JP2003348079A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of providing a print with high reliability by preventing tampering of digital data to be transmitted and received via a communication means and replay by a third person. <P>SOLUTION: External equipment 2 that transmits file data to the image forming apparatus 1 attaches the electronic signature to the generated file data and transmits the file data to the image forming apparatus 1. The image forming apparatus 1 that receives the file data with the attached electronic signature verifies the file data on the basis of the electronic signature and provides a user with authentication information as a verification result with the file data. The user prints or deletes the file data and the authentication information together after confirming that no tampering or no replay is performed to the file data by browsing the authentication information when printing the file data. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus for printing digital data using an electronic signature technique.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus, a multifunction peripheral based on a copying machine and having functions such as a printer and a facsimile has been widely used. Such an image forming apparatus includes communication means for receiving file data from an external computer, facsimile, or the like, receives file data transmitted via a network, and transfers the file data to printing paper by a printing means. And output it.

[0003] The file data transmitted via the communication means is electronic data, and is therefore easily processed. Therefore, the file data may be intercepted during communication, and the file data may be tampered with by a third party. For this reason, it has been necessary to prove that the file data transmitted and received via the communication means has not been tampered with.

[0004] For example, as a method of preventing falsification of an e-mail transmitted / received via a network such as the Internet, a method of attaching an electronic signature to an e-mail is known. A conventional digital signature system will be described with reference to FIG. As shown in FIG. 6, first, the transmitting side of the e-mail generates an e-mail, calculates digital data of the e-mail by a hash function, and obtains a hash value 1. Subsequently, the obtained hash value 1 is encrypted with the secret key A possessed only by the transmission side, and this is obtained as an electronic signature. Then, the transmitting side attaches the obtained electronic signature to the electronic mail and transmits the electronic mail.

Here, the hash function is a calculation method for generating a pseudo-random number having a fixed length from given digital data, and includes an irreversible one-way function. Therefore, the digital data of the original text is reproduced from the obtained hash value. I can't. Also, it is extremely difficult to create different digital data having the same hash value.

[0006] On the other hand, the side receiving the e-mail acquires a public key A 'corresponding to the encryption key A in advance. And
The electronic signature attached to the received electronic mail is used as the public key A '
And a hash value 1 is obtained. Also, the digital data of the received e-mail is calculated using a hash function,
Get hash value 2. Then, it is checked whether the hash value 1 obtained by decrypting the electronic signature matches the hash value 2 obtained by calculating the e-mail, and when the hash value 1 and the hash value 2 match, It is proved that the received e-mail is not falsified on the way.

Further, since the secret key A and the public key A 'are paired, when an electronic signature not encrypted by the secret key A is decrypted by the public key A', a hash value 1 and a hash value Value 2 does not match. That is, if the two values do not match, it is determined that the electronic mail is not an e-mail transmitted from a sender who can use the secret key A, so that "spoofing" by a third party can be prevented.

[0008]

However, in the conventional image forming apparatus, since the received file data is printed and output as it is, it is not possible to confirm whether the file data has been falsified. Was. Further, in the conventional image forming apparatus, since information for identifying the sender is insufficient, there is a possibility that "spoofing" in which a third party transmits file data by falsifying the sender name is performed. There was a problem. Therefore, there is a problem that the print created in the conventional image forming apparatus has low reliability with respect to security.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of providing a reliable print by preventing falsification of digital data transmitted / received via communication means and impersonation by a third party. .

[0010]

According to an aspect of the present invention, there is provided a communication apparatus for receiving digital data to which an electronic signature is attached via a network, and receiving the digital data via a network. Digital data,
Verification means for verifying whether or not the digital data has been tampered or spoofed based on the electronic signature; and presence or absence of tampering or spoofing of the digital data based on a result verified by the verification means. And a printing unit that prints the digital data and the authentication information on a print medium.

[0011] Therefore, by printing the digital data received by the communication means and the authentication information relating to the digital data on a print medium, it is possible to confirm whether the printed digital data has been tampered with or spoofed. Can be improved in reliability.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, there is provided a list information generating means for generating list information including at least information on the digital data and authentication information corresponding to the digital data. ,
Display control means for displaying the list information generated by the list information generation means on a display means.

