JP2007279816A - Data processor and data processing method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent the leakage of image information, and to prevent the deterioration of processing efficiency. <P>SOLUTION: In erasing processed data stored in a storage device by overwriting the data only by the preliminarily set overwrite limit, when the processing request of new data is generated during the erasure processing of the processed data, the erasure processing is interrupted. Then, an unerased region 202 whose erasure processing has not been ended is erased by the number of times which is one smaller than the set of overwrite limit, and a temporary erasure region 203 is set. Then, new data are written in the temporary erasure region 203, and the data are overwritten only once in the region where any new data have not been written in the temporary erasure region 203, to be defined as an erased region. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a data processing apparatus and a data processing method for storing data to be processed in a storage device and erasing processed data stored in the storage device after data processing.

  In recent years, a hard disk is used as a storage device for holding image data in image processing apparatuses such as copying machines and printers. However, when these image processing apparatuses are discarded together with the hard disk, there is a problem that information held in the discarded hard disk leaks. For this reason, the necessity of erasing unnecessary information in the hard disk is increasing, and various methods for erasing information in the hard disk have been proposed.

  As a technique for performing such erasing, Patent Document 1 discloses that when there is a new write request to the storage device during the erasure processing of the image information written in the storage device, the erasure processing is temporarily interrupted and unerased. There has been disclosed a technique for effectively preventing a decrease in processing efficiency as well as preventing the outflow of image information by writing image information in an area.

  In this method, new image information is overwritten in the unerased area of the image information written in the storage device, so it seems that the image information in the unerased area is erased. Only one overwrite process is performed.

  However, in a storage device that stores data using magnetic fields such as a hard disk, there is a possibility that the underlying data may not be completely erased by only overwriting the data once. The reason is that there are cases where the contents can be restored by disassembling the HDD (Hard Disk Drive) and reading the residual magnetism on the disk with a special reading device.

  Therefore, as a method for erasing data on the HDD, a US Security Assurance Service (NSA) recommended method (a method of overwriting with a random number for the first time and a second time with a random value for the third time) is generally known. As another method, there is generally known a method for increasing the number of overwriting to further increase the erasing effect.

However, in an image processing apparatus such as a copying machine, every time image processing is performed, image data is erased by performing a predetermined number of times of overwriting, so that the next image processing is performed until the overwriting processing is completed. Cannot be performed and the processing efficiency is reduced.
Japanese Patent Laid-Open No. 2004-357078

  In the conventional image processing apparatus described above, if a specified number of overwriting processes are executed each time image processing is performed in an attempt to reliably prevent leakage of image information, the processing efficiency is reduced. was there.

  An object of the present invention is to provide a data processing apparatus and a data processing method capable of reliably preventing leakage of image information and preventing a decrease in processing efficiency.

[Data processing device]
In order to achieve the above object, a data processing device of the present invention comprises data storage means for storing data to be processed in a storage device;
Erasing data stored in the storage device by the data storage means by erasing the data less than a preset number of overwrites as a temporary erase area, and writing new data on the temporary erase area for erasure Means.

  According to the present invention, when a new data processing request is generated during the processing of erasing processed data, for example, a preset overwrite is performed on an unerased area that has not yet been erased. Temporary erasure that erases less than the number of times is performed, and then writing to the temporary erasure area is performed using new data instead of dummy data, thus reliably preventing leakage of image information At the same time, it is possible to obtain the effect of preventing the processing efficiency from being lowered.

  Preferably, the erasing unit overwrites data in an area in which no new data has been written in the temporary erasing area to erase the data, thereby setting the total number of overwriting as the preset number of overwriting.

  Preferably, when the data stored in the storage device is erased to form a temporary erasure area, the erasure unit performs erasure with a number of times less than a preset overwrite number.

  Preferably, the storage device is a hard disk drive.

  Preferably, the data stored in the storage device is image data.

[Data processing method]
The data processing method of the present invention is a data processing method for storing data to be processed in a storage device and erasing processed data stored in the storage device after data processing,
For the data stored in the storage device, erase the number of times less than the preset number of overwrites to make a temporary erase area,
New data is written on the temporary erase area and erased.

