JP2006094068A - Image processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor having a means of generating encryption keys. <P>SOLUTION: When an illegal access is received, and when encrypted data stored in a user data storage area is erased and when an instruction to change the encryption key is received from a manager (S31, S36, S40: YES), the encryption key stored in an encryption key storing part is deleted (S32), and a new encryption key (second encryption key) is generated (S33). Then, the generated encryption key is stored in the encryption key storing part (S34), and a flag showing the type of the encryption key is set to "2" (S35). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus having encryption key generation means.

  Conventionally, as data storage means equipped with a function for protecting confidential data, means for generating an encryption key, volatile memory for holding the generated encryption key, and nonvolatile storage means for storing data And a data storage device that performs encryption using an encryption key written in a volatile memory when storing data in the storage means has been proposed (for example, see Patent Document 1).

In this way, when data is encrypted using an encryption key, the management of the encryption key is very important together with the encryption method, the encryption algorithm, and the like. In general, a malicious third party fraudulently encrypts an encryption key by updating the encryption key using a randomly generated seed or managing the access to the encryption key with sufficient control. I try to prevent you from getting it. In addition, since the encryption key written in the volatile memory disappears when the power supply of the apparatus is turned off, unauthorized extraction of the encryption key is prevented.
JP 62-107352 A

  In recent years, image processing apparatuses such as printers, facsimile machines, and digital multi-function peripherals are also equipped with storage means such as a hard disk, and data processed by these image processing apparatuses can be stored. Yes. The accumulated data can be arbitrarily read by the user operating the image processing apparatus, and the data can be reused. For this reason, when it is necessary to protect the confidentiality of the stored data, the data is encrypted using the encryption key as described above.

  However, since it is necessary to process a large amount of data without stagnation in the image processing apparatus, it is difficult from the viewpoint of processing efficiency to generate an encryption key for each received data and manage the encryption key together with the data. There are many cases. Also, in a digital multi-function peripheral having a facsimile function, it is common that the power is always turned on to receive facsimile data at night, and the data received at night cannot be decoded the next day. Therefore, it is difficult to generate an encryption key according to the reception date and time.

  Therefore, in a conventional image processing apparatus, it is generally performed that an encryption key is generated using information unique to the apparatus such as a manufacturing number and data to be protected is encrypted using the encryption key. . However, if the plaintext data that is the seed of the encryption key is fixed, the stored user data may be illegally retrieved if a malicious third party illegally obtains the encryption key. Arise. In addition, in image processing apparatuses and the like, since information unique to the apparatus such as a serial number is generally used as a seed, it is easy to guess the encryption key itself, and illegal data is obtained using the estimated encryption key. There is a problem that it may be taken out.

  The present invention has been made in view of such circumstances, and includes an encryption key generation unit that generates an encryption key, and a control unit that controls the timing at which the encryption key generation unit generates an encryption key. An image that can prevent an encryption key from being taken out illegally by using a key to encrypt image data to be stored in the storage means and to decrypt image data read from the storage means. An object is to provide a processing apparatus.

  Another object of the present invention is to generate an encryption key by using one algorithm among a plurality of algorithms for generating an encryption key, and to include a switching means for switching to another algorithm. An object of the present invention is to provide an image processing apparatus capable of making it difficult to guess an encryption key even when the same seed is used.

  An image processing apparatus according to the present invention includes a storage unit that stores image data. In the image processing apparatus that performs processing based on the image data read from the storage unit, an encryption key generation unit that generates an encryption key; Using the control means for controlling the timing at which the key generation means generates the encryption key and the encryption key generated by the encryption key generation means, the image data to be stored in the storage means is encrypted and read out from the storage means Means for decoding image data.

  The present invention includes an encryption key generation unit that generates an encryption key and a control unit that controls the timing at which the encryption key generation unit generates the encryption key, and encrypts image data using the generated encryption key. Since encryption and decryption are performed, it is possible to control not to generate an encryption key under a situation where image data is illegally extracted.

  An image processing apparatus according to the present invention comprises means for receiving an encryption key generation instruction, and when the means receives the generation instruction, the control means controls the encryption key generation means to generate an encryption key. It is characterized by the above.

  In the present invention, since an encryption key is generated when an instruction for generating an encryption key is accepted, for example, an administrator of the device considers the necessity of encryption in consideration of the use environment, It is possible to control to generate an encryption key only when encryption is necessary.

