JP5017136B2 - Encryption / decryption device for hard disk drive and hard disk drive device - Google Patents

Description

  The present invention relates to an encryption / decryption device for a hard disk drive and a hard disk drive device.

  This is an encryption method that encrypts data in units of blocks, and uses the initial vector (IV) when encrypting the top data, and for data other than the top data, the data immediately before that data is used. As a block encryption method for performing encryption, an AES (Advanced Encryption Standard) CBC (Cipher Block Chaining) mode is known.

  In the AES CBC mode, data other than the head data of the data block is encrypted using the data immediately before the data. Therefore, even when data is decrypted, the data block unit is in order from the head. Without decryption, data cannot be decrypted correctly.

  When encrypting a data file stored in the hard disk drive in the AES CBC mode, if an initial vector is set for each file, the data other than the head data of the file is encrypted using the data immediately before that data. Therefore, even when data is decrypted, data cannot be decrypted correctly unless it is decrypted in order from the top in file units.

  However, when using a hard disk drive, there are cases where it is desired to extract and access data at a specific location in a file. Therefore, as a method for encrypting and decrypting data to be stored in the hard disk drive, a method is known in which an initial vector is set for each sector of the hard disk drive, and encryption and decryption are performed in the AES CBC mode ( For example, see Patent Document 1.)

In the technique described in Patent Literature 1, when data encrypted by an initial vector set for each sector is read, a sector to be read is designated, and decryption is performed using the initial vector set for the sector. Data encrypted in the AES CBC mode can be accessed in units of sectors.
JP 2007-183514 A

  By the way, the hard disk drive corresponding to the NCQ of SATA has a buffer for queuing 32 commands. When a plurality of commands are queued, the hard disk drive side automatically issues commands so that the access efficiency is improved. Change the execution order. Since each command specifies the sector number to be accessed, when the command execution order is changed, the sector order of the command instructed from the outside and the order of sectors actually accessed by the hard disk drive are changed. It will be different.

  For example, when a write command is transmitted to the hard disk drive in the order of sectors 0, 1, 2, and 3, the write execution order is changed to, for example, sectors 2, 1, 0, and 3 in the hard disk drive. In order to read out this data, when a read command is transmitted to the hard disk drive again in the order of sectors 0, 1, 2, and 3, the hard disk drive reads out data in the order of sectors 1, 0, 3, and 2, for example. Data is read in an order different from the sector number order specified by the read command.

  Using such a hard disk drive corresponding to SATA NCQ, for example, using the technique described in Patent Document 1, the initial vector (IV) is set when encrypting the head data as in the AES CBC mode. If the data other than the head data is stored using the block encryption method in which the data immediately before the data is encrypted, the following inconvenience is caused. Arise.

  For example, when a write command is transmitted to the hard disk drive in the order of sectors 0, 1, 2, and 3, the hard disk drive changes the write execution order, for example, sector 2, 1, 0, and 3 from the memory to the sector 2 , 1, 0, 3 are read in this order and transferred to the hard disk drive.

  At this time, even if an encryption device provided outside the hard disk drive attempts to encrypt data transferred from the memory to the hard disk drive using the block encryption method described above, the command is input in the sector number order. And the sector number order corresponding to the data transferred from the memory to the hard disk drive will be different, so that the initial vector set for each sector cannot be correctly associated with the transfer data, and as a result, it is encrypted correctly. There was an inconvenience that it was not possible.

  Even when reading data stored in the hard disk drive in this way, the read-out sector order is changed arbitrarily by the hard disk drive as in the case of writing, so the data transferred from the hard disk drive to the memory is changed. As a result, it becomes impossible to correctly correspond to the initial vector set for each sector. As a result, there is a disadvantage that decoding cannot be performed correctly.

  The present invention has been made in view of such circumstances, and queues a plurality of commands that request data transfer with a memory that stores data, and sets the execution order of the queued commands. When storing data in the hard disk drive to be determined, when encrypting the data in block units, the initial vector is used when encrypting the top data, and for data other than the top data, the data immediately before the data is used. An object of the present invention is to provide an encryption / decryption device for a hard disk drive and a hard disk drive device that can perform encryption and decryption using a block encryption method that performs encryption using data.

