KR20100001741A - Eraser system including nonvolatile memory and driving method thereof - Google Patents

Abstract

The mobile erasure system according to the present invention is a terminal equipped with a mobile platform such as a mobile communication terminal, a personal digital assistant (PDA), an industrial PDA, a smart phone, and the like. Physically erases the data area recorded by the user or the like into the storage device (i.e., the internal nonvolatile memory and the external nonvolatile memory).

The mobile erasure system according to the present invention downloads the mobile erasure engine to the terminal by selectively using the wireless Internet, the Internet, serial communication, etc. according to the environment of the terminal, and the file of the terminal. Analyze the system and completely delete the user data from recovery. Therefore, the terminal whose user data has been completely deleted is reused in the same environment as when shipped from the factory.

Description

Eraser system including nonvolatile memory and its driving method {ERASER SYSTEM INCLUDING NONVOLATILE MEMORY AND DRIVING METHOD THEREOF}

The present invention relates to a flash memory, and more particularly, to an apparatus and a method for completely erasing user data stored in a terminal equipped with a flash memory.

Digital information takes up more than 95% in the production and distribution of information in recent years, and as the performance and storage capacity of terminals equipped with mobile platforms increase, mobile terminals are used as a storage medium for digital information. The trend is increasing. In addition, the terminal often stores personal financial information, other important personal information, and corporate secret information.When replacing the terminal, such important information is simply deleted using only the deletion function provided by the terminal. Replace the terminal. However, the deletion function provided by the terminal deletes only the metadata of the file system and does not delete the physical area in which the actual user data is stored. Thus, terminals distributed in second-hand markets face a reality in which important information is exposed or misused by crime by data recovery programs provided on the Internet.

Accordingly, a terminal equipped with a mobile platform such as a mobile communication terminal, a personal digital assistant (PDA), an industrial PDA, a smart phone, or the like may be transmitted, input, stored, It is necessary that the user data, which is generated or received, input, stored, or generated by the counterpart's actions, is completely deleted from the storage device of the terminal and completely impossible to recover.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems, and an object of the present invention is to provide an apparatus and a method for completely physically deleting a data area of a terminal equipped with a mobile platform such that it is not recoverable.

Eraser system according to an embodiment of the present invention comprises a terminal including a nonvolatile memory; And an erasing engine including an erasing algorithm for deleting the nonvolatile memory, wherein the erasing algorithm is stored in the nonvolatile memory via a network.

The erase engine may further include a file system analysis algorithm that extracts file system state information of the nonvolatile memory and lists files stored in a data area using the extracted file system state information. .

In an embodiment, the deletion algorithm deletes the file using an instruction set that controls the nonvolatile memory.

In an embodiment, the state information of the file system includes at least one of a Master Boot Recorder (MBR), a BIOS Parameter Block (BPB), a Super Block Info, and a Partition Info.

The terminal may include: an external memory for expanding storage capacity; And a memory controller controlling the nonvolatile memory and the external memory.

In an embodiment, the terminal further includes a central processing unit for driving the erase algorithm stored in the nonvolatile memory and controlling the memory controller.

The nonvolatile memory may include a code area for storing a boot code for driving the terminal and a data area for storing user data.

In example embodiments, the nonvolatile memory may include any one of a NAND flash memory, a Noah flash memory, and a OneNAND flash memory.

In an embodiment, the terminal includes an electronic device using a nonvolatile memory as a storage medium.

In an embodiment, the terminal is a mobile communication terminal, a personal digital assistant (PDA), an industrial PDA, a smart phone, a PMP using a flash memory as a storage medium, and a solid state disk. Disk) as a storage medium.

In an embodiment, the network includes wired and wireless networks.

According to another aspect of the present invention, there is provided a method of driving an erasure system, comprising: extracting state information of a file system of the nonvolatile memory; Listing files stored in a data area by using the extracted state information of the file system; And deleting a file stored in the data area by using an instruction set for controlling the nonvolatile memory.

User data stored in a terminal such as a mobile phone is stored in the terminal's internal and external non-volatile memory (NVM).

Non-volatile memory is divided into system code area and data area, system binary program is stored in system code area, personal information, stored files, text, pictures, videos, voice recordings, applications, and file system information are stored in data area. And metadata information. That is, the data area stores data that is transmitted, received, input, stored, and generated by the user or the counterpart after the user purchases the terminal. The built-in nonvolatile memory of the terminal includes both the system code area and the data area, and the external nonvolatile memory of the terminal includes only the data area.

