JP2011041325A - Storage device and data leakage prevention method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage device and data leakage prevention method in which recorded data can be prevented from leaking. <P>SOLUTION: The present invention relates to a control apparatus for controlling a storage device, in which data are encrypted on the basis of an encryption key and stored in a storage region and the data stored in the storage region are decrypted, on the basis of the encryption key. The control apparatus includes an information generator for generating, when the storage device is turned on, information different from information in the previous turn-on as modification information, and an encryption key generator for generating the encryption key, on the basis of the modification information generated by the information generating unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  Embodiments described herein relate generally to a storage device and a data leakage prevention method.

  A storage device that automatically encrypts recorded data is known as a storage device that prevents leakage of information to be recorded. Such a function of the storage device is known as an FDE (Full Disk Encryption) function. In the storage device having the FDE function, the encryption key is generated based on the set password, and the encrypted data can be decrypted by inputting the password to the storage device.

  In addition, as a related art related to the present invention, a magnetic disk device, an encryption processing method, and a program that make data unrecoverable by changing an encryption key in encryption of recorded data when discarded are known. (For example, refer to Patent Document 1).

JP 2004-341768 A

  However, when the storage device having the FDE function is stolen, the encryption key is generated based on the password. Therefore, the encrypted data is decrypted by a third party due to the password attack or the leakage of the password, There is a problem that data that should be kept secret is leaked.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a storage device and a data leakage prevention method capable of preventing leakage of recorded data.

  The storage device of the embodiment encrypts data based on the corresponding encryption key and stores the data in a plurality of storage areas each associated with an encryption key, and stores the data in the plurality of storage areas, respectively. A storage device that decrypts data based on the corresponding encryption key, and when the storage device is turned on, an information generation unit that generates, as change information, information different from the previous power-on, and An encryption key generation unit that generates the encryption key based on the change information generated by the information generation unit.

  The data leakage prevention method of the embodiment encrypts data based on the corresponding encryption key and stores the data in a plurality of storage areas each associated with an encryption key, and stores the data in the plurality of storage areas. A data leakage prevention method in a storage device that decrypts each stored data based on the corresponding encryption key, and changes information that is different from the previous power-on when the storage device is turned on. And an encryption key generation step of generating the encryption key based on the change information generated by the information generation step.

FIG. 1 is a diagram illustrating a hardware configuration of the magnetic disk device according to the first embodiment. FIG. 2 is a diagram illustrating a functional configuration of the magnetic disk device according to the first embodiment. FIG. 3 is a diagram illustrating the operation of the encryption key generation process according to the first embodiment. FIG. 4 is a diagram showing a functional configuration of the magnetic disk device according to the first embodiment. FIG. 5 is a diagram showing a storage area of the magnetic disk device according to the second embodiment. FIG. 6 is a diagram showing setting information of the magnetic disk device according to the second embodiment. FIG. 7 is a diagram illustrating the operation of the encryption key generation process according to the second embodiment. FIG. 8 is a diagram showing a storage area of the magnetic disk device according to the third embodiment. FIG. 9 is a diagram illustrating a functional configuration of the magnetic disk device according to the third embodiment. FIG. 10 is a diagram illustrating the operation of the encryption key generation process according to the third embodiment.

<Embodiment 1>
First, the configuration of the magnetic disk device according to the first embodiment will be described. FIG. 1 shows a hardware configuration of a magnetic disk device according to the present embodiment.

  As shown in FIG. 1, a magnetic disk device 2 (storage device) according to the first embodiment is connected to a host device 1 as a host device, and includes a disk medium 21, a head 22, an SPM (Spindle Motor) 23, a VCM ( Voice-Coil Motor) 24, servo control unit 25, head IC 26, read channel 27, encryption circuit 28, encryption circuit control unit 29, buffer memory 30, host IF (Interface) 31, host IF control unit 32, flash memory 33, An MPU (Micro Processing Unit, control device) 34 is provided.

