Abstract:
A storage device includes a switching unit which switches an access destination in a storage area between a first storage area and a second storage area in response to an access request from a host device; and a nonvolatile storage medium which stores a first host device information used to identify the host device in the second storage area, and a software module executed by a CPU provided in the host device, the software module comprising causing the an authority grant unit which transmits a control signal for switching the access destination to the first storage area to the switching unit of the storage device, when the acquired first and second host device information are compared to find that the first and second host device information match with each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2010-79051 filed on Mar. 30, 2010, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The present application relates to a storage device, a data processing device, a registration method, and a recording medium that prevent data leakage. 
       BACKGROUND 
       [0003]    As one of technologies for preventing leakage of information stored in a personal computer (PC), for example, there is known a technology for preventing, when a PC is stolen, information leakage from the stolen PC by erasing an encryption key of an encrypted hard disk drive (HDD) provided in the PC by an instruction from remote. That is, by erasing the encryption key, it becomes impossible to decrypt encrypted information in the HDD so that the information leakage may be prevented. 
         [0004]    However, in the above-described technology, since the encryption key may not be erased when the HDD is detached from the PC before the instruction from remote is received, there is a possibility that the encrypted information in the HDD is decrypted by using other PCs. 
         [0005]    As a technology capable of solving such problem, for example, as described in Japanese Laid-open Patent Publication No. 2009-258979, there is a HDD including a self-erasing function in which a disk erasing program and a circuit for executing the erasing program are mounted and, when configuration between a BIOS and the HDD fails, the erasing program is executed to erase information in the HDD. 
         [0006]    With this technology, for example, after the HDD is detached from the PC, when trying to connect the HDD to another PC to view the information in the HDD, the information in the HDD is erased at the point when the HDD is connected to another PC to be activated. 
         [0007]    However, since the above-described HDD including the self-erasing function may be required modification of hardware, the HDD includes a problem that it is difficult for companies that develop anti-theft technologies for PCs to incorporate the anti-theft technologies in existing HDDs. 
       SUMMARY 
       [0008]    A storage device disclosed in the present application includes a switching unit which switches an access destination in a storage area between a first storage area and a second storage area in response to an access request from a host device; and a nonvolatile storage medium which stores a first host device information used to identify the host device in the second storage area, and a software module executed by a CPU provided in the host device, the software module comprising: causing the host device to function as a first host device information acquisition unit which acquires the first host device information stored in the second storage area, causing the host device to function as a second host device information acquisition unit which acquires a second host device information used to identify the host device from a nonvolatile storage medium stored by the host device that is different from the storage device, and causing the an authority grant unit which transmits a control signal for switching the access destination to the first storage area to the switching unit of the storage device, when the acquired first and second host device information are compared to find that the first and second host device information match with each other. 
         [0009]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]      FIG. 1  is a schematic view illustrating a schematic structure of a storage device according to the present embodiment; 
           [0012]      FIG. 2  is a schematic view explaining a functional structure of the storage device; 
           [0013]      FIG. 3  is a flowchart illustrating a processing procedure on boot-up; 
           [0014]      FIG. 4  is a schematic view illustrating a structure at the time of an initial setting; 
           [0015]      FIG. 5  is a flowchart illustrating a procedure for the initial setting; 
           [0016]      FIG. 6  is a schematic view illustrating a structure at the time of maintenance processing; 
           [0017]      FIG. 7  is a flowchart explaining a procedure for the maintenance processing; and 
           [0018]      FIG. 8  is a schematic view illustrating a device structure of a second embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0019]    The present invention will be specifically described hereinbelow on the basis of the drawings illustrating embodiments thereof. 
       First Embodiment 
       [0020]      FIG. 1  is a schematic view illustrating a schematic structure of a storage device according to the present embodiment. A storage device  1  according to the present embodiment is a storage device in conformity with TCG Opal SSC specifications (Trusted Computing Group Opal Security Subsystem Class) standardized by TCG (Trusted Computing Group). Specifically, the storage device  1  according to the present embodiment is a storage device such as a HDD (Hard Disk Drive), a SSD (Solid State Drive), or the like. 