  The image processing apparatus according to the present invention includes means for accepting selection relating to the necessity of encryption of image data, and when the selection requiring encryption is accepted, the control means is configured to generate an encryption key. The encryption key generation means is controlled.

  In the present invention, when the selection relating to the necessity of encryption of the image data is accepted and the selection requiring the encryption is accepted, an encryption key is generated, so that the apparatus can be encrypted Only below is an encryption key generated.

  The image processing apparatus according to the present invention is characterized in that the control means controls the encryption key generation means to generate an encryption key when power to supply power to each means is turned on. To do.

  In the present invention, since the encryption key is generated only when the power is turned on, for example, even when the storage means is illegally taken out at night when the device is not turned on, The image data is prevented from being taken out from the storage means.

  The image processing apparatus according to the present invention is characterized in that the encryption key generation means is capable of generating a plurality of types of encryption keys by a plurality of algorithms.

  In the present invention, since a plurality of types of encryption keys are generated by a plurality of algorithms, the encryption keys can be used properly according to the usage environment and usage status of the apparatus, and are stored in the storage means. It is difficult to illegally retrieve existing data.

  In the image processing apparatus according to the present invention, the encryption key generation unit generates an encryption key using one of the algorithms, and a switching unit that switches an algorithm used for generating the encryption key to another algorithm. It is characterized by providing.

  In the present invention, the encryption key is generated using one of the plurality of algorithms, and the algorithm used for generating the encryption key is switched to another algorithm. It is possible to use different encryption keys according to the usage environment and usage status, and even when the same seed is used, it is difficult to illegally extract data stored in the storage means.

  In the image processing apparatus according to the present invention, the encryption key generation means includes a plurality of encryption key generation circuits corresponding to each algorithm, and the encryption key generation circuit generates a plurality of types of encryption keys. It is characterized by.

  In the present invention, since the encryption key generation circuit corresponding to each algorithm is provided, it is possible to generate a plurality of types of encryption keys by switching the encryption key generation circuit to be used.

  The image processing apparatus according to the present invention comprises means for receiving an erasure instruction for image data stored in the storage means, and means for erasing the image data when the erasure instruction is accepted by the means. When the data is erased, the switching means switches the algorithm used for generating the encryption key.

  In the present invention, when the image data stored in the storage means is erased, the algorithm used for generating the encryption key is switched. Therefore, when the installation environment of the apparatus is changed, the change is made. Accordingly, the encryption key is also changed.

  When the image processing apparatus according to the present invention determines that an unauthorized read request for the image data stored in the storage unit has been received and determines that the unauthorized read request has been received, the switching unit includes: It is characterized in that the algorithm used for generating the encryption key is switched.

  In the present invention, when an illegal read request for image data stored in the storage means is accepted, the algorithm used for generating the encryption key is switched, so that there is a possibility that the data may be leaked. Switches.

  The image processing apparatus according to the present invention is configured to determine whether an unauthorized processing request based on image data read from the storage unit is received, and when determining that the unauthorized processing request is received by the unit, The switching means is characterized in that the algorithm used for generating the encryption key is switched.

  In the present invention, when an illegal process based on image data is accepted, the algorithm used for generating the encryption key is switched. Therefore, the algorithm is switched when there is a risk of data leakage.

  The image processing apparatus according to the present invention includes means for storing information unique to the apparatus, and the encryption key generation means generates an encryption key based on the information.

  In the present invention, since the encryption key is generated based on the information unique to the apparatus, it is not necessary to generate the encryption key for each image data even when a large number of image data is received.

  In the case of the present invention, an encryption key generating means for generating an encryption key and a control means for controlling the timing at which the encryption key generating means generates the encryption key are provided, and image data is encrypted using the generated encryption key. And decryption. Therefore, it is possible to control not to generate an encryption key under a situation where image data is taken out illegally.

  According to the present invention, an encryption key is generated when an encryption key generation instruction is accepted. Therefore, for example, it is possible for the administrator of the apparatus to consider whether or not encryption is necessary in consideration of the use environment, and to control to generate an encryption key only when encryption is necessary.

  According to the present invention, a selection relating to the necessity of encryption of image data is accepted, and an encryption key is generated when a selection requiring encryption is accepted. Therefore, an encryption key is generated only under a situation where data can be encrypted as an apparatus, and an inadvertent outflow of the encryption key can be avoided, and an image data protection function can be enhanced.

  In the case of the present invention, the encryption key is generated only when the power is turned on. Therefore, for example, even when the storage means is illegally taken out at night when the apparatus is not turned on, image data is prevented from being taken out from the storage means, and data leakage is prevented. Can do.

