KR20020067372A - Method for sending and receiving Secure Webmail supporting S/MIME Standard - Google Patents

Abstract

PURPOSE: A method for transmitting/receiving a security web mail for observing an S/MIME(Secure Multipurpose Internet Mail Extension) criterion is provided to receive a certificate of authentication through an authentication server and transmit/receive a security web mail to all mail clients who observe an S/MIME criterion at any space having a web browser. CONSTITUTION: If a transmitter connects to a web mail server through an Internet network(200), the web mail server searches whether the transmitter is a plug-in user, and performs a user authentication, downloads a plug-in, and installs the plug-in at a web browser of the transmitter(232). The transmitter prepares a web mail through the web browser(234) and selects a kind of a mail to be transmitted. If the transmitter wishes to have an electronic signature mail(222), the plug-in requests and receives a private key of the transmitter stored in the web mail server(238), and creates/transmits an electronic signature mail having a certificate of authentication of the transmitter using the private key(240). If the transmitter wishes to have a password mail(258), the plug-in requests a certificate of authentication of a receiver to the web mail server(246). If the certificate of authentication of a receiver is stored in a private key and certificate storing unit, the stored certificate is received(252). If the transmitter wishes to have an electronic signature and password mail, an electronic signature and password mail is created through a combination process of the electronic signature mail case with the password mail case and transmitted.

Description

Method for sending and receiving Secure Webmail supporting S / MIME Standard}

The present invention relates to a secure webmail transmission and reception method, and more particularly, to a secure webmail transmission and reception method that fully supports S / MIME, a standard for secure mail.

Secure webmail refers to e-signed or encrypted mail that can be sent or received securely with a web browser by adding encryption or digital signature functions not provided by the existing webmail service. This means that the e-mail is sent by encrypting the e-mail with the recipient's public key so that only the recipient can verify the contents.The signature mail uses the sender's private key to verify that the sender has not been tampered with. Means mail sent with the electronic signature of the sender. Of course, secure webmail also includes mail encrypted with an electronic signature. Such encrypted mails and signature mails are required at the present time when there is a growing concern about the leakage of personal information due to hacking, etc. due to the frequent transmission and reception of mails through e-mails. Therefore, in order to meet these demands, some authentication service providers currently provide certificate issuance services for secure mail, but there is a problem in that these services cannot be used without a PC with a certificate installed. Also, although Daily Secure (www.dailysecure.co.kr) and Lycos (www.lycos.co.kr) provide secure webmail service that overcomes the above problems, all of them use their own security mail format. Therefore, it is possible to send and receive secure webmail only between service subscribers, and it is still incompatible with the S / MIME standard.

Therefore, the present invention has been made to solve the problems of the conventional secure webmail transmission and reception method as an object of the present invention to be issued by the certificate itself through the interworking with the authentication server anywhere in the web browsing space S It provides a secure webmail sending and receiving method that is fully compliant with the S / MIME standard that can send and receive secure webmail with all mail clients that conform to the / MIME standard.

Another object of the present invention is a secure webmail transmission and reception that is fully compatible with the S / MIME standard that can send and receive secure webmail as well as certificates issued by other public or private certification authority as well as certificates issued by itself To provide a way.

Still another object of the present invention is to provide a secure webmail transmission / reception method that is fully compatible with the S / MIME standard while supporting not only a plug-in but also an SSL method as a security method between the webmail server and the user browse.

1 is an overall configuration diagram of a system for implementing the secure webmail transmission and reception method of the present invention.

2 is an overall configuration diagram of a system for implementing a secure webmail transmission and reception method of the present invention using a plug-in method.

3 is an overall configuration diagram of a system for implementing the secure webmail transmission and reception method of the present invention using the SSL method.

Figure 4 is a flow chart illustrating a secure webmail transmission and reception method of the present invention.

5 is a flowchart illustrating a process of decoding a received secure webmail using the secure webmail transmitting / receiving method of the present invention.

Figure 6a is an example of a web page showing a search for a recipient's certificate and storing the certificate in the form of a file for secure webmail transmission and reception of the present invention.

6B is an example of a web page illustrating the selection of a default certificate to use or importing and exporting a certificate from another certificate authority.

