JP2019071025A - Image forming device, image forming method, and data deletion program - Google Patents

Abstract

To allow deleting data of the whole area in a non-volatile storage area and proving data deletion thereof.SOLUTION: An image forming device comprises: an image forming unit for forming images in an image forming medium; a non-volatile storage unit for storing data used for forming the images; a data deletion section for executing first overwriting processing with first data, executing second overwriting processing with second data different from the first data by excluding a first residual sector, and executing third overwriting processing with third data different from both the first data and the second data by excluding a second residual sector representing at least one of the sectors neighboring the first residual sector; and a data deletion proving section for outputting an image which proves that the completion of data deletion in the storage unit by using data read out from a sector in which the first residual sector, the second residual sector and the third overwriting processing are executed, and that is a third residual sector representing at least one of the sectors neighboring the second residual sector.SELECTED DRAWING: Figure 1

Description

  The present invention relates to data erasing in an image forming apparatus and an image forming method.

  Some image forming apparatuses such as multi-functional printers and multifunction peripherals (MFPs) include a storage unit that stores image data and user information. Since the image data and the user information include confidential data, for example, when the image forming apparatus is exchanged from an old model to a new model, data stored in the storage area of the old model is erased. Under these circumstances, it has been required that the user prove that the data has been erased reliably. From such a point of view, Patent Document 1 proposes a technique for storing a history of invalidation processing applied to data and enabling presentation and certification of information indicating that the data has been invalidated. In this technology, the issuance of the certificate is performed by printing the date and time when the data was erased, the statement to prove that the data was erased, the name and serial number of the MFP, and a predetermined mark on the sheet. It takes place. Patent Document 2 proposes a technology for visually presenting the user that the data area after deletion is in a state equivalent to that at the time of factory shipment.

JP 2005-311719 A JP 2012-155488 A

  However, none of the above-described techniques have the essential problem that they can not erase all the data in the storage area. That is, Patent Document 1 needs to secure the area for storing the history of invalidation processing after erasing data without erasing it, and Patent Document 2 needs to exclude the state at the time of shipping from the factory as a target of erasing data. There is.

  The present invention has been made in view of such a situation, and it is an object of the present invention to provide a technology that enables data erasure proof while erasing data in all areas of the nonvolatile storage area.

  An image forming apparatus according to the present invention includes an image forming unit for forming an image on an image forming medium, a non-volatile storage unit for storing data used for forming the image, and a first data. And execute a second overwriting process leaving a first remaining sector with a second data different from the first data, and performing either of the first data and the second data. A data erasing unit that executes a third overwriting process while leaving the second remaining sector that is at least one sector adjacent to the first remaining sector with the third data that is also different from the above, and the first remaining sector And data read from the second remaining sector and the third remaining sector which is the sector on which the third overwriting process has been performed and is adjacent to the second remaining sector. Using the above And a data erasure proof unit that outputs the image to prove that the data erasing 憶部 is completed.

  An image forming method according to the present invention comprises an image forming step of forming an image on an image forming medium, a storing step of storing data used for forming the image in a non-volatile storage unit, and a first data. Execute the first overwrite process, and execute the second overwrite process while leaving the first remaining sector with the second data different from the first data, and executing the second data and the second data. A data erasing step of executing a third overwriting process leaving a second remaining sector which is at least one sector adjacent to the first remaining sector with third data different from any of the data; A second remaining sector, and a third remaining sector which is a sector on which the third overwriting process has been performed and which is at least one sector adjacent to the second remaining sector. Read data And a data erasure proof step of generating an image to prove that the data erasure of the storage unit is completed using.

