External storage device, program, and information processing method

Abstract

Prevent unauthorized use and information leaks caused by taking out information processing devices such as PCs. [Solution] A USB device 70 detachable to a PC 1 that starts an OS based on GPT information detected by a search means that searches for GPT information in an HDD 90 at startup causes the PC 1 to function as a first processing means that stores a specific program 710 stored in the USB device 70 in the PC main unit and stores the GPT information in the USB device 70 (GPT storage means 120), and a second processing means that, if GPT information is detected from the HDD 90 by the search means at startup, starts the OS based on the GPT information, and if GPT information is not detected, restores the GPT information in the HDD 90 based on the GPT information stored in the USB device 70, and the specific program 710 deletes the GPT information from the HDD 90 when the main unit is shut down (GPT deletion means 110).

Description

[Technical Field]

[0001] The present invention relates to an external storage device, a program, and an information processing method that can prevent information leakage, unauthorized use, etc., caused by taking a personal computer out of the home. [Background technology]

[0002] In modern society, personal computers (hereinafter referred to as "PCs") have become so widespread that there are no companies or individuals who do not use PCs to carry out their work. In such a situation, there is no end to fraudulent activities such as taking PCs and leaking information through unauthorized logins. To address this problem, the following techniques have been proposed.

[0003] For example, Patent Document 1 discloses a startup method for an information processing device, the startup method comprising: an information processing unit that executes information processing in an information processing device that includes a storage that has a master boot record including a partition table that stores partition information, and a connector that allows the attachment and detachment of an external storage medium that stores data in a rewritable manner; a step in which, before shutting down the device, an information processing unit that executes information processing determines whether the external storage medium is attached to the connector, and if it is determined that the external storage medium is attached, stores the partition information in the external storage medium and writes information different from the partition information in the partition table; and a step in which, after starting up the device, the information processing unit determines whether the external storage medium is attached to the connector, and if it is determined that the external storage medium is attached, recognizes the external storage medium and writes the partition information stored therein to the partition table, and then reads the master boot record of the storage. This makes it possible to prevent information stored in a storage device from being leaked even if the storage device attached to the information processing device is taken out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2009-251680 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the information processing device of Patent Document 1 determines that an external storage medium is attached to the device when the device is stopped (before the device is stopped) and stores partition information in the external storage device, and also determines that an external storage medium is attached to the connector when the device is started (after the device is started), and writes the partition information stored in the external storage medium to the device side (partition table). In other words, the object of the invention of Patent Document 1 cannot be achieved unless the external storage medium is attached when the device is stopped and when the device is started. In this case, for example, the user must insert the USB device (USB memory) when starting up the PC and also when shutting down the PC, so the user must insert the USB device both when starting up and when shutting down the PC. For this reason, it is possible to keep the USB device attached from startup to shutdown. However, with this type of operation, there is a risk that while the user (legitimate user) is away on business while using the PC, the PC and the USB device may be taken away (stolen) by a malicious third party. In this case, a third party can use the PC with the USB device attached, making it impossible to prevent fraudulent activity. Furthermore, if a USB device is left attached to a PC, it occupies the USB connector and takes up space around the PC. In particular, portable devices such as laptops and mobile PCs are often moved around, and USB devices become a physical hindrance when moving them. On the other hand, it is also possible to remove the USB device immediately after starting up the PC, meaning that the user keeps the USB device in their possession while using the PC. However, in this case, the purpose of the invention cannot be achieved unless the device is attached at least at the time of shutdown, which would require the user to perform many operations (actions). In other words, in this case, you will need to insert the USB device when starting up the PC (operation 1), remove the USB device immediately after starting up the PC (operation 2), and then reinsert the USB device when shutting down the PC (operation 3). Such numerous operations are cumbersome for the user.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide an external storage device that is detachable from an information processing device such as a PC, which, in response to the attachment of the external storage device, installs a specific program in the information processing device that deletes GPT information from the auxiliary storage device at shutdown, executes a setup process that copies (stores) the GPT information stored in the auxiliary storage device to the external storage device, and, at startup after setup, records a program that executes processes such as restoring the GPT information to the auxiliary storage device, as well as related programs and an information processing method. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, an external storage device according to one embodiment of the present invention is a removable external storage device for an information processing device that has a search means for searching for GPT information stored in an auxiliary storage device provided in the main device when the main device is started up and is capable of starting an OS based on the GPT information detected by the search means, and causes the information processing device to function as: a first processing means that stores a specific program stored in the external storage device in the main device and stores the GPT information stored in the auxiliary storage device in the external storage device; and a second processing means that, if GPT information is detected from the auxiliary storage device by the search means when the main device is started up, starts the OS based on the GPT information, and if the GPT information is not detected, restores the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device, and is configured to record a program characterized in that the specific program is a program that deletes the GPT information from the auxiliary storage device when the main device is shut down.

