JP2006108898A - Communication interface device, cipher communication method, image-forming device, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the setting of key information in each device when performing the radio communication of data between the devices. <P>SOLUTION: A communication interface device for performing encryption communication comprises: a detector for detecting a communication request of information on file data; a key generator for generating key information for performing the encryption communication; a first communication section for communicating the key information generated at the key generator by other communication interface devices and a first communication system according to detection by the detection section; and a second communication section for making cipher communication to the file data requested by other communication interface devices in a second communication system by the key information generated at the key generation section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication interface device that performs cryptographic communication, a cryptographic communication method, an image forming apparatus including the communication interface device, a program, and a recording medium.

  In recent years, wireless communication technologies such as wireless LAN, BlueTooth, IrDA (infrared communication), and RFID (radio frequency identification) have been developed. Such image forming apparatuses tend to increase.

  Among these, wireless communication using radio waves such as wireless LAN and BlueTooth is the most advanced wireless network introduction because the data transfer speed and transfer distance are relatively better than other wireless communication. It is a communication means.

  However, on the other hand, wireless communication using radio waves has a higher security concern such as wiretapping or falsification of data between communications than other wireless communication means due to the length of the transfer distance. It was.

  As a countermeasure against the risk of eavesdropping and tampering between such wireless communications using radio waves, encryption technology based on an encryption standard called WEP (Wired Equivalent Privacy) is generally used. In WEP, the user first determines a 5-byte or 13-byte ASCII character string and sets it on both the data transmission and reception sides. This ASCII character string is converted to a hexadecimal number, combined with a 24-bit length initialization vector, and the encrypted data is sent using a 64-bit or 128-bit value as the encryption key. Decrypt data.

As the above-described prior art, for example, there are those shown in Patent Documents 1 to 4 below.
JP2003-188885 JP 2002-359623 A JP 2003-152735 A Japanese Patent Laid-Open No. 2002-312155

  However, the above-described encryption technology using WEP has a problem that it is necessary to set an ASCII character string serving as an original key in advance on both sides of data transmission / reception, which requires complicated work for the user.

  In addition, in connection with the above problem, when the device is small, it is difficult to provide an input unit for setting an ASCII character string, and it is not possible to improve wireless communication security by WEP encryption. there were.

In order to solve the above problem, a communication interface apparatus for performing encrypted communication according to the present invention includes:
Detection means for detecting a communication request for information on file data;
Key generation means for generating key information for performing the encrypted communication;
In response to detection by the detection means, first communication means for communicating key information generated by the key generation means in accordance with a first communication method with another communication interface device;
And second communication means for performing encrypted communication of the file data requested by the other communication interface device by the second communication method based on the key information generated by the key generation means.

  According to the present invention, it is possible to save the user from setting key information by transmitting the key information for encryption communication to another device and using it.

  Alternatively, even if the device is small, key information can be used without providing a key information input unit.

  Alternatively, the key information is transmitted to another device by a first communication method such as wireless communication having directivity using infrared rays or wired communication, thereby preventing eavesdropping by the third device and ensuring security. It becomes possible.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a schematic configuration of a wireless communication system configured within a wireless LAN communication possible range, and a system configuration when applied to an MFP apparatus 101 and storage devices (102, 103) as wireless devices An example is shown.

  In FIG. 1, an MFP device 101 is a multifunction peripheral device equipped with functions such as a printer, a scanner, and a FAX. Reference numerals 102 and 103 denote memory devices that can read and write data transmitted and received by wireless communication. The PC 104 is a personal computer.

  Each of the devices 101 to 104 includes a wireless communication interface control unit including a wireless LAN interface and an IrDA interface (a wired communication interface in addition to a wireless communication interface having directivity using infrared rays). It is assumed that they exist within a range in which data can be transmitted and received by LAN communication (wireless LAN communication range: for example, within a radius of 25 m circle).

  FIG. 2 is a block diagram illustrating a configuration of the MFP apparatus 101. The CPU 201 executes various control processes such as a control process and a transmission control process for each unit of the MFP apparatus. The ROM 202 stores various control programs executed by the CPU 201, parameters, and the like. The RAM 203 is a storage area that stores images, parameters, and the like when the CPU 201 performs various processes.

  A printer interface 204 appropriately processes an image on the RAM 203 and transmits the image to the printer 205. A printer 205 performs a printing process on the image data transmitted from the printer interface 204.