  An encryption / decryption device for a hard disk drive according to the present invention queues a plurality of commands for requesting data transfer with a memory and determines an execution order of the queued commands. An encryption / decryption device, corresponding to a plurality of commands queued in the hard disk drive, sector address information indicating a sector address of the hard disk drive specified by each command, and the transfer in the memory An information table that stores the address range of the requested data in association with each other, a control unit that receives an access request from the hard disk drive and outputs an address for accessing the memory, and the information table The address output from the control unit A sector address acquisition unit that searches the address range and acquires a sector address based on sector address information corresponding to the found address range, and on the basis of the sector address acquired by the sector address acquisition unit, An initial vector generation unit that generates an initial vector and an initial vector generated by the initial vector generation unit when encrypting the head data when encrypting the data in units of blocks. Is an encryption unit that encrypts data transferred from the memory to the hard disk drive by a block encryption method that encrypts data using the previous data, and an encryption method that uses the block encryption method. The converted data is converted into an initial vector generated by the initial vector generation unit. Using Le, and a decoding unit for decoding as it is transferred from the hard disk drive to the memory.

  According to this configuration, the control unit outputs an address for accessing the memory in response to an access request from the hard disk drive. Then, the address range stored in the information table including the address output from the control unit is searched by the sector address acquisition unit, and the sector stored in the information table corresponding to the found address range A sector address is acquired based on the address information. Further, an initial vector is generated by the initial vector generation unit based on the sector address acquired by the sector address acquisition unit and supplied to the encryption unit and the decryption unit. In this case, even if the execution order of the commands queued in the hard disk drive is changed, an initial vector is generated based on the address actually output to access the memory, and this is performed in the encryption unit. Encryption is performed using the initial vector, and decryption is performed using the initial vector in the decryption unit. Therefore, a plurality of commands for requesting data transfer to and from the memory storing the data are queued. When the data is stored in the hard disk drive that determines the execution order of the commands queued together with the data, the initial vector is used when encrypting the head data when the data is encrypted in units of blocks. Data is encrypted using the previous data. Using click encryption method, it is possible to perform encryption and decryption.

  The information table stores the address range of the data as a start address of the data requesting the transfer in the memory and a size of the data requesting the transfer, and the sector address acquisition unit includes the control unit It is preferable to search for an address range that satisfies the condition that the address output from is greater than or equal to the start address and does not satisfy the address obtained by adding the start address and the data size.

  According to this configuration, the address range of data is stored in the information table as the start address of the data requesting transfer in the memory and the size of the data requesting transfer. Then, the sector address acquisition unit performs control by searching for an address range in which the address output from the control unit is equal to or more than the start address and satisfies the condition that does not satisfy the address obtained by adding the start address and the data size. The address range stored in the information table including the address output from the section can be found.

  In addition, the information table further stores, as the sector address information, the head of a sector address specified by each command, and the sector address acquisition unit includes an address output from the control unit and an information table. A value obtained by dividing the difference between the head address stored in association with the found address range by the sector size of the hard disk drive is stored in association with the found address range in the information table. Preferably, the sector address is calculated by adding to the existing sector address information.

  According to this configuration, the information table further stores the head of the sector address specified by each command as sector address information. The sector address acquisition unit is a value obtained by dividing the difference between the address output from the control unit and the head address stored in association with the address range found in the information table by the sector size of the hard disk drive. Is added to the sector address information stored in association with the found address range in the information table, whereby the sector address corresponding to the address output from the control unit can be calculated.

  The hard disk drive preferably corresponds to NCQ (Native Command Queuing) of SATA (Serial Advanced Technology Attachment).

  According to this configuration, when data is stored in a hard disk drive corresponding to NCQ of SATA, when encrypting data in units of blocks, the initial vector is used when encrypting the top data, and other than the top data Data can be encrypted and decrypted using a block encryption method in which data is encrypted using data immediately before the data.

