JP4608949B2 - Data destruction detection device and method, and data recovery device and method - Google Patents

Description

  The present invention relates to a data destruction detection apparatus and method, a data restoration apparatus and method, and an image forming apparatus management apparatus. For example, the present invention relates to an image forming apparatus such as a printer, a facsimile machine, a copier, and a multifunction machine having these functions. The present invention relates to a data destruction detection apparatus and method for detecting data destruction relating to usage conditions and usage restrictions, a data recovery apparatus and method using the same, and an image forming apparatus management apparatus using the data destruction detection method or data recovery apparatus.

  Image forming apparatuses such as printers, facsimile machines, copiers, and multifunction machines having these functions often incorporate a management apparatus for storing user management information or are externally connected to the management apparatus. In such a management apparatus, when the user management information on the memory is destroyed due to hardware factors or software factors (for example, bugs), three problems mainly occur as follows.

  First, there is a problem that the management apparatus cannot manage users correctly. The management apparatus has a function of authenticating a user who intends to use the image forming apparatus and granting permission to use the image forming apparatus. For this reason, when the user management information is destroyed, the management apparatus cannot correctly manage the user, and a user who can use the image forming apparatus originally cannot use the image forming apparatus.

  Secondly, there arises a problem that the management apparatus cannot count the usage records of the image forming apparatus. In many cases, the management apparatus has a function of counting the usage records of the image forming apparatus. For this reason, when the above problem occurs, the user who has used the image forming apparatus cannot be known, the user who has not used the image forming apparatus has used the image forming apparatus, or the usage record value becomes normal information. The problem of not becoming (abnormal value) will also occur.

  Thirdly, in a system in which the management apparatus authenticates a plurality of image forming apparatuses based on the usage record information, an error occurs in the usage record of the user, causing a problem that hinders the user's business. For example, in the case where the upper limit number of users that can be used is managed, the user may not be able to use the system if the actual number of used records becomes a large value due to destruction of the user management information.

  In order to avoid such data destruction on the memory, the following techniques have been proposed.

  Patent Document 1 proposes a RAM protection device for a copying apparatus that protects important specific stored data such as a program by designating an arbitrary area of a random access memory as a protection area for prohibiting writing. The RAM protection device of the copying apparatus includes a protection unit that prohibits a write operation to a specific area of the RAM, a protection area setting unit that sets the protection area, a write permission unit that permits writing to the protection area, And an abnormal operation detecting means for detecting an abnormal operation to be written to the protected area where writing is prohibited, and an abnormal signal is output when the abnormal operation is detected by the abnormal operation detecting means.

Patent Document 2 proposes a counting device that improves the reliability of the soft counter. The counting device includes an execution detecting means for detecting that a predetermined operation has been executed, a plurality of storage means for commonly storing information relating to the number of executions each time the execution is detected, and storing the information. When performing, when it is detected that the information stored in each storage means has been destroyed, and when the information in one storage means is detected to be destroyed, The present invention is characterized in that a correction means for correcting using the information in the storage means is provided.
JP-A-5-020202 JP 2000-089622 A

  However, the techniques described in Patent Documents 1 and 2 cannot be used in an image forming system due to cost and design reasons.

  In addition, the management device is required to have high responsiveness to changes in the state of the image forming apparatus (for example, paper feed, paper discharge). However, the techniques described in Patent Documents 1 and 2 are not very responsive and may not meet the above requirements.

  The present invention has been proposed in order to solve the above-described problem, and a data destruction detection apparatus and method for detecting destruction of data related to a user without protecting the response, and protecting the data, and data recovery. An object is to provide an apparatus and method.

Data corruption detection apparatus according to the present invention, for managing the user management information, and data management information including at least an update flag indicating that it is updated if a hash value and on the user management information a storage means for storing, and the user management information, and copying the data management information stored in the storage means, and control means for performing control to store a plurality of said data management information in said storage means calculates a digest value of a plurality of said data management information stored in the storage means for each of said data management information, based on whether or not all the calculated digest value matches, the data management information issued for computing and data management information breakdown detecting means for detecting the presence or absence of destruction, the hash value of the user management information stored in said storage means Whether or not the user management information is destroyed is detected based on whether or not the value calculation means, the hash value included in the data management information, and the hash value calculated by the hash value calculation means match. And when the update process is interrupted during the update process of the plurality of data management information, the number of the data management information in which the update flag is off is the update flag is on If more than the number of the data management information, the hash value of the data management information for which the update flag is off is overwritten on the hash value of the data management information for which the update flag is on, and If the number of the data management information for which the update flag is off is less than the number of the data management information for which the update flag is on, the update flag Grayed is provided with, and excludes the data management information updating means from the detection target of the data management information the user management information fracture detection means is on.