The present invention downloads the Mobile Eraser Engine in two ways depending on the mobile platform environment mounted on the terminal. First, in the case of a terminal capable of wireless networking, the terminal according to the present invention downloads the mobile erasure engine through a wireless network. Second, in the case of a terminal that is not capable of wireless networking, the terminal downloads the mobile erasure engine through a wired network such as the Internet or serial communication. The downloaded Mobile Eraser Engine reads File System State Info such as Master Boot Recorder (MBR), BIOS Parameter Block (BPB), Super Block Info, and Partition Info of the terminal file system. In addition, the code area and the data area of the nonvolatile memory of the terminal are divided, and the user data is physically completely deleted by directly manipulating the memory controller of the terminal.

The downloaded mobile erasure engine is loaded in a RAM area, which is a volatile memory of the terminal, and is driven by a central processing unit. In other words, the central processing unit drives the mobile erasure engine to delete all user data of the terminal, and simultaneously deletes the mobile erasure engine.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention.

1 is a block diagram illustrating a mobile erasure system according to an embodiment of the present invention.

Referring to FIG. 1, a mobile erasure system 100 according to an embodiment of the present invention includes a mobile erasure engine 10, a wireless network 20, a terminal 30, and an external memory. (External Memory; 40). The terminal 30 includes a central processing unit 31, a nonvolatile memory 32, a memory controller 35 controlling the same, a RAM 36, and a system bus 37 connecting them. The nonvolatile memory 32 includes a code area 33 for storing a system driving program and a data area 34 for storing user data. The wireless network 20 is provided by a service provider (ie, an Internet service provider) or illustrates another wireless Internet environment (eg, Wi-Fi, Bluetooth, etc.). The external memory 40 is a nonvolatile memory used to expand the capacity in the terminal.

The mobile erasure system 100 loads a mobile erasure engine (Mobile Eraser Engine) 10 into the data area 34 in the terminal 30 via the wireless network 20.

The central processing unit 31 loads the mobile erasure engine 10 stored in the data area 34 into the RAM 36 to drive the mobile erasure engine 10.

The CPU 31 drives the mobile erasure engine 10 to analyze the file system, distinguish the code area 32 from the data area 33, and physically delete the user data. The mobile erasure engine 10 is described in detail in FIG. The driving method of the mobile erasure engine according to the embodiment of the present invention is described in detail with reference to FIG. 5.

FIG. 2 is a block diagram illustrating the mobile erasure engine 10 shown in FIG. 1. The mobile erasure engine 10 is an application binary program that operates by downloading through the wireless Internet, the Internet, serial communication, and the like.

1 and 2, the mobile erasure engine 10 may include a user interface (UI) 11, a perfect erase algorithm (12), a file system analyzer (13), and the like. Non-Volatile Memory Controller Command Set (14).

The user interface 11 is a graphical user interface (GUI) for a mobile eraser engine optimized for a platform (WIPI, Windows Mobile OS, Brew, Windows CE, etc.) of the terminal 30.

The nonvolatile memory control command set 14 is a command set that can directly control a nonvolatile memory of a terminal to perform a read and write of a storage device. The nonvolatile memory control command set 14 is a set of instructions that serves as an interface between the file system analyzer 13 and the nonvolatile memory, the erasure algorithm 12, and the nonvolatile memory.

The file system analyzer 13 analyzes the file system of the terminal 30 to provide file system state information such as a master boot record (MBR), a bios parameter block (BPB), and a super block info. Search for, separate the code and data areas, find the node and cluster information in the data area and list the files.

BPB (Bios Parameter Block) is a structure block that contains important metadata information required for driving a file system, such as a file system version and size, in a FAT-based file system. Master Boot Record (MBR) is a system block having a boot code address and important metadata location in a FAT-based file system. Super Block Info is a structure block that contains the version of the file system and important metadata information required to run the file system in the Unix-like file system. Nodes are meta data structures that make up files and directories in a Unix-like file system. A cluster is a conversion table that points to actual data (physical areas) of files and directories in a FAT-based file system. FAT-based file systems include FAT12, FAT16, FAT32, NTFS, and TFS4. There are file systems such as EFS, EFS2, YFFS, and EFFS in Unix-like file systems. Each file system has different file system state information and is optimized for each file system.