  The block encryption method is preferably an AES (Advanced Encryption Standard) CBC (Cipher Block Chaining) mode.

  According to this configuration, when queuing a plurality of commands that request data transfer with a memory that stores data and determining the execution order of the queued commands, the data is stored in the hard disk drive. Encryption and decryption can be performed using the AES CBC mode.

  The hard disk drive device according to the present invention queues the encryption / decryption device for the hard disk drive described above, a memory, and a plurality of commands requesting data transfer between the memory and the queuing And a hard disk drive for determining the execution order of the executed commands.

  According to this configuration, when queuing a plurality of commands that request data transfer with a memory that stores data and determining the execution order of the queued commands, the data is stored in the hard disk drive. When encrypting data in units of blocks, block encryption that uses an initial vector when encrypting the top data, and encrypts data other than the top data using the data immediately before the data Encryption and decryption can be performed using the method.

  The hard disk drive encryption / decryption device and hard disk drive device configured as described above queue a plurality of commands that request data transfer with a memory that stores data, and When storing data in the hard disk drive that determines the execution order, when encrypting data in units of blocks, the initial vector is used when encrypting the top data, and for data other than the top data, Encryption and decryption can be performed using a block encryption method that performs encryption using the previous data.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted. FIG. 1 is a block diagram showing an example of a configuration of a hard disk drive device including an encryption / decryption device for a hard disk drive according to an embodiment of the present invention.

  A hard disk drive device 1 shown in FIG. 1 includes an encryption / decryption device 2, a hard disk drive (HDD) 3, and a memory 4. The hard disk drive device 1 is connected to a CPU (Central Processing Unit) 100. The CPU 100 is a CPU on the device side that accesses the hard disk drive device 1.

  The encryption / decryption device 2 is configured using, for example, an ASIC (Application Specific Integrated Circuit), and includes an encryption unit 5, a decryption unit 6, an initial vector supply unit 7, a SATA host controller (control unit) 8, and An encryption key storage unit 9 is provided. The ASIC including the memory 4 together with the encryption / decryption device 2 may be used.

  The hard disk drive 3 is a hard disk drive that supports SATA NCQ, for example, and queues 32 commands for requesting data transfer to and from the memory so that the disk access efficiency is improved. Determine the command execution order and execute it. The hard disk drive 3 executes a memory access via the SATA host controller 8 by outputting a memory access request to the SATA host controller 8 when executing a command and transferring data to and from the memory. It has become.

  The SATA host controller 8 is configured in accordance with, for example, the SATA AHCI (Advanced Host Controller Interface) protocol. Then, the SATA host controller 8 transmits a command to the hard disk drive 3 in response to an access request from the CPU 100. When the SATA host controller 8 receives a memory access request from the hard disk drive 3, the SATA host controller 8 outputs a memory address addr (address) or a control signal to the memory 4 in response to the request, and reads data from the memory 4 or the memory 4. Write data to.

  The encryption key storage unit 9 is configured by storage means such as a RAM (Random Access Memory) or a register, for example, and an encryption key used for encryption and decryption is stored in advance.

  The encryption unit 5 is provided between the memory 4 and the SATA host controller 8. Then, the encryption unit 5 determines the memory address addr output from the SATA host controller 8 based on the encryption key stored in the encryption key storage unit 9 and the initial vector generated by the initial vector supply unit 7. In response, the data 41 transferred from the memory 4 to the SATA host controller 8 is encrypted in real time and output to the SATA host controller 8 as encrypted data 51. The encryption unit 5 uses, for example, AES CBC mode as a block encryption method.

  The decryption unit 6 is provided between the SATA host controller 8 and the memory 4. Then, the decryption unit 6 writes the encrypted data 81 output from the SATA host controller 8 and the encryption key stored in the encryption key storage unit 9 in order to write to the memory address addr output from the SATA host controller 8. The data is decoded in real time based on the initial vector generated by the initial vector supply unit 7 and output to the memory 4 as decoded data 61.