  In the case of the present invention, since a plurality of types of encryption keys are generated by a plurality of algorithms, the encryption keys can be used properly according to the use environment and use status of the apparatus, and are stored in the storage means. Unauthorized data retrieval becomes difficult.

  According to the present invention, an encryption key is generated using one of a plurality of algorithms, and the algorithm used for generating the encryption key is switched to another algorithm. Therefore, it becomes possible to use the encryption key properly according to the use environment and use situation of the apparatus, and even if the same seed is used, it is difficult to illegally extract the data stored in the storage means. it can.

  According to the present invention, an encryption key generation circuit corresponding to each algorithm is provided. Accordingly, it is possible to generate a plurality of types of encryption keys by switching the encryption key generation circuit to be used, and it is possible to enhance the data protection function by properly using them according to the use environment and use status of the apparatus.

  According to the present invention, when the image data stored in the storage means is deleted, the algorithm used for generating the encryption key is switched. Therefore, when the installation environment or the like of the device is changed, the encryption key is also changed with the change, and the data protection function can be enhanced.

  According to the present invention, when an illegal read request for image data stored in the storage means is received, the algorithm used for generating the encryption key is switched. Therefore, the algorithm is switched when there is a risk of data leakage, and the data protection function can be enhanced.

  In the case of the present invention, when an illegal process based on image data is accepted, the algorithm used for generating the encryption key is switched. Therefore, the algorithm is switched when there is a risk of data leakage, and the data protection function can be enhanced.

  In the case of the present invention, the encryption key is generated based on the information unique to the apparatus. Therefore, even when a large number of image data is received, it is not necessary to generate an encryption key for each image data, and the processing efficiency is not lowered.

Hereinafter, an embodiment in which the image processing apparatus of the present invention is applied to a digital multi-function peripheral having a printer function, a scanner function, a copy function, and a facsimile transmission function will be specifically described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing the internal configuration of the digital multifunction peripheral according to this embodiment. The digital multi-function peripheral 100 according to the present embodiment includes a CPU 101. The CPU 101 loads a control program stored in advance in the ROM 102 onto the RAM 103 and executes it, whereby hardware connected via the bus 120 is executed. Are controlled to operate as an image processing apparatus according to the present invention as a whole. In addition to the basic functions described above, the digital multi-function peripheral 100 has a filing function for storing processed image data, a log management function for taking a history of processed image data, an encryption function for encrypting data, and an encryption / decryption process Has a cryptographic key management function for generating and managing cryptographic keys (common keys) used in the system, and the CPU 101 is configured to execute processing based on these functions by controlling each hardware. Yes.

Hereinafter, the configuration of various hardware connected to the bus 120 will be described.
The management unit 104 includes a nonvolatile semiconductor memory, and a part of the storage area is used as a filing data management unit 104a, a history management unit 104b, an encryption key generation flag management unit 104c, and a unique information storage unit 104d. ing.

  The filing data management unit 104a manages the storage location of image data to be accumulated using the filing function, the stored date and time, and user information in association with each other. The history management unit 104b manages the storage location of the image data accumulated by the log management function and the stored date and time in association with each other. The encryption key generation flag management unit 104c manages a flag for distinguishing whether or not an encryption key is generated and the type of the generated encryption key. In the present embodiment, two types of encryption keys (first encryption key and second encryption key) can be generated. When the encryption key is not generated, the flag is set to “0”, and the first encryption key is set. The flag when it is generated is set to “1”, and the flag when the second encryption key is generated is set to “2”. The unique information storage unit 104d stores information unique to the device such as a manufacturing number. In the present embodiment, the unique information stored in the unique information storage unit 104d is used as a seed for generating an encryption key.

  The operation panel 105 includes an operation unit 105a that receives an operation by a user and a display unit 105b that displays information to be notified to the user. The operation unit 105a includes various operation keys, numerical keys, and the like for accepting settings such as a function switching operation, the number of output sheets in print processing, scaling in copy processing, density adjustment, and a transmission destination in facsimile transmission processing. The display unit 105b includes a liquid crystal display device, and displays the operation status of the digital multi-function peripheral 100, setting values input from the operation unit 105a, and the like. In addition, a part of the display unit 105b includes a software key configured to accept a setting selection by a user's pressing operation.