Figure 7a is an example of a web page for transmitting the encrypted mail on a web browser using the secure webmail transmission and reception method of the present invention

7B is an example of a web page where a recipient checks an encrypted mail received in MS Outlook using the secure webmail transmission / reception method of the present invention.

8A illustrates an example of a web page for transmitting an electronic signature and an encrypted mail on a web browser using the secure webmail transmitting / receiving method of the present invention.

8B is an example of a web page where a recipient checks an electronic signature and a password mail in MS Outlook using the secure webmail transmission / reception method of the present invention.

9A is an example of a web page in which an MS Outlook user sends a signature mail using the secure webmail sending / receiving method of the present invention.

Figure 9b is an example of a web page to verify the signature mail sent by the MS Outlook user using the secure webmail transmission and reception method of the present invention.

FIG. 10 is an example of a web page showing a sender confirming a mail through an electronic signature (left side of the drawing) and a forged mail in the middle without an electronic signature. FIG.

The secure webmail system enabling the secure webmail transmission / reception method of the present invention requests the issuance of a certificate to a web server unit connected to the Internet network and a private key manager and an authentication server to generate a user's private key, and is issued by another certificate authority. A webmail server including a certificate management and retrieval unit for retrieving a certificate, a mail server connected to the webmail server to perform secure webmail transmission and reception, and a certificate issued when the webmail server requests to issue a certificate; An authentication server (CA server), a directory server (LDAP server) for storing a copy of a certificate issued by the authentication server and a certificate issued by another certificate authority searched by the certificate management and retrieval unit of the webmail server, and the web. User information storage unit for receiving and storing the user's registration information from the mail server and stores the private key and certificate Includes an information storage server private key and certificate part consisting of storage.

In addition, the webmail server is SSL-connected to the sender or receiver terminal to generate and transmit secure webmail using the private key or certificate stored in the private key and certificate storage unit, or read the received secure webmail. The webmail server further includes a generation and parsing unit, or the webmail server requests transmission of a private key or certificate stored in the private key and certificate storage unit, and generates and sends or receives secure webmail using the transmitted private key or certificate. It is characterized in that the plug-in for reading secured webmail is transmitted to the user terminal and installed in a web browser.

In the secure webmail transmitting and receiving method of the present invention using the secure webmail system as described above, a user accesses a webmail server using a terminal connected to the Internet network, and the webmail server determines whether the user is a registered member. And a second step of allowing a member to log in, and if not a member, induce member registration, generate a private key in the private key management unit of the webmail server, and request a certificate issuance request of the certificate management and search unit of the webmail server. Interlocking and issuing a certificate from the authentication server, storing the private key and certificate in the private key and certificate storage of the information storage server, and storing the user registration information in the user information storage of the information storage server; If the member wants to send or read secure webmail, the private key and certificate storage unit of the information storage server Using a private key or certificate of membership stored and a fourth step transmit or read by creating a secure web mail.

In the third step, the certificate management and retrieval unit of the webmail server retrieves a directory server of another certification authority, obtains a certificate conforming to the S / MIME standard, and stores the certificate in the private key and certificate storage unit of the information storage server. It may further include.

In the third step, the member registration step includes a step of allowing a user to select either a plug-in method or an SSL method when registering a member, and / or checking whether there is a certificate issued by another certification authority when registering a member and registering the certificate. It may further comprise the required step.

The second step may further include a SSL connection between the webmail server and the member terminal, and the fourth step may include a private key of the information storage server and a private key stored in the certificate storage unit of the webmail server. Alternatively, the secure webmail may be generated and transmitted using a certificate, or the received secure webmail may be read.

In the second step, the plug-in is downloaded from the webmail server, installed in a web browser of a member terminal, and a private key or certificate is requested to the webmail server to receive the private key or certificate stored in the private key and certificate storage unit. In addition, the fourth step may be characterized in that the plug-in generates and sends a secure webmail using the transmitted private key or certificate or read the received secure webmail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows the overall configuration of the present invention in which the terminal (100,110) and the webmail server 120 and the like of the sender and receiver is connected to the Internet network.

The sender and receiver terminals 100 and 110 write a mail or read a mail received through the Internet network in order to transmit the mail through the Internet network.