[0008] In addition, to achieve the above-mentioned object, a program according to one embodiment of the present invention causes a computer that is equipped with a search means for searching for GPT information stored in an auxiliary storage device provided in the main body when the main body is started, is capable of starting an OS based on the GPT information detected by the search means, and is capable of attaching and detaching an external storage device, to function as: a first processing means that stores a specific program stored in the external storage device in the main body and stores the GPT information stored in the auxiliary storage device in the external storage device; and a second processing means that, if GPT information is detected from the auxiliary storage device by the search means when the main body is started, starts the OS based on the GPT information, and if GPT information is not detected, restores the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device, and the specific program deletes the GPT information from the auxiliary storage device when the main body is shut down.

[0009] In addition, in order to achieve the above-mentioned object, an information processing method according to one embodiment of the present invention is an information processing method in a system including an information processing device that has a search means for searching for GPT information stored in an auxiliary storage device provided in the main device when the main device is started, and that is capable of starting an OS based on the GPT information detected by the search means, and an external storage device that is detachable from the information processing device, and includes the following steps: a first step of storing a specific program stored in the external storage device in the main device and storing the GPT information stored in the auxiliary storage device in the external storage device; a second step of causing the specific program to delete the GPT information from the auxiliary storage device when the main device is shut down; a third step of restoring the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device because the search means does not detect the GPT information from the auxiliary storage device when the main device is started; and a fourth step of starting the OS based on the GPT information restored in the third step. [Effects of the Invention]

[0010] According to the present invention, the external storage device of the present invention is attached when the information processing device is started up, and after the start-up, the user can continue to use the information processing device while removing the external storage device and keeping it separately. However, even if a third party takes away the information processing device while it is in use, the information processing device cannot be started up unless the external storage device is attached, so that unauthorized use and information leakage can be effectively prevented. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a hardware configuration diagram of a PC and a USB device according to an embodiment of an information processing apparatus and an external storage device. [Figure 2] This is a diagram of the GPT format on a HDD. [Figure 3] This is a tree diagram of the system partition. [Figure 4] FIG. 1 is a tree diagram of Data Partition. [Figure 5] FIG. 2 is a functional block diagram of a PC and a USB device. [Figure 6] 10 is a flowchart showing a process at the time of setup. [Figure 7] 10 is a flowchart showing a process at the time of startup after setup. [Figure 8] 10 is a flowchart showing the OS startup process when power is turned on. DETAILED DESCRIPTION OF THE INVENTION

[0012] The external storage device of the present invention will now be described. FIG. 1 is a hardware configuration diagram of a PC and a USB device (USB memory) according to an embodiment of an information processing device and an external storage device. The information processing device is not limited to a PC, but may be any of various information processing devices having a function of communicating via a network, such as a server device with a built-in computer, a portable information processing terminal, or the like. The external storage device is not limited to a USB device, but may be a storage device that can be attached to a PC or a portable storage device such as a portable SSD or SD card.