  The disk medium 21 is a storage medium that records data as a signal. The head 22 writes a signal to the storage medium 21 and reads a signal written to the storage medium 21. The SPM 23 drives the disk medium 21 to rotate. The VCM 24 drives the head 22. The servo control unit 25 controls the SPM 23 and the VCM 24. The head IC 26 amplifies the signal written to the disk medium 21 by the head 22 and the signal read from the disk medium 21. The read channel 27 converts data written to the disk medium 21 into a signal, and converts a signal read from the disk medium 21 into data. The encryption circuit 28 encrypts data written to the disk medium 21 and decrypts data read from the disk medium 21. The encryption circuit control unit 29 controls the encryption circuit 28. The buffer memory 30 temporarily stores data written to the disk medium 21 and data read from the disk medium 21. In addition, the host IF 31 contributes to communication related to transmission / reception of data and commands between the host device 1 and the magnetic disk device 2. Further, the host IF control unit 32 controls communication transmitted / received via the host IF 31. The flash memory 33 is a non-volatile memory that stores a program executed by the MPU 34 or settings related to processing. The MPU 34 controls the operation of the entire magnetic disk device 2.

  Further, the magnetic disk device 2 receives the password input by the user and authenticated by the host device 1 via the host IF 31, and generates an encryption key based on the received password.

  Next, a functional configuration of the magnetic disk device according to the first embodiment will be described. FIG. 2 shows a functional configuration of the magnetic disk device according to the present embodiment.

  As shown in FIG. 2, the magnetic disk device 2 according to the first embodiment includes a determination unit 41 (reference unit, determination unit) and a generation unit 42 (information generation unit, encryption key generation unit) as functions. The determination unit 41 executes a determination related to the process. The generation unit 42 generates an encryption key used for data encryption and decryption by the encryption circuit 28 based on the password (authentication information) authenticated by the host device 1. Note that these units are functions realized by the MPU 34.

  Next, the operation of the encryption key generation process according to Embodiment 1 will be described. FIG. 3 shows the operation of the encryption key generation process according to the first embodiment.

  As shown in FIG. 3, first, the determination unit 41 refers to a security flag (setting information) stored in the flash memory 33 as a setting (S101, reference step), and determines whether the state is ON. (S102, determination step). This security flag is indicated by ON or OFF, and is set by the user via the host device 1 or the like, for example. In the security flag, ON indicates that an encryption key is generated based on a random number, and OFF indicates that an encryption key is generated based on a password.

  When the security flag is not ON (S102, NO), the generation unit 42 generates an encryption key based on the password authenticated by the host device 1 (S103, encryption key generation step).

  In step S101, when the security flag is ON (S102, YES), the generation unit 42 generates a random number (change information) and generates an encryption key based on the random number (S104, information generation step, Encryption key generation step). The information based on the generation of the encryption key is not limited to a random number, and may be information other than the information (for example, password) based on the generation of the encryption key at the previous power-on.

  The encryption key generated based on the password or the random number in this way is used for encryption of write data and decryption of read data by the encryption circuit 28. As described above, when the security flag is ON, an encryption key is generated based on the random number when the magnetic disk device 2 is activated. Therefore, the already written data is encrypted by the encryption key based on the password, and therefore cannot be correctly decrypted by the encryption circuit 28. Thus, by changing the information based on the generation of the encryption key by turning on the power again, for example, when the magnetic disk device 2 is stolen, it becomes impossible to read data at the theft destination.

  In the present embodiment, the security flag is not essential, and the encryption key may be generated based on information different from the previous power-on with the power-on of the magnetic disk device 2 as a trigger. For example, an encryption key may be generated based on a different random number each time the power is turned on. According to this, when the magnetic disk device 2 is used in a large-scale system, the magnetic disk device 2 is powered on during operation. Leakage can be prevented.

<Embodiment 2>
The second embodiment is different from the first embodiment in that whether or not to change the encryption key is individually set for a plurality of areas in the storage area of the magnetic disk device 2. Hereinafter, configurations and operations different from those of the first embodiment will be described.

  First, a functional configuration of a magnetic disk device different from the first embodiment will be described. FIG. 4 shows a functional configuration of the magnetic disk device according to the second embodiment. FIG. 5 shows a storage area of the magnetic disk device according to the second embodiment. FIG. 6 shows setting information of the magnetic disk device according to the second embodiment.

  As shown in FIG. 4, the magnetic disk device 2 according to the second embodiment is different from the first embodiment in that a selection unit 43 is provided as a function in addition to the determination unit 41 and the generation unit 42. The selection unit 43 selects a plurality of regions as shown in FIG. Further, the determination unit 41 determines whether to change the encryption key for each of the plurality of areas with reference to the setting information shown in FIG. In this setting information, each of the plurality of areas is associated with a security flag, and it is determined whether or not to change the encryption key based on the security flag for each area. Note that this setting information is stored in the flash memory 33.