Data corruption detection method according to the present invention, for managing the user management information, and data management information including at least an update flag indicating that it is updated if a hash value and on the user management information A control step for performing a control of copying the data management information from a storage unit storing the user management information and storing a plurality of data management information in the storage unit ; and storing the user management information in the storage unit calculating a plurality of the digest value of the data management information for each of said data management information, based on whether or not all the calculated digest value matches, the data management information for detecting the presence or absence of destruction of the data management information a breakdown detection process, reads the user management information from the storage unit, and the hash value calculation step of calculating a hash value of the user management information, before Whether or not the user management information is destroyed based on whether or not the hash value included in the data management information stored in the storage unit matches the hash value calculated by the hash value calculation step When the update process is interrupted during the user management information destruction detection step for detecting the update and a plurality of update processes for the data management information, the number of the data management information for which the update flag is off indicates that the update flag is on. And the hash value of the data management information for which the update flag is off is overwritten on the hash value of the data management information for which the update flag is on, When the number of the data management information whose update flag is off is smaller than the number of the data management information whose update flag is on, New flag includes a exclude data management information updating step from detection target of the data management information the user management information fracture detection means is on, the.

The data management information is information including at least a hash value of the user management information for managing the user management information and an update flag indicating that updating is performed when the user management information is on, and is stored in a storage unit in advance. Has been. The data management information is used, for example, when reading user management information or checking user management information. The storage means stores user management information and data management information. Here, while the user management information is being used, the user management information may be destroyed due to hardware factors or software factors.

  The control means performs control for copying the data management information stored in the storage means as it is and storing a plurality of the same data management information in the storage means. Thereafter, the data management information is read each time the user management information is used. However, data management information may be destroyed due to hardware factors or software factors.

Therefore, the data management information destruction detection means calculates the digest values of the plurality of data management information stored in the storage means for each of the data management information, and determines whether all the calculated digest values match. On the basis of the result, the presence or absence of destruction of the data management information is detected. Here, the data management information is not destroyed when they all match, and the data management information is destroyed when there is a mismatched portion. The hash value calculation means calculates a hash value for the user management information stored in the storage means. Then, the user management information destruction detection unit detects whether the user management information is destroyed based on the hash value included in the data management information and the calculated hash value. That is, when these hash values do not match, it is considered that the user management information has been destroyed, and thereby, the destruction of the data management information is detected.

In the data recovery device according to the present invention, when the data destruction detection device and the data destruction detection device detect that the data management information is destroyed, the number of data management information that coincides When the user management information is detected to be destroyed by the data management information data recovery means for recovering other data management information based on the data management information having the largest number of data management information and the data destruction detection device, the user management User management information data recovery means for reading the user management information from an information storage device storing information in advance and recovering the user management information destroyed in the storage means .

In the data recovery method according to the present invention, when the data destruction detection method and the data destruction detection method detect that the data management information is destroyed, the number of data management information that matches is detected. User management information when it is detected that the user management information is destroyed by the data destruction information recovery step and the data destruction detection method based on the data management information having the largest number of data management information. A user management information recovery step of reading the user management information from the information storage device storing the information in advance and recovering the user management information destroyed in the storage unit .

  When it is detected that the data management information is destroyed, it is usually considered that a small number of data management information is destroyed, not all of the plurality of data management information.

Therefore, when the data management information recovery means detects that the data management information is destroyed, the data management information recovery means, based on the data management information with the largest number of matching among the plurality of data management information, Restore management information. Thus, data can be recovered without providing special data protection hardware.

The user management information recovery means reads the user management information from an information storage device that stores user management information in advance. That is, since user management information is read from a location different from the location where the data is destroyed, the user management information can be reliably recovered without being affected by the data destruction.

The image forming apparatus management apparatus according to the present invention is configured to detect when the data management information is destroyed by the data destruction detection method and when the user management information is detected to be destroyed. In at least one of the cases, the image forming apparatus use prohibiting means for prohibiting the use of the connected image forming apparatus, or the period during which the data management information is recovered by the data recovery method and the data management information are recovered. The image forming apparatus use prohibiting means for prohibiting the use of the connected image forming apparatus can be provided in at least one of the periods .

