transmission terminal 1 as the mail identifier. Based on the identification, the identified email may be verified.

  Further, the e-mail verification method of the present embodiment obtains an e-mail that matches an electronic signature and a correction e-mail attached with the e-signature in association with each other, and displays the contents of the correction e-mail instead of the e-mail contents A display step (step S206) may be provided. However, when the correction mail is extracted in the correction mail extraction step (YES in step S203) and when the electronic signature is matched with the received electronic mail in the verification step (YES in step S204), the correction display step ( In step S206), the content of the correction mail may be displayed instead of the content of the electronic mail. In the correction display step (step S206), when the content of the correction mail is displayed, the difference between the content of the electronic mail that matches the electronic signature and the content of the correction mail may be highlighted.

  Furthermore, the e-mail verification method according to the present embodiment is a user selection step that allows the receiving user using the receiving terminal 2 to select which of the contents of the e-mail that matches the electronic signature and the contents of the correction mail is displayed ( Step S205), and when the receiving user selects to display the content of the correction mail in the user selection step (Step S205) (YES in Step S205), the content of the correction mail in the correction display step (Step S206) May be displayed.

  When the correction mail is not extracted at the correction mail extraction step (NO at step S203), when the electronic signature is not compatible with the received electronic mail at the verification step (NO at step S204), or at the user selection step, the receiving user Selects to display the contents of the electronic mail (NO in step S205), the correction mail received together with the electronic signature is handled in the same manner as a normal electronic mail. Therefore, when displaying the correction mail, it may be displayed as a normal electronic mail (step S207). In this case, when the correction mail is stored in the storage unit 24, it may not be associated with other electronic mail.

  In order to realize the e-mail verification method of the present embodiment, the transmission terminal 1 may include the following e-mail transmission method. That is, the e-mail transmission method of the present embodiment includes a key generation step (step S101) for generating a public key and a secret key that is paired with the public key, and transmits the e-mail to the receiving terminal 2 and receives the public key. An e-mail transmission step (step S102) provided to the terminal 2 and a correction e-mail generated by correcting the e-mail and an electronic signature generated based on the e-mail using the secret key are both sent to the receiving terminal 2. And a correction mail transmission step (step S103) for transmission.

  In order to realize the e-mail verification method of the present embodiment, the receiving terminal 2 may include the following e-mail receiving method. That is, the e-mail receiving method according to the present embodiment receives an e-mail from the transmitting terminal 1 and receives an e-mail receiving step (step S201) provided with the public key generated by the transmitting terminal 1, and the transmitting terminal 1 The correction mail receiving step (step S202) for receiving both the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the private key paired with the public key from the transmission terminal 1 And a verification step (step S204) for verifying whether the electronic signature received together with the correction mail from the transmission terminal 1 is compatible with the electronic mail received from the transmission terminal 1 using the public key (step S204). Also good.

  Further, in the e-mail receiving method of the present embodiment, the correction e-mail includes unique correction e-mail information, and a correction e-mail extraction step of extracting the correction e-mail from the received e-mail based on the correction e-mail information (step S203). May be provided.

  Further, in the e-mail receiving method of the present embodiment, the e-mail receiving step (step S201) receives an e-mail given a mail identifier for identifying the e-mail, and the corrected e-mail receiving step (step S202) The mail identifier assigned to the e-mail is added to the correction mail generated by correcting the e-mail, and the verification step (step S204) is an electronic mail corresponding to the correction mail among the e-mails received from the transmission terminal 1. Mail may be identified based on the mail identifier and verified against the identified email.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  For example, FIG. 1 illustrates that the transmission terminal 1 has only a function related to the transmission of electronic mail and the reception terminal 2 has only a function related to the reception of electronic mail. A function may be provided, and the receiving terminal 2 may be provided with a function related to transmission of an e-mail. That is, the e-mail processing unit 13 and the e-mail processing unit 23 include an e-mail generation unit 131, a key generation unit 132, an e-mail transmission unit 133, a correction mail transmission unit 134, a verification unit 231, a correction mail extraction unit 232, an e-mail Any of the receiving unit 233 and the correction mail receiving unit 234 may be provided.

