JP2005184735A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more completely ensure security of stored images in an image forming apparatus which is capable of outputting (image formation or transfer to an external device) using the stored images. <P>SOLUTION: Encrypting process is performed on the pre-stage of image storage. Input image data are sorted to a plurality of encryption schemes 1 to N having different encryption algorithms in an encryption section 104 and are encrypted. Even if a method of decrypting one encryption scheme is known, the sorted other encryption schemes can not be decrypted, thereby improving a security function. The input data are sorted by an input selector 102 which is operated by an encryption scheme select signal. The encryption scheme select signal is switched by a signal detecting the head of lines in the input image and select data for determining the encryption schemes 1-N to sort the input image data are dependent upon user setting or random data are used to be functioned as double keys. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus (for example, a copying machine, a facsimile machine, a printer, etc.), and more specifically, an image forming apparatus having an input image storage unit and capable of expanding functions by using the storage unit. The present invention relates to an image forming apparatus provided with means for encrypting image data in order to ensure security for stored images.

In recent years, a copying machine is equipped with a large-capacity data storage device that does not lose data even after the power is turned off, such as an HDD, and this storage device can be used as a storage unit for image data input to the copying machine. Yes. At this time, from the aspect of security of stored data (so that data is not freely used), it is conceivable that image data is encrypted and then stored in a data storage device.
Ensuring the security of such information is a common problem when managing information, not limited to copiers, and has been increasingly emphasized in recent years. In general, various encryption methods have been proposed to protect security. Has been. However, it is difficult to obtain a complete method, and it is now possible to break the encryption if it is not easy if it is attempted to break it at the present time when the speed of personal computers is remarkable.
Incidentally, as an example of a conventional copying apparatus provided with image data encryption means, the following Patent Document 1 can be cited. Japanese Patent Application Laid-Open No. 2004-228561 describes an apparatus that is intended to allow security check by leaving image data that has been copied or transmitted using a copying apparatus as data that can be decrypted only by an administrator. . In Patent Document 1, after the image data is reduced, this data is encrypted and stored, and only the administrator who holds the decryption key can decrypt the data on one sheet of paper. A plurality of images are created and used by the administrator for checking.
JP 2002-165101 A

As described above, if it is difficult to decrypt the code even if it is difficult, the conditions to make it possible are now being prepared, it is necessary to ensure strict security for the image data stored in the copying machine. It is easy to configure and no effective means are provided.
In addition, the copying apparatus with security function described in the above-described Patent Document 1 encrypts and stores image data used for copying, and only an administrator who can decrypt the encryption can check a plurality of images at a time. It is intended to encrypt a reduced image under the limited purpose of doing so, and is not intended to ensure the security of the stored data itself that enables reuse of the input image. In addition, the encryption method used is not special, and it is difficult to say that a method that can ensure sufficient security is used, and as described above, it does not solve the security problem for stored image data. Absent.
The present invention has been made in order to solve the above-described problems in the prior art, and the problem to be solved is to have an input image storage unit and to expand the function by using the storage unit. In the image forming apparatus (for example, a copying machine, a facsimile machine, a printer, etc.), the security of the stored image is more completely secured by using an encryption unit that can be configured easily and cannot be easily decrypted. .

The invention according to claim 1 is an image forming apparatus having an image storage means for storing an input image, and enabling image output through the image storage means, wherein the image is encrypted by a plurality of encryption methods. A possible image encrypting means, a selector for selecting an encryption method in order to encrypt the inputted image into a plurality of encryption methods of the encrypting means, and an image encrypted by the encrypting means An image forming apparatus comprising: an image storage unit that stores image data; and an image output unit that extracts and outputs an image from the image storage unit.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the selector is a means that enables an input image to be divided into a plurality of encryption methods in units of scanning lines. It is what.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the selector sets selection data used for distributing an image to a plurality of encryption methods, and the selection data is input. An operation means is provided.
According to a fourth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to third aspects, wherein the selector sets selection data used for distributing an image into a plurality of encryption methods; and the selection data Is provided as means for generating random data as random data.