[0013] The CPU 10 is connected to a flash ROM (Read Only Memory) 20, an HDD (Hard Disk Drive) 90, a memory (RAM: Random Access Memory) 30, an input unit 40, an output unit 50, and a USB_IF 60 via a bus BA. The CPU 10 executes a program (software) to control each part of the PC 1 and perform processing to realize the functions of the information processing device.

[0014] The flash ROM 20 stores a Unified Extensible Firmware Interface (UEFI) or a Basic Input Output System (BIOS). "UEFI" is an abbreviation for UEFI firmware, and is considered an evolution of "BIOS," which is also called legacy BIOS. The memory 30 corresponds to a main storage device, and the flash ROM 20, the HDD 90, and the USB device 70 correspond to an auxiliary storage device. The auxiliary storage device may be an SSD (Solid State Drive), an SD card (Secure Digital Card), an optical disc (CD, DVD), an external HDD / SSD, online storage, or the like.

[0015] The HDD 90 is a computer (processor) readable recording medium, and stores various data and programs. The HDD 90 stores, for example, an OS 31 (Operating System), various application programs (APPs), and necessary data (information). Data is managed as partitions.

[0016] When the PC 1 starts up, the memory 30 is loaded with programs and the like stored in an auxiliary storage device (for example, the flash ROM 20, the HDD 90), and also temporarily stores information during processing.

[0017] The input unit 40 includes a keyboard, a mouse, a touch panel, etc., and is used to input information and give instructions for processing. A display unit that displays an image can be exemplified as the output unit 50. Note that the output unit 50 may also be a printer unit, a communication unit that connects to a network such as the Internet and outputs (transmits) information, or a combination of these.

[0018] The USB_IF 60 is an interface (connector) that allows the USB device 70 to be attached to and detached from the PC main body. The USB device 70 is an external storage device that can store programs and data. The USB device 70 of this embodiment stores, in advance, the following programs: a GPT deletion program 710, a GPT storage program 720, a GPT restoration program 730 (UEFI module), a reboot program 740, an ID storage program 750, and an authentication program 760 (see FIG. 5).

[0019] The information processing device of the present invention is realized by processes, means, and functions executed by a computer in accordance with instructions from a program (software). The program sends commands to each component of the computer, causing it to perform the specified processes, functions, etc. of the present invention. In other words, each process, means, and function of the present invention is realized by specific means formed by the program and the computer working together. All or part of the program is stored in a computer-readable recording medium (USB device 70), and the program is read from the recording medium and installed / loaded onto the computer (PC 1) for execution. In other words, the program of the present invention is recorded in a computer-readable recording medium, read from the recording medium, and executed.

[0020] FIG. 2 is a diagram showing the GPT (GUID Partition Table) format configuration of the HDD 90. As shown in FIG. 2, the HDD 90 is formatted using a partitioning method called the GPT format. In GPT, the start and end positions of partitions are managed using LBA (Logical Block Addressing). A PMBR (Protective Master Boot Record) 910 is fixed at LBA=0, and a GPT Header 912 is located in the sector following the PMBR 910 (LBA=1). The GPT Header 912 stores a signature (identification information) indicating that the drive is in the GPT format and the LBA of the GPT Partition Entry 913 . The GPT Partition Entry 913 stores an LBA that can identify the range of the disk that each partition occupies. Specifically, the LBAs of the system partition 914 and the data partition 915 are stored. The system partition 914 stores information and files necessary for booting (such as boot loaders and UEFI modules). The Data Partition 915 stores OS31 and user data, as well as an OS loader that works in conjunction with the boot loader to start OS31.