         [0021]    A conventional HDD (a HDD that is not in conformity with TCG Opal SSC specifications) is capable of including only one image that may be activated in a storage area, but a storage device in conformity with TCG Opal SSC specifications (hereinafter referred to as a TCG-HDD) is capable of including two images. One is in a data storage area  11  where user&#39;s data is stored, and the other one is in a PBA area  12  (PBA: PreBoot Authentication) that includes an authentication function, and is generated for the purpose of carrying out authentication before boot-up of a PC. 
         [0022]    The storage device  1  according to the present embodiment includes the above-mentioned data storage area  11  and PBA area  12 , and includes an image switching unit  10  for switching the storage area to be used on boot-up. 
         [0023]    The image switching unit  10  performs image load control and access control of the data storage area  11  and the PBA area  12 . In the data storage area  11 , there are stored an OS (Operating System) booted by a PC  2  as a connection destination (see  FIG. 2 ), data created by a user of the PC  2 , and the like. In the PBA area  12 , the OS image may also be stored similarly to the storage area, and the capacity of 128 Mbytes is secured. 
         [0024]    As operational modes of the TCG-HDD, there are two types of an ATA mode and a TCG mode. In the ATA mode, the HDD may be controlled from the outside (BIOS and OS) by using the same ATA command as that for the conventional HDD, and the same usage as that for the conventional HDD may be adopted. However, the image switching or the preboot authentication (PBA) that characterize the TCG-HDD do not function. 
         [0025]    On the other hand, in the TCG mode, the HDD is controlled by using a TCG command that is different from the conventional command. In addition, in the TCG mode as well, it is possible to set use/non-use of the PBA area  12  and, when the PBA area  12  is not used, the OS image in the data storage area  11  is activated similarly to the conventional HDD. 
         [0026]    The storage device  1  according to the present embodiment is constituted such that the image switching unit  10  and the PBA area  12  function by adopting a setting in which the TCG mode and the PBA area  12  are used. In the conventional HDD, a MBR (Master Boot Record) is provided at the head portion of the storage area and, when the control is shifted from the BIOS to the HDD, the MBR is firstly read. In the TCG-HDD as well, a Shadow-MBR is provided in the PBA area  12 . 
         [0027]    In a case where the control is shifted to the image switching unit  10  from the BIOS, when the preboot authentication (PBA) is used, the image switching unit  10  loads the image in the PBA area  12  in order to read the Shadow-MBR. When the image is switched from the image in the PBA area  12  to the image in the data storage area  11 , a program stored in the PBA area  12  performs the control. A CPU (not illustrated) in the PC  2  executes a “MBR-DONE” command as the TCG command, and the image switching unit  10  thereby loads the image in the data storage area  11  to switch the OS image. 
         [0028]    As will be described later, when a PC as a connection destination is not authenticated, the storage device  1  erases data stored in the data storage area  11 . The erasing of data may be implemented by directly overwriting the data by 0. 
         [0029]    In addition, since the TCG-HDD includes an encryption function using hardware, the erasing of the data may also be implemented by re-generating an encryption key instead of the erasing by directly overwriting the data. Specifically, a “GenKey” command as the TCG command is used. The “GenKey” command is an erasing command corresponding to “Security Erase Unit” as the ATA command. 
         [0030]      FIG. 2  is a schematic view explaining the functional structure of the storage device  1 .  FIG. 2  also illustrates the schematic structure of the PC  2  as the connection destination for the explanation. The PC  2  is, e.g., a personal computer, and includes a CPU, a ROM, a RAM and the like. A device information storing unit  21  of the PC  2  stores information that uniquely identifies the PC  2  (device information). For example, it is possible to use a unique information of 18 digits (FMVAB1Z300R1234567 or the like) obtained by combining the model name and the production number of the PC  2 . 
         [0031]    In the present embodiment, although the device information is stored in the device information storing unit  21 , the device information may also be stored in a NVRAM of a BIOS  20 . 
