JP2009253530A - Server device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which enables a user of a server device to verify the validity of a root certificate and enhances the degree of freedom of condition of use. <P>SOLUTION: A root certificate issuing part 12 issues a root certificate on the basis of set contents by a manager of a digital composite machine 1. A printing part 14 prints the root certificate stored in the root certificate issuing part 12. A display operating part 25 displays a root certificate stored in a root certificate storing part 22. The user of the digital composite machine 1 compares a thumbmark displayed in a client terminal 2 with a thumbmark printed by the digital composite machine 1. The user of the digital composite machine 1 can verify the validity of the root certificate, enhancing the degree of freedom of the condition of use. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for effectively verifying the validity of a root certificate indicating the validity of a server certificate in a server apparatus that performs cryptographic communication with a client apparatus.

  The server device and the client device may execute cryptographic communication. That is, the server device issues a public key and a private key, and transmits a server certificate to the client device. The client device receives the server certificate from the server device and acquires the public key. The client device transmits the encrypted data to the server device using the public key. The server device uses the secret key to decrypt the encrypted data received from the client device.

  A device other than the server device may impersonate the server device. Therefore, the user of the server device needs to verify the validity of the server certificate using the root certificate. Further, the user of the server device needs to verify the validity of the root certificate. As a method for verifying the validity of the root certificate by the user of the server device, the following method can be mentioned.

  In the first method, the user of the server device uses a disk attached to the server device when purchasing the server device. The client device acquires the root certificate from the disk. The root certificate stored on the disk is a trusted root certificate. Therefore, the user of the server device can verify the validity of the root certificate.

  In the second method, the user of the server device uses a manual attached to the server device when purchasing the server device. The client device acquires a root certificate from the server device. The user of the server device compares the thumbprint displayed on the client device with the thumbprint printed on the manual. The thumbprint printed on the manual is a reliable thumbprint. Therefore, the user of the server device can verify the validity of the root certificate.

  In the third method disclosed in Patent Document 1, the user of the server device uses a thumbprint printed by the server device. The client device acquires a root certificate from the server device. The user of the server device compares the thumbprint displayed on the client device with the thumbprint printed by the server device. The thumbprint printed by the server device is a reliable thumbprint. Therefore, the user of the server device can verify the validity of the root certificate.

JP 2007-274457 A

  In the first method, the root certificate with which the user of the server device can verify the validity is a root certificate stored on the disk. In the second method, the root certificate with which the user of the server apparatus can verify the validity is a root certificate including a thumbprint printed on a manual. In the third method disclosed in Patent Document 1, the root certificate that can be verified by the user of the server device is a root certificate including a thumbprint printed by the server device.

  By the first to third methods, the user of the server device can verify the validity of the root certificate. However, since the contents of the root certificate are fixed, the degree of freedom of usage is low.

  In view of the above problems, an object of the present invention is to provide a technique that allows a user of a server device to verify the validity of a root certificate and increases the degree of freedom of use.

  In order to solve the above-described problem, the invention according to claim 1 is a server device that executes cryptographic communication with a client device, and transmits a server certificate indicating a public key of the server device to the client device. Certificate issuing unit, a setting content input unit for inputting the setting content of the root certificate indicating the validity of the server certificate for a predetermined setting item, and a root certificate including the setting content input by the setting content input unit A route certificate issuing unit for transmitting a certificate to the client device, and a route certificate printing unit for printing the route certificate stored in the server device.

  According to a second aspect of the present invention, the server apparatus according to the first aspect further includes a root certificate display unit that displays a root certificate stored in the server apparatus.

  According to a third aspect of the present invention, there is provided a server device that executes cryptographic communication with a client device, a server certificate issuing unit that issues a server certificate indicating a public key of the server device, and validity of the server certificate. A setting content input unit that inputs the setting content of the root certificate indicating a predetermined setting item, a root certificate issuing unit that issues a root certificate that includes the setting content input by the setting content input unit, and And a root certificate copy unit that copies the root certificate stored in the server device to the portable memory.

  The root certificate issuing unit provided in the server device issues a root certificate based on the setting contents by the administrator of the server device. The root certificate printing unit included in the server device prints the root certificate stored in the own device. The root certificate display unit provided in the client device displays the root certificate stored in the own device.

  The user of the server device compares the thumbprint displayed on the client device with the thumbprint printed by the server device. The user of the server device can verify the validity of the root certificate, and the degree of freedom of use form is increased.