The webmail server 120 registers user information connected to the Internet network, generates and stores a public key and a private key of the user, requests a certificate issuance to its own authentication server 140, and further another private certification authority (for example, To use certificates issued by Verisign, Yahoo, Infospace, etc.) or accredited certification authorities, search the directory servers (LDAP servers) of these certification authorities.

The authentication server 140 issues a certificate in connection with the certificate issuing request from the webmail server 120.

The information storage server 150 is interlocked with the webmail server 120 to store user registration information, a private key and a certificate, and keeps the stored information secret so as not to be disclosed to a third party.

Directory server 160, also known as an LDAP server, stores a copy of a certificate issued by an authentication server and discloses the stored certificate information to a third party.

The mail server 130 is responsible for transmitting and receiving secure webmail.

Referring to Figure 2, a description will be given of a secure webmail system that can implement the secure webmail transmission and reception method of the present invention using a plug-in method. .

In principle, the sender or receiver should use the plug-in method or the SSL method.

The web mail server 120 generates a web server unit 121 connected to the Internet network, and generates a private key of the user and requests for issuance of a certificate to the authentication server (if the plug-in method is selected, the plug-in generates a private key). A key management unit 122 and a certificate management and retrieval unit 123 for retrieving a directory server (LDAP server) of these certificate authorities in order to send encrypted mail to a counterpart using a certificate issued by another certificate authority (FIG. 6a, 6b).

The authentication server (CA server) 140 issues its own certificate when the webmail server 120 requests to issue a certificate.

The information storage server 150 receives a user's registration information from the webmail server 120 and stores the user information storage unit 152, a private key generated by the webmail server 120, and the authentication server ( It consists of a private key and certificate storage unit 151 for storing a certificate issued by itself at 140 and a certificate issued by another certificate authority retrieved by the certificate management and retrieval unit 123.

Hereinafter, a secure webmail transmission process using the plug-in method will be described with reference to FIG. 4.

When the sender accesses the webmail server 120 through the Internet network (200), the webmail server 120 detects whether the sender is a plug-in user, authenticates the user, and downloads a plug-in. It is installed in the sender's web browser (232). The sender then composes the webmail via a web browser (234) and selects the type of mail to send: whether it is an electronic signature mail, an encrypted mail, an electronic signature, and an encrypted mail.

When the sender wants the electronic signature mail (222), the plug-in requests and sends the private key of the sender stored in the webmail server (238), and uses it to generate and send the electronic signature mail with the sender's certificate attached ( 240,222).

In addition, if the sender wants encrypted mail (258), the plug-in requests the recipient's certificate from the webmail server (246), and if the recipient's certificate is stored in the private key and certificate storage unit 151, it is received ( 252) Otherwise, the certificate of the recipient registered with another certificate authority compliant with S / MIME is searched and registered in the private key and certificate storage unit 151 (250), and the certificate is received (252) The cipher mail is generated and transmitted using the public key of the certificate (254, 258).

In addition, when the sender wants the electronic signature and the encrypted mail (256), the plug-in generates a digital signature and the encrypted mail through a combination of the electronic signature mail and the encrypted mail. That is, the digital signature and the encrypted mail are generated and transmitted by combining the encryption process 254 with the electronic signature process 240.

FIG. 3 shows an overall configuration diagram of a secure webmail system capable of implementing the secure webmail transmitting / receiving method of the present invention using the SSL method. Hereinafter, a secure webmail system using the SSL method will be described with reference to FIG.

The webmail server 120 generates a secure webmail using a user private key and an authentication certificate stored in the private key and certificate storage unit 151 connected to the user terminal by SSL plug-in to the webmail server. It further includes an S / MIME message generation and parsing unit 123 that reads the transmitted or received secure webmail.

The mail server 130, the authentication server 140, the information storage server 150 and the directory server (LDAP server, 160) is a mail server 130, the authentication server 140, the information storage server 150 described in the plug-in method And the same as the directory server (LDAP server 160), the description thereof will be omitted, and the following describes the transmission process of the secure webmail using the SSL method with reference to FIG.

When the sender accesses the webmail server 120 through the Internet network, an SSL connection is established between the sender's web browser and the webmail server 120, and the sender composes and sends the mail on the web browser, that is, the electronic signature. Select whether it is mail, password mail, digital signature, or password mail.