  A data erasing program according to the present invention comprises an image forming unit for forming an image on an image forming medium, a non-volatile storage unit for storing data used for forming the image, and a first overwriting with the first data. A process is executed, and a second overwrite process is performed leaving a first remaining sector with the second data different from the first data, and the second overwrite process is different from either the first data or the second data. A data erasing unit that executes a third overwrite process leaving a second remaining sector that is at least one sector adjacent to the first remaining sector with the third data to be transferred; and the first remaining sector; The data read from the second remaining sector and the third remaining sector which is the sector on which the third overwrite processing has been performed and which is at least one sector adjacent to the second remaining sector are used The The data erasure of the storage unit is an image forming apparatus to function as a data erasure proof unit that outputs the image to prove that it has completed.

  According to the present invention, it is possible to provide a technology that enables data erasure verification while erasing data in all the non-volatile storage regions.

2 is a block diagram showing a functional configuration of an image forming apparatus 100 according to an embodiment of the present invention. It is a flowchart which shows the content of the data deletion process which concerns on one Embodiment. It is a flowchart which shows the content of the data overwrite process which concerns on one Embodiment. It is explanatory drawing which shows the content of the data overwrite process which concerns on one Embodiment. It is an explanatory view showing a data deletion certificate concerning one embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a functional configuration of an image forming apparatus 100 according to an embodiment of the present invention. The image forming apparatus 100 includes a control unit 110, an image forming unit 120, an operation display unit 130, a storage unit 140, and an external interface unit (also referred to as an external I / F unit) 150. The external I / F unit 150 has a communication interface function and can also be connected to an external storage device (for example, a USB memory (not shown)).

  The control unit 110 includes a data deletion unit 111 and a data deletion verification unit 112. The functions of the data eraser 111 and the data eraser prover 112 will be described later. The control unit 10 includes a main storage unit such as a RAM and a ROM, and a control unit such as an MPU (Micro Processing Unit) and a CPU (Central Processing Unit). The control unit 10 also has a controller function related to interfaces such as various I / O, USB (universal serial bus), bus, and other hardware, and controls the entire image forming apparatus 100.

  The image forming unit 120 includes an image reading unit 121, an image processing unit 122, and an image output unit 123. The image reading unit 121 reads an image from a document and generates scan data. The image processing unit 122 processes the scan data according to the print setting to generate print data. The image output unit 123 forms an image on a print medium (also referred to as an image forming medium) based on the print data.

  The operation display unit 130 includes a display 131 and an operation processing unit 138. The display 131 functions as a touch panel and displays various menus as an input screen. The operation processing unit 138 receives a user's operation input from the display 131 functioning as a touch panel, various buttons and switches (not shown).

  The storage unit 140 is a storage device such as a hard disk drive or a flash memory, which is a non-temporary recording medium, and stores control programs and data of processing executed by the control unit 110. In the storage unit 140, data positions are managed by logical block addressing (LBA). LBA is a unique serial number assigned to all sectors from the first sector to the last sector.

  Management of data locations is not necessarily limited to the use of logical block addressing. However, it is preferable that the storage unit 140 be a non-volatile storage unit having a plurality of sectors managed by addresses continuing between the start sector and the end sector.

  The storage unit 140 further includes an address book 141, a box storage area 142, and a user information storage area 143. In the present embodiment, in the user information storage area 143, authentication user information (user name and password) of each user is recorded. A storage area available for each user is allocated to the box storage area 142. The user information storage area 143 stores an authentication password and other personal information of each user, and is linked to the user record recorded in the address book 141. As described above, the storage unit 140 stores data including confidential information such as image data at the time of copying, image data of the storage area 142 for box, and user information as data used for forming an image. Is customary.

  FIG. 2 is a flow chart showing the contents of the data erasing process according to an embodiment. In step S100, the user performs restart in the data erase mode. The data deletion mode is activated by a system administrator or the like according to a preset procedure. The data erase mode is also referred to as a ROM start mode, and operates with a control program stored in the ROM 113, which is a read only storage unit, using the RAM as a work area without using the storage unit 140. It is.