  Reference numeral 206 denotes a scanner interface that appropriately processes image data scanned by the scanner 207 and stores the processing result in the RAM 203. Reference numeral 207 denotes a scanner that transmits an image obtained by scanning to the scanner interface 206. .

  A wireless communication interface control unit 208 includes a wireless LAN interface and an IrDA interface.

  The CPU 201, the ROM 202, the RAM 203, the printer interface 204, the scanner interface 206, and the wireless communication interface control unit 208 are connected by a system bus 209, thereby transferring data.

  FIG. 3 is a block diagram showing a configuration of the memory device 102. A RAM 301 is a storage unit that stores data, and a wireless communication interface control unit 208 is included in the memory device 102.

  The memory controller 303 is a control unit that arbitrates access to the RAM 301 between the wireless communication interface control unit 208 and a wired communication interface 304 such as USB.

  The memory device 103 is assumed to have the same configuration as the memory device 102.

  FIG. 4 is a block diagram illustrating a configuration example of the wireless communication interface control unit 208 (FIGS. 2 and 3). An IrDA interface 401 is a part that performs data communication according to IrDA (Infared Data Association), and 402 is a wireless LAN interface that performs data communication by wireless LAN. The encryption key generation unit 403 is a part that generates a random encryption key, and the RAM 404 is a storage area that stores an encryption key for encryption or decryption, and temporarily stores data to be transmitted and received. These are all connected to the wireless communication controller 405.

  The wireless communication controller 405 includes an encryption unit used at the time of data transmission, a decryption unit used at the time of data reception, and a bus switch. By switching the bus switch, the wireless communication controller 405 switches between the encryption unit and the decryption unit. The key generation unit 403 can be controlled. The wireless communication controller 405 can control wireless communication by switching the IrDA interface 401 and the wireless LAN interface 402 according to the security of data to be transmitted.

  The IrDA interface 401 and the wired communication interface 304 having directivity using infrared rays function as a first communication unit for transmitting / receiving an encryption key, and the wireless LAN interface 402 is a second communication for transmitting / receiving encrypted data. Functions as a means.

  FIG. 5A illustrates an overall process in which the MFP apparatus 101 receives file list information stored in the memory device 102, receives a print file selected from the file list information from the memory device 102, and performs printing. It is a flowchart explaining a flow.

  Here, FIG. 5B is a flowchart for explaining a specific processing flow related to transmission / reception of file list information in step S501 of FIG. 5A, and FIG. 5C shows a flow of processing related to transmission / reception of print file in step S504 of FIG. 5A. FIG. 5D is a flowchart for explaining a specific processing flow related to the wireless LAN communication end processing in step S506 in FIG. 5A.

  The encrypted wireless communication between the MFP apparatus 101 and the memory device 102 is performed twice for transmission / reception of the file list information (S501) and transmission / reception of the selected print file (S504).

(Processing of step S501)
First, in step S501 (FIG. 5A), when the user instructs the MFP 101 to display a list of files stored in the memory device 102, the CPU 201 issues a file list acquisition command to the wireless communication interface control unit 208.

  Receiving the file list acquisition command, the wireless communication controller 405 in the wireless communication interface control unit 208 transmits a file list reception request to the memory device 102 via the IrDA interface 401 (S507 in FIG. 5B).

  When the memory device 102 receives the file list reception request transmitted from the wireless communication interface control unit 208 of the MFP 101, the encryption key generation unit 403 performs data transmission over the wireless LAN in accordance with an instruction from the wireless communication controller 405 in the memory device 102. An encryption key is generated (S508 in FIG. 5B), and the encryption key is transmitted to the MFP apparatus 101 via the IrDA interface 401 (S509 in FIG. 5B).

  Upon receiving the encryption key by the wireless communication interface control unit 208 (S510 in FIG. 5B), the MFP apparatus 101 transmits a wireless LAN connection confirmation signal to the memory device 102 through the wireless LAN interface 402 (S511 in FIG. 5B).

  When the memory device 102 receives the wireless LAN connection confirmation signal, the wireless communication interface control unit 208 encrypts the file list information stored in the RAM 301 with the encryption key stored in the RAM 404 (S512 in FIG. 5B). The encrypted data is sequentially transmitted to the MFP apparatus 101 in accordance with the wireless LAN protocol (S513 in FIG. 5B).