         [0032]    The storage device  1  is capable of acquiring the device information via the BIOS  20  of the PC  2 . It may be considered that the method for acquiring the device information differs according to a model or a manufacturer. In this case, the storage device  1  is not capable of registering another model or a PC manufactured by another manufacturer as a registered PC. However, the storage device  1  may recognize that the PC is different from the registered PC by not being able to acquire the device information, it is possible to execute the erasing of data in the data storage area  11 . 
         [0033]    The PBA area  12  of the storage device  1  includes a device authentication unit  121 , an erasing unit  122 , and a registered device information storing unit  123  that function by being run by the CPU of the PC  2  when the authentication of the HDD or the data erasing is performed, and a maintenance processing unit  124  and a maintenance device information storing unit  125  that function by being run by the CPU of the PC  2  at the time of the maintenance of the HDD. 
         [0034]    The device authentication unit  121  compares the device information of the PC  2  to which the device (storage device  1 ) is connected with a device information retained in the registered device information storing unit  123  to perform authentication. When the device authentication unit  121  authenticates the connected PC  2 , the device authentication unit  121  grants access authority to the data storage area  11  to the image switching unit  10 , and causes the image switching unit  10  to load the OS image in the data storage area  11 . When the device authentication unit  121  does not authenticate the connected PC  2 , the device authentication unit  121  instructs the erasing unit  122  to erase data stored in the data storage area  11 . 
         [0035]    In addition, when there is no device information registered in the registered device information storing unit  123 , the registered device information storing unit  123  acquires the device information of the PC  2  to which the device (storage device  1 ) is connected, and registers the acquired device information. 
         [0036]    The erasing unit  122  receives the instruction of the device authentication unit  121  to erase data in the data storage area  11 . In the present embodiment, the data erasing is performed by resetting an encryption key with which data is encrypted. 
         [0037]    In the registered device information storing unit  123 , the device information acquired from the PC  2  to which the device (storage device  1 ) is connected is registered at the time of initial registration. In addition, it is also possible to register the device information by providing an application for registering the device information (registration application) in the PBA area  12  or on the OS. For example, there may be considered a method in which a registration application that displays a menu screen in the PC  2  when a specific operation is performed at a certain timing is provided in the PBA area  12  in advance, and the device information is registered from the menu screen. 
         [0038]    In the present embodiment, the registered device information storing unit  123  is assumed to be capable of registration of a plurality of devices. It is assumed that the first device to be registered is automatically registered by an initial setting, and the second and subsequent devices are additionally registered by a user using the registration application in the PBA area  12  or on the OS. 
         [0039]    The maintenance processing unit  124  compares the device information of the PC  2  to which the device (storage device  1 ) is connected with a device information retained in the maintenance device information storing unit  125 , and executes maintenance processing when the device information match with each other. In the maintenance processing, the device information stored in the registered device information storing unit  123  and the maintenance device information storing unit  125  are cleared. By clearing the registered device information storing unit  123 , it becomes possible to re-register the device. When the device information do not match with each other, the device information stored in the maintenance device information storing unit  125  is cleared, and the processing is shifted to the device authentication unit  121 . When the device information is not retained in the maintenance device information storing unit  125 , the processing is shifted to the device authentication unit  121  without carrying out any operation. 
         [0040]    In the maintenance device information storing unit  125 , the device information of a PC for maintenance (PC  2 ) is registered. The reason why the device information retained therein is cleared every time the maintenance processing is performed is to prevent the avoidance of execution of the HDD erasing on boot-up by registering the PC for maintenance. 
         [0041]      FIG. 3  is a flowchart illustrating a processing procedure on boot-up. When the PC  2  is booted (at S 11 ), the PC  2  executes processing of the BIOS  20  (at S 12 ). When the storage device  1  in conformity with the TCG Opal SSC specifications is connected to the PC  2 , the PC  2  loads the image in the PBA area  12  into a storage of the PC  2  such as the RAM or the like, and runs the image by the CPU of the PC  2  (at S 13 ). The image in the PBA area  12  is loaded and run by the CPU of the PC  2 , whereby the device authentication unit  121 , the erasing unit  122 , and the maintenance processing unit  124  function in the PC  2 . 