According to the invention of claim 1, even if a decryption method of one encryption method is found by distributing and encrypting an input image into a plurality of encryption methods, Since it cannot be deciphered, the security function can be maintained.
According to the second aspect of the present invention, since a plurality of encryption methods are assigned to each scanning line, an effective security function for the input image data of the image forming apparatus can be easily incorporated into the apparatus.
According to the invention of claim 3, since the select data used for the distribution of the encryption method can be designated by the user's operation, the security function can be further enhanced. That is, even if a decryption method of one encryption method is discovered, it becomes a double key because it cannot be easily decrypted because it is like a semantic key with select data that is information on which line the encryption method is used. .
According to the invention of claim 4, since the means for generating the select data used for the distribution of the encryption method as a random value is provided, the input operation by the user as in the invention of claim 3 is applied. It is possible to save time and improve security functions.

An image forming apparatus according to the present invention will be described based on the following embodiments shown in the accompanying drawings. In the present embodiment, the present invention reads an image from a document, such as a composite copying machine, temporarily stores the obtained image data in an image storage device, and uses the stored data to form an image (copy output), or An example applied to an image forming apparatus capable of performing image output such as distribution of image data to an external device will be described.
In the following, the basic configuration of an image forming apparatus provided with an encryption processing apparatus that encrypts stored input image data is described in “Embodiment 1”, and “Embodiment 2” to “Embodiment 4” In each of the encryption processes, an embodiment in which an encryption method selection device that distributes an image into a plurality of encryption methods is added in a different manner is shown.

“Embodiment 1”
First, an image forming apparatus capable of outputting an input image data once stored in the image storage apparatus in the form of image formation (copy output) in the apparatus or distribution to an external device will be described.
FIG. 1 shows a schematic configuration of a system in which an image forming apparatus according to the present embodiment and an external device using image output from the image forming apparatus are connected.
The system shown in FIG. 1 is configured by connecting an image forming apparatus 10 and an external device 8 via a network. The external device 8 may be any device that uses the transferred image data, and corresponds to a device that can support a PC, a copier, a facsimile, or the like.
The image forming apparatus 10 reads a document and reads a color image signal input means 1 such as a scanner, and performs various corrections and conversions such as normalization processing, γ correction, and color conversion on the read image signal, An image processing device 2 that processes data that can be used for image reproduction (for example, copy output), an encryption processing device 3 that encrypts processed input image data, and input image data that has been encrypted The image storage device 4 that stores the file by compressing or file processing, the decryption processing device 6 that decrypts the encrypted image data extracted from the image storage device 4, and the image processing device 2 that decrypts the decrypted image data. A writing device 7 that modulates a laser with a writing signal obtained by passing the image and forms an image on an image carrier (photosensitive member) is provided as an element necessary for image formation. Since a known configuration can be applied to a processing device that forms an image (visualized image) after writing by the writing device 7, this configuration portion is omitted in FIG.
Further, the image forming apparatus 10 includes an image transfer apparatus 5 that transfers an image file stored in the image storage apparatus 4 as an element for transferring input image data to the external device 8. Since the image transfer device 5 transfers the stored image, the encrypted image is transferred. However, in order to use a specific user (having the key to decrypt), adopt a configuration that can send the composited image, and set the usage conditions to set the conditions. Only certain users who meet can be able to transfer the decoded image.