  When the MFP apparatus 101 receives the encrypted data transmitted from the memory device 102 via the wireless LAN interface 402, the MFP apparatus 101 decrypts the encrypted data using the encryption key received in step S510 in the wireless communication interface control unit 208 (FIG. 5B S514), the data is stored in the designated address of the RAM 203 (S515 in FIG. 5B).

  When the memory device 102 finishes transmitting all requested data, the memory device 102 transmits a transmission end signal to the MFP apparatus 101 (S516 in FIG. 5B).

  The MFP apparatus 101 receives the transmission end signal from the memory device 102 (S517 in FIG. 5B), but does not transmit the wireless LAN transfer end signal to the memory device 102 and holds the encryption key as it is.

  Also in one memory device 102, since the wireless LAN transfer end signal is not transmitted from the MFP apparatus 101, the encryption key is held.

(Processing of steps S502 and S503)
In step S502, the MFP apparatus 101 selects a print file by a user operation based on the file list information received by the process in step S501.

  If printing of the selected file is canceled in step S503 (S503-Yes), the process proceeds to step S506, and the CPU 201 instructs the wireless communication interface control unit 208 to end wireless LAN communication (S525 in FIG. 5D). . Receiving the instruction to end the wireless LAN communication, the wireless communication interface control unit 208 transmits a wireless LAN communication end signal to the memory device 102 via the wireless LAN interface 402 (S526 in FIG. 5D).

  Upon receiving the wireless LAN communication end signal, the memory device 102 transmits a reception confirmation signal to the MFP apparatus 101 via the wireless LAN interface 402, and then discards the encryption key held in the memory device 102 (see FIG. 5D S528), the wireless LAN communication sequence is terminated.

  In step S527, when the MFP apparatus 101 receives the reception confirmation signal from the memory device 102 via the wireless LAN interface 402, the MFP apparatus 101 discards the encryption key held in the MFP apparatus 101 (S527 in FIG. 5D) and performs wireless LAN communication. End the sequence.

(Steps S504 and S505)
On the other hand, if printing of the print file selected in step S502 is not canceled in step S503 (S503-No), the CPU 201 transmits a transfer instruction signal for the print file selected in step S502 to the wireless LAN interface 208.

  Receiving the print file transfer instruction, the wireless communication interface control unit 208 transmits a print file reception request to the memory device 102 via the wireless LAN interface 402 (S518 in FIG. 5C).

  Upon receiving the print file reception request, the memory device 102 encrypts the designated print file (S519 in FIG. 5C), and transmits the encrypted print file to the MFP apparatus 101 by the wireless LAN interface 402 (S520 in FIG. 5C). ).

  When the MFP apparatus 101 receives the encrypted print file data, the print data is decrypted in the wireless communication interface control unit 208 (S521 in FIG. 5C) and stored in the designated address of the RAM 203 ( S522 of FIG. 5C).

  When the transmission of the print file data is completed, the memory device 102 transmits a print file data transmission end signal to the MFP apparatus 101 (S523 in FIG. 5C).

  When the MFP apparatus 101 receives the print file data transmission end signal (S524 in FIG. 5D), the CPU 201 transmits the print data on the RAM 203 to the printer 205 through the printer interface 204, and performs print processing (S505 in FIG. 5A). .

  The processes in steps S502 to S505 described above are repeated until the printing process is canceled. In addition, a time since wireless LAN communication is started is counted by a clock circuit (not shown) included in the wireless communication controller 405 in the wireless communication interface control unit 208, and communication via the wireless LAN interface 402 is performed for a predetermined time or more. If there is no password, the respective encryption keys are discarded and the wireless LAN communication sequence is terminated.

  According to the present embodiment, it is possible to save the user from setting the encryption key by transmitting the encryption key generated by one device to the other device and using it.

  Alternatively, even if the device is small, an encryption key can be used without providing an encryption key input unit.

  Alternatively, the encryption key generated by one device can be transmitted to another device by directivity wireless communication or wired communication using infrared rays, and used for encryption and decryption, so that the wireless LAN communication range can be obtained. Wireless communication security can be secured by invalidating eavesdropping by a third device.