         [0042]    The device authentication unit  121  acquires the device information from the PC  2  to which the device (storage device  1 ) is connected, and compares the device information with the device information retained in the registered device information storing unit  123  to determine whether or not the device information match with each other, whereby the device authentication unit  121  performs device authentication (at S 14 ). 
         [0043]    When the device information match with each other (S 14 : YES), an authority grant signal for granting the access authority to the data storage area  11  to the image switching unit  10  is transmitted from the PC  2  to the device (storage device  1 ), and the image in the data storage area  11  is activated (at S 15 ). That is, the image in the data storage area  11  is loaded into the storage of the PC  2  such as the RAM or the like, and the image is run by the CPU of the PC  2 . 
         [0044]    When the device information do not match with each other (S 14 : NO), the device authentication unit  121  instructs the erasing unit  122  to erase data in the data storage area  11 , and the erasing unit  122  resets the encryption key to erase data stored in the data storage area  11  (at S 16 ). 
         [0045]    With these operations, even when trying to detach the storage device  1  connected to the authorized PC  2  and obtain data therein by connecting the storage device  1  to another PC, the data in the data storage area  11  is erased at the point when the PC is booted so that the leakage of secret information may be prevented. 
         [0046]    Next, a description will be given of a procedure when the authentication function and the erasing function according to the present embodiment are set in the TCG-HDD.  FIG. 4  is a schematic view illustrating the structure at the time of an initial setting. In order to set the authentication function and the erasing function in the TCG-HDD, it is preferable to set execution programs for implementing the above-described device authentication unit  121 , erasing unit  122 , and maintenance processing unit  124 , and storage areas for the registered device information storing unit  123  and the maintenance device information storing unit  125  in the PBA area  12 . 
         [0047]    Since there is a possibility that such initial setting is made by a manufacturing plant or a user, as a method that allows the manufacturing plant and the user to easily make the initial setting, a structure is adopted in which an external medium  3  such as a CD-ROM, a USB memory or the like includes an initial setting unit  31  and execution programs to be installed. 
         [0048]    The above-mentioned execution programs stored in the external medium  3  are captured into the PBA area  12  of the storage device  1  via an IF unit  22  of the PC  2 . 
         [0049]    Since the registered device information is set in the initial setting processing, when the setting is completed, it is preferable to avoid the execution of an unnecessary initial setting. For example, there may be considered a method in which it is determined whether or not the programs are already installed in the PBA area  12  at the beginning of the processing by the initial setting unit  31 , and the initial setting processing is stopped when the programs are already set, or the like. 
         [0050]    Further, in the method utilizing the PBA area  12 , a structure may also be adopted in which an initial setting program is stored in the PBA area  12 , the initial setting program downloads the execution programs from the external medium  3  at the first boot-up, and the initial setting program is erased at a stage where various settings are completed. 
         [0051]      FIG. 5  is a flowchart illustrating a procedure for the initial setting. The flowchart illustrated in  FIG. 5  illustrates a procedure when the initial setting is performed by a user. This initial setting is performed during boot-up of the OS. First, during boot-up of the OS, the external medium  3  such as the CD-ROM , the USB memory or the like is connected to the IF unit  22  of the PC  2 , and the initial setting processing by the initial setting unit  31  is executed (at S 21 ). The initial setting unit  31  may be automatically run when the external medium  3  is inserted into a drive. 
         [0052]    The initial setting unit  31  firstly performs authentication (at S 22 ). In the authentication, it is possible to use user authentication, and device authentication. For example, by requiring password input, it is possible to allow only an authorized user to execute the initial setting. In addition, it is also possible to perform authentication in which manufacturer information of a device is acquired from the BIOS  20  in advance, and the initial setting is terminated when the device is a PC manufactured by the other manufacturers, or the manufacturer information is not obtained. The manufacturer information is retained in the NVRAM of the BIOS  20  similarly to a model number and the like. 