When the sender wants to transmit the electronic signature mail, the sender's personal stored in the S / MIME message generation and parsing unit 123 of the webmail server stored in the private key and certificate storage unit 151 of the information storage server 150. Using the key, an electronic signature mail having a sender's certificate attached thereto is generated and transmitted through the mail server 130 (220 and 222).

If the sender wants to send the encrypted mail, the recipient's certificate is stored in the private key and certificate storage unit 151. If the sender wants to send the encrypted mail, the sender's certificate is used. After registration (228) in the key and certificate storage unit 151 generates and transmits an encrypted mail using the certificates (230, 258).

In addition, when the sender wants the electronic signature and the encrypted mail, the S / MIME message generation and parsing unit 123 of the webmail server goes through the process of combining the electronic signature and the encrypted mail. Create and send a password mail. That is, the digital signature and the encrypted mail are generated and transmitted by combining the encryption process 254 with the digital signature process 240.

The receiver can read the secure webmail received using the plug-in method or the SSL method using his private key, which will be described in detail with reference to FIG. 5.

When the recipient receives the electronic signature mail, the receiver uses the sender's certificate attached to the electronic signature mail. If the receiver uses the plug-in method, the receiver downloads the plug-in from the webmail server 120 and installs it in the web browser (308). Request the root certificate of the certificate attached to the webmail server 120 (318) to verify the signature of the electronic signature mail in the plug-in (326), if the recipient is a member using the SSL method, the electronic signature on the webmail server 120 Verify the signature of the mail (316,324).

In addition, when receiving the encrypted mail, the receiver uses a private key corresponding to the certificate used for encryption. If the receiver is a member using a plug-in method, the plug-in is downloaded from the webmail server 120 and installed in a web browser. 308 decodes the encrypted mail from the plug-in by receiving a private key from the webmail server 120 (320), and if the receiver is a member using the SSL method, the webmail server 120 itself. Decode the received encrypted mail (322).

In the case of receiving the digital signature and encrypted mail, the digital signature and encrypted mail are decoded by combining the decoding of the electronic signature mail and the decoding of the encrypted mail.

FIG. 6A shows a method of storing a recipient's certificate in a file form by searching for a directory server (LDAP server) of another certification authority by inputting a recipient's name (386), an e-mail address (384), and a search location (382). 380), and FIG. 6B selects (392) a certificate to be used by default when the sender uses secure webmail. When the sender clicks the 390 button, a certificate (including a private key and a public key) issued by another certificate authority is displayed. Importing (396) the certificate if it exists (396) or exporting the certificate to a file (394), and clicking the 388 button causes the webpage to indicate that it is possible to add a directory server of another certificate authority (398) to retrieve the recipient's certificate. Is one example.

7A is an example of a web page for transmitting an encrypted mail on a web browser using the secure webmail transmitting / receiving method of the present invention. A sender accesses a webmail server 120 and selects an email address of a recipient from an address book. Indicate 400 is transmitted.

7B is an example of a web page where a recipient checks an encrypted mail received in MS Outlook by using the secure webmail transmission / reception method of the present invention, and shows that the mail received through the top 402 of the webpage is an encrypted mail. Doing.

8A illustrates an example of a web page for transmitting an electronic signature and encrypted mail on a web browser by using the secure webmail transmission / reception method of the present invention, wherein mail to be transmitted through the top 404 of the webpage screen is electronically signed and encrypted. It is shown that.

FIG. 8B is an example of a web page in which a recipient checks an electronic signature and an encrypted mail in MS Outlook using the secure webmail transmission / reception method of the present invention, and shows that the received mail is an electronically signed and encrypted mail. 406,408).

9A is an example of a web page in which an MS Outlook user sends a webmail using the secure webmail transmitting / receiving method of the present invention. According to the purpose of use, secure webmail is selected by using either encryption or digital signature, or both. It is shown that it can be made (410).

9B is an example of a web page showing mail decoded using a secure webmail system of the present invention with secure webmail sent by an MS Outlook user.