  The user authentication unit 106 includes an information reading unit for reading the personal authentication information from a card-type recording memory such as a magnetic card or an IC card that stores the user's personal authentication information, and the personal authentication information read by the information reading unit. And a determination unit for comparing and determining personal authentication information registered in advance in the digital multifunction peripheral 100. A determination result by the determination unit is notified to the CPU 101.

  In this embodiment, the user authentication unit 106 has been described as a device that reads personal authentication information from a card-type recording memory. However, the recording medium for carrying the personal authentication information is not limited to the card-type memory. It is. For example, the personal authentication information is acquired by establishing a connection state with a communication device such as a mobile phone having a communication function such as wireless communication, infrared communication, Bluetooth, PDA (Personal Digital Assistant), wireless tag, and performing communication. It may be a configuration. In addition, when the user authentication is performed using the operation panel 105, it is needless to say that the user authentication unit 106 is not necessarily provided separately.

  The image input unit 107 includes one or more interfaces that accept input of image data. Examples of interfaces that can be employed in the image input unit 107 include a scanner unit that optically reads an image of a document, a communication interface that receives a print job from an external computer, and a facsimile modem that receives facsimile data from an external facsimile apparatus.

  The image data acquired by the scanner unit is subjected to image processing such as scaling and density adjustment by the image processing unit 108, and then transferred to the buffer memory 109, which is a volatile semiconductor memory. Temporarily retained. The print job received via the communication interface is developed into image data for output by the image processing unit 108, transferred to the buffer memory 109, and temporarily held in the buffer memory 109. The facsimile data received by the facsimile modem is decoded by the image processing unit 108, transferred to the buffer memory 109, and temporarily held in the buffer memory 109.

  The image output unit 110 includes one or a plurality of interfaces related to image data output. Interfaces that can be employed in the image output unit 110 include a printer unit that transfers an image onto a sheet to form an image, a communication interface that transmits image data to an external computer, and a facsimile modem that transmits facsimile data to an external facsimile apparatus Is mentioned.

  Of course, the communication interface and the facsimile modem need not be provided in both the image input unit 107 and the image output unit 110, and may be configured to transmit and receive using a common interface.

  The encryption key generation unit 111 is an arithmetic circuit that generates an encryption key based on information unique to the device stored in the unique information storage unit 104d. The encryption key generation unit 111 stores a first encryption key generation program 111a and a second encryption key generation program 111b in advance, and uses two different encryption keys (referred to as a first encryption key and a second encryption key). So that it can be generated. The CPU 101 refers to the flag managed by the encryption key generation flag management unit 104c to determine whether or not to generate an encryption key and the type of encryption key to be generated. By executing either the encryption key generation program 111a or the second encryption key generation program 111b, either the first encryption key or the second encryption key is generated.

  The first and second encryption key generation programs may be configured to be stored in the encryption key generation unit 111 as resident programs, and stored in the encryption key generation unit 111 as executable programs. It may be configured to start as necessary.

  The encryption key storage unit 112 is configured by a volatile semiconductor memory, and stores the encryption key generated by the encryption key generation unit 111. In the present embodiment, either the first encryption key or the second encryption key generated by the encryption key generation unit 111 is stored.

  The encryption / decryption processing unit 113 encrypts and decrypts image data using the encryption key generated by the encryption key generation unit 111 as a common key. Therefore, the encryption / decryption processing unit 113 includes an input buffer that inputs data to be encrypted or decrypted, an arithmetic unit that performs arithmetic processing including a predetermined encryption algorithm on the data set in the input buffer, It is composed of an output buffer or the like that holds the result of operation by the device. Data to be encrypted or data to be decrypted is input to the input buffer, the input data set in the input buffer is extracted, the arithmetic unit performs arithmetic processing, and when the arithmetic processing is completed, the arithmetic result is output to the output buffer. Write to. The CPU 101 acquires the data encrypted by the encryption / decryption processing unit 113 or the decrypted data by taking out the data for which the computation has been completed from the output buffer.

  The HDD 115 is a storage unit having a disk-shaped magnetic recording medium. A part of the storage area is a user data storage area 115a for storing user data, and a history management area 115b for storing processed image data as a history. It is used as. The HDD 115 is connected to the bus 120 via the HDD controller 114. The HDD controller 114 issues a command for reading data stored in the HDD 115 and a command for writing data to be stored in the HDD 115 to the HDD 115 based on an instruction from the CPU 101. The HDD 115 performs a process of writing data on the magnetic recording medium based on a command issued from the HDD controller 114, and conversely, a process of reading from the magnetic recording medium.