[0021] FIG. 3 is a tree diagram of the system partition 914. FIG. 4 is a tree diagram of the Data Partition 915. For convenience, UEFI firmware and legacy BIOS will be collectively referred to as "BIOS." Note that a UEFI module is a program that can be executed in a UEFI environment configured by UEFI firmware. On a disk configured with GPT, a System Partition 914 is created and formatted as FAT32. In Figure 3, "bootx64.efi" shown in *1 and "Bootmgfw.efi" shown in *2 are boot loaders. In Figure 4, "Winload.efi" shown in *3 is the OS loader. The procedure for starting OS31 will be explained. First, when the PC starts up (powers on), the BIOS executes the UEFI module "EFI\Boot\bootx64.efi" (*1). However, PC1 (a so-called Windows PC) is designed to use Windows (registered trademark; the same applies in this specification), and is designed to execute "EFI\Microsoft\Boot\bootmgfw.efi" (*2) as BIOS registration information, and if this does not exist, to execute "EFI\Boot\bootx64.efi" (*1) (first phase). When the first phase boot loader is executed, the OS loader "\Windows\System32\winload.efi" (*3) in Data Partition 915 is executed. In other words, when PC1 starts up, the BIOS identifies the LBAs of the above-mentioned boot loader and OS loader via GPT Partition Entry 913, GPT Header 912, etc., so the BIOS can search (detect) each loader based on each LBA and identify them, thereby being able to start OS31. The GPT Header 912 and GPT Partition Entry 913 are normally used as the Primary Partition Table 911, and their backups, the GPT Header 918 and GPT Partition Entry 917, are used as the Backup Partition Table 916 for recovery purposes. In the present invention, the PMBR 910, the Primary Partition Table 911 (GPT Header 912 and GPT Partition Entry 913), and the Backup Partition Table 916 (GPT Header 918 and GPT Partition Entry 917) are referred to as "GPT information."

[0022] FIG. 5 is a functional block diagram of the PC 1 and the USB device 70 according to this embodiment. As shown in FIG. 5, the PC 1 includes a GPT deletion unit 110, a GPT storage unit 120, a GPT restoration unit 130, a restart unit 140, an ID storage unit 150, and an authentication unit 160. The USB device 70 stores (contains) a GPT deletion program 710, a GPT storage program 720, a GPT restoration program 730 (UEFI module), a reboot program 740, an ID storage program 750, and an authentication program 760 in advance. In addition, PC1 is equipped with a search means (BIOS) that searches for GPT information stored in the HDD90 (auxiliary storage device) provided in the PC main body when the PC main body is started up, and has the basic function of starting the OS based on the GPT information detected by the search means. That is, as described above, when PC1 starts up, the BIOS searches (detects) each loader (see *1 to *3) based on the LBA, and starts the OS loader identified by the search, thereby starting OS31.

[0023] The GPT deletion means 110 deletes the GPT information from the HDD 90 (auxiliary storage device) when the PC main body is shut down. Specifically, when a GPT deletion program 710 (specific program) stored in advance in a USB device 70 is attached to the PC 1 during setup, the GPT deletion program 710 is installed in the PC 1. By installing the program, the GPT deletion program 710 stored in the USB device 70 is set up by being stored in the HDD 90 of the PC 1. The GPT deletion program 710 set up in this way is loaded into the memory 30 when the PC 1 is shut down, and as a result, the GPT information is deleted from the HDD 90. That is, since the GPT deletion program 710 is installed in advance on the PC 1, the GPT information can be deleted from the HDD 90 even if the USB device 70 is removed at the time of shutdown. In other words, in the past, if the GPT deletion program 710 stored in the USB device 70 was to be started at shutdown, it was necessary to attach the USB device 70 to the PC1 at shutdown. However, as in the present invention, by storing the GPT deletion program 710 on the PC1 side (in advance) at setup, it is possible to start the GPT deletion program at shutdown even if the USB device 70 is removed from the PC1.

[0024] The GPT storage means 120 stores the GPT information stored in the HDD 90 (auxiliary storage device) of the PC 1 in the USB device 70 (external storage device). Specifically, when the GPT deletion program 710 is installed, the CPU 10 reads the GPT storage program 720 that has been stored in the USB device 70 in advance. As a result, the CPU 10 stores (copies) the GPT information stored in the HDD 90 in the USB device 70.