[Embodiment 2]
In the first embodiment described above, it is assumed that file data stored in the memory device 102 is printed by the MFP apparatus 101. However, image data scanned by the MFP apparatus 101 is stored in the memory device 102 or the memory. The wireless communication technique according to the present invention can also be applied when storing in the device 103.

  FIG. 6 is a flowchart for explaining a flow of processing in which the MFP apparatus 101 transmits image data acquired from the scanner 207 to the memory device 102 and stores it.

  First, in step S 601, when the user instructs the MFP apparatus 101 to store the image data captured by the scanner 207 in the memory device 102, the CPU 201 passes the image data captured by the scanner 207 through the scanner interface control unit 208. The file is stored on the RAM 203 and a file storage command to the memory device 102 is issued to the wireless communication interface control unit 208. The wireless communication controller 405 in the wireless communication interface control unit 208 that has received the file storage command transmits a file storage request to the memory device 102 through the IrDA interface 401 (S601).

  When the memory device 102 receives the file storage request via the IrDA interface 401, the memory device 102 checks the remaining storage capacity of the RAM 301. When the memory device 102 determines that the file can be stored, the memory device 102 generates a data reception preparation completion signal and passes the IrDA interface 401. Is transmitted to the MFP apparatus 101 (S602).

  Upon receiving the data reception preparation completion signal from the memory device 102, the MFP apparatus 101 generates an encryption key for data transmission via the wireless LAN by the encryption key generation unit 403 according to an instruction from the wireless communication controller 405 (S603). The encryption key is transmitted to the memory device 102 through the IrDA interface 401 (S604).

  When the memory device 102 receives the encryption key via the IrDA interface 401, the memory device 102 generates a wireless LAN connection confirmation signal and transmits the wireless LAN connection confirmation signal to the MFP apparatus 101 via the wireless LAN interface 402 (S605).

  Upon receiving the wireless LAN connection confirmation signal from the memory device 102, the MFP apparatus 101 encrypts the image file stored in the RAM 203 within the wireless communication interface control unit 208 using the encryption key generated in step S603 (S606), The encrypted data is sequentially transmitted to the memory device 102 in accordance with the wireless LAN protocol (S607).

  When the memory device 102 receives the encrypted data transmitted from the MFP apparatus 101 (S608), the memory device 102 decrypts it within the wireless communication interface control unit 208 (S609) and stores it in the designated address of the RAM 301 (S610).

  When the MFP apparatus 101 finishes transmitting all the stored image data (S611), it transmits a wireless LAN communication end signal to the memory device 102 via the wireless LAN interface 402 (S612).

  When the memory device 102 receives the wireless LAN communication end signal via the wireless LAN interface 402 (S613), the memory device 102 generates a reception confirmation signal (S614), and transmits the reception confirmation signal to the MFP apparatus 101 via the wireless LAN interface 402. (S615) The stored encryption key is discarded (S617), and the wireless LAN communication sequence is terminated.

  Upon receiving the reception confirmation signal from the memory device 102, the MFP apparatus 101 discards the held encryption key (S616) and ends the wireless LAN communication sequence.

  According to the present embodiment, it is possible to save the user from setting the encryption key by transmitting the encryption key generated by one device to the other device and using it.

  Alternatively, even if the device is small, an encryption key can be used without providing an encryption key input unit.

  Alternatively, the encryption key generated by one device can be transmitted to another device by directivity wireless communication or wired communication using infrared rays, and used for encryption and decryption, so that the wireless LAN communication range can be obtained. Wireless communication security can be secured by invalidating eavesdropping by a third device.

[Modification of Embodiments 1 and 2]
In the first and second embodiments described above, file data stored on the memory device 102 is printed by the MFP apparatus 101, or image data scanned and input by the MFP apparatus 101 is stored in the memory device 102. For example, when the image data scanned by the wireless scanner 702 is transmitted to the wireless printer 701 by wireless LAN communication and the image data is printed as shown in FIG. In addition, since the printer 701 and the scanner 702 include the wireless communication interface control unit according to the embodiment of the present invention, the encryption key generated by one device is transmitted to the other device and used, so that the encryption for the user can be performed. It becomes possible to save the trouble of setting the key.

  Further, as a modification of the above-described first and second embodiments, instead of using the memory device 102, the PC 104 within the wireless LAN communication range with the MFP device 101 is used, and the data on the hard disk of the PC 104 is transferred to the MFP device 101 side. The present invention can also be applied to the case where the received data is printed and the image data scanned and input by the MFP apparatus 101 is stored in the hard disk on the PC 104.