The complete erase algorithm 14 physically completely deletes the cell (minimum storage unit of the nonvolatile memory) so that the data area divided by the file system analyzer 13 cannot be recovered, and the memory can be reused.

For example, if the nonvolatile memory is NAND Flash Memory, the bad block information and wear leveling information in the spare area are maintained, the initialization of the ERROR COLLECT CODE (ECC) value, the logical Sector Number) value is initialized. This is to make the same environment as when the user purchased the first mobile communication terminal shipped from the factory.

3 is a block diagram illustrating in detail a code region and a data region of a nonvolatile memory in the terminal illustrated in FIG. 1.

1 and 3, a nonvolatile memory 32 according to an embodiment of the present invention illustrates one of a one NAND flash memory, a NAND flash memory, and a Noah flash memory.

The nonvolatile memory 32 includes a code area 33 and a data area 34. The code area 33 stores a system binary program for managing all the systems inside the terminal. Therefore, when the code area 33 is deleted, the terminal 30 does not operate. The code area 33 includes a boot code 33a and an embedded code 33b.

The data area 34 stores a user's personal information, files, texts, pictures, videos, voice recordings, application data such as application programs (34a), and memory as the internal capacity of the terminal increases. Other partition (34b) divided by the first, the first and second file system state information (File System State Info1-2; 34c, 34d) containing the respective memory management information, the mobile erasure engine 10 is stored Area 34b. The data area 34 is an area that is completely deleted by the mobile erasure engine 10.

FIG. 4 is a block diagram illustrating a directory of a file system when the mobile erasure engine shown in FIG. 1 is downloaded.

1 to 4, a wireless network 20 according to an embodiment of the present invention illustrates WiPI. For example, the terminal 30 downloads the mobile erasure engine 10 through Wifi, a type of mobile platform capable of wireless internet.

The downloaded mobile erasure engine 10 is stored in the 'W' directory, which is a WIPI directory of the terminal, and the WIPI platform recognizes the 'W' directory as a root directory. However, the WIPI platform has a security structure that cannot access other directories such as PIMS (text organizer) and SMS (text store) in the 'W' directory.

In order to overcome this, the nonvolatile memory control command set 14 embedded in the mobile erasure engine 10 directly accesses the nonvolatile memory 32 without finding the user data 34 in the file system directory, thereby allowing the user data 34 to be accessed. ) To physically delete it.

FIG. 5 illustrates a physical structure of one page of a NAND flash memory, which is one type of the nonvolatile memory 32 shown in FIG. 1.

The NAND flash memory includes a main area and a spare area. The NAND flash memory additionally has a spare area due to the physical characteristics of the flash.

The spare area has a size of 16 bytes per 512 bytes of NAND flash memory. In the spare area, bad block information, wear leveling information, ERROR COLLECT CODE (ECC) information, and the like are stored.

6 is a flowchart illustrating an operation of the mobile erasure engine of FIG. 2.

1 to 6, the file system analyzer 13 extracts file system state information 34c and 34e from the nonvolatile memory 32 using the nonvolatile memory control instruction set 14 (S11).

The file system analyzer 13 separates the code area 33 and the data area 34 of the nonvolatile memory 32 by using the retrieved file system state information 34c and 34e, and thus the node in the data area 34. ) And cluster information (S12).

The central processing unit 31 determines the presence or absence of the external memory 40 (S13).

If there is an external memory, the file system analyzer 13 extracts node and cluster information from the external memory (S14).

The extracted node and cluster information is searched and listed in the entire file constituting the user data using the corresponding information as metadata of the file system (S15).

If there is a file that is necessary in the terminal or a file that should not be deleted among the searched file list, the file is copied to the RAM 36. Then, all physical data areas in which the actual files of the entire file list are stored are deleted. Thereafter, the file stored in the RAM 36 is copied to the data area (S16).

7 is a block diagram illustrating a mobile erasure system according to another embodiment of the present invention.

Referring to FIG. 7, a mobile erasure system 200 according to another embodiment of the present invention may include a mobile erasure engine 110, a wired network 120, a terminal 130, and a mobile erasure engine; External memory 140 is included. The mobile erasure system 200 loads a mobile eraser engine 10 into the data area 34 in the terminal 30 via the wired network 120. The wired network 120 refers to a serial communication (Serial Protocol, USB, JTAG, etc.), a wired Internet as a communication connection environment for wired communication of a terminal that is not wireless networking.