         [0053]    When the authentication is successful (S 22 : YES), the initial setting unit  31  determines whether or not the execution programs are already installed in the PBA area  12  (at S 23 ). When the authentication is unsuccessful in the at S 22  (S 22 : NO), or when the execution programs are installed in the PBA area  12  (S 23 : YES), the processing according to the present flowchart is terminated. 
         [0054]    When the authentication is successful (S 22 : YES) and it is determined that the execution programs are not installed in the PBA area  12  (S 23 : NO), the initial setting unit  31  starts the initial setting. 
         [0055]    The initial setting unit  31  firstly installs the respective execution programs of the device authentication unit  121 , the erasing unit  122 , and the maintenance processing unit  124  in the PBA area  12  (at S 24 ). After the installation of the execution programs, the initial setting unit  31  secures areas for the registered device information storing unit  123  and the maintenance device information storing unit  125 , and sets the device information of the PC  2  to which the device (storage device  1 ) is currently connected in the registered device information storing unit  123  (at S 25 ). 
         [0056]    The above-described operations complete the initial setting. On the next or subsequent boot-up, when the storage device  1  is connected to a PC other than the registered PC  2 , and the PC is booted, data stored in the data storage area  11  of the storage device  1  is erased. 
         [0057]    Next, the maintenance processing will be described.  FIG. 6  is a schematic view illustrating the structure at the time of the maintenance processing. Similarly to the initial setting, a structure is adopted in which the maintenance processing is executed by using an external medium  4 . A maintenance device registration unit  41  is contained in the external medium  4  that may be activated from the BIOS  20  of the PC  2 , and the PC  2  is registered as a device for maintenance in the storage device  1  only when the BIOS  20  activates the external medium  4 . 
         [0058]    In the present embodiment, although a structure is adopted in which the maintenance device registration unit  41  is contained in the external medium  4 , a structure may also be adopted in which the maintenance device registration unit  41  is contained in the PC  2 , the PBA area  12  of the storage device  1 , a server on a network, or the like. 
         [0059]    In addition, in the storage device  1  including the self-erasing function as described in the present embodiment, since data in the data storage area  11  is erased when a maintenance operation fails, it is desirable that the maintenance processing without any operational mistake may be executed. When the maintenance device registration unit  41  is contained in the PC  2  or the storage device  1 , it is preferable for a person in charge of the maintenance to perform an operation for reporting a timing for the maintenance at a specific timing. Accordingly, there is a possibility that mistakes are made due to the intervention of manual work by the person. 
         [0060]    When the maintenance device registration unit  41  is contained in the server on the network, the maintenance processing is possible only in an environment that allows connection to the network. 
         [0061]    When the external medium  4  is utilized, the maintenance processing is executed at a timing at which the external medium  4  is connected to the PC  2 . In particular, in a setting of a device startup sequence in the BIOS  20 , the external medium  4  such as the CD-ROM, the USB memory or the like is prioritized over the HDD, whereby the maintenance processing may be reliably started only by connecting the external medium  4  and booting the PC  2 . 
         [0062]    However, when the external medium  4  is prioritized to be activated without limitation, there is a possibility that the operation becomes a method for avoiding the erasing of the HDD. Consequently, it is preferable to include some limitation that prevents the activation of the external medium  4  for the maintenance. For example, similarly to the initial setting, it is preferable to screen a device capable of using the external medium  4  by acquiring the manufacturer information from the PC  2  to allow the maintenance only with a device manufactured by a specific manufacturer, acquiring the model number of the device to allow the maintenance only when the model numbers match with each other, or the like. In addition, there may be considered a method in which a different password is set for each external medium  4  and the password may be required before the maintenance processing is executed. With this method, it becomes possible to screen a user capable of using the external medium  4 . 