  In step S200, the data erasing unit 111 executes data overwrite processing. In the data overwriting process, the data erasing unit 111 erases the data completely by sequentially overwriting with a 0 value, a 1 value, and a random value.

  FIG. 3 is a flowchart showing the contents of the data overwrite process according to an embodiment. In step S210, the data erasing unit 111 acquires the maximum value Xmax of the LBA. The maximum value Xmax is the maximum value of LBA, that is, an address (number) for specifying the last sector. In this example, the maximum value Xmax is assumed to be 10000 for convenience of explanation. The maximum value Lmax of LBA can be obtained, for example, by using the READ MAX NATIVE ADDRESS command. The final sector may be the beginning sector of the data overwrite process or the end sector of the data overwrite process.

  FIG. 4 is an explanatory view showing the content of the data overwrite process according to the embodiment. FIG. 4A shows the storage unit 140 in which the overwrite process is performed with the all 0s, that is, all the data as 0 values. In step S220, the data erasing unit 111 overwrites the 0 value in the bits of all the sectors from the first sector (address 1) to the last sector (address 10000) (first overwrite processing). That is, the data erasing unit 111 operates in a data erasing operation mode in which overwriting processing is performed on a plurality of sectors in the order of addresses continuing from the start sector to the end sector.

  The storage unit 140 uses two different physical states (magnetic states), and stores 0 value or 1 value in each bit. The data erasing unit 111 realizes effective data erasing by performing overwrite processing using data 0 and data 1 (F in hexadecimal notation) which are fixed values corresponding to two physical states. Data 0 is also referred to as first data. Data 1 is also referred to as second data.

  In step S230, the data erasing unit 111 overwrites the value of 1 in the bits of all the sectors from the first sector to the sector (address 9999) at the address (Xmax-1) immediately preceding the final sector (second Overwrite processing). FIG. 4B shows the storage unit 140 in which the overwrite process has been executed as all 1's. In FIG. 4B, it is written as "F" in hexadecimal. Thus, the history of the overwrite process (step S220) with data 0 is left in the last sector (address 10000). The last sector (address 10000) is also referred to as the first remaining sector.

  In step S240, the data erasing unit 111 overwrites the random value on the bits of all the sectors from the first sector to the sector (the address 9998) at the address (Xmax-2) two places before the final sector (Xmax-2). Overwrite processing). FIG. 4C shows, in hexadecimal, the storage unit 140 on which the overwrite process has been executed as a random value. The random value is also referred to as third data.

  Thereby, in addition to the overwrite processing (step S 220) of data 0 of the sector 10000 at the storage unit 140, data 1 of the sector 9999 (also called the second remaining sector) adjacent to the address 10000 The history of the overwriting process (step S230) at step S2 is left. Furthermore, random values are overwritten on the bits of all the sectors from the first sector of the storage unit 140 to the 9998th sector (also called the third remaining sector) of the address (Xmax-2) two places before the last sector (Xmax-2). The processed history is left. Control unit 110 advances the process to step S300 according to the completion of the overwriting process with a random value.

  Preferably, in the actual operation of the image forming apparatus 100, the control unit 110 manages the addresses with the sectors from address 9998 to address 10000 of the storage unit 140 as a non-use area. Specifically, the control unit 110 can make it a non-use area by writing data (for example, a random value) preset in the sectors of address 9998 to address 10000 of the storage unit 140 immediately after formatting, for example. Further, the first to third remaining sectors do not necessarily have to be one sector, and may be plural. That is, each of the first to third remaining sectors may be at least one sector.

  In step S300, the control unit 110 executes a normal restart process. The control unit 110 starts a normal restart and starts reading data from the storage unit 140. Control unit 110 advances the process to step S500 according to the detection of the erase completion pattern, and continues normal restart according to the non-detection of the erase completion pattern (step S400). The erase completion pattern is a pattern indicating that data erase by overwrite processing is completed, and may be, for example, sector data at address 9999 (all “F”) and data at sector 10000 (all “0”).