Therefore, the user can confirm the presence or absence of tampering or spoofing by using the authentication information corresponding to the received digital data. Therefore, after confirming with the authentication information, the user prints or deletes the digital data. be able to. Accordingly, unnecessary digital data is not printed, and the printing process can be performed efficiently. In addition, by displaying information on digital data and authentication information corresponding to the information on digital data on the display unit, it is possible to easily recognize whether the digital data has been tampered with or impersonated, and efficiently manage the digital data. can do.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, if the received digital data is tampered or spoofed based on a result verified by the verification means, The digital still camera further includes a deletion unit that deletes the digital data.

[0015] Therefore, digital data that may be falsified or spoofed is automatically deleted, so that unnecessary digital data does not waste resources of the image forming apparatus. In addition, the time and effort of the user who manages the digital data can be saved, and the digital data can be managed efficiently.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated example. Here, the correspondence relationship between each component in the image forming apparatus according to the present invention and the image forming apparatus 1 in the present embodiment will be specified. That is, the communication unit of the image forming apparatus according to the present invention corresponds to the communication unit 14 of the image forming apparatus 1 according to the present embodiment, and the verification unit, the authentication information generating unit, the display control unit, and the deleting unit correspond to the present embodiment. Corresponds to the control unit 11. Further, the printing means of the present invention,
The display unit of the present invention corresponds to the display unit 12 of the present embodiment, and corresponds to the print unit 17 of the present embodiment. Further, the information relating to digital data of the present invention is, for example, information including the file name, ID number, sender, transmission date and time of the file data in the present embodiment.

First, the configuration will be described. FIG. 1 is a conceptual diagram illustrating a system configuration of a printing system 100 according to the present embodiment. As shown in FIG.
Is configured by connecting an image forming apparatus 1 and a plurality of external devices 2 via a network N.

The image forming apparatus 1 is a multifunction peripheral having functions such as a copying machine, a printer, and a facsimile. This is a device that performs verification based on an electronic signature, generates authentication information indicating a result of the verification, and prints out the authentication information together with file data.

The external device 2 is composed of, for example, a personal computer, a facsimile, etc., generates file data, generates an electronic signature based on the file data, and transmits the file data and the electronic signature to the image via the network N. This is a device for transmitting to the forming device 1.

The network N is a telephone line network, ISDN
Circuit network, leased line, mobile communication network, communication satellite line, CAT
It includes various communication lines such as a V-line network and base stations connecting them. The network N only needs to be connectable at any time, and need not always be connected. In addition, the network N, from the viewpoint of the reliability of information management,
It is desirable that the network be secured so that only specific users can access it.

Next, the printing system 100 of the present embodiment
The details of the respective components constituting will be described below.

FIG. 2 is a block diagram showing a main configuration of the image forming apparatus 1 shown in FIG. As shown in FIG. 1, the image forming apparatus 1 includes a control unit 11, a display unit 12, an operation unit 13,
It comprises a communication unit 14, an image processing unit 15, a scanner unit 16, a printer unit 17, a storage unit 18 and the like, and each unit is connected by a bus.

The control unit 11 includes a CPU (Centra
l Processing Unit), RAM (Random Access Memor)
y), ROM (Read Only Memory), etc.
The CPU reads various control programs stored in the ROM, and according to the control programs, reads the image forming apparatus 1.
Centrally control the operation of each component that constitutes.

Specifically, the control unit 11 reads out a file data authentication processing program stored in the ROM,
The file data authentication process described later (see FIG. 5) is executed. When executing this file data authentication process,
When receiving the file data and the electronic signature via the network N, the control unit 11 acquires the ID number attached to the header information of the received file data, and
The public key A ′ corresponding to the number is obtained from the storage unit 18, the received electronic signature is decrypted, and the hash value 1 is obtained. In addition, the control unit 11 calculates a hash value 2 by calculating the received file data using a hash function.

Subsequently, the control unit 11 compares the obtained hash value 1 with the obtained hash value 2 and verifies whether there is tampering or spoofing. That is, hash value 1 and hash value 2
If the two values are different from each other, the control unit 11 determines that the received file data may be falsified or spoofed, and generates authentication information of “authentication NG”. When the hash value 1 and the hash value 2 match, the control unit 11 alters the received file data,
Or, assuming that no spoofing has been performed,
K "authentication information is generated.