  The data destruction detection apparatus and method according to the present invention can reliably detect unexpected data destruction. The data recovery apparatus and method according to the present invention can recover corrupted data without providing hardware for data protection.

  The image forming apparatus management apparatus according to the present invention can be managed to prohibit use of the image forming apparatus when data destruction is detected or during a period in which data management information is restored.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[System configuration]
FIG. 1 is a diagram showing an overall configuration of an image forming system according to an embodiment of the present invention. The image forming system 1 includes a plurality of multifunction peripherals 10, a plurality of management devices 20 provided corresponding to the multifunction peripherals 10, and a management server 30 that manages the entire system.

  The multifunction machine 10 has functions of copying, facsimile transmission / reception, and printing, and can execute the above functions after a user ID is input to the management apparatus 20.

  The management apparatus 20 is connected to the multifunction machine 10 to be managed. The management device 20 may be externally connected to the multifunction device 10 or may be provided inside the multifunction device 10.

  The management device 20 stores user management information for managing users who use the multifunction device 10 and data management information for managing user management information.

  When a user ID is input to the multifunction device 10, the management device 20 determines whether to permit or prohibit the use of the multifunction device 10 based on the user management information, and switches the state of the multifunction device 10 according to the determination result. Further, even when the multifunction device 10 gives the user permission to use the multifunction device 10, the color copying is prohibited or the upper limit number of usable papers is set so that the user can use the multifunction device 10. Restrictions can also be made.

  The management server 30 is connected to each management apparatus 20 via a communication line (for example, a LAN or a telephone line). The management server 30 reads user management information from all the management devices 20 and manages the user management information of the entire system in an integrated manner. The management server 30 can also set usage restrictions on the functions of the multifunction machine 10 for each user, or set usage restrictions for each multifunction machine 10.

  Further, the management server 30 reads the user management information from the management device 20 as necessary, updates a part of its own user management information, or uses the user management information of the predetermined management device 20. Update user management information. Furthermore, the management server 30 can accumulate and aggregate the usage results of the user's multifunction machine 10.

  FIG. 2 is a block diagram illustrating a configuration of the management apparatus 20.

  The management device 20 includes an operation unit 21 for a user to perform a predetermined operation, a display unit 22 for displaying the contents of user management information and predetermined information, a user reception unit 23 for receiving information such as a user ID, and the multifunction machine 10. A multifunction device control unit 24 for controlling the management server, a management server communication unit 25 for communicating with the management server 30, a storage unit 26 for storing data management information, user management information, management device setting information, etc. And a control unit 27 that controls the entire apparatus.

  FIG. 3 is a diagram illustrating a configuration of data management information and user management information stored in the management apparatus 20. Each data management information is associated with predetermined data management information.

  The user management information represents the usage status and usage restrictions of the user's multifunction machine 10. Specifically, the user management information includes “user ID”, “current total number of used sheets”, “total number of used conditions”, “number of used black and white prints”, “upper number of black and white prints”, “color printing” “Number of sheets used”, “maximum number of sheets for color printing”, and “next information pointer” indicating a pointer to next user management information.

  The “next information pointer” represents the head position of user management information following the user management information. The user management information is continuous with other user management information by the “next information pointer”. Hereinafter, the user management information that is continuous by the “next information pointer” is referred to as a “linear list”. The linear list includes not only two or more continuous user management information but also only one user management information. When the “next information pointer” is blank or predetermined information (NULL), the user management information is the end point of the linear list.

  It should be noted that the user management information shown here is merely an example, and it is needless to say that other configurations may be used.

  The data management information is information for managing each corresponding linear list (one or more user management information), and has “linear list head pointer”, “update flag”, and “hash value”. .

  The “linear list head pointer” represents the head storage position of the corresponding linear list. The “update flag” is a flag indicating whether or not the user management information is being updated. The flag is turned on when updating and is turned off when not updating. “Hash value” indicates the hash value of the entire corresponding linear list. The hash value is not particularly limited as long as it can be used as an error check code, and may be a digest value (for example, CRC value, MD5 value, etc.).

  The control unit 27 of the management apparatus 20 shown in FIG. 2 copies the data management information and develops, for example, three identical data management information on the storage unit 26 for one linear list.

  In the image forming system configured as described above, when the user ID is input, the management apparatus 20 permits use of the multifunction device 10 and restricts use of the multifunction device 10 as follows. The usage status of the multifunction machine 10 is managed.