  For example, a terminal including the e-mail processing unit 13 or the e-mail processing unit 23 transmits a public key and a key generation unit 132 that generates a private key that is paired with the public key, an e-mail to the reception source, and a public key. Correction for transmitting to the receiver both the e-mail transmission unit 133 that provides the e-mail to the receiver, and the correction e-mail generated by correcting the e-mail and the electronic signature generated based on the e-mail using the private key A mail transmitter 134, an email received from the sender, an email receiver 233 provided with the public key generated by the sender, and a correction generated by correcting the email at the sender A correction mail receiving unit 234 that receives from the transmission source both an electronic signature generated based on the electronic mail using a private key paired with the mail and the public key; A verification unit 231 for electronic signature received with correct mail from the original is verified using the public key whether conform to the electronic mail received from the source at the receiving source may be provided.

  When the key generation unit 132, the e-mail transmission unit 133, the correction e-mail transmission unit 134, the verification unit 231, the e-mail reception unit 233, and the correction e-mail reception unit 234 included in the terminal are realized by a program, the program A key generation process that generates a private key that is paired with this, an e-mail to be sent to the receiving source, an e-mail sending process that provides the public key to the receiving source, and an e-mail received from the sending source In addition, an e-mail receiving process provided with a public key generated at the transmission source, a correction e-mail generated by correcting the e-mail, and an e-signature generated based on the e-mail using the private key Both the correction mail transmission process that is sent to the receiver, and the secret that is paired with the correction mail generated by correcting the email at the sender and the public key Corrected mail reception process that receives both the electronic signature generated based on the email using the key from the sender, and the electronic signature received together with the corrected mail from the sender matches the email received from the sender It is possible to cause a terminal (computer) including the e-mail processing unit 13 or the e-mail processing unit 23 to execute a verification process for verifying whether or not the reception source uses a public key. Note that the program may be stored in each of the storage unit 14 and the storage unit 24, and a processor that reads the program may be included in the email processing unit 13 and the email processing unit 23, respectively.

  Further, in FIG. 2, when the electronic signature is not compatible with the electronic mail received in the verification step (NO in step S204), the correction mail received together with the electronic signature in the normal display step is displayed as a normal electronic mail ( Step S207). However, in this case, since the correctness of the sender of the correction mail is not guaranteed, the correction mail received together with the electronic signature may be discarded.

It is a block diagram of the receiving terminal and transmitting terminal which concern on embodiment of this invention. It is a flowchart of the e-mail verification method which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission terminal 11 Display part 12 Operation input part 13 Email processing part 131 Email generation part 132 Key generation part 133 Email transmission part 134 Correction mail transmission part 14 Storage part 15 Communication part 2 Reception terminal 21 Display part 22 Operation input part 23 Email processing unit 231 Verification unit 232 Correction mail extraction unit 233 Email reception unit 234 Correction mail reception unit 24 Storage unit 25 Communication unit 3 Network

Claims (24)