  In step S500, the data erasure verification unit 112 starts activation in the ROM activation mode. The ROM 113 also stores control programs for operating in the ROM start mode, and data regarding the specifications and control method of the storage unit 140.

  In step S600, the data erasure certifying unit 112 causes the display 131 of the operation display unit 130 to display a screen (not shown) inquiring of the system administrator or the like whether the data erasure certification is necessary. When the system administrator or the like inputs that the data erasure certificate is not necessary through the operation processing unit 138, the process is ended, and when it is inputted that the data erasure certificate is necessary, the process is terminated. The process proceeds to step S700.

  FIG. 5 is an explanatory view showing a data erasure certificate P according to an embodiment. The data erasure certificate P indicates that the data written in the office has been erased from all the writable nonvolatile storage devices of the image forming apparatus 100 (in this example, the storage unit 140).

  In step S700, the data erasure proving unit 112 reads data from the sectors from address 9998 to address 10000 of the storage unit 140. The data of the sectors from the 9998th address to the 10000th address are used to generate the data erasure certificate P. The data (0 value) of the sector 10000 indicates the contents of the first overwrite process. The data (10 values) of the sector 9999 indicates the contents of the second overwrite process. The data (random value) of the sector 9998 indicates the contents of the third overwrite process.

  In step S800, the data erasure certifying unit 112 generates an image of the data erasure certificate P, and displays the image together with a print icon (not shown) on the display 131 of the operation display unit 130 (one mode of image output). . The data erasure certifying unit 112 can also execute print output (one aspect of image output) of the data erasure certificate P in response to a touch on a print icon (not shown).

  The data erasure certificate P further displays the print date and time and the specifications of the storage unit 140 in the text area T1, and displays the procedure for reuse in the text area T2. The control unit 110 can set the operation mode in which the storage unit 140 is not used, by limiting the use of the image forming apparatus 100 until the preset procedure for reuse is performed. As a result, it is possible to suppress the problem that a user other than the system administrator or the like inadvertently uses the image forming apparatus 100 and inadvertently writes confidential data in the storage unit 140 after the data is erased.

  The specification of the storage unit 140 is data read from the ROM 113. The print date and time use date and time information from the clock of the image forming apparatus 100, for example, and indicate the date and time when the erase completion pattern is confirmed.

  As described above, according to the image forming apparatus 100 according to an embodiment, since a non-volatile area for storing history information, status information, and the like is not necessary, the entire storage unit 140 can be used without using other non-volatile memories. The storage unit 140 can be used to make it possible to prove the data erasure while erasing the data in the area of. Thereby, the image forming apparatus 100 can realize the proof of data erasure while setting the entire area of the nonvolatile memory as the data erasure target.

  The present invention can be implemented not only in the above-described embodiments but also in the following modifications.

C. Modifications Modification 1: In the above embodiment, a control program (also referred to as a data deletion program) for data deletion is stored in the ROM provided inside the image forming apparatus 100. It does not have to be equipped inside. Specifically, for example, the control program is stored in a USB memory (not shown), attached to external I / F unit 150, and activated to operate image forming apparatus 100 in an operation mode for erasing data. May be

  Modification 2: In the above embodiment, the data used in the data overwrite process is left as a history in the first to third remaining sectors, but the data necessarily needs to be the data used in the data overwrite process. Absent. Specifically, it may be, for example, related data associated with data used in data overwrite processing. The related data may be, for example, a hash value, an AND value, or an OR value of data used in data overwrite processing.

  Variation 3: In the above embodiment, the number of overwrites is three, and the overwrite data is in the order of data 0, data 1, and random values, but the number of overwrites and the order / content of the overwrite data are not limited thereto.