[0025] That is, the USB device 70 stores a program that causes the information processing device to function as a first processing means that stores the GPT deletion program 710 (specific program) stored in the USB device 70 (external storage device) in the PC main body and stores the GPT information stored in the HDD 90 (auxiliary storage device) in the USB device 70 (external storage device). As a result, the GPT deletion program 710 causes the CPU 10 to delete the GPT information from the HDD 90 when the PC main body is shut down.

[0026] If the search means of PC1 does not detect GPT information from HDD90 (auxiliary storage device) when the PC main body is started after setup, i.e., after execution of the first processing means, the GPT restoration means 130 restores the GPT information in HDD90 (auxiliary storage device) based on the GPT information stored in the USB device 70 (external storage device). Specifically, the UEFI module stored in advance in the USB device 70 functions as the GPT restoration means 130. More specifically, this UEFI module functions as a GPT restoration means 130 when the PC main body is started up, and restores the GPT information to the HDD 90. In other words, the GPT information deleted by the GPT deletion means 110 is restored. In other words, when the PC main body is started, if GPT information is detected from the HDD90 (auxiliary storage device) by the search means, the PC1 starts up the OS31 based on the GPT information, and if the GPT information is not detected, the PC1 functions as a second processing means that restores the GPT information in the HDD90 (auxiliary storage device) based on the GPT information stored in the USB device 70 (external storage device). However, simply restoring the GPT information will not allow you to boot OS31. This is because when PC1 starts up, the LBA of each partition is referenced, each loader (*1 to 3) is identified based on that LBA, and OS31 is started. Therefore, when the GPT information is deleted, each LBA is recognized as not existing. Therefore, in the present invention, after the GPT restoration means 130 is executed, the PC itself is restarted.

[0027] The restarting means 140 restarts the PC 1 after the GPT restoring means 130 is executed. When the PC is restarted, the BIOS recognizes each LBA contained in the GPT information. This will identify each loader (*1 to 3) and start OS31. In other words, the USB device 70 causes the PC 1 to function as a restart means 140 that restarts the PC itself after restoring the GPT information.

[0028] The ID storage means 150 stores a UUID (Universally Unique IDentifier) ​​in the USB device 70 (external storage device) during setup. That is, the ID storage means 150 is loaded into the memory 30 of the PC 1 by reading the ID storage program 750 stored in advance in the USB device 70 during setup, and is then executed during setup. The UUID is identification information that can uniquely identify PC1, and is stored in a structure provided by the BIOS. The UUID is loaded into memory 30 and is referenced and used by software such as OS 31. Therefore, the ID storage means 150 refers to this UUID and stores it in a predetermined area.

[0029] The authentication means 160 allows the use of PC1 if the UUID stored by the ID storage means 150 matches the UUID stored in PC1 at the next startup with the USB device 70 (external storage device) attached, and does not allow the use of PC1 if they do not match. The authentication means 160 reads an authentication program stored in advance in the USB device 70, loads it into the memory 30 of the PC 1, and executes it. "Permitted / non-permitted use" is controlled by whether or not the GPT restoration means 130 is executed. Therefore, the authentication means 160 is executed before the GPT restoration means 130 is executed.

[0030] (Information processing method) An information processing method executed in the PC 1 of the present invention will be described. The information processing method described below corresponds to a processing flow executed by a computer in accordance with instructions of the program (software) of the present invention.

[0031] FIG. 6 is a flowchart showing the setup process. As shown in FIG. 6, during setup, first, the GPT deletion program is installed (S11). Specifically, when a USB device 70 (external storage device of the present invention) storing the programs shown in Figure 5 is attached to a PC1 on which OS31 is running normally, the PC1 responds to this attachment by executing a setup program (not shown) stored (memorized) in the USB device 70, and installs a GPT deletion program 710. The GPT deletion program 710 is a program that deletes GPT information when the OS 31 is shut down. The setup program (GPT deletion program 710) stored in the USB device 70 is read and installed only when the device is first attached. Next, the GPT information is copied to the USB device 70 (S12). In other words, the GPT information stored in the HDD 90 is stored in the USB device 70. This completes the setup. After the setup is complete, the user removes the USB device 70 from the PC1 and uses the PC1. When the user has finished using the PC1, the user performs a shutdown operation on the PC1. In response to this operation, the PC1 (OS31) executes a shutdown, and along with the shutdown, the CPU 10 reads the GPT deletion program 710 that was installed in advance, thereby deleting the GPT information from the HDD 90 (S13).