A key generation unit that generates a public key and a secret key that is paired with the public key at the transmission terminal;
An e-mail transmitting unit for transmitting an e-mail from the transmitting terminal to the receiving terminal and providing the public key to the receiving terminal;
A correction mail transmitting unit that transmits the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key from the transmission terminal to the reception terminal;
A verification unit that verifies whether the electronic signature received together with the correction mail from the transmission terminal matches the electronic mail received from the transmission terminal using the public key at the reception terminal;
An e-mail verification system comprising: The e-mail verification system according to claim 1.
The correction email contains unique correction email information,
An e-mail verification system comprising: a correction e-mail extraction unit that extracts the correction e-mail from the e-mail received by the receiving terminal based on the correction e-mail information. The e-mail verification system according to claim 1 or 2,
The e-mail transmission unit, when transmitting the e-mail, gives the e-mail a mail identifier for identifying the e-mail,
The correction mail transmitting unit transmits the correction mail generated by correcting the electronic mail and the mail identifier assigned to the electronic mail,
The verification unit identifies the electronic mail corresponding to the correction mail from the electronic mail received from the transmission terminal based on the mail identifier, and verifies the identified electronic mail. E-mail verification system characterized by The e-mail verification system according to any one of claims 1 to 3,
A storage unit that associates and stores the electronic mail that matches the electronic signature and the correction mail to which the electronic signature is attached;
Obtaining the correction mail together with the electronic mail matched with the electronic signature from the storage unit, and displaying the content of the correction mail instead of the content of the electronic mail;
An e-mail verification system comprising: The e-mail verification system according to claim 4.
The display unit causes the receiving user using the receiving terminal to select whether to display the content of the electronic mail that matches the electronic signature or the content of the correction mail. system. The e-mail verification system according to claim 4 or 5,
The display unit, when displaying the correction mail, highlights and displays the difference between the content of the electronic mail that matches the electronic signature and the content of the correction mail. A key generation unit that generates a public key and a secret key that is paired with the public key;
An email sending unit for sending an email to the receiving terminal, and providing the public key to the receiving terminal;
A correction mail transmitting unit that transmits the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the receiving terminal;
A transmission terminal comprising: An e-mail receiving unit that receives an e-mail from the transmitting terminal and is provided with the public key generated by the transmitting terminal;
Correction for receiving both a correction mail generated by correcting the electronic mail at the transmission terminal and an electronic signature generated based on the electronic mail using a private key paired with the public key from the transmission terminal An email receiver;
A verification unit that verifies, using the public key, whether the electronic signature received together with the correction mail from the transmission terminal is compatible with the electronic mail received from the transmission terminal;
A receiving terminal comprising: The receiving terminal according to claim 8, wherein
The correction email contains unique correction email information,
A receiving terminal, comprising: a correction mail extracting unit that extracts the correction mail from the received electronic mail based on the correction mail information. In the receiving terminal according to claim 8 or 9,
The e-mail receiving unit receives the e-mail given a mail identifier for identifying the e-mail,
The correction mail receiving unit receives the correction mail generated by correcting the electronic mail and the mail identifier assigned to the electronic mail,
The verification unit identifies the electronic mail corresponding to the correction mail from the electronic mail received from the transmission terminal based on the mail identifier, and verifies the identified electronic mail. A receiving terminal characterized by. A key generation step of generating a public key and a secret key that is paired with the public key at the transmission terminal;
Sending an e-mail from the transmitting terminal to the receiving terminal, and providing the public key to the receiving terminal;
A correction mail transmission step of transmitting both the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key from the transmission terminal to the reception terminal;
A verification step of verifying whether or not the electronic signature received together with the correction mail from the transmission terminal matches the electronic mail received from the transmission terminal using the public key at the reception terminal;
An e-mail verification method comprising: The e-mail verification method according to claim 11,
The correction email contains unique correction email information,
An e-mail verification method comprising: a correction e-mail extraction step for extracting the correction e-mail from the e-mail received at the receiving terminal based on the correction e-mail information. The e-mail verification method according to claim 11 or 12,
The e-mail sending step, when sending the e-mail, gives a mail identifier for identifying the e-mail to the e-mail,
The correction mail transmission step transmits the correction mail generated by correcting the electronic mail and the mail identifier assigned to the electronic mail,
The verification step identifies the electronic mail corresponding to the correction mail from the electronic mail received from the transmission terminal based on the mail identifier, and verifies the identified electronic mail. E-mail verification method characterized by. The e-mail verification method according to any one of claims 11 to 13,