Here, the encryption processing apparatus 3 provided in the image forming apparatus for realizing the object of the present invention will be described.
The encryption processing device 3 according to the present embodiment intends to make it difficult to decrypt the encryption by using means capable of encrypting an image by a plurality of encryption methods.
In other words, the input image data is divided into a plurality of encryption methods with different encryption algorithms and encrypted, and even if a decryption method of one encryption method is found, the other encrypted methods cannot be decrypted. The function can be maintained.
Therefore, any number of encryption methods can be incorporated in the encryption processing apparatus. However, the larger the number, the more difficult the decryption is.
FIG. 2 is a block diagram showing the encryption processing apparatus of this embodiment.
In FIG. 2, the encryption processing apparatus 101 shown in FIG. 2 is used for the apparatus shown as the encryption processing apparatus 3 in FIG. The encryption processing apparatus 101 includes an encryption unit 104 that performs encryption processing using a plurality of encryption methods 1 to N, and an encryption unit 104 that selects input image data to be encrypted by an encryption method select signal. An input selector 102 that inputs to one of the systems 1 to N, and an output selector 103 that outputs encrypted data from one of the encryption systems 1 to N selected by the encryption system select signal in the same manner as the input Prepare. The encryption method select signal is a signal transmitted by a controller of a device (not shown) in synchronization with the input of image data from the image processing device 2, and the encryption method designated according to the sorting order is determined in advance. It will be sent at the timing of switching.

The related operation of the encryption processing apparatus 101 will be described. When input image data from the image processing apparatus 2 is input to the encryption processing apparatus 101 having a plurality of encryption algorithms, an input that operates according to the encryption method select signal. The selector 102 sequentially distributes the data to the encryption unit 104 of the designated encryption method.
The sorted image data is subjected to encryption processing using different encryption algorithms for the encryption methods 1 to N of the encryption unit 104. Note that the encryption method used at this time can be implemented by applying an existing encryption algorithm.
The encrypted data is output through the output selector 103 that operates according to the encryption method select signal, similarly to the input selector 102.
Thereafter, the encrypted image data is temporarily stored in the image storage device 4. When the image data stored in the image storage device 4 is used for image formation (copy output), it is necessary to return to the (original) image before being encrypted. I do. The decryption processing device 6 prepares a decryption unit corresponding to each of the encryption methods 1 to N of the encryption processing device 101 in the decryption unit, and inputs similar to those used for input and output in the encryption processing device 101. By using the output selector and inputting the select signal at the time of encryption as the decryption select signal for operating the selector, it is possible to distribute the encrypted input image to the corresponding decryption method of the decryption unit. is there. The decoded image is subjected to image processing necessary for writing normally performed by the image processing apparatus 2, and the writing apparatus is operated by the obtained writing signal to form an image.

When image formation (copy output) for an input image is requested at the same time as the scanner input of the reading means 1 (normal copy operation), image formation (copy output) is performed by executing the above operations as a series of flows. ) Is performed. However, in addition to the scanner input, when image formation (copy output) is requested for the stored image of the image storage device 4, whether or not to permit decoding (make normal output), It is necessary to check by confirming the operator's ID or confirming the encryption key. Otherwise, the encrypted meaning is lost.
In addition, when image transfer from the image forming apparatus 10 to the external device 8 is performed, the image transfer apparatus 5 transfers the stored image encrypted from the image storage apparatus 4. Since it cannot, the security of the image is protected during the transfer.

“Embodiment 2”
In the present embodiment, an embodiment in which an encryption method selection device for distributing an input image to a plurality of encryption methods is added to the encryption processing device based on the basic configuration of the above-described “Embodiment 1”.
The present embodiment is intended to distribute the input image to a plurality of encryption methods in units of scanning lines on the assumption that the input image is line scanning like scanner input. An encryption method selection device is provided in front of the same encryption processing device (having a plurality of encryption methods).
FIG. 3 is a block diagram showing an encryption processing apparatus provided with the encryption method selection apparatus of the present embodiment.
The entire apparatus shown in FIG. 3 is used as the encryption processing apparatus 3 in FIG. 3 corresponds to the encryption processing apparatus 101 of the first embodiment (FIG. 2). Accordingly, the description of the configuration overlapping with that of the first embodiment is not made, and the above description is referred to.