FIG. 10 is an example of a web page showing a sender who has confirmed the sender through the electronic signature (left side of the drawing) and a forged mail (the right side of the drawing) in the middle without the electronic signature. The confirmed e-mail has a portion 412 at the bottom of the figure indicating that the contents of the message have not been tampered, while the e-mail modulated in the middle has a portion 414 at the bottom of the figure indicating that the contents of the message have been tampered with. )

In the above, the recipient includes a person who is registered with the webmail server 120 and receives a private key and certificate by itself, as well as a person who has been issued a certificate from another private and authorized certificate authority that conforms to the S / MIME standard. As can be seen in Figure 6a, if the recipient is a person authenticated in another private and public certification authority, the certificate management and retrieval unit 122 to the directory server (LDAP server) of the other private and public certification authority Search and store in the private key and certificate storage unit 151 of the information storage server 150 of the present invention, as can be seen in Figure 6b, the sender is a certificate issued by another certificate authority (including private key and public key) If there is a digital ID import / export (390) can be imported and written.

Therefore, the recipient can receive secure webmail from the sender wherever the web browser is located, regardless of the type of certification authority, as long as the certificate authority that issued the certificate complies with the S / MIME standard. Regardless of the type of certification authority, as long as the certification authority that issued the certificate complies with the S / MIME standard, the secure webmail can be sent to the recipient wherever the web browser is installed.

The scope of the present invention is not limited to the above-described embodiment, and may be changed by those skilled in the art to which the present invention pertains and include modifications that implement the technical idea of the present invention.

The present invention has the effect of allowing the certificate server to be issued by itself through the interworking with the authentication server, and send and receive secure webmail with all mail clients complying with the S / MIME standard anywhere in the web browsing space.

In addition, the present invention has the effect that it is possible to send and receive a secure mail using a certificate issued by not only a certificate issued by itself, but also by another public certification authority or private certification authority.

In addition, the present invention has the effect of supporting not only the plug-in method but also the SSL method.

In addition, the present invention has the effect of eliminating the inconvenience of having to apply for a certificate separately because it issues a certificate itself during the user registration process.

Claims (5)

A web mail server including a web server unit, a certificate management and retrieval unit, and a private key management unit, a mail server, an authentication server, a directory server, and an information storage server including a private key and certificate storage unit, and interworking thereof. In the method of sending and receiving secure webmail using a secure webmail system for sending and receiving secure webmail, A first step in which a user accesses a webmail server through a terminal connected to an internet network, and the webmail server determines whether the user is a registered member; If you are a member, take the second step to allow login, If not a member, induce member registration, generate a private key from the private key management unit of the webmail server, issue a certificate from the certificate server in conjunction with a certificate issuance request from the certificate management and search unit of the webmail server, and generate the private key and A third step of storing a certificate in a private key and certificate storage of the information storage server and the user registration information in a user information storage of the information storage server; If the member wants to transmit or read the secure webmail, the fourth step of generating and transmitting or reading the secure webmail using the member's private key or certificate stored in the private key and certificate storage of the information storage server includes S. How to send and receive secure webmail that conforms to the / MIME standard. 2. The method of claim 1, wherein the third step retrieves a directory server of another certification authority from a certificate management and retrieval unit of the webmail server to obtain a certificate conforming to the S / MIME standard, and to obtain the private key and certificate of the information storage server. A method of sending and receiving secure webmail that conforms to the S / MIME standard further comprising the step of storing in the storage. The secure web conforming to the S / MIME standard according to claim 1 or 2, wherein the registration of the third step further comprises a step of allowing a user to select either a plug-in method or an SSL method when registering a member. How to send and receive mail. 3. The method of claim 1 or 2, wherein the second step further comprises the step of connecting the member terminal to the webmail server by SSL, and the fourth step is performed by the webmail server. A method for transmitting / receiving secure webmail that conforms to the S / MIME standard, wherein secure webmail is generated and read or received by using a private key or certificate stored in a private key and certificate storage. The method of claim 1 or 2, wherein the second step is to download the plug-in from the webmail server, install it in a web browser of a member terminal, and request the private key or certificate from the webmail server to store the private key and certificate. And receiving a private key or certificate stored in the data storage unit, and the fourth step includes generating the secure webmail using the transmitted private key or certificate and reading the received secure webmail. A method for sending and receiving secure webmail that conforms to the S / MIME standard.