  The decryption unit 6 performs decryption using the same encryption method as that of the encryption unit 5. Note that the encryption unit 5 and the decryption unit 6 are not limited to the example using the AES CBC mode, and are encryption methods for encrypting data in units of blocks. Any data other than the head data may be used as long as it uses a block encryption method in which encryption is performed using data immediately before the data.

  The initial vector supply unit 7 is configured using, for example, various logic circuits and sequential circuits. FIG. 2 is a block diagram showing an example of the configuration of the initial vector supply unit 7 shown in FIG. The initial vector supply unit 7 illustrated in FIG. 2 includes, for example, a command determination unit 71, a sector address calculation unit 72, an initial vector generation unit 73, and an information table 74.

  The information table 74 stores 32 pieces of command information corresponding to 32 commands queued in the hard disk drive 3 with command numbers of 0 to 31. Specifically, the initial vector supply unit 7 monitors an access request from the CPU 100 to the SATA host controller 8, and command information corresponding to a command output from the SATA host controller 8 to the hard disk drive 3 in response to the access request. Is stored as an information table 74.

  Each command information stored in the information table 74 includes Exist [I] indicating whether or not the command I (I is a command number) exists, and the sector address of the hard disk drive 3 that requests access. It includes Start_LBA [I] which is information indicating the start, Start_Address [I] which is information indicating the start address of the transfer data area in the memory 4, and Sector_Size [I] which is information indicating the sector size of the transfer data. Yes.

  In this case, an example of sector address information is configured by Start_LBA [I] and Start_Address [I], and an example of an address range is configured by Start_Address [I] and Sector_Size [I] (data size).

  The command determination unit 71 searches the address range including the memory address addr output to access the memory from the SATA host controller 8 with reference to the information table 74, and command number I of command information specifying the address range. To get.

  The sector address calculation unit 72 calculates the sector address LBA of the transfer data based on Start_LBA [I] and Start_Address [I] of the command number I acquired by the command determination unit 71.

  In this case, the command determination unit 71 and the sector address calculation unit 72 constitute an example of a sector address acquisition unit.

  The initial vector generation unit 73 performs predetermined arithmetic processing such as exclusive OR operation on the sector address LBA calculated by the sector address calculation unit 72 to generate an initial vector IV, and the encryption unit 5 and the decoding unit 6. Thereby, the encryption strength is improved. Note that the initial vector generation unit 73 may output the sector address LBA as it is as the initial vector IV.

  Next, operations of the encryption / decryption device 2 and the hard disk drive device 1 configured as described above will be described. First, when writing data to the hard disk drive device 1, if there are a plurality of access requests for requesting data transfer from the CPU 100 to the SATA host controller 8 and from the memory 4 to the hard disk drive 3, the SATA host controller 8 causes the SATA host controller 8 to A plurality of commands corresponding to the access request are transmitted to the hard disk drive 3 in accordance with the AHCI protocol. Then, the plurality of commands are queued in the hard disk drive 3.

  At this time, the information vector 74 is generated by the initial vector supply unit 7 based on the access request from the CPU 100.

  Next, the execution order of the queued commands is determined by the hard disk drive 3 so that the access efficiency to the disk is improved, and the commands are executed in the determined execution order. Then, a memory access request corresponding to the executed command is transmitted from the hard disk drive 3 to the SATA host controller 8.

  Then, the memory address addr corresponding to the memory access request is transmitted from the SATA host controller 8 to the memory 4. At this time, the memory address addr is acquired by the initial vector supply unit 7, and the initial vector supply unit 7 generates the initial vector IV and outputs it to the encryption unit 5 and the decryption unit 6.

  FIG. 3 is a flowchart showing an example of the operation of the initial vector supply unit 7 shown in FIG. First, the memory address addr is acquired by the command determination unit 71. Then, the command determination unit 71 searches for a command number I satisfying the following expression (1) based on Start_Address [I] and Sector_Size [I] in each command information stored in the information table 74 ( Step S1).