  In this embodiment, the encryption key generation unit 111, the encryption key storage unit 112, and the encryption / decryption processing unit 113 are mounted as separate hardware. However, the encryption key generation unit 111 and the encryption key storage unit 112 may be configured by one piece of hardware, and the encryption key generation unit 111, the encryption key storage unit 112, and the encryption / decryption processing unit 113 may be configured by one piece of hardware. It is.

  The filing function, data encryption function, and log management function described above can be enabled or disabled by operating the operation panel 105 by the administrator of the apparatus. Therefore, before accepting these settings, first, user authentication is performed by the user authentication unit 106, and the settings are accepted only when the user is authenticated as an administrator.

  FIG. 2 is a schematic diagram illustrating an example of various setting screens displayed on the display unit 105 b of the operation panel 105. FIG. 2A shows an example of a setting screen for turning on / off the filing function. The filing setting screen 11 displays a message asking whether or not to enable the filing function, and includes a selection button 11a that is selected when the filing function is enabled and a selection button 11b that is selected when the filing function is disabled. Has been placed. Similarly, FIG. 2B is an example of a setting screen for turning on / off the encryption function. The encryption setting screen 12 displays a message asking whether or not to enable the encryption function, and a selection button 12a that is selected when the encryption function is enabled and a selection button 12b that is selected when the encryption function is disabled. And are arranged. FIG. 2C shows an example of a setting screen for turning on / off the log management function. The log management setting screen 13 displays a message asking whether or not to enable the log management function, and a selection button 13a that is selected when the log management function is enabled and a selection button 13b that is selected when the log management function is disabled. And are arranged.

Hereinafter, processing executed by the digital multi-function peripheral 100 will be described.
FIG. 3 is a flowchart for explaining the operation of the digital multi-function peripheral 100 when the power is turned on. When the power of the digital multifunction peripheral 100 is turned on (step S11), the CPU 101 refers to the encryption key generation flag management unit 104c in the management unit 104 and determines whether or not the flag is set to “1” (step S11). Step S12).

  When it is determined that the flag is set to “1” (S12: YES), the CPU 101 executes the first encryption key generation program 111a by giving an instruction to the encryption key generation unit 111, and the encryption key (the first encryption key). Key) is generated (step S13). The CPU 101 stores the encryption key generated by the encryption key generation unit 111 in the encryption key storage unit 112 (step S14). After the encryption key is stored, the digital multi-function peripheral 100 enters a standby state waiting for user operations, external data, and the like (step S15).

  As a result of referring to the encryption key generation flag management unit 104c, when it is determined that the flag is not set to “1” (S12: NO), the CPU 101 determines whether or not the flag is set to “2”. (Step S16).

  When it is determined that the flag is set to “2” (S16: YES), the CPU 101 gives an instruction to the encryption key generation unit 111 to execute the second encryption key generation program 111b and execute an encryption key (second encryption). Key) is generated (step S17). The CPU 101 stores the encryption key generated by the encryption key generation unit 111 in the encryption key storage unit 112 (S14). After the encryption key is stored, the digital multifunction peripheral 100 enters a standby state (S15). If it is determined in step S16 that the flag is not set to “2” (S16: NO), the process proceeds to a standby state without generating an encryption key (S15).

  FIG. 4 is a flowchart for explaining the operation when the digital multi-function peripheral 100 is installed. The CPU 101 determines whether or not initial setting has been performed (step S21). The initial settings are settings performed by the apparatus administrator when the digital multifunction peripheral 100 is installed for the first time or when the installation environment is changed, such as setting its own communication address, energy saving setting, and paper size to be used. Contains settings related to the usage environment. Initial settings can be made through the operation panel 105.

  If it is determined that initialization has been performed (S21: YES), an encryption key is generated (step S22). The encryption key generated at this stage is the first encryption key, and the CPU 101 generates the first encryption key by executing the first encryption key generation program 111a by giving an instruction to the encryption key generation unit 111. Next, the CPU 101 stores the encryption key generated by the encryption key generation unit 111 in the encryption key storage unit 112 (step S23). Then, the CPU 101 sets the flag managed by the encryption key generation flag management unit 104c to “1” (step S24).

  If it is determined in step S21 that initialization has not been performed (S21: NO), the CPU 101 determines whether initialization has been performed (step S25). Initialization refers to a process for returning the setting value relating to the use environment to the initial value, and is performed through the operation panel 105. If it is determined that initialization has been performed (S25: YES), the processing from step S22 to step S24 described above is executed. As a result, the first encryption key is stored in the encryption key storage unit 112, and the flag managed by the encryption key generation flag management unit 104c is set to “1”.