A correction display step of acquiring the electronic mail matched with the electronic signature and the correction mail attached with the electronic signature in association with each other, and displaying the content of the correction mail instead of the content of the electronic mail; A featured email verification method. 15. The email verification method according to claim 14,
A user selection step for causing a receiving user using the receiving terminal to select which of the content of the electronic mail and the content of the correction mail that matches the electronic signature is displayed;
An e-mail verification method, wherein when the receiving user selects to display the content of the correction mail in the user selection step, the content of the correction mail is displayed in the correction display step. The e-mail verification method according to claim 14 or 15,
The correction display step emphasizes and displays the difference between the content of the electronic mail matched with the electronic signature and the content of the correction mail when displaying the correction mail. . A key generation step of generating a public key and a private key that is paired with the public key;
Sending an e-mail to a receiving terminal, and providing an e-mail to provide the public key to the receiving terminal;
A correction mail transmission step of transmitting both the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the receiving terminal;
An e-mail transmission method comprising: Receiving an e-mail from the sending terminal, and providing an e-mail receiving step provided with the public key generated at the sending terminal;
Correction for receiving both a correction mail generated by correcting the electronic mail at the transmission terminal and an electronic signature generated based on the electronic mail using a private key paired with the public key from the transmission terminal An email receiving step;
A verification step of verifying whether the electronic signature received together with the correction mail from the transmission terminal is compatible with the electronic mail received from the transmission terminal, using the public key;
An e-mail receiving method comprising: The e-mail receiving method according to claim 18,
The correction email contains unique correction email information,
An e-mail receiving method comprising: a corrected e-mail extracting step of extracting the corrected e-mail from the received e-mail based on the corrected e-mail information. The e-mail receiving method according to claim 18 or 19,
The e-mail receiving step receives the e-mail given a mail identifier for identifying the e-mail,
The correction mail receiving step transmits the correction mail generated by correcting the electronic mail and the mail identifier assigned to the electronic mail,
The verification step identifies the electronic mail corresponding to the correction mail from the electronic mail received from the transmission terminal based on the mail identifier, and verifies the identified electronic mail. An e-mail receiving method characterized by the above. A key generation process for generating a public key and a private key paired therewith,
An email sending process for sending an email to a receiving terminal and providing the public key to the receiving terminal;
A correction mail transmission process for transmitting the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the private key to the receiving terminal;
A program that causes a computer to execute. An e-mail receiving process that receives an e-mail from the transmitting terminal and is provided with the public key generated by the transmitting terminal;
Correction for receiving both a correction mail generated by correcting the electronic mail at the transmission terminal and an electronic signature generated based on the electronic mail using a private key paired with the public key from the transmission terminal Email reception processing,
A verification process for verifying whether the electronic signature received together with the correction mail from the transmission terminal is compatible with the electronic mail received from the transmission terminal, using the public key;
A program that causes a computer to execute. A key generation unit that generates a public key and a secret key that is paired with the public key;
An email sending unit for sending an email to a receiving source and providing the public key to the receiving source;
A correction mail transmitting unit that transmits both the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the receiver;
An e-mail receiving unit that receives an e-mail from a sender and is provided with a public key generated by the sender;
Correction for receiving both a correction mail generated by correcting the electronic mail at the transmission source and an electronic signature generated based on the electronic mail using a secret key paired with the public key from the transmission source An email receiver;
A verification unit that verifies whether the electronic signature received together with the correction mail from the transmission source matches the electronic mail received from the transmission source, using the public key at the reception source;
An e-mail processing terminal comprising: A key generation process for generating a public key and a private key paired therewith,
An email sending process for sending an email to a recipient and providing the public key to the recipient;
A correction mail transmission process for transmitting the correction mail generated by correcting the electronic mail and the electronic signature generated based on the electronic mail using the secret key to the receiver;
An email receiving process that receives an email from the sender and is provided with the public key generated by the sender;
Correction received from the sender together with a correction email generated by correcting the email at the sender and an electronic signature generated based on the email using a secret key paired with the public key Email reception processing,
A verification process for verifying whether the electronic signature received together with the correction mail from the transmission source is compatible with the electronic mail received from the transmission source using the public key;
A program that causes a computer to execute.

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