[Permission to use MFP 10]
When the control unit 27 of the management apparatus 20 detects that a user ID of a certain user is input via the user ID receiving unit 23, the control unit 27 calculates a hash value using a hash function as shown in FIG. The control unit 27 selects a set (one or more data management information) corresponding to the hash value, and selects data management information corresponding to the user ID from the set. When there is no user management information corresponding to the user ID, the control unit 27 newly generates user management information and registers it in the storage unit 26.

  Next, the control unit 27 reads the first user management information of the linear list from the storage position described in the linear list head pointer of the selected data management information. If the read user management information is not for the desired user, the control unit 27 reads another user management information from the storage location described in the “next information pointer”.

  After reading out the desired user management information, the control unit 27 determines whether the user is permitted to use or not to be used based on the user management information. For example, when the “current total number of used sheets” of the user management information has reached the “total number of used conditions”, the “maximum number of black and white printing” and the “upper number of color printing” are both set to zero. In this case, it becomes unavailable. If it does not fall under any of the above, it will be used.

  When the control unit 27 determines that the use is permitted for the user, the control unit 27 transmits a use permission notification signal to the multi-function device 10 via the multi-function device control unit 24. As a result, the multifunction machine 10 accepts the use of the user.

[Update user management information]
When the multifunction machine 10 is used by a user, the control unit 27 of the management apparatus 20 updates the user management information to reflect the usage status. For example, when the user causes the multifunction machine 10 to execute monochrome printing, the control unit 27 updates the “current total number of used pages” and “number of used pages for monochrome printing” of the user management information.

  The control unit 27 can also add new user management information to the storage unit 26 when a new user is registered via the operation unit 21 or the user reception unit 23.

[Update data management information]
The control unit 27 of the management apparatus 20 updates the data management information when updating the user management information or adding user management information (for example, when registering a new user). Hereinafter, a case where the user management information is updated and the data management information is updated along with the user management information will be described as an example.

  First, the control unit 27 turns on the “update flag” of the data management information corresponding to the linear list including the updated user management information, and declares that the data management information is being updated.

  Next, the control unit 27 calculates a new hash value for the linear list including the updated user management information. Finally, the control unit 27 overwrites the “hash value” of the data management information with a new hash value, then turns off the “update flag” and ends the process.

  Thereby, the “update flag” is turned on when the data management information is being updated, but is turned off when the update processing has been completed.

  In the present embodiment, there are three pieces of data management information having the same configuration. Therefore, the control unit 27 executes the update process as described above for each data management information.

[Processing after update processing is interrupted]
When the control unit 27 of the management apparatus 20 interrupts the power management or the like (1) the user management information addition process is interrupted, or (2) the data management information update process (hash value update process) is interrupted, The following processing is executed.

(1) When adding user management information If the user management information addition process is interrupted, it may be added again, and it is not a big problem that only the new data added is lost.

  Therefore, the control unit 27 of the management apparatus 20 refers to each of the three pieces of data management information, and determines the number of data management information that suggests that the user management information has been added.

  If there are two pieces of data management information suggesting that user management information has been added, the control unit 27 may register the user management information as it is. On the other hand, when there is only one data management information suggesting that user management information has been added, the control unit 27 may delete the registration of the user management information (delete from the storage unit 26). However, in this case, re-registration of user management information is required.

(2) At the time of data management information update processing When the data management information update processing (hash value update processing) is interrupted, the control unit 27 checks the “update flag” of each of the three data management information and turns it on. Alternatively, the number of “update flags” that are turned off is determined. The reason is that it is possible to determine how much the update of the three data management information is completed by confirming the number of “update flags” which are turned on or off.

  Specifically, when there is one ON “update flag” and two OFF “update flags”, the update of two of the three data management information has been completed. Therefore, the control unit 27 overwrites the “hash value” of the data management information having the “update flag” of OFF with the “hash value” of the other data management information. Accordingly, the control unit 27 can update the “hash value” of each data management information to the same value.

  On the other hand, if there are two “update flags” that are on and one “update flag” that is off, the “hash values” are different and an error occurs. Therefore, the control unit 27 may remove the “update flag” from the inspection target, or use a hash function that can identify a garbled place and can be corrected.

[Detection and recovery of destruction of data management information]
The control unit 27 of the management device 20 detects the destruction of the data management information in the storage unit 26 by performing the following processing.