  Next, the operation of the encryption key generation process according to the second embodiment will be described. FIG. 7 shows the operation of the encryption key generation process according to the second embodiment.

  As shown in FIG. 7, when the power of the magnetic disk device 2 is turned on, the selection unit 43 selects a predetermined area from a plurality of areas in the storage area of the magnetic disk device 2 (S201) and determines The unit 41 refers to the setting information (S202, reference step), and determines whether or not the security flag corresponding to the area selected by the selection unit 43 is ON (S203, determination step).

  When the security flag corresponding to the selected area is not ON (S203, NO), the generation unit 42 generates an encryption key based on the authenticated password (S204, encryption key generation step). Next, the determination unit 41 determines whether all areas in the storage area of the magnetic disk device 2 have been selected (S205).

  If all areas have been selected (S205, YES), the encryption key generation process is terminated.

  On the other hand, when all the areas are not selected (S205, NO), the selection unit 43 selects a predetermined area from the unselected areas among the plurality of areas in the storage area of the magnetic disk device 2 (S201). ).

  In step S203, when the security flag for the selected area is ON (S203, YES), the generation unit 42 generates a random number (information generation step), and generates an encryption key based on the random number (S206). , Encryption key generation step). Next, the determination unit 41 determines again whether all the areas in the storage area of the magnetic disk device 2 have been selected (S205).

  As described above, by changing the encryption key according to the setting of each of the plurality of areas, for example, it is possible to prevent only data in an area where data to be concealed is written from being read.

<Embodiment 3>
The third embodiment is similar to the second embodiment in that the encryption key is generated for each of a plurality of areas, but the point that the encryption key other than the backup area is changed among the plurality of areas is implemented. This is different from the second form. Hereinafter, a magnetic disk device according to the third embodiment will be described.

  First, the storage area of the magnetic disk device according to the third embodiment will be described. FIG. 8 shows a storage area of the magnetic disk device according to the third embodiment.

  As shown in FIG. 8, the recording area of the magnetic disk device 2 according to the third embodiment includes at least a system area and a backup area of the system area. An OS (Operating System) is installed in the system area, and data in the system area is copied in the backup area.

  Next, a functional configuration of the magnetic disk device according to the third embodiment will be described. FIG. 9 shows a functional configuration of the magnetic disk device according to the third embodiment.

  As shown in FIG. 9, the magnetic disk device 2 according to the third embodiment is provided with a setting unit (area setting unit) 44 as a function in addition to the determination unit 41, the generation unit 42, and the selection unit 43. This is different from the second form. The setting unit 44 sets the backup area as the system area.

  Next, the operation of the magnetic disk device according to the third embodiment will be described. FIG. 10 shows the operation of the encryption key generation process according to the third embodiment.

  As shown in FIG. 10, first, when the power of the magnetic disk device 2 is turned on, the selection unit 43 selects a predetermined area from a plurality of areas in the storage area of the magnetic disk apparatus 2 (S301, selection step). ) The determination unit 41 refers to the setting information to determine whether the area selected by the selection unit 43 is a backup area (S302, determination step).

  When the selected area is a backup area (S302, YES), the generation unit 42 generates an encryption key based on the authenticated password (S303, encryption key generation step). Next, the setting unit 44 sets the backup area as a system area (S304, area setting step), and the determination unit 41 determines whether all areas in the storage area of the magnetic disk device 2 have been selected (S305). .

  If all areas have been selected (S305, YES), the encryption key generation process is terminated.

  On the other hand, when all the areas are not selected (S305, NO), the selection unit 43 selects a predetermined area from among the unselected areas among the plurality of areas in the storage area of the magnetic disk device 2 (S301). ).

  In step S302, when the selected area is not a backup area (S302, NO), the generation unit 42 generates a random number and generates an encryption key based on the random number (S306, information generation step, encryption Key generation step). Next, the determination unit 41 determines again whether all areas in the storage area of the magnetic disk device 2 have been selected (S305).