[program]
The program of the present invention is a program for causing a computer to execute a data processing method for storing data to be processed in a storage device and erasing processed data stored in the storage device after data processing. And
Erasing the data stored in the storage device with a number of times less than a preset number of overwrites to form a temporary erase area;
Writing new data on the temporary erasure area and erasing the data.

  As described above, according to the present invention, when a processing request for new data occurs during the processing for erasing processed data, the new data is used instead of dummy data to perform processing data overwrite processing. As a result, it is possible to obtain an effect of reliably preventing leakage of image information and preventing a reduction in processing efficiency.

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a hardware configuration of an image processing apparatus having a data processing apparatus 70 according to an embodiment of the present invention, centering on the data processing apparatus 70.
As shown in FIG. 1, the image processing apparatus according to the present embodiment includes a CPU 10, a RAM 20, a ROM 30, a communication interface unit 40, a user interface unit 50, a FAX interface unit 60, a data processing device 70, The scanner 80, an HDD (Hard Disk Drive) 90, and the print engine 100 are included.

  The communication interface unit 40 performs communication processing with other devices. The user interface unit 50 performs user interface processing such as setting input from the user and display processing for the user. The FAX interface unit 60 performs FAX communication processing with other FAX apparatuses via a telephone line.

  The print engine 100 performs processing for printing image data and the like processed by the data processing device 70. The CPU 10 controls operations of the RAM 20, ROM 30, communication interface unit 40, user interface unit 50, FAX interface unit 60, data processing device 70, scanner 80, and print engine 100.

  The data processing device 70 is, for example, a general-purpose computer in which a data processing program is installed, and performs predetermined data processing on image data captured via the scanner 80 based on an instruction from the CPU 10. Then, when performing data processing, the data processing device 70 temporarily stores image data to be processed in the HDD 90 which is a storage device, and then performs data processing designated by the CPU 10.

The data processing program controls the operation of the data processing device 70 by being read and installed in a data processing device 70 from a recording medium such as a magnetic disk or a semiconductor memory (not shown).
Note that all or part of the functions realized by the data processing program may be realized by hardware such as ASIC (Application Specific IC).

FIG. 2 is a diagram illustrating a functional configuration of the data processing device 70 in FIG. 1 realized by executing the data processing program.
As shown in FIG. 2, the data processing device 70 includes a data storage unit 71 and an erasing unit 72. The data processing device 70 stores image data and the like captured via the scanner 80 in the HDD 90 as a storage device by the data storage means 71. Then, after the data processing is performed, the processed data stored in the HDD 90 is erased by the erasing means 72. During the erasure process, the erasure unit 72 erases the storage area in the HDD 90 where the processed data is stored by overwriting the dummy data with a plurality of preset overwrite times three times. Here, the unit of each data to be erased may be a file unit or a job unit.

  The erasing unit 72 interrupts the erasing process when a new data processing request is generated during the erasing process of the processed data. Then, the erasing unit 72 temporarily erases the unerased area in the storage area where the processed data is stored, which has not been erased, by erasing it once less than the set number of overwriting times, that is, twice. Let it be an erase area. Further, the erasing unit 72 writes new data on the temporary erasure area, and erases the area in the temporary erasure area where the new data has not been written by overwriting the dummy data only once. That is, the erasing unit 72 overwrites the dummy data in the area where new data in the temporary erasure area has not been written, and erases the total number of overwritings by three times as many as the preset number of overwritings. And

Next, a data processing method in the image processing apparatus of the present embodiment will be described with reference to the flowchart of FIG.
(1) When the print processing of the image data read via the scanner 80 or the like is completed, the CPU 10 instructs the data processing device 70 to erase the print processed image data stored in the storage device (HDD 90). .

  (2) Therefore, the erasing unit 72 in the data processing device 70 starts erasing the processed data stored in the HDD 90 (overwriting the random number data three times) (S101).