{Components of the digital multi-function peripheral system}
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing a digital multi-function peripheral system. FIG. 2 is a block diagram showing components of the digital multi-function peripheral system.

  In FIG. 1, the digital multi-function peripheral system includes a digital multi-function peripheral 1, client terminals 2, 2, 2, a LAN (Local Area Network) 3, and the like.

  The digital multi-function peripheral 1 executes fax processing, print processing, scanning processing, and the like. The client terminals 2, 2, and 2 instruct the digital multi-function peripheral 1 through the LAN 3 for fax processing, print processing, scanning processing, and the like.

  Of the client terminals 2, 2, 2, one client terminal 2 is a terminal operated by an administrator of the digital multi-function peripheral 1. Of the client terminals 2, 2, 2, the two client terminals 2, 2 are terminals operated by the user of the digital multi-function peripheral 1.

  The administrator of the digital multifunction peripheral 1 sets a root certificate issued by the digital multifunction peripheral 1 in the client terminal 2 for the administrator. The user of the digital multi-function peripheral 1 obtains a root certificate issued by the digital multi-function peripheral 1 at the user client terminals 2 and 2.

  In FIG. 2, the digital multifunction peripheral 1 includes a web server 11, a root certificate issuing unit 12, a server certificate issuing unit 13, a printing unit 14, a display operation unit 15, a memory interface 16, and the like.

  The web server 11 transmits content for operating the digital multifunction peripheral 1 to the client terminal 2 via the LAN 3.

  The root certificate issuing unit 12 issues a root certificate for the client terminal 2. The server certificate issuing unit 13 issues a server certificate for the client terminal 2.

  The printing unit 14 prints the root certificate issued by the root certificate issuing unit 12. The display operation unit 15 displays the root certificate issued by the root certificate issuing unit 12. The memory interface 16 stores the root certificate issued by the root certificate issuing unit 12 in a portable memory not shown in FIG.

  2, the client terminal 2 includes a web browser 21, a root certificate storage unit 22, a server certificate storage unit 23, a server certificate verification unit 24, a display operation unit 25, a memory interface 26, and the like.

  The web browser 21 receives content for operating the digital multifunction peripheral 1 from the digital multifunction peripheral 1 via the LAN 3.

  The root certificate storage unit 22 acquires a root certificate from the digital multi-function peripheral 1. The server certificate storage unit 23 acquires a server certificate from the digital multi-function peripheral 1. The server certificate verification unit 24 verifies the server certificate stored in the server certificate storage unit 23 using the root certificate stored in the root certificate storage unit 22.

  The display operation unit 25 displays the root certificate stored in the root certificate storage unit 22. The memory interface 26 acquires a root certificate issued by the root certificate issuing unit 12 from a portable memory not shown in FIG.

{Root certificate setting method}
Next, a method in which the administrator of the digital multi-function peripheral 1 sets a root certificate issued by the digital multi-function peripheral 1 in the client terminal 2 for the administrator will be described. FIG. 3 is a diagram showing a root certificate setting screen 4. FIG. 4 is a diagram showing the detailed contents 5 of the root certificate.

  In FIG. 3, the administrator uses the display operation unit 25 to activate the web browser 21. The web browser 21 receives the content constituting the setting screen 4 from the web server 11 via the LAN 3 and causes the display operation unit 25 to display the content.

  The administrator uses the display operation unit 25 to input the following setting contents as issuer information: “Inc. X” in the issuer name input box 41, “JP” in the country number input box 42, In the expiration date input box 43, “July 2, 2010”. The administrator uses the display operation unit 25 to press the root certificate setting button 44.

  The web server 11 receives the setting contents input on the setting screen 4 from the web browser 21 via the LAN 3 and notifies the root certificate issuing unit 12 of the setting contents. The root certificate issuing unit 12 issues a root certificate based on the setting contents input on the setting screen 4.

  In FIG. 4, the root certificate issuing unit 12 issues a root certificate including the following detailed contents 5: “Incorporated X” in the issuer name column 51, “JP” in the country number column 52, and valid The term field 53 is “July 2, 2010”, the thumbprint algorithm field 54 is “sha1”, and the thumbprint field 55 is “2f 17 3f 7d e9”.