  In this way, the host device 1 generates the encryption key for the backup area based on the password and the encryption key for the other area based on the random number, thereby preventing the leakage of the data on the magnetic disk device 2. The OS can be started. Further, the above-described embodiments can be used in combination. Further, although the magnetic disk device 2 has been described as the device according to each embodiment described above, the present invention can be realized as long as it is a storage device.

As mentioned above, according to this Embodiment, the technical idea shown with the following additional remarks is disclosed.
(Appendix 1) A control device that controls a storage device that encrypts data based on an encryption key and stores the data in a storage region, and decrypts the data stored in the storage region based on the encryption key,
An information generating unit that generates, as change information, information different from the previous power-on by turning on the power of the storage device;
A control device comprising: an encryption key generation unit that generates the encryption key based on the change information generated by the information generation unit.
(Supplementary note 2) In the control device according to supplementary note 1,
A reference unit that refers to setting information indicating whether or not to generate the change information by the information generation unit, which is a setting for the storage area by turning on the power of the storage device;
A determination unit that determines whether the setting information referred to by the reference unit indicates generation of the change information;
When the determination unit determines that the setting information indicates generation of the change information, the information generation unit generates the change information, and the encryption key generation unit adds the setting information based on the change information. A control device that generates an encryption key for a corresponding storage area.
(Supplementary Note 3) In the control device described in Supplementary Note 2,
When the determination unit determines that the setting information does not indicate generation of the change information, the encryption key generation unit responds to the setting information based on authentication information authenticated by a host device of the storage device. A control apparatus for generating an encryption key for a storage area to be stored.
(Supplementary Note 4) In the control device according to Supplementary Note 1,
The storage device has a plurality of storage areas including at least a system area and a backup area of the system area,
A selection unit that selects each of the plurality of storage areas by turning on the power of the storage device;
The storage unit selected by the selection unit further includes a determination unit that determines whether the storage region is a backup region,
When the determining unit determines that the storage area selected by the selecting unit is not a backup area, the information generating unit generates the change information, and the encryption key generating unit is based on the change information. A control device that generates an encryption key for the storage area selected by the selection unit.
(Additional remark 5) In the control apparatus of Additional remark 4,
A control device further comprising: an area setting unit configured to set the storage area selected by the selection unit as a system area when the determination unit determines that the storage area selected by the selection unit is a backup area.
(Supplementary Note 6) A storage device that encrypts data based on an encryption key and stores the data in a storage area, and decrypts the data stored in the storage area based on the encryption key,
An information generating unit that generates, as change information, information different from the previous power-on by turning on the power of the storage device;
A storage device comprising: an encryption key generation unit that generates the encryption key based on the change information generated by the information generation unit.
(Supplementary note 7) In the storage device according to supplementary note 6,
A reference unit that refers to setting information indicating whether or not to generate the change information by the information generation unit, which is a setting for the storage area by turning on the power of the storage device;
A determination unit that determines whether the setting information referred to by the reference unit indicates generation of the change information;
When the determination unit determines that the setting information indicates generation of the change information, the information generation unit generates the change information, and the encryption key generation unit adds the setting information based on the change information. A storage device that generates an encryption key for a corresponding storage area.
(Supplementary note 8) In the storage device according to supplementary note 7,
When the determination unit determines that the setting information does not indicate generation of the change information, the encryption key generation unit responds to the setting information based on authentication information authenticated by a host device of the storage device. A storage device that generates an encryption key for a storage area to be stored.
(Supplementary note 9) In the storage device according to supplementary note 6,
The storage device has a plurality of storage areas including at least a system area and a backup area of the system area,
A selection unit that selects each of the plurality of storage areas by turning on the power of the storage device;
The storage unit selected by the selection unit further includes a determination unit that determines whether the storage region is a backup region,
When the determining unit determines that the storage area selected by the selecting unit is not a backup area, the information generating unit generates the change information, and the encryption key generating unit is based on the change information. A storage device that generates an encryption key for the storage area selected by the selection unit.
(Supplementary note 10) In the storage device according to supplementary note 9,
A storage device further comprising an area setting unit that sets the storage area selected by the selection unit as a system area when the determination unit determines that the storage area selected by the selection unit is a backup area.
(Supplementary Note 11) A data leakage prevention method in a storage device that encrypts data based on an encryption key and stores the data in a storage area, and decrypts the data stored in the storage area based on the encryption key,
An information generation step of generating information different from the previous power-on as change information by turning on the storage device;
A data leakage prevention method comprising: an encryption key generation step for generating the encryption key based on the change information generated by the information generation step.
(Supplementary note 12) In the data leakage prevention method described in supplementary note 11,
A reference step for referring to setting information indicating whether or not the change information is generated by the information generation step by setting the storage area by turning on the power of the storage device;
A determination step of determining whether or not the setting information referred to in the reference step indicates generation of the change information,
When the determination step determines that the setting information indicates generation of the change information, the information generation step generates the change information, and the encryption key generation step adds the setting information based on the change information. A data leakage prevention method characterized by generating an encryption key for a corresponding storage area.
(Supplementary note 13) In the data leakage prevention method described in supplementary note 12,
When it is determined by the determination step that the setting information does not indicate generation of the change information, the encryption key generation step corresponds to the setting information based on authentication information authenticated by a host device of the storage device. A data leakage prevention method comprising generating an encryption key for a storage area to be stored.
(Supplementary note 14) In the data leakage prevention method described in supplementary note 10,
The storage device has a plurality of storage areas including at least a system area and a backup area of the system area,
A selection step of selecting each of the plurality of storage areas by turning on the power of the storage device;
A determination step of determining whether or not the storage area selected in the selection step is a backup area;
When the determination step determines that the storage area selected in the selection step is not a backup area, the information generation step generates the change information, and the encryption key generation step is based on the change information. A data leakage prevention method, comprising: generating an encryption key for the storage area selected in the selection step.
(Supplementary note 15) In the data leakage prevention method described in supplementary note 14,
The data leakage prevention method further comprising an area setting step of setting the storage area selected in the selection step as a system area when the determination step determines that the storage area selected in the selection step is a backup area. .