         [0063]      FIG. 7  is a flowchart explaining the procedure for the maintenance processing. First, the PC  2  is booted from the external medium  4  (at S 31 ), and the device information of the PC  2  is acquired (at S 32 ). Next, the maintenance device registration unit  41  of the external medium  4  sets the acquired device information of the PC  2  in the maintenance device information storing unit  125  provided in the PBA area  12  of the storage device  1  (at S 33 ). With the above-described steps, the device information of the device for maintenance is registered in the storage device  1 . When the device information is registered, the PC  2  is temporarily shut down (at S 34 ). The shutdown may be automatically performed by the maintenance device registration unit  41 , or may be manually performed by a user. 
         [0064]    When the PC  2  is rebooted (at S 35 ), the maintenance processing unit  124  determines whether or not the device information is set in the maintenance device information storing unit  125  (at S 36 ). When the device information is not set in the maintenance device information storing unit  125  (S 36 : NO), the processing in and after the at S 14  is executed according to the same procedure as that in the flowchart illustrated in  FIG. 3 . 
         [0065]    When the device information is set in the maintenance device information storing unit  125  (S 36 : YES), the device information set in the maintenance device information storing unit  125  is compared with the device information acquired from the currently connected device, and it is thereby determined whether or not the currently connected device is the device for maintenance (at S 37 ). 
         [0066]    When it is determined that the currently connected device is not the device for maintenance (S 37 : NO), the maintenance device information storing unit  125  is cleared (at S 38 ), and the processing in and after the at S 14  is then executed. 
         [0067]    On the other hand, when it is determined that the currently connected device is the device for maintenance (S 37 : YES), both of the registered device information storing unit  123  and the maintenance device information storing unit  125  are cleared (at S 39 ). 
         [0068]    In the maintenance processing, when home-visit repair service by a serviceman is assumed, e.g., in a case where a motherboard of the PC  2  is replaced with new one, a device information of the new motherboard is not registered in the registered device information storing unit  123  in the storage device  1  so that data in the data storage area  11  is erased. That is, when the registered PC  2  breaks down, it is not possible to use the storage device  1  in other PCs. Consequently, by executing the maintenance processing of which the procedure is illustrated in  FIG. 7 , it is possible to continuously use the storage device  1  in other PCs. 
       Second Embodiment 
       [0069]    In the first embodiment, although the structure is adopted in which the execution programs for implementing the device authentication unit, the erasing unit, and the maintenance processing unit are installed in the PBA area  12  of the storage device  1  by utilizing the external storage medium  3 , a structure may also be adopted in which these execution programs are downloaded from a server connected to a network. 
         [0070]    In the second embodiment, a description will be given of a structure in which the execution programs are downloaded from the server to perform the initial setting. 
         [0071]      FIG. 8  is a schematic view illustrating a device structure of the second embodiment. The structures of the storage device  1  and the PC  2  are exactly the same as those described in the first embodiment. The IF unit  22  of the PC  2  is connected to a server  50  via a communication network N. 
         [0072]    As described in the first embodiment, it is preferable to set the execution programs for implementing the device authentication unit  121 , the erasing unit  122 , and the maintenance processing unit  124 , and storage areas for the registered device information storing unit  123  and the maintenance device information storing unit  125  in the PBA area  12  of the storage device  1 . 
         [0073]    In the second embodiment, the execution programs for implementing the device authentication unit  121 , the erasing unit  122 , and the maintenance processing unit  124  are stored in the server  50 . 
         [0074]    The PC  2  acquires the above-described execution programs stored in the server  50  via the communication network N at a timing at which the initial setting is performed, and installs the execution programs in the PBA area  12  of the storage device  1 . The procedure for the installation is exactly the same as the procedure described in  FIG. 5  of the first embodiment. 
         [0075]    In the present embodiment, although the connection to the communication network N may be required at the time of the initial setting, the present embodiment includes an advantage that, even when the TCG-HDDs are collectively introduced in units of several hundreds, or several thousands, the introduction thereof is facilitated. 
         [0076]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification related to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alternations could be made hereto without departing from the spirit and scope of the invention.