{Verification method of root certificate}
Next, a method in which the user of the digital multi-function peripheral 1 verifies the root certificate issued by the digital multi-function peripheral 1 in the user client terminal 2 will be described. FIG. 5 shows a root certificate download screen 6. 6, 7 and 8 are flowcharts showing the flow of processing for verifying the first, second and third root certificates, respectively.

[First root certificate verification method]
A method for verifying the first root certificate will be described with reference to FIG. The user activates the web browser 21 using the display operation unit 25. The web browser 21 receives content constituting the download screen 6 from the web server 11 via the LAN 3 and causes the display operation unit 25 to display the content.

  The user presses the root certificate download button 61 using the display operation unit 25. The web server 11 receives from the web browser 21 via the LAN 3 that the root certificate should be downloaded, and notifies the root certificate issuing unit 12 of the fact. The root certificate issuing unit 12 transmits a previously issued root certificate. The root certificate storage unit 22 stores a root certificate issued in advance.

  The user uses the display operation unit 25 to display the root certificate stored in the root certificate storage unit 22 (step S1). In order to print the root certificate stored in the root certificate issuing unit 12, the user presses the root certificate print button 62 using the display operation unit 25 (step S2). The web server 11 receives from the web browser 21 via the LAN 3 that the root certificate should be printed, and notifies the printing unit 14 of it. The printing unit 14 prints a root certificate issued in advance.

  The user moves from the user client terminal 2 to the digital multi-function peripheral 1. The user acquires the print result of the root certificate stored in the root certificate issuing unit 12 in the digital multi-function peripheral 1 (step S3).

  The user moves from the digital multifunction peripheral 1 to the user client terminal 2. The user collates the display result of the root certificate stored in the root certificate storage unit 22 and the print result of the root certificate stored in the root certificate issuing unit 12 (step S4).

  A case where the display result and the print result match will be described (YES in step S5). The user can determine that any of the detailed contents 5 has not been altered in the communication process by a malicious third party (step S6). By confirming that both the thumbprint algorithm column 54 and the thumbprint column 55 match in the display result and the print result, the user can easily make a determination.

  A case where the display result and the print result do not match will be described (NO in step S5). The user can determine that any of the detailed contents 5 has been tampered with in the communication process by a malicious third party (step S7). By confirming that either the thumbprint algorithm column 54 or the thumbprint column 55 does not match in the display result and the print result, the user can easily make a determination.

  The server certificate issuing unit 13 transmits a previously issued server certificate. The server certificate storage unit 23 stores a previously issued server certificate. The server certificate verification unit 24 verifies the server certificate stored in the server certificate storage unit 23 using the root certificate stored in the root certificate storage unit 22.

  When it is determined that the server certificate is valid, the client terminal 2 acquires a public key from the server certificate. The client terminal 2 transmits the encrypted data to the digital multifunction device 1 using the public key. The digital multi-function peripheral 1 decrypts the encrypted data received from the client terminal 2 using the secret key. When it is determined that the server certificate is not valid, the client terminal 2 does not acquire a public key from the server certificate.

[Second root certificate verification method]
The second root certificate verification method will be described with reference to FIG. In the second root certificate verification method, when the user is moving from the user client terminal 2 to the digital multifunction peripheral 1, the print result of the root certificate stored in the root certificate issuing unit 12 is: Forgery by a malicious third party can be prevented.

  The root certificate download process before verifying the second root certificate is executed in the same manner as the root certificate download process before verifying the first root certificate. Steps S11 to S13 in FIG. 7 are the same as steps S1 to S3 in FIG. 6, respectively.

  The user uses the display operation unit 15 to display the root certificate stored in the root certificate issuing unit 12 (step S14). The user collates the display result of the root certificate stored in the root certificate issuing unit 12 and the print result of the root certificate stored in the root certificate issuing unit 12 (step S15).

  A case where the display result and the print result match will be described (YES in step S16). The user can determine that the print result of the root certificate stored in the root certificate issuing unit 12 has not been forged by a malicious third party (step S17). By confirming that both the thumbprint algorithm column 54 and the thumbprint column 55 match in the display result and the print result, the user can easily make a determination.

  A case where the display result and the print result do not match will be described (NO in step S16). The user can determine that the print result of the root certificate stored in the root certificate issuing unit 12 has been forged by a malicious third party (step S18). By confirming that either the thumbprint algorithm column 54 or the thumbprint column 55 does not match in the display result and the print result, the user can easily make a determination.