In FIG. 3, the encryption method selection device 202 is provided in the preceding stage of the encryption processing device 201, and includes a selection signal switching device 203 and a line head detection device 204 as components.
The line head detection device 204 is a device that detects the head of the line of the input image data that is sequentially transmitted for each line as a result of line scanning, and uses this detection signal as a trigger for the switching operation in the select signal switching device 203.
The select signal switching device 203 receives an encryption method select signal transmitted from a controller of the device (not shown), that is, an encryption method designated according to the sorting order, and a trigger signal for switching operation from the line head detection device 204. The encryption method selection signal is input to the encryption processing device 201 at the timing when the trigger signal is received.
As described above, the select signal switching device 203 can input to the encryption processing device 201 an encryption method select signal for switching the encryption method used for each line of image data in synchronization with the line.
As shown in the above operation, since the encryption method selection device 202 takes the input timing of the selection signal to the encryption processing device 201, the encryption method selection signal transmitted by the controller of the device (not shown) is designated. Only data representing the encryption method is required.
In this embodiment, the encryption method selection signal transmitted from the controller of the device (not shown) can be specified by the user from the operation unit. That is, an encryption method select signal is generated based on select data for which the user designates the order of distribution of encryption methods, and the encryption processing apparatus 201 performs processing according to the encryption method selected by this signal. This method makes it possible to use an encryption method select signal as a key for decrypting a cipher usable only by a user.

“Embodiment 3”
In this embodiment, another embodiment in which an encryption method selection device for distributing an input image to a plurality of encryption methods is added to the encryption processing device based on the basic configuration of the above-described “Embodiment 1”. .
The embodiment in which the user can specify the encryption order is shown in the second embodiment. However, this embodiment is not limited to the user specification, but is automated on the device side to obtain the same effect. Is. In this embodiment, the input image is distributed to a plurality of encryption methods in units of scanning lines on the assumption that the input image is a line scan like a scanner input.
FIG. 4 is a block diagram showing an encryption processing apparatus provided with the encryption method selection apparatus of the present embodiment.
The entire apparatus shown in FIG. 4 is used as the encryption processing apparatus 3 in FIG. Also, the encryption processing apparatus 301 in FIG. 4 corresponds to the encryption processing apparatus 101 in the first embodiment (FIG. 2). Accordingly, the description of the configuration overlapping with that of the first embodiment is not made, and the above description is referred to.

In FIG. 4, the encryption method selection device 302 is provided in the preceding stage of the encryption processing device 301 (having the same plurality of encryption methods as described in the first embodiment), and includes select signal switching device 303, line A head detection device 304 and a random signal generator 305 are provided.
The line head detection device 304 is a device that detects the head of the line of the input image data that is sequentially transmitted for each line as a result of line scanning, and uses this detection signal as a trigger for the switching operation in the select signal switching device 303.
The random signal generator 305 is a means specific to the present embodiment for generating select data for specifying the distribution order of the encryption method. Here, a random value is generated, and the select data used for distribution can be easily obtained. Do not. The random signal generator itself can be implemented by applying an existing device. However, since data for generating a random value is used for decoding, it is necessary to manage data such as an algorithm used for generating a random signal.
The select signal switching device 303 receives the trigger signal of the switching operation from the line head detection device 304, and encrypts the encryption method select signal based on the random value generated by the random signal generator 305 at the timing when the trigger signal is received. 301 is input.
As described above, the select signal switching device 303 is a random signal generated on the device side without the user setting the encryption method select signal for switching the encryption method used for each line of the image data in synchronization with the line. The value can be input to the encryption processing apparatus 301 and set to operate. By adopting such a method, in order to decrypt the cipher, the correct original image cannot be restored unless information on the decryption method of all the encryption methods and the method of obtaining a random value is obtained. It becomes possible to enhance the security function.

“Embodiment 4”
In this embodiment, another embodiment in which an encryption method selection device for distributing an input image to a plurality of encryption methods is added to the encryption processing device based on the basic configuration of the above-described “Embodiment 1”. .
Although the embodiment in which the designation of the sorting order of the encryption scheme is automated by using a random value generated by a random signal generator has been shown in the third embodiment, this embodiment is another embodiment for achieving automation. The form is shown. In this embodiment as well, the input image is distributed to a plurality of encryption methods in units of scanning lines on the assumption that the input image is a line scan as in the case of scanner input.
FIG. 5 is a block diagram showing an encryption processing apparatus provided with the encryption method selection apparatus of the present embodiment.
The entire apparatus shown in FIG. 5 is used as the encryption processing apparatus 3 in FIG. Also, the encryption processing apparatus 401 in FIG. 5 corresponds to the encryption processing apparatus 101 in the first embodiment (FIG. 2). Therefore, the description of the configuration overlapping with that of the first embodiment is not made, and the above description is referred to.