[0032] FIG. 7 is a flowchart showing the process at startup after setup. As shown in FIG. 7, when PC1 is started (powered on), a search for a GPT disk is performed by the BIOS (search means, synonymous with "UEFI BIOS" described later) (S21). First, the BIOS determines whether GPT information is present (stored) on the HDD 90 (S22). If the HDD 90 has GPT information (S22-Yes), the OS 31 is started based on the GPT information stored in the HDD 90, but if the HDD 90 does not have GPT information (S22-No), the process proceeds to S24. In the case of the present invention, the process proceeds to S24. In S24, the BIOS determines whether the USB device 70 has GPT information. If the USB device 70 does not have GPT information (S24-No), the startup is stopped (S25), but if the USB device 70 has GPT information (S24-Yes), the process proceeds to S26. In the case of the present invention, the process proceeds to S26. In S26, the BIOS executes the UEFI module (GPT restoration program 730) stored in the USB device 70. As a result, the original GPT information is restored in the HDD 90 (S27). That is, the CPU 10 reads the GPT restoration program 730 to restore the GPT information. Then, the restart means 140 restarts the PC 1 (S28). This will start up the OS31 (see Figure 8).

[0033] FIG. 8 is a flowchart showing the startup process of the OS 31 when the power is turned on. As shown in FIG. 8, when the power is turned on in the PC1, the UEFI BIOS (BIOS) starts up (S31) and recognizes devices connected to the PC1 (S32). In response to this, the BIOS searches for a bootable disk (S33). In this embodiment, the HDD 90 and the USB device 70 are exemplified as bootable disks (boot disks). If a boot disk is present (S34-Yes), the BIOS executes (starts) the OS boot loader (S35). As a result, the OS 31 is started (S36). If there is no boot disk (S34-No), PC1 (OS31) displays an error message (S37) and stops booting (S38).

[0034] (Linking USB device 70 to PC1) Immediately after the power supply to the PC 1 is turned on, the BIOS is executed by the CPU 10 . This BIOS is stored in the ROM 20, which is a non-volatile memory, and is loaded into the memory 30. The BIOS loaded into the memory 30 stores a UUID (Universally Unique IDentifier). The UUID is identification information that indicates the uniqueness of the PC 1 (hardware) and is currently referenced and used in software such as the OS 31 and applications. Therefore, in the present invention, this UUID is stored in the USB device 70 during setup, and at the next startup (first startup), this UUID (USB device side ID) is compared with the UUID (PC side ID) stored in ROM 20 or memory 30 to perform authentication. Specifically, if both the USB device ID and the PC ID match, the restoration of the GPT information is allowed and the use of PC1 is permitted; if they do not match, the restoration of the GPT information is prohibited (restricted) and the use of PC1 is not permitted. The UUID may be stored at the first startup, and in this case, authentication may be performed at the next startup (startup after the first startup). That is, the external storage device of the present invention records (stores) a program that causes PC1 (information processing device) to function as an ID storage means 150 that stores the ID in the USB device 70 (external storage device) at a predetermined timing when the USB device 70 (external storage device) is attached, and as authentication means 160 that, when the USB device 70 (external storage device) is subsequently started up with the USB device 70 (external storage device) attached, allows use of PC1 (information processing device) if the ID (USB device side ID) stored by the ID storage means 150 matches the ID (PC side ID) stored in PC1 (information processing device), and does not allow use of PC1 (information processing device) if they do not match. This links the USB device 70 used for setup with the PC 1 that has been set up, so that the PC 1 (OS 31) cannot be started unless the dedicated USB device 70 is used. This makes it possible to more reliably prevent fraudulent acts by third parties.