Further, the control unit 11 stores the file data and the authentication information in the storage unit 18 in association with each other.
Generate list information. Here, the list information is information including a file name of file data, an ID number, a sender, a transmission date and time, authentication information, and the like. Subsequently, the control unit 11
Performs the authentication of the password corresponding to the input ID number when the ID number and the password are input via the operation unit 13, and corresponds to the input ID number when the password is a legitimate one. The list information of the file data to be displayed is displayed on the display unit 12 as a list.

When an arbitrary file name is designated from the displayed list information via the operation unit 13, the control unit 11 displays the authentication information corresponding to the designated file name on the display unit 12. To be displayed. Subsequently, the control unit 11
When a print instruction is input by the user via the operation unit 13, the specified file data and authentication information are acquired from the storage unit 18, output to the image processing unit 15, and converted into printable print data. Then, the printer unit 17 prints the print data. When a deletion instruction is input via the operation unit 13, the control unit 11 deletes the specified file data and authentication information from the storage unit 18.

The display unit 12 is a CRT (Cathode Ray Tub).
e), a monitor including an LCD (Liquid Crystal Display) or the like, and according to an instruction input from the control unit 11, display information input from the operation unit 13,
Display information including list information and the like generated by the control unit 11 is displayed on a monitor.

The operation unit 13 includes a touch panel provided so as to cover the display unit 12 constituted by a CRT, an LCD, or the like. The coordinates are detected, and the detected coordinates are output to the control unit 11 as a position signal. The operation unit 13 may be configured to include a keyboard having cursor keys, numeric input keys, and various function keys, and a pointing device such as a mouse.

The communication unit 14 has a LAN (Local Area Network).
rk), an interface connectable to a transmission medium connected to a network N such as a WAN (Wide Area Network) or the Internet. The interface can be connected to an external device 2 such as a personal computer or a facsimile connected via the network. Controls communication.

The image processing unit 15 performs predetermined processing on image data, file data, and the like input from the communication unit 14, the scanner unit 16, the storage unit 18, and the like, and converts the data into print data that can be printed by the printer unit 17. The print data is stored in an image memory (not shown), and the control unit 11
Is output to the printer unit 17 in accordance with the control of.

The scanner unit 16 includes a light source (not shown), a lens, a CCD (Charge Coupled Device), and the like. The scanner unit 16 forms an image of reflected light of the light scanned from the light source onto the document under the control of the control unit 11. The original image is read by photoelectric conversion, and the read image data is output to the image processing unit 15.

The printer unit 17 includes a paper feeding unit (not shown) on which continuous paper or cut paper is mounted as a printing paper, and a paper discharging unit (not shown). The print data input from the processing unit 15 is transferred to the print paper by an electrophotographic method using infrared laser light or light emitted from an LED (Light-Emitting Diode), and the print data is output.

The storage unit 18 is a recording medium (not shown) in which programs, data, and the like are stored in advance.
D: Hard Disk Drive), and the recording medium is a magnetic or optical recording medium or a semiconductor memory. The recording medium is fixedly provided in the storage unit 18 or is removably mounted. The recording medium stores a system program, various processing programs corresponding to the system, data processed by the various processing programs, and the like. Remember. Specifically, the storage unit 18 stores a public key for decrypting the electronic signature received from the external device 2 in advance in association with the ID number. Also, it stores file data received via the network N, authentication information corresponding to the file data, and the like.

Next, as shown in FIG. 3, for example, the external device 2 includes a control unit 21, a display unit 22, an operation unit 23, and a communication unit 2.
4, a personal computer having a storage unit 25 and the like, or a facsimile having a scanner unit (not shown). Note that each component has substantially the same configuration as that of the image forming apparatus 1 described above, and a detailed description thereof will be omitted. Hereinafter, the characteristic configuration and function of the external device 2 in the present embodiment will be described.

Specifically, the control unit 21 of the external device 2
The file data transmission processing program stored in the OM is read, and the file data transmission processing described later (FIG. 4)
Execute When executing this file data transmission process, the control unit 21 causes the operation unit 23 to input an ID number and a password. When file data to be transmitted is generated, the input ID number and password are attached to the header information of the file data.