In FIG. 5, the encryption method selection device 402 is provided in the preceding stage of the encryption processing device (having the same plurality of encryption methods as described in the first embodiment) 401, and includes the select signal switching device 403, the line A head detection device 404 is provided.
The line head detection device 404 is a device that detects the head of the line of the input image data that is sequentially transmitted for each line as a result of line scanning, and uses this detection signal as a trigger for the switching operation in the select signal switching device 403.
As means specific to the present embodiment, some information obtained in the course of processing in the encryption processing apparatus 401 is used as data for defining select data for designating the sorting order of encryption methods. Since this feedback information is information related to the encryption process, it always has a fluctuating data value, that is, corresponds to a random value. Therefore, as in the case of the random value generated in the third embodiment, the distribution data can be easily obtained. Because it is not possible, it has the necessary conditions to protect security. However, since this feedback information is used for decryption, the information used as the distribution data for the encryption method needs to be managed.
The select signal switching device 403 receives the trigger signal for the switching operation from the line head detection device 404, and inputs the select signal of the encryption method specified by the feedback information to the encryption processing device 401 at the timing when the trigger signal is received. To do.
As described above, the select signal switching device 403 provides feedback generated by the encryption processing device 401 without the user setting select data for switching the encryption method used for each line of image data in synchronization with the line. Information is used. By adopting such a method, in order to decrypt the cipher, the correct original image cannot be restored without obtaining the decryption method and feedback signal of all the cryptosystems, so it becomes possible to enhance the security function. There is no need to newly provide a random generator as in the third embodiment.

1 shows a schematic configuration of a system in which an image forming apparatus and an external device according to the present invention are connected. 1 is a block diagram illustrating an encryption processing apparatus (first embodiment) of an image forming apparatus according to the present invention. It is a block diagram which shows the encryption processing apparatus (Embodiment 2) provided with the encryption system selection apparatus. It is a block diagram which shows the encryption processing apparatus (Embodiment 3) provided with the encryption system selection apparatus. It is a block diagram which shows the encryption processing apparatus (Embodiment 4) provided with the encryption system selection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reading apparatus, 2 ... Image processing apparatus,
3, 101, 201, 301, 401 ... encryption processing device,
102 ... Input selector, 104 ... Encryption unit,
103 ... Output selector,
202, 302, 402... Encryption method selection device,
203, 303, 403... Select signal switching device,
204, 304, 404 ... line head detection device,
305 ... Random signal generator, 4 ... Image storage device,
5 ... Image transfer device, 6 ... Decoding processing device,
7: Writing device, 8 ... External device,
10: Image forming apparatus.

Claims (4)

  An image forming apparatus that includes an image storage unit that stores an input image and that can output an image through the image storage unit, the image encryption unit capable of encrypting an image by a plurality of encryption methods; A selector that selects an encryption method for allocating and encrypting an input image to a plurality of encryption methods of the encryption unit; and an image storage unit that stores an image encrypted by the encryption unit; An image forming apparatus comprising image output means for extracting and outputting an image from the image storage means.   2. The image forming apparatus according to claim 1, wherein the selector is means for allowing an input image to be divided into a plurality of encryption methods in units of scanning lines.   3. The image forming apparatus according to claim 1, further comprising means for setting select data used by the selector to sort images into a plurality of encryption methods and an operation means for inputting the select data. A featured image forming apparatus.   4. The image forming apparatus according to claim 1, wherein the selector sets selection data used for distributing an image to a plurality of encryption methods, and the selection data is generated as random data. An image forming apparatus comprising the means.

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