100 image forming apparatus 110 CPU
111 Data erasing unit 112 Data erasing proving unit 120 Image forming unit 121 Image reading unit 122 Image processing unit 123 Image output unit 130 Operation display unit 131 Display 140 Storage unit 141 Address book 142 Storage area for box 143 User information storage area 150 External I / F section

Claims (8)

An image forming unit for forming an image on an image forming medium;
A non-volatile storage unit storing data used to form the image;
A first overwriting process is performed on the first data, and a second overwriting process is performed leaving the first remaining sector on the second data different from the first data, and the first data and A data erasing unit that executes a third overwriting process while leaving a second remaining sector that is at least one sector adjacent to the first remaining sector with third data different from any of the second data; ,
A third remaining sector which is the first remaining sector, the second remaining sector, and the sector on which the third overwriting process has been executed, and which is at least one sector adjacent to the second remaining sector. A data erase proving unit for outputting an image proving that the data erasing of the storage unit is completed using data read out from the sector;
An image forming apparatus comprising: The image forming apparatus according to claim 1,
The storage unit has a plurality of sectors managed by addresses contiguous between the start sector and the end sector, and
The first overwriting process is a data erasing operation mode in which the data erasing unit executes the overwriting process on the plurality of sectors in the order of the consecutive addresses in the direction of the sector at the beginning to the sector at the end. An image forming apparatus that executes a second overwriting process and the third overwriting process. The image forming apparatus according to claim 2,
The data erasing unit executes the first overwriting process from the sector at the beginning to the sector at the end, and is at least one sector including the sector at the end in the direction from the sector at the beginning to the sector at the end The second overwriting process is executed leaving the first remaining sector, and the second one being at least one sector adjacent to the first remaining sector in the direction from the leading sector to the end sector An image forming apparatus that executes the third overwriting process while leaving a remaining sector. The image forming apparatus according to any one of claims 1 to 3, wherein
The storage unit stores data in two different physical states:
The image forming apparatus according to claim 1, wherein two of the first data, the second data, and the third data are fixed values corresponding to the two physical states. The image forming apparatus according to any one of claims 1 to 4, further comprising:
An image forming apparatus comprising: a read only storage unit storing a data erasing program for causing the image forming apparatus to function as the image forming unit, the storage unit, the data erasing unit, and the data erasure proving unit. The image forming apparatus according to any one of claims 1 to 4, further comprising:
An external interface unit for reading out a data erasing program for causing the image forming apparatus to function as the image forming unit, the storage unit, the data erasing unit, and the data erasure proving unit;
A control unit that causes the image forming apparatus to function as the image forming unit, the storage unit, the data erasing unit, and the data erasure proving unit by executing the read data erasing program;
An image forming apparatus comprising: An image forming step of forming an image on an image forming medium;
Storing the data used for forming the image in a non-volatile storage unit;
A first overwriting process is performed on the first data, and a second overwriting process is performed leaving the first remaining sector on the second data different from the first data, and the first data and A data erasing step of executing a third overwriting process while leaving a second remaining sector which is at least one sector adjacent to the first remaining sector with third data different from any of the second data; ,
A third remaining sector which is the first remaining sector, the second remaining sector, and the sector on which the third overwriting process has been executed, and which is at least one sector adjacent to the second remaining sector. A data erase proving step of outputting an image proving that the data erasing of the storage unit is completed using the data read from the sector;
An image forming method comprising: An image forming unit for forming an image on an image forming medium;
A non-volatile storage unit storing data used to form the image;
A first overwriting process is performed on the first data, and a second overwriting process is performed leaving the first remaining sector on the second data different from the first data, and the first data and A data erasing unit that executes a third overwriting process while leaving a second remaining sector that is at least one sector adjacent to the first remaining sector with third data different from any of the second data; And a third remaining sector which is the first remaining sector, the second remaining sector, and a sector on which the third overwriting process has been performed, and which is adjacent to the second remaining sector. A data erasing program that causes an image forming apparatus to function as a data erase proving unit that outputs an image proving that the data erasing of the storage unit is completed using data read out from a remaining sector.

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