[0035] In summary, by connecting a dedicated USB device 70 to the PC 1 on which the OS 31 is running, the setup program stored in the USB device 70 is executed. Accordingly, a GPT deletion program 710 is installed that deletes the GPT information (marked with * in FIG. 2) configuring the HDD 90 of PC 1 when the OS 31 is shut down. In other words, when PC 1 is shut down, the GPT information is deleted from the HDD 90 (GPT deletion means 110), and at the time of setup, the GPT information to be deleted (GPT information used for restoration, which will be described later) is stored in the USB device 70 (GPT storage means 120). As a result, the next time PC1 starts up, PC1 (BIOS) searches for the partition where the OS31 file (loader) is stored, but because it was deleted when OS31 was shut down, it will not be able to start up as is. In other words, the PC1 (OS31) cannot be started unless the USB device 70 of the present invention is attached. Also, even if the HDD 90 is removed from the PC1 and accessed using another terminal or OS, it cannot be mounted because there is no partition information. Therefore, by having the USB device 70 individually owned by the user, even if the set-up PC1 is unintentionally taken away by a third party, it is possible to prevent the PC1 from being used without permission or information from being extracted (leaked) from the HDD 90.

[0036] After the setup, when the USB device 70 is attached to the PC1 and the power is turned on, the BIOS of the PC1 is executed. The BIOS searches for disks installed and mounted on PC1, but since there is no GPT information on HDD90 after setup, an error will occur if left as is. However, if USB device 70 is installed, the BIOS will find the UEFI module in USB device 70 and execute it. The UEFI module restores the GPT information on the HDD 90 using the GPT information of the HDD 90 copied into the USB device 70 (GPT restoration means 130). However, since the BIOS cannot recognize the LBA of the GPT information simply by restoring it, it is restarted (restart means 140). This is because the BIOS recognizes the GPT information (LBA) at startup, but if the GPT information is deleted, it will continue to recognize that the GPT information does not exist until the system is restarted. Therefore, after rebooting, the BIOS finds the GPT information on HDD90 and executes the OS boot loader, which starts up OS31 (PC1).

[0037] In other words, the external storage device (USB device 70) of the present invention is a removable external storage device for PC1 (information processing device) that has a search means for searching for GPT information stored in an HDD90 (auxiliary storage device) provided in the PC main body when the PC main body is started up, and is capable of starting up OS31 based on the GPT information detected by the search means, and causes PC1 (information processing device) to function as: first processing means that stores a GPT deletion program (specific program) stored in the USB device 70 (external storage device) in the PC main body and stores the GPT information stored in the HDD90 (auxiliary storage device) in the USB device 70 (external storage device); and second processing means that, if GPT information is detected in the HDD90 (auxiliary storage device) by the search means when the PC main body is started up, starts up OS31 based on the GPT information, and if GPT information is not detected, restores the GPT information in HDD90 (auxiliary storage device) based on the GPT information stored in the USB device 70 (external storage device), and the specific program has recorded thereon a program that deletes the GPT information from the HDD90 (auxiliary storage device) when the PC main body is shut down. Furthermore, the external storage device (USB device 70) of the present invention records (stores) a program that causes the PC 1 (information processing device) to function as a restart means that restarts the main body after restoring the GPT information.

[0038] As a result, by attaching the external storage device of the present invention when starting up the information processing device, the user can continue to use the information processing device after start-up by removing the external storage device and keeping it separately, but even if a third party takes away the information processing device alone, such as the information processing device being used, the information processing device cannot be started up unless the external storage device is attached. In contrast, with conventional technology (such as the technology disclosed in JP 2009-251680 A), while a user (authorized user) is away from their desk for business while using a PC, a malicious third party may take (steal) the PC along with the USB device. In that case, the third party can continue to use the PC with the USB device still attached, making it impossible to prevent fraudulent activity. In addition, USB devices require frequent plugging and unplugging, and there was also the problem of taking up space around them if they were left attached to the PC. According to the present invention, it is possible to solve these problems that cannot be solved by conventional techniques.