The control unit 21 calculates the generated file data by using a hash function to obtain a hash value 1. Next, the control unit 11 acquires the secret key A from the storage unit 25, encrypts the hash value 1 with the secret key A, and acquires an electronic signature. Then, the control unit 21 adds, to the file data in which the ID number and the password are attached to the header information,
An electronic signature is attached and transmitted to the image forming apparatus 1.

It is assumed that the storage unit 25 of the external device 2 stores in advance a secret key A for encrypting the hash value 1 calculated from the generated file data to obtain an electronic signature. The secret key A stored in the storage unit 25 is preferably managed by an ID number and a password so that only a specific user can use the secret key A in order to maintain security.

Next, the operation of this embodiment will be described. It is to be noted that, as a premise of the description of the operation, a program for realizing each process described in the following flowchart includes a control unit 11 of the image forming apparatus 1 and a control unit
Are stored in the form of readable program code in the ROM, and the control unit 11 and the control unit 21 sequentially execute operations according to the program code.

FIG. 4 is a flowchart showing a file data transmission process executed by the control unit 21 of the external device 2. As shown in FIG. 4, the control unit 21 includes an operation unit 23
When an ID number and a password are input via the PC (step S1) and file data is generated (step S1).
2) Attach the input ID number and password to the file data as header information.

Further, the control unit 21 calculates the generated file data by a hash function to obtain a hash value 1 (step S3). Subsequently, the control unit 21 acquires the secret key A from the storage unit 25, encrypts the hash value 1 acquired with the secret key A, and acquires an electronic signature (step S4). Then, the control unit 21 attaches the obtained digital signature to the file data and transmits the file data to the image forming apparatus 1 (step S5).

Subsequently, referring to FIG. 5, image forming apparatus 1
The file data authentication process executed by the control unit 11 will be described. As shown in FIG. 5, the control unit 11
When the file data and the electronic signature are obtained from the external device 2 via the network N (step S11), the public key A ′ corresponding to the ID number attached to the header information of the file data is obtained from the storage unit 18, The received electronic signature is decrypted with the public key A ', and a hash value 1 is obtained (step S12). Further, the control unit 11 calculates the received file data by a hash function to obtain a hash value 2 (step S13).

Subsequently, the control unit 11 compares the obtained hash value 1 with the obtained hash value 2 to verify whether the file data has been tampered with or impersonated (step S14). Here, when the hash value 1 and the hash value 2 match, the control unit 11 generates authentication information indicating that the authentication is successful, and when the hash value 1 does not match with the hash value 2, Authentication information indicating that the authentication has failed is generated (step S15). Subsequently, the control unit 11 stores the generated authentication information and file data in association with each other in the storage unit 18 and generates list information (step S1).
6).

Further, the control section 11 determines whether or not an ID number and a password have been input by the user via the operation section 13 (step S17), and when the ID number and the password have been input (step S17; YES), it is determined whether the password has been authenticated (step S1)
8). Here, when the password is authenticated (step S18; YES), the control unit 11 causes the display unit 12 to list the list information corresponding to the input ID number (step S19).

Then, the authentication information of the designated file name in the list information displayed on the list is displayed on the display unit 12 (step S20), and it is determined whether or not a print instruction is input (step S21). Here, when a print instruction is input (step S21; YES), the control unit 11
Acquires the file data and the authentication information of the designated file name from the storage unit 18, outputs the acquired file data to the image processing unit 15 and converts the data into printable print data.
And print the file data and the authentication information on the printing paper (step S22). And the control unit 11
Ends the file data authentication process.

If a print instruction has not been input (step S21; NO), the control unit 11 determines whether a delete instruction has been input (step S23), and if a delete instruction has been input (step S23). ; YES), storage unit 1
8, the corresponding file data and authentication information are deleted (step S24), and the file data authentication process ends.

As described above, according to the present embodiment, the external device 2 that transmits file data to the image forming apparatus 1
Attaches an electronic signature to the generated file data and transmits it to the image forming apparatus 1. On the other hand, the image forming apparatus 1 that has received the file data to which the digital signature has been attached verifies the file data based on the digital signature, and provides the user with the authentication information as the verification result together with the file data. When printing the file data, the user browses the authentication information to check whether the file data has been tampered with or spoofed, and then prints or deletes the file data and the authentication information together.