  Steps S19 to S22 in FIG. 7 are the same as steps S4 to S7 in FIG. 6, respectively. The encrypted communication after the verification of the second root certificate is executed in the same manner as the encrypted communication after the verification of the first root certificate.

[Third root certificate verification method]
A third root certificate verification method will be described with reference to FIG. Also in the third root certificate verification method, when the user is moving from the user client terminal 2 to the digital multifunction peripheral 1, the print result of the root certificate stored by the root certificate issuing unit 12 is Forgery by a malicious third party can be prevented.

  The root certificate download process before the verification of the third root certificate is executed in the same manner as the root certificate download process before the verification of the first root certificate. Step S31 in FIG. 8 is the same as step S1 in FIG.

  The user moves from the user client terminal 2 to the digital multi-function peripheral 1. The user activates the printing unit 14 by using the display operation unit 15 in order to print the root certificate stored in the root certificate issuing unit 12 (step S32). The printing unit 14 prints a root certificate issued in advance. The user has moved to the digital multi-function peripheral 1. Therefore, the user can easily determine that the print result of the root certificate stored in the root certificate issuing unit 12 has not been forged by a malicious third party.

  Steps S33 to S37 in FIG. 8 are the same as steps S3 to S7 in FIG. 6, respectively. The encrypted communication after the verification of the third root certificate is executed in the same manner as the encrypted communication after the verification of the first root certificate.

{Portable method of root certificate}
Next, a method in which the user of the digital multi-function peripheral 1 uses the portable memory to carry the root certificate issued by the digital multi-function peripheral 1 will be described. FIG. 9 is a flowchart showing a flow of processing for carrying a root certificate.

  A user inserts a portable memory into the memory interface 16 in the digital multi-function peripheral 1. The user uses the display operation unit 15 to copy a previously issued root certificate from the root certificate issuing unit 12 to the portable memory (step S41).

  The user inserts a portable memory into the memory interface 26 in the client terminal 2. The user uses the display operation unit 25 to copy the previously issued root certificate from the portable memory to the root certificate storage unit 22 (step S42).

  Encrypted communication after carrying the root certificate is executed in the same manner as encrypted communication after verifying the first to third root certificates.

  The user can easily copy a pre-issued root certificate from the digital multi-function peripheral 1 to the client terminal 2. The user does not need to determine whether or not a previously issued root certificate has been altered by a malicious third party. The user does not need to determine whether the print result of the root certificate issued in advance has been forged by a malicious third party.

1 is a conceptual diagram illustrating a digital multi-function peripheral system. 1 is a block diagram illustrating a digital multi-function peripheral system. It is a figure which shows the setting screen of a root certificate. It is a figure which shows the detailed content of a root certificate. It is a figure which shows the download screen of a root certificate. It is a flowchart which shows the flow of the process which verifies a root certificate. It is a flowchart which shows the flow of the process which verifies a root certificate. It is a flowchart which shows the flow of the process which verifies a root certificate. It is a flowchart which shows the flow of the process which carries a root certificate.

Explanation of symbols

1 Digital MFP 2 Client Terminal 3 LAN
11 Web server 12 Root certificate issuing unit 13 Server certificate issuing unit 14 Printing unit 15 Display operation unit 16 Memory interface 21 Web browser 22 Root certificate storage unit 23 Server certificate storage unit 24 Server certificate verification unit 25 Display operation unit 26 Memory interface

Claims (3)

A server device that performs cryptographic communication with a client device,
A server certificate issuing unit that transmits a server certificate indicating the public key of the server device to the client device;
A setting content input unit for inputting the setting content of the root certificate indicating the validity of the server certificate for a predetermined setting item;
A root certificate issuing unit for transmitting a root certificate including the setting content input by the setting content input unit to the client device;
A root certificate printing unit for printing a root certificate stored in the server device;
A server device comprising: The server apparatus according to claim 1, further comprising:
A root certificate display unit for displaying a root certificate stored in the server device;
A server device comprising: A server device that performs cryptographic communication with a client device,
A server certificate issuing unit for issuing a server certificate indicating a public key of the server device;
A setting content input unit for inputting the setting content of the root certificate indicating the validity of the server certificate for a predetermined setting item;
A root certificate issuing unit for issuing a root certificate including the setting content input by the setting content input unit;
A root certificate copy unit that copies the root certificate stored in the server device to a portable memory;
A server device comprising:

Images