  Specifically, the control unit 27 determines whether or not the three pieces of data management information match at regular time intervals (match test). As the coincidence test, there are a method of comparing all areas of the data management information and calculating and comparing digest values (for example, CRC value, MD5 value, etc.) of the data management information.

  When the three pieces of data management information match, the control unit 27 determines that “data management information is not destroyed”, and when they do not match, detects “data management information is destroyed”. Note that the control unit 27 can increase the usefulness of the data that can be acquired by log registration at the time of abnormality detection if the time interval for performing the coincidence test within a range that does not hinder the operation is sufficiently small.

  When the destruction of the data management information is detected, the control unit 27 restores the destroyed data management information by majority decision of each data management information.

  Specifically, among the three data management information, the control unit 27 treats the data management information that matches each other as not destroyed, and treats the data management information that does not match as destroyed. The control unit 27 restores the destroyed data management information by overwriting the undestructed data management information over the destroyed data management information.

  As described above, the management apparatus 20 according to the embodiment of the present invention copies the data management information and stores the three data management information, based on whether the three data management information matches. By detecting the destruction of the data management information, it is possible to reliably detect the unexpected data destruction.

  Further, when the management device 20 detects data destruction, it is necessary to provide memory protection hardware by overwriting and copying the data management information that has not been destroyed to the data management information that has been destroyed. Data recovery can be performed automatically while maintaining high responsiveness. As a result, the management apparatus 20 can access the user management information using the data management information.

[Detection and recovery of user management data corruption]
The control unit 27 of the management device 20 detects the destruction of the user management information in the storage unit 26 by performing the following processing. Prior to the destruction detection, the control unit 27 determines whether the “update flag” of the data management information is on or off, and performs the next process using the determination result.

(1) When the determination flag is off The control unit 27 determines one or more pieces of user management information that are consecutive according to the linear list to be checked (“next information pointer”) based on the “linear list head pointer” of the data management information. ) To calculate the hash value of this linear list. Then, the control unit 27 determines whether or not the “hash value” of the data management information stored in the storage unit 26 matches the calculated hash value. The control unit 27 determines that “the user management information is not destroyed” when the two hash values match, and detects “the destruction of the user management information” when they do not match.

  When the control unit 27 detects the destruction of the user management information, the control unit 27 downloads the user management information to be checked from the management device 20 via the management server communication unit 25, and the user management information in which the destruction is detected. Is overwritten. Note that the control unit 27 may download not only the user management information to be checked but also all user management information and overwrite all user management information.

  After detecting the destruction of the user management information, the control unit 27 notifies the multifunction device 10 that the multifunction device 10 cannot be used via the multifunction device control unit 24. At this time, the control unit 27 not only disables all functions of the multifunction machine 10 but also notifies some functions that cannot be used (for example, user authentication by the management apparatus 20, data update function, etc.). Also good.

  Further, when the function of the multifunction device 10 is stopped, the control unit 27 may leave a stop log indicating that the function of the multifunction device 10 is stopped. The contents of the stop log may be, for example, stop time, task handler address, etc., so that software bugs can be easily traced. This makes it possible to analyze the destruction factor.

  Further, the control unit 27 may notify the management server 30 of the occurrence of abnormality via the management server communication unit 25.

(2) When the determination flag is on As described above, the control unit 27, based on the “linear list head pointer” of the data management information, checks the linear list to be checked (one continuous by the “next information pointer”). The above user management information) is read out, and the hash value of this linear list is calculated.

  The control unit 27 overwrites the “hash value” of the data management information stored in the storage unit 26 with the calculated hash value, and finally turns off the “update flag” of the data management information. Thus, when the data management information update process is being performed, the control unit 27 executes the hash value update process with priority over the destruction detection.

  As described above, the management device 20 according to the embodiment of the present invention calculates the hash value of the linear list (one or more continuous user management information) to be checked, and calculates the calculated hash value and the storage unit 26. It is possible to reliably detect an unexpected data destruction based on whether or not the “hash value” of the data management information stored in FIG.

  Moreover, since the management apparatus 20 does not provide hardware for memory protection by reading the user management information from the management server 30 when the destruction of the user management information is detected, while maintaining high responsiveness, User management information can be restored.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can also be applied to a design modified within the scope described in the claims.

  In the above embodiment, the MFP 10 has been described as an example of the management target of the management apparatus 20, but the present invention is not limited to this. For example, the management target of the management device 20 may be a device (computer) in which a predetermined program is installed.