  (3) Here, if no new print processing or the like occurs, the erasing unit 72 erases the designated area to the end (S102, S103). However, if the CPU 10 instructs the data processing device 70 to store new print data in the HDD 90 before the erasing process is completed (Yes in S102), the erasing unit 72 interrupts the erasing process ( S104).

  (4) Then, the erasure unit 72 changes the number of overwriting of the random number data in the erasure process of the unerased area from 3 times to 2 times (S105), and executes the temporary erasure process of the unerased area that has not been erased. Thus, a temporary erase area is set (S106).

  (5) When the temporary erasure processing of the unerased area is completed (Yes in S107), the erasing unit 72 overwrites new print data in the temporary erasure area (S108).

(6) When the writing of the new print data is completed (Yes in S109), the erasing unit 72 determines whether or not there is an unerased area that is an area in which the new print data is not overwritten in the temporary erase area ( (S110) If there is an unerased area in which no new print data has been written in the temporary erase area, the number of overwrites is changed from 2 to 1 (S111), and then the unerased area is changed to random number data. The erasing process (residual erasing process) for overwriting is started (S112). Then, when the remaining erasing process is completed, the erasing unit 72 ends all the processes and enters a standby state (S113).
By performing the above processing, data is overwritten a total of three times for all unerased areas.

Next, with reference to FIG. 4, how the process shown in FIG. 3 is performed will be specifically described.
First, as shown in FIG. 4A, the data processing apparatus 70 stores image data in a certain area on the HDD 90 and performs print processing. Then, the data processing apparatus 70 tries to erase the data storage area after the end of printing, but it is assumed that a new printing process occurs before the erasing process ends, and the process is interrupted. Then, as shown in FIG. 4B, the data storage area is divided into an erased area 201 in which data has been erased and an unerased area 202 in which data has not been erased.

  For this reason, the data processing device 70 performs two overwriting processes on the unerased area 202 twice, which is one less than the normal overwriting frequency of 3 times. As a result, as shown in FIG. 4C, the unerased area 202 becomes a provisional erase area 203 that has been erased twice.

  Next, the data processing device 70 writes new print data on the temporary erasure area 203. Therefore, as shown in FIG. 4D, a part of the temporary erasure area 203 becomes a new data storage area 204.

  However, since the new data storage area 204 is narrower than the temporary erasure area 203 here, the temporary erasure area 203 remains. Therefore, the data processing device 70 performs a remaining erasure process in which the remaining temporary erasure area 203 is overwritten only once. As a result, the temporary erasure area 203 that has not been written with the new print data is also subjected to a total of three overwrite processes. As shown in FIG. It becomes.

  According to the data processing method of the present embodiment, when a new data processing request is generated during the erasing process of processed print data, the erasing process is interrupted, and the erasing process is not completed. The temporary erasure process is performed twice, which is one less than the preset overwrite count of 3. Then, the new print data is overwritten on the temporary erase area where the temporary erase process has been performed, and the area where the new print data is not written in the temporary erase area is overwritten with dummy data only once. Process.

As a result, it is guaranteed that the overwrite process is performed three times for all the data storage areas where the processed print data has been stored. Since the new print data is used in place of the dummy data to perform the overwrite processing of the printed data, it is possible to reduce the data write processing amount as compared with the conventional method. . Therefore, it is possible to reliably prevent leakage of image information and prevent a decrease in processing efficiency.
[Modification]

  In the above-described embodiment, the preset number of overwrites is described as three. However, the present invention is not limited to such a case, and is necessary for completely erasing processed data. Any number of overwrites may be set.

  Further, in the above-described embodiment, the number of overwriting of the temporary erasing process performed on the unerased area after the erasing process is interrupted after a new data processing request is generated during the erasing process is set to be larger than the preset number of overwriting. Although described as being less than once, the present invention is not limited to such a case.

  In other words, the number of overwrites in the temporary erasure process may be reduced by a specified number of times from a preset number of overwrites. In this case, the overwriting process is performed a prescribed number of times for the area in the new erasure area where new data has not been written. For example, the number of temporary erasure overwrites is reduced by two times from the preset number of overwrites, and new data in the temporary erasure area is overwritten twice last time. Processing may be performed.