  If it is determined in step S25 that initialization has not been performed (S25: NO), the CPU 101 determines whether the encryption function is turned on through the encryption setting screen 12 shown in FIG. (Step S26). If it is determined that the encryption function is turned on (S26: YES), the processing from step S22 to step S24 described above is executed. As a result, the first encryption key is stored in the encryption key storage unit 112, and the flag managed by the encryption key generation flag management unit 104c is set to “1”.

  If it is determined in step S26 that the encryption function is not turned on (S26: NO), the CPU 101 determines whether or not the log management function is turned on through the log management setting screen 13 shown in FIG. (Step S27). If it is determined that the log management function is turned on (S27: YES), the processing from step S22 to step S24 described above is executed. As a result, the first encryption key is stored in the encryption key storage unit 112, and the flag managed by the encryption key generation flag management unit 104c is set to “1”.

  If it is determined in step S27 that the log management function has not been turned on (S27: NO), the processing by this routine is terminated. In this case, the flag value managed by the encryption key generation flag management unit 104c holds the value at the start of this routine.

  FIG. 5 is a flowchart for explaining a procedure of processing executed in the standby state. In a standby state in which a user's operation, external data, and the like are awaited, the CPU 101 determines whether or not unauthorized access is accepted at an appropriate time interval (step S31). For example, when an unauthorized read request is received for data stored in the user data storage area 115a, or when an unauthorized processing request is received through the operation panel 105, it is determined that an unauthorized access has been received (S31: YES), the encryption key stored in the encryption key storage unit 112 is erased (step S32).

  The CPU 101 then executes the second encryption key generation program by giving an instruction to the encryption key generation unit 111, and generates a new encryption key (second encryption key) (step S33). The CPU 101 stores the generated encryption key in the encryption key storage unit 112 (step S34), and sets the flag managed by the encryption key generation flag management unit 104c to “2” (step S35).

  If it is determined in step S31 that unauthorized access has not been accepted (S31: NO), the CPU 101 determines whether or not the data (encrypted data) stored in the user data storage area 115a has been deleted (step S31). S36). If it is determined that the encrypted data has been erased (S36: YES), the processing from step S32 to step S35 described above is executed. As a result, the second encryption key is stored in the encryption key storage unit 112, and the flag managed by the encryption key generation flag management unit 104c is set to “2”.

  When it is determined in step S36 that the encrypted data has not been erased (S36: NO), it is determined whether an encryption key change request has been received through the operation panel 105 (step S37). If it is determined that an encryption key change request has not been accepted (S37: NO), the processing of this routine is terminated.

  If an encryption key change request is accepted (S37: YES), the CPU 101 displays an input screen on the display unit 105b of the operation panel 105 to request an administrator code input (step S38). The CPU 101 determines whether an administrator code has been input through the input screen displayed on the display unit 105b (step S39). When it is determined that the administrator code has not been input (S39: NO), the process waits until the administrator code is input. When it is determined that the administrator code has been input (S39: YES), the administrator code is assigned. Based on this, it is determined whether or not the administrator can be authenticated (step S40).

  If it is determined that the administrator cannot be authenticated (S40: NO), the process according to this routine is terminated. If it is determined that the administrator can be authenticated (S40: YES), the processes from step S32 to step S35 described above are executed. To do. As a result, the second encryption key is stored in the encryption key storage unit 112, and the flag managed by the encryption key generation flag management unit 104c is set to “2”.

  As described above, in this embodiment, since the encryption key to be used is changed when unauthorized access is accepted, for example, the data read from the user data storage area 115a cannot be decrypted. Thus, information leakage is prevented.

  FIG. 6 is a flowchart for explaining the procedure of processing executed when data is received from the outside. When data is received by the image input unit 107 (step S51), the CPU 101 expands the received data into image data for output (step S52). Specifically, when an image of a document is optically read by the image input unit 107, image processing such as scaling and density adjustment is performed based on setting conditions instructed through the operation unit 105a, and an output image Get the data. When the image input unit 107 receives a print job from an external computer, the image data for output is acquired by decoding PDL (Page Description Language) describing the print job. Further, when facsimile data is received by the image input unit 107, output facsimile data is obtained by decoding the facsimile data. The developed image data is temporarily stored in the buffer memory 109.