FIG. 8 is a block diagram illustrating a file system directory when the mobile erasure engine shown in FIG. 7 is downloaded.

7 and 8, the terminal 130 downloads the mobile erasure engine 10 through a wired network. The downloaded mobile erasure engine 110 may be stored anywhere in the nonvolatile memory 132.

9 is a flowchart illustrating a method of a mobile erasure system according to the present invention.

1 to 9, first, it is determined whether the terminal 30 is capable of a wireless network (S21). If wireless networking is possible, the mobile erasure engine 10 is downloaded to the terminal using the wireless networking 20, and the mobile erasure engine 10 is executed by the central processing unit 31 (S22).

If the wireless networking 20 is not, the mobile erasure engine 110 is downloaded to the terminal 130 using the wired networking 120, and the mobile erasure engine 110 is executed by the central processing unit 131. (S23).

The mobile erasure engine 10 analyzes the file system of the terminal 30 and checks a user data area (S24). The file system of the terminal varies according to the mobile platform of the terminal and has file system-specific status information (File System Info) such as MBR, BPB, and Super Block Info to distinguish the system code area from the user data. The mobile erasure engine 10 completely deletes the user data in a non-recoverable manner according to the complete deletion algorithm 12 (S25).

As described above, the present invention recovers the data area in a terminal equipped with a mobile platform such as a mobile communication terminal, a personal digital assistant (PDA), an industrial PDA, a smart phone, and the like. You can physically delete it completely to make it impossible.

In the above drawings and the specification has been disclosed the best embodiment. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram illustrating a mobile erasure system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating the mobile erasure engine 10 shown in FIG. 1.

3 is a block diagram illustrating in detail a code region and a data region of a nonvolatile memory in the terminal illustrated in FIG. 1.

FIG. 4 is a block diagram illustrating a directory of a file system when the mobile erasure engine shown in FIG. 1 is downloaded.

FIG. 5 illustrates a physical structure of one page of a NAND flash memory, which is one type of the nonvolatile memory 32 shown in FIG. 1.

6 is a flowchart illustrating an operation of the mobile erasure engine of FIG. 2.

7 is a block diagram illustrating a mobile erasure system according to another embodiment of the present invention.

FIG. 8 is a block diagram illustrating a file system directory when the mobile erasure engine shown in FIG. 7 is downloaded.

9 is a flowchart illustrating a method of a mobile erasure system according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: Mobile Eraser Engine

20: wireless network

30: a terminal equipped with a mobile platform

Claims (13)

A terminal including a nonvolatile memory; And Including an eraser engine including a deletion algorithm for deleting the nonvolatile memory, And said erasing algorithm is stored in said nonvolatile memory via a network. The method of claim 1, The erasure engine, And a file system analysis algorithm that extracts file system state information of the nonvolatile memory and lists files stored in a data area using the extracted file system state information. The method of claim 2, And the erasing algorithm deletes the file using an instruction set for controlling the nonvolatile memory. The method of claim 2, The state information of the file system includes at least one of Master Boot Recorder (MBR), BIOS Parameter Block (BPB), Super Block Info, and Partition Info. The method of claim 1, The terminal, External memory for expanding storage capacity; And And a memory controller controlling the nonvolatile memory and the external memory. The method of claim 5, wherein The terminal, And a central processing unit for driving said erase algorithm stored in said nonvolatile memory and controlling said memory controller. The method of claim 1, The nonvolatile memory may include a code area for storing a boot code for driving the terminal and a data area for storing user data. The method of claim 1, The nonvolatile memory includes any one of a NAND flash memory, a NOR flash memory, and a One NAND flash memory. The method of claim 1, The terminal comprises an electronic device using a nonvolatile memory as a storage medium. The method of claim 1, The terminal includes a mobile communication terminal, a personal digital assistant (PDA), an industrial PDA, a smart phone, a PMP using a flash memory as a storage medium, and a solid state disk. Eraser system comprising any of the computers used. The method of claim 1, The network comprises an wired and wireless network. In a method of driving an erasure system comprising a terminal comprising a nonvolatile memory: Extracting state information of a file system of the nonvolatile memory; Listing files stored in a data area by using the extracted state information of the file system; And And deleting a file stored in the data area by using an instruction set for controlling the nonvolatile memory. The method of claim 12, The state information of the file system includes at least one of a master boot recorder (MBR), a BIOS parameter block (BPB), a super block info, and a partition info.

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