  In this case, in a region where new data is written, there may be a case where the erasure process with a preset number of overwrites is not realized. However, since the erase process is interrupted when a new data write request is generated, the new data process is performed rather than performing the preset number of times for all the erase designated areas. Such a method may be selected when priority is given to. In other words, the number of times to be reduced over the number of overwriting when the temporary erasure processing is performed may be determined based on whether security or processing efficiency is given priority. Further, the number of times of reduction may be selected by the user.

  Further, in the above-described embodiment, the description has been made assuming that random number data is used as dummy data when overwriting, but the present invention is not limited to such a case, and fixed value data is used as dummy data. Alternatively, these data may be used in combination.

  In the above embodiment, the data processing apparatus that stores the image data to be processed in the HDD has been described. However, the present invention is not limited to such a case, and other flash memory or the like may be used. The present invention can be similarly applied to erasure confirmation of data stored in a nonvolatile memory or a volatile memory.

  Furthermore, in the above embodiment, the case where image data is subjected to print processing has been described. However, the present invention can be similarly applied to cases where processing other than print processing (processing such as FAX / net communication) is performed. The data handled may be data other than image data.

It is a block diagram which shows the hardware constitutions of the image processing apparatus which has a data processing device of one Embodiment of this invention. FIG. 2 is a block diagram illustrating a functional configuration of a data processing device 70 in FIG. 1. It is a flowchart which shows operation | movement of the data processor of one Embodiment of this invention. It is a figure for demonstrating the data processing method with the data processor of one Embodiment of this invention.

Explanation of symbols

10 CPU
20 RAM
30 ROM
40 Communication Interface Unit 50 User Interface Unit 60 FAX Interface Unit 70 Data Processing Unit 71 Data Storage Unit 72 Erasing Unit 80 Scanner 90 HDD
100 Print Engine S101-S113 Step 201 Erased Area 202 Unerased Area 203 Temporary Erase Area 204 New Storage Area

Claims (11)

Data storage means for storing data to be processed in a storage device;
Erasing data stored in the storage device by the data storage means by erasing the data less than a preset number of overwrites as a temporary erase area, and writing new data on the temporary erase area for erasure And a data processing apparatus.   2. The data according to claim 1, wherein the erasing unit sets the total number of overwriting to the preset number of overwriting by overwriting and erasing an area in the temporary erasing area where new data has not been written. Processing equipment.   3. The data according to claim 1, wherein the erasing unit performs erasing with a number of times less than a preset number of overwriting when erasing data stored in the storage device to form a temporary erasing area. Processing equipment.   The data processing apparatus according to claim 1, wherein the storage device is a hard disk drive.   The data processing apparatus according to claim 1, wherein the data stored in the storage device is image data. A data processing method for storing data to be processed in a storage device and erasing processed data stored in the storage device after data processing,
For the data stored in the storage device, erase the number of times less than the preset number of overwrites to make a temporary erase area,
A data processing method for writing new data on the temporary erasure area and erasing it.   7. The data processing method according to claim 6, wherein a total overwrite count is set to the preset overwrite count by overwriting and erasing an area in the temporary erase area where new data has not been written.   8. The data processing method according to claim 6, wherein when the data stored in the storage device is erased to form a temporary erase area, the data is erased with a number of times less than a preset number of overwrites. A program for causing a computer to execute a data processing method for storing data to be processed in a storage device and erasing processed data stored in the storage device after data processing,
Erasing the data stored in the storage device with a number of times less than a preset number of overwrites to form a temporary erase area;
A program for causing a computer to execute a step of writing and erasing new data on the temporary erasure area.   10. The computer further executes the step of setting the total number of overwriting times to the preset number of overwriting times by overwriting and erasing data in the temporary erasing region where new data has not been written. Program.   The program according to claim 9 or 10, wherein when erasing data stored in the storage device to form a temporary erasure area, erasure is performed with a number of times less than a preset number of overwrites.

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