  Next, the CPU 101 determines whether or not saving by the filing function is instructed (step S53). Data storage by the filing function is performed when the user gives an instruction through the operation unit 105a, when the default operation of the apparatus is set on the filing setting screen 11 shown in FIG. 2A, or at the time of print processing This is performed when it is designated by a print job. The CPU 101 acquires these pieces of information to determine whether data storage is instructed.

  If it is determined that storage is instructed by the filing function (S53: YES), the CPU 101 determines whether the encryption function is valid (step S54). That is, whether or not the encryption function is effective is determined by determining whether or not encryption of data to be stored by the filing function is specified on the encryption setting screen 12 shown in FIG. Judgment is made.

  If it is determined that the encryption function is valid (S54: YES), the image data is encrypted (step S55). In other words, the image data is encrypted by transferring the output image data stored in the buffer memory 109 and the encryption key stored in the encryption key storage unit 112 to the encryption / decryption processing unit 113. Then, the CPU 101 instructs the HDD controller 114 to store the encrypted image data in the user data storage area 115a in the HDD 115 (step S56).

  If it is determined in step S54 that the encryption function is not valid (S54: NO), the image data is stored in the user data storage area 115a in the HDD 115 without encrypting the image data (step S57).

  When the storage of the image data in the user data storage area 115a is completed (S56, S57), or when it is determined in step S53 that storage by the filing function is not instructed (S53: NO), the CPU 101 performs log management. It is determined whether or not the function is valid (step S58). That is, it is determined whether or not the log management function is specified to be enabled on the log management setting screen 13 shown in FIG.

  If it is determined that the log management function is valid (S58: YES), the image data is encrypted (step S59). In other words, the image data is encrypted by transferring the output image data stored in the buffer memory 109 and the encryption key stored in the encryption key storage unit 112 to the encryption / decryption processing unit 113. If the image data is encrypted by the process at step S55, the process at step S59 may be omitted. Then, the CPU 101 instructs the HDD controller 114 to store the encrypted image data in the history management area 115b in the HDD 115 (step S60).

  When the storage of the image data in the history management area 115b is completed (S60), or when it is determined in step S58 that the log management function is not valid (S58: NO), an output process is executed (step S61). In the output process, the image data held in the buffer memory 109 is transferred to the image output unit 110 to form an image on a sheet, send the image data to an external computer, or send the facsimile data to an external facsimile apparatus. Send.

  In the present embodiment, only the administrator can view the history managed in the history management area 115b. FIG. 7 is a flowchart for explaining the processing procedure for confirming the history stored in the history management area 115b. The CPU 101 determines whether a history browsing request has been received through the operation panel 105 (step S71). When the browsing request is not received (S71: NO), it waits until the browsing request is received.

  If it is determined that the browsing request has been accepted (S71: YES), an input screen is displayed on the display unit 105b of the operation panel 105 to request an input of an administrator code (step S72). The CPU 101 determines whether an administrator code has been input through the input screen displayed on the display unit 105b (step S73). If it is determined that the administrator code has not been input (S73: NO), the process waits until the administrator code is input. If it is determined that the administrator code has been input (S73: YES), the administrator code is assigned. Based on this, it is determined whether or not the administrator can be authenticated (step S74).

  When it is determined that the administrator cannot be authenticated (S74: NO), the process according to this routine is terminated, and when it is determined that the administrator can be authenticated (S74: YES), the history of the process is stored in the history management area 115b. The existing image data is decoded (step S75). Specifically, the data stored in the history management area 115b is read out, temporarily held in the buffer memory 109, and transferred to the encryption / decryption processing unit 113 together with the encryption key stored in the encryption key storage unit 112. To perform decryption. Then, the history is displayed by displaying the decoded image data on the display unit 105b (step S76).

Embodiment 2. FIG.
In the first embodiment, two types of encryption keys are generated by a program stored in advance in the encryption key generation unit 111, but an encryption key is generated using an encryption key generation unit configured as hardware. It may be. In the present embodiment, an encryption key generating unit configured by hardware will be described. Since the configuration other than the encryption key generation unit is exactly the same as that of the first embodiment, the description thereof will be omitted.

  FIG. 8 is a block diagram showing the internal configuration of the encryption key generation unit. The encryption key generation unit 121 according to the present embodiment includes a controller 121a, a first encryption key generation circuit 121b, a second encryption key generation circuit 121c, and an output buffer 121d. The controller 121a temporarily holds the unique information transferred from the unique information storage unit 104d, and in addition to the first encryption key generation circuit 121b or the second encryption key generation circuit 121c based on an instruction from the CPU 101. The stored unique information is sent out. That is, the controller 121a constitutes a switch circuit that operates based on an instruction from the CPU 101.