  The present invention can also be applied to the case where data is transmitted and received between the hard disk of the PC 104 and the memory device 102 or 103 using the PC 104 instead of the MFP apparatus 101.

  Also in the modification shown here, it is possible to save the user from setting the encryption key by using the encryption key generated by one device by transmitting it to the other device. Alternatively, even if the device is small, an encryption key can be used without providing an encryption key input unit.

Alternatively, the encryption key generated by one device can be transmitted to another device by directivity wireless communication or wired communication using infrared rays, and used for encryption and decryption, so that the wireless LAN communication range can be obtained. Wireless communication security can be secured by invalidating eavesdropping by a third device.
Also, if a file list display instruction is given without performing an operation for shifting to a setting mode for setting key information for encrypted communication, key information is communicated in a secure environment, and then the list is displayed. Since the encrypted communication of information and print files is performed, there is no need to perform an operation for the setting mode.

[Other embodiments]
As described above, the object of the present invention is to provide a storage medium storing software program codes for realizing the functions of the contactless IC card operation apparatus 101 according to the embodiment to the system or apparatus. This can also be achieved by a computer (or CPU or MPU) reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying such a program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like is used. Can do.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code Includes a case where the function of the above-described embodiment is realized by performing part or all of the actual processing.

  Furthermore, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the function is determined based on the instruction of the program code. This includes the case where the CPU of the expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows schematic structure of the radio | wireless communications system comprised within the wireless LAN communication possible range. 2 is a block diagram illustrating a configuration of the MFP apparatus 101. FIG. 3 is a block diagram showing a configuration of a memory device 102. FIG. 3 is a block diagram illustrating a configuration example of a wireless communication interface control unit 208. FIG. 10 is a flowchart for explaining a flow of processing in which the MFP apparatus 101 receives file list information stored in the memory device 102, receives a print file selected from the file list information from the memory device 102, and performs printing. . It is a flowchart explaining the flow of the specific process regarding transmission / reception of the file list information in step S501 of FIG. 5A. It is a flowchart explaining the flow of the process regarding print file transmission / reception in step S504 of FIG. 5A. It is a flowchart explaining the flow of the specific process regarding the wireless LAN communication end process in step S506 of FIG. 5A. 10 is a flowchart for explaining a flow of processing for transmitting image data captured by the MFP apparatus 101 from the scanner 207 to the memory device 102 and storing the image data. It is a figure explaining the modification of Embodiment 1,2.

Claims (10)

A communication interface device for encrypted communication,
Detection means for detecting a communication request for information on file data;
Key generation means for generating key information for performing the encrypted communication;
In response to detection by the detection means, first communication means for communicating key information generated by the key generation means in accordance with a first communication method with another communication interface device;
A communication interface device comprising: second communication means for cryptographically communicating file data requested by the other communication interface device by a second communication method based on key information generated by the key generation means. The communication interface device according to claim 1, wherein the first communication unit is capable of infrared communication. The communication interface apparatus according to claim 1, wherein the second communication unit is capable of wireless LAN communication. The communication request is a file data list information transmission request, and communication of list information requested from the other communication interface device and communication of file data specified based on the list information are The communication interface device according to claim 1, wherein communication is performed by two communication units. The control means performs encryption or decryption according to the WEP standard, and the encryption key transmitted and received by the first communication means is an ASCII character string having a length of 5 bytes or 13 bytes. The communication interface device described. An image forming apparatus comprising the communication interface device according to claim 1. A communication interface device for encrypted communication,
Receiving means for receiving a transmission request for file list information by the first communication method;
Transmitting means for transmitting key information for performing the encrypted communication to another communication device by the first communication method in response to reception of the transmission request by the receiving means;
A communication interface device comprising: communication means for communicating encrypted communication of the list information and the file designated by the other communication device using the key information by a second communication method. An encryption communication method,
In response to detection of an instruction to display file data by the user, communication of key information for encryption communication is performed between communication devices by the first communication method,
A cryptographic communication method, wherein data for displaying file data is cryptographically communicated by a second communication method based on the communicated key information. A program for causing a computer to execute the encryption communication method according to claim 8. A computer-readable storage medium storing the program according to claim 9.

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