  In addition, the control unit 27 of the management apparatus 20 generates three data management information by copying one data management information, but not limited to three, generates four or more data management information. Also good.

  In the above embodiment, the management apparatus 20 can execute various processes after detecting data destruction, but may execute only one of these processes or perform only a plurality of arbitrary processes. May be executed.

1 is a diagram illustrating an overall configuration of an image forming system according to an embodiment of the present invention. It is a block diagram which shows the structure of a management apparatus. It is a figure which shows the structure of the data management information in a management apparatus, and user management information.

Explanation of symbols

10 MFP 20 Management Device 24 MFP Control Unit 26 Storage Unit 27 Control Unit 30 Management Server

Claims (6)

Data management information for managing user management information, including at least a hash value of the user management information and an update flag indicating that updating is performed when ON, and the user management information are stored Storage means;
And copying the data management information stored in the storage means, and control means for performing control to store a plurality of said data management information to said storage means,
Calculating a digest value of a plurality of said data management information stored in the storage means for each of said data management information, based on whether or not all the calculated digest value matches, the destruction of the data management information Data management information destruction detection means for detecting the presence or absence of,
Hash value calculation means for calculating a hash value of the user management information stored in the storage means;
User management information destruction that detects whether or not the user management information is destroyed based on whether or not the hash value included in the data management information matches the hash value computed by the hash value computation means Detection means;
If the update process is interrupted during the update process of a plurality of the data management information, the number of the data management information whose update flag is off is larger than the number of the data management information whose update flag is on In the case, the hash value of the data management information whose update flag is off is overwritten on the hash value of the data management information whose update flag is on, and the data whose update flag is off Data that excludes the data management information for which the update flag is on from the detection target of the user management information destruction detection means when the number of management information is smaller than the number of the data management information for which the update flag is on Management information update means;
A data destruction detection device. Data management information for managing user management information, including at least a hash value of the user management information and an update flag indicating that updating is performed when ON, and the user management information are stored A control step of performing a control of copying the data management information from the storage unit and storing a plurality of data management information in the storage unit;
Calculating a digest value of a plurality of said data management information stored in the storage unit for each of the data management information, based on whether or not all the calculated digest value matches, the destruction of the data management information Data management information destruction detection process to detect the presence or absence,
A hash value calculation step of reading the user management information from the storage unit and calculating a hash value of the user management information;
Based on whether or not the hash value included in the data management information stored in the storage unit and the hash value calculated by the hash value calculation step match, the destruction of the user management information User management information destruction detection process to detect presence,
If the update process is interrupted during the update process of a plurality of the data management information, the number of the data management information whose update flag is off is larger than the number of the data management information whose update flag is on In the case, the hash value of the data management information whose update flag is off is overwritten on the hash value of the data management information whose update flag is on, and the data whose update flag is off Data that excludes the data management information for which the update flag is on from the detection target of the user management information destruction detection means when the number of management information is smaller than the number of the data management information for which the update flag is on Management information update process,
A data destruction detection method. A data destruction detection device according to claim 1,
When it is detected that the data management information is destroyed by the data destruction detection device, other data management information is obtained based on the data management information having the largest number of matching among the plurality of data management information. Data management information data recovery means to recover,
When it is detected by the data destruction detection device that the user management information is destroyed, the user management information is read from an information storage device that stores user management information in advance, and is destroyed in the storage means. User management information data recovery means for recovering existing user management information;
Data recovery device with The data destruction detection method according to claim 2 ,
When it is detected that the data management information is destroyed by the data destruction detection method, other data management information is obtained based on the data management information having the largest number of matching among the plurality of data management information. Data management information recovery process to recover,
When it is detected that the user management information is destroyed by the data destruction detection method, the user management information is read from an information storage device that stores user management information in advance, and is destroyed in the storage unit. User management information recovery process for recovering existing user management information;
Data recovery method with. The connection is established when the data management information is detected to be destroyed by the data destruction detection method according to claim 2 and at least one of the cases when the user management information is detected to be destroyed . An image forming apparatus management apparatus including an image forming apparatus use prohibiting unit that prohibits use of an image forming apparatus. The use of the connected image forming apparatus is prohibited during at least one of the period in which the data management information is restored by the data restoration method according to claim 4 and the period in which the data management information is restored. An image forming apparatus management apparatus provided with image forming apparatus use prohibiting means.

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