1 Host device 2 Magnetic disk device 21 Disk medium 22 Head 23 SPM
24 VCM
25 Servo Control Unit 26 Head IC
27 Read channel 28 Cryptographic circuit 29 Cryptographic circuit control unit 30 Buffer memory 31 Host IF
32 Host IF control unit 33 Flash memory 34 MPU
41 determination unit 42 generation unit 43 selection unit

Claims (6)

Data is encrypted based on the corresponding encryption key and stored in a plurality of storage areas each associated with an encryption key, and the data stored in the plurality of storage areas is associated with the encryption key. A storage device for decoding based on
An information generating unit that generates, as change information, information different from the previous power-on by turning on the power of the storage device;
An encryption key generation unit that generates the encryption key based on the change information generated by the information generation unit;
A storage device. A reference unit that refers to setting information that is set independently in each of the plurality of storage areas by turning on the power of the storage device, and that indicates whether the change information is generated by the information generation unit;
A determination unit that determines whether the setting information referred to by the reference unit indicates generation of the change information;
Further comprising
When the determination unit determines that the setting information indicates generation of the change information, the information generation unit generates the change information, and the encryption key generation unit adds the setting information based on the change information. Generate an encryption key for the corresponding storage area,
The storage device according to claim 1. When the determination unit determines that the setting information does not indicate generation of the change information, the encryption key generation unit responds to the setting information based on authentication information authenticated by a host device of the storage device. Generating an encryption key for a specific storage area among the plurality of storage areas;
The storage device according to claim 2. Data is encrypted and stored based on the corresponding encryption key in a plurality of storage areas each associated with an encryption key, and the data stored in the plurality of storage areas is associated with the encryption key A data leakage prevention method in a storage device that performs decryption based on:
An information generation step of generating information different from the previous power-on as change information by turning on the storage device;
An encryption key generation step of generating the encryption key based on the change information generated by the information generation step. A step of referring to setting information indicating whether or not the change information is generated by the information generation step, each of which is independently set in the plurality of storage areas by turning on the power of the storage device;
A determination step of determining whether the setting information referred to in the reference step indicates generation of the change information;
Further including
When the determination step determines that the setting information indicates generation of the change information, the information generation step generates the change information, and the encryption key generation step adds the setting information based on the change information. Generate an encryption key for the corresponding storage area,
The data leakage prevention method according to claim 4. When it is determined by the determination step that the setting information does not indicate generation of the change information, the encryption key generation step corresponds to the setting information based on authentication information authenticated by a host device of the storage device. Generating an encryption key for a specific storage area among the plurality of storage areas;
The data leakage prevention method according to claim 5.

Images