  The first encryption key generation circuit 121b includes a register that holds unique information (plaintext data) sent from the controller 121a, a division register for dividing the plaintext data held in the register into a plurality of blocks, and a divided block. On the other hand, it is composed of an arithmetic unit that performs operations such as inversion, logical product, addition, and rotation. The encryption key (first encryption key) generated by the first encryption key generation circuit 121b is sent to the output buffer 121d, and is output to the encryption key storage unit 112 through the output buffer 121d.

  The second encryption key generation circuit 121c has the same circuit configuration as the first encryption key generation circuit 121b, and generates an encryption key different from the encryption key generated by the first encryption key generation circuit 121c. The encryption key (second encryption key) generated by the second encryption key generation circuit 121c is sent to the output buffer 121d and output to the encryption key storage unit 112 through the output buffer 121d.

1 is a block diagram showing an internal configuration of a digital multifunction peripheral according to an embodiment. It is a schematic diagram which shows an example of the various setting screens displayed on the display part of an operation panel. 5 is a flowchart for explaining the operation of the digital multi-function peripheral when power is turned on. 6 is a flowchart for explaining an operation at the time of installation of the digital multifunction peripheral. It is a flowchart explaining the procedure of the process performed in a standby state. It is a flowchart explaining the procedure of the process performed when data are received from the outside. It is a flowchart explaining the process sequence in the case of confirming the log | history memorize | stored in the log | history management area | region. It is a block diagram which shows the internal structure of an encryption key production | generation part.

Explanation of symbols

100 Image processing apparatus 101 CPU
102 ROM
103 RAM
104 Management Unit 105 Operation Panel 107 Image Input Unit 108 Image Processing Unit 109 Buffer Memory 110 Image Output Unit 111 Encryption Key Generation Unit 112 Encryption Key Storage Unit 113 Encryption / Composite Processing Unit 114 HDD Controller 115 HDD

Claims (11)

In an image processing apparatus comprising storage means for storing image data, and performing processing based on the image data read from the storage means,
An encryption key generation unit that generates an encryption key, a control unit that controls the timing at which the encryption key generation unit generates an encryption key, and a storage unit that stores the encryption key generated by the encryption key generation unit An image processing apparatus comprising: means for encrypting image data; and means for decrypting image data read from the storage means.   A means for receiving an encryption key generation instruction is provided, and when the generation instruction is received by the means, the control means controls the encryption key generation means to generate an encryption key. The image processing apparatus according to claim 1.   A means for accepting selection relating to the necessity of encryption of the image data; and when the selection requiring encryption is accepted, the control means controls the encryption key generation means to generate an encryption key. The image processing apparatus according to claim 1, wherein:   2. The image processing according to claim 1, wherein when the power to supply power to each of the units is turned on, the control unit controls the encryption key generation unit to generate an encryption key. apparatus.   The image processing apparatus according to claim 1, wherein the encryption key generation unit is capable of generating a plurality of types of encryption keys using a plurality of algorithms.   6. The encryption key generation unit is configured to generate an encryption key using one of the algorithms, and includes a switching unit that switches an algorithm used for generating the encryption key to another algorithm. An image processing apparatus according to 1.   6. The encryption key generation means includes a plurality of encryption key generation circuits corresponding to each algorithm, and the encryption key generation circuit generates a plurality of types of encryption keys. Image processing apparatus.   A means for receiving an erasure instruction for image data stored in the storage means; and a means for erasing the image data when the erasure instruction is accepted by the means. When the image data is erased, the switching is performed. 8. The image processing apparatus according to claim 5, wherein the means is configured to switch an algorithm used for generating the encryption key.   The means for judging whether or not an illegal read request for the image data stored in the storage means has been accepted, and the switching means, when judging that the illegal read request has been accepted, switches the algorithm used for generating the encryption key. The image processing apparatus according to claim 5, wherein the image processing apparatus is configured as described above.   The means for judging whether or not an illegal processing request based on the image data read from the storage means has been accepted, and the switching means for generating an encryption key when judging that the means has accepted an illegal processing request. 8. The image processing apparatus according to claim 5, wherein an algorithm to be used is switched.   11. The apparatus according to claim 1, further comprising a unit that stores information unique to the apparatus, wherein the encryption key generation unit generates an encryption key based on the information. Image processing apparatus.

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