[0039] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, GPT is used as an example of the disk format, but MBR (Master Boot Record) may be used instead of GPT, or an external storage device may be used that stores a program that is compatible with both GPT and MBR. The GPT information may include system partition information. In other words, the present invention can also be realized by deleting and restoring GPT information including system partition information. [Explanation of symbols]

[0040] 1: PC (information processing device), 10: CPU (processor), 110: GPT deletion means, 120: GPT storage means, 130: GPT restoration means, 140: restart means, 150: ID storage means, 160: authentication means, 20: flash ROM, 30: memory (RAM), 31: OS, 40: input unit, 50: output unit, 60: USB_IF, 70: USB device (external storage device), 90: HDD (hard disk drive, auxiliary storage device), 710: GPT deletion program (specific program), 720: GPT storage program, 730: GPT restoration program (UEFI module), 740: restart program, 750: ID storage program, 760: authentication program, 910: PMBR, 911: Primary Partition Table (912: GPT Header, 913: GPT Partition Entry), 914: System Partition, 915: Data Partition, 916: Backup Partition Table(917:GPT Partition Entry, 918:GPT Header)

Claims

1. An external storage device that is detachable from an information processing device that includes a search unit that searches for GPT information stored in an auxiliary storage unit provided in the main body when the main body is started, and that can start an OS based on the GPT information detected by the search unit, The information processing device a first processing means for storing the specific program stored in the external storage device in the main body and for storing the GPT information stored in the auxiliary storage device in the external storage device; when the search means detects GPT information from the auxiliary storage device at the time of booting the main body, the search means functions as a second processing means that boots an OS based on the GPT information, and when the search means does not detect GPT information, restores the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device; The specific program is This is a program that deletes GPT information from the auxiliary storage device when the main unit is shut down. An external storage device having a program recorded thereon.

2. The information processing device 2. The external storage device according to claim 1, further comprising a program recorded thereon that functions as a restarting means for restarting the main body after execution of the second processing means.

3. The information processing device stores a unique ID for each main body, The information processing device ID storage means for storing the ID in the external storage device; When the ID stored in the ID storage means matches the ID stored in the information processing device, the use of the information processing device is permitted, and when they do not match, the use of the information processing device is not permitted.

3. The external storage device according to claim 1 or 2.

4. The GPT information is The information includes at least the PMBR, the Primary Partition Table, and the Backup Partition Table.

4. The external storage device according to claim 3.

5. A computer that includes a search means for searching for GPT information stored in an auxiliary storage device provided in the main body when the main body is started, and that can start an OS based on the GPT information detected by the search means, and that can detachably connect an external storage device, a first processing means for storing the specific program stored in the external storage device in the main body and for storing the GPT information stored in the auxiliary storage device in the external storage device; when the search means detects GPT information from the auxiliary storage device at the time of booting the main body, the search means functions as a second processing means that boots an OS based on the GPT information, and when the search means does not detect GPT information, restores the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device; The specific program is This is a program that deletes GPT information from the auxiliary storage device when the main unit is shut down. A program characterized by:

6. An information processing method for a system including an information processing device that has a search means for searching for GPT information stored in an auxiliary storage device provided in a main body when the main body is started, and that is capable of starting an OS based on the GPT information detected by the search means, and an external storage device that is detachable from the information processing device, a first step of storing the specific program stored in the external storage device in the main body and storing the GPT information stored in the auxiliary storage device in the external storage device; a second step of causing the specific program to delete the GPT information from the auxiliary storage device when the main body is shut down; a third step of restoring the GPT information in the auxiliary storage device based on the GPT information stored in the external storage device when the search means does not detect the GPT information in the auxiliary storage device at the time of booting the main body; a fourth step of starting an OS based on the GPT information restored by the third step.

1. An information processing method comprising:

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