Accordingly, since the authentication information is printed together with the file data on the printing paper, it is possible to attach a proof that tampering or spoofing has not been performed to the print, thereby improving the reliability of the printed print.
Also, since the secret key can be managed by the ID number and the password, and the file data can be managed by the specific sender and the specific recipient, the impersonation by the third party can be prevented, and the important file data can be prevented. Is not viewed, edited, or deleted by a third party, and the security can be further improved.

Further, by generating list information and displaying a list of file names, senders, ID numbers, authentication information, etc., it is possible to easily recognize file data which may be falsified or spoofed, Can efficiently manage information on file data on which the file has been performed. Thereby, the reliability of the print printed by the image forming apparatus 1 can be greatly improved.

The above description of the present embodiment is an example of a suitable image forming apparatus according to the present invention, and the present invention is not limited to this. For example, in the present embodiment, the authentication information is displayed on the display unit 12 and the file data is deleted according to the user's instruction. However, when the authentication information is “authentication NG” by the initial setting, Alternatively, the corresponding file data may be automatically deleted. As a result, file data that may be falsified or spoofed is not stored and printed, so that the user's effort can be saved and the resources of the image forming apparatus can be effectively used.

In addition, the detailed configuration and the detailed operation of the components of the image forming apparatus 1 and the external device 2 in the present embodiment can be appropriately changed without departing from the gist of the present invention.

[0052]

According to the first aspect of the present invention, the digital data received by the communication means and the authentication information on the digital data are printed on a print medium, thereby falsifying or spoofing the printed digital data. Can be checked, and the reliability of the printed matter can be improved.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the user can confirm the presence or absence of falsification or impersonation based on the authentication information corresponding to the received digital data. Therefore, after confirming with the authentication information, the digital data can be printed or deleted. Accordingly, unnecessary digital data is not printed, and the printing process can be performed efficiently. In addition, by displaying information on digital data and authentication information corresponding to the information on digital data on the display unit, it is possible to easily recognize whether the digital data has been tampered with or impersonated, and efficiently manage the digital data. can do.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, digital data which may be falsified or spoofed is automatically deleted. No device resources are wasted. In addition, the time and effort of the user who manages the digital data can be saved, and the digital data can be managed efficiently.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a system configuration of a printing system 100 according to an embodiment to which the present invention is applied.

FIG. 2 is a block diagram showing a main configuration of the image forming apparatus 1 shown in FIG.

FIG. 3 is a block diagram showing a main configuration of the external device 2 shown in FIG.

4 is a flowchart showing a file data transmission process executed by a control unit 21 shown in FIG.

FIG. 5 is a flowchart showing a file data recognition process executed by a control unit 11 shown in FIG. 2;

FIG. 6 is a conceptual diagram showing a conventional electronic signature system.

[Explanation of symbols]

1 Image forming apparatus 11 Control part 12 Display 13 Operation section 14 Communication unit 15 Image processing unit 16 Scanner section 17 Printer section 18 Memory 2 External devices 21 Control unit 22 Display 23 Operation section 24 Communication unit 25 Memory N network

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H04N 1/44 H04L 9/00 675B F-term (reference) 2C187 AC07 AD03 AD04 AD14 AE07 BF26 BF34 GD02 GD04 5B021 AA30 BB04 BB10 CC07 NN18 PP04 5C075 EE03 EE06 5J104 AA08 AA09 LA03 LA06 PA14

Claims (3)

[Claims] 1. A communication means for receiving digital data to which an electronic signature is attached via a network, and falsification or spoofing of the digital data based on the digital data received by the communication means and the electronic signature. Verification means for verifying whether or not the authentication has been performed; authentication information generation means for generating authentication information indicating presence or absence of falsification or impersonation of the digital data based on a result verified by the verification means; and An image forming apparatus, comprising: printing means for printing data and the authentication information on a print medium. 2. A list information generating means for generating list information including at least information on the digital data and authentication information corresponding to the digital data; and displaying the list information generated by the list information generating means on a display means. The image forming apparatus according to claim 1, further comprising: display control means for displaying. 3. The apparatus according to claim 1, further comprising a deletion unit for deleting the digital data when the received digital data has been falsified or spoofed based on a result verified by the verification unit. Item 2. The image forming apparatus according to Item 1.