Start_Address [I] ≦ Addr <(Start_Address [I] + Sector_Size [I] × 512) (1)
Expression (1) shows an example in which one sector of the hard disk drive 3 is 512 bytes. And the command determination part 71 acquires the command number I searched in this way as applicable command number Is (step S2).

  Next, the sector address calculation unit 72 calculates the sector address LBA by the following equation (2) based on the corresponding command number Is.

LBA = Start_LBA [Is] + (Addr−Start_Address [Is] / 512) (2)
Expression (2) shows an example in which one sector of the hard disk drive 3 is 512 bytes.

  Next, a predetermined arithmetic processing Make_Iv set in advance is applied to the LBA by the initial vector generation unit 73 to generate an initial vector IV (step S4), and the initial vector IV is encrypted with the encryption unit 5 and decrypted. Is output to the unit 6 (step S5).

  Then, the encryption unit 5 stores the data 41 output from the memory 4 in response to the memory address addr from the SATA host controller 8 in the initial vector IV output from the initial vector generation unit 73 and the encryption key storage unit 9. Based on the stored encryption key, encryption is performed in the AES CBC mode, and the encrypted data 51 is output to the SATA host controller 8. The SATA host controller 8 outputs the encrypted data 51 to the hard disk drive 3 and stores it.

  In this case, even when the command execution order is changed by the SATA NCQ in the hard disk drive 3, the initial vector generation unit 73 generates the correct initial vector IV based on the memory address addr that is actually accessed. Since the encryption by the encryption unit 5 is executed based on the correct initial vector IV, the encrypted data 51 correctly encrypted in the AES CBC mode can be stored in the hard disk drive 3.

  Next, when reading the encrypted data stored in the hard disk drive 3, if there are a plurality of access requests for requesting data transfer from the CPU 100 to the SATA host controller 8 and from the hard disk drive 3 to the memory 4, the SATA host controller 8. Accordingly, a plurality of commands corresponding to the access request are transmitted to the hard disk drive 3 in accordance with the SATA AHCI protocol. Then, the plurality of commands are queued in the hard disk drive 3.

  At this time, the information vector 74 is generated by the initial vector supply unit 7 based on the access request from the CPU 100.

  Next, the execution order of the commands queued so as to improve the access efficiency to the disk is determined by the hard disk drive 3, and the commands are executed in the determined execution order. Then, a memory write request corresponding to the executed command and encrypted data 81 read from the hard disk drive 3 are output from the hard disk drive 3 to the SATA host controller 8.

  Then, the memory address addr indicating the write address corresponding to the memory access request is transmitted from the SATA host controller 8 to the memory 4 and the encrypted data 81 is output to the decryption unit 6. At this time, the memory address addr is acquired by the initial vector supply unit 7, and the initial vector IV is generated by the initial vector supply unit 7 by the operations in steps S 1 to S 5, as in the case of writing data to the hard disk drive 3 described above. It is generated and output to the encryption unit 5 and the decryption unit 6.

  Then, the decryption unit 6 stores the encrypted data 81 output from the SATA host controller 8 together with the memory address addr in the initial vector IV output from the initial vector generation unit 73 and the encryption key storage unit 9. Based on the encryption key, decryption is performed in the AES CBC mode, and the decrypted data 61 is output to the memory 4 for storage.

  In this case, even when the command execution order is changed by the SATA NCQ in the hard disk drive 3, the initial vector generation unit 73 generates the correct initial vector IV based on the memory address addr that is actually accessed. Since the decoding unit 6 performs decoding based on the correct initial vector IV, the decoded data 61 correctly decoded in the AES CBC mode can be stored in the memory 4.

  As described above, according to the hard disk drive device 1 using the encryption / decryption device 2 shown in FIG. 1, data encrypted using the AES CBC mode to the hard disk drive 3 that executes SATA NCQ. Can be stored correctly in real time, and can be correctly decoded and read out in real time.

It is a block diagram which shows an example of a structure of a hard-disk drive apparatus provided with the encryption / decryption apparatus for hard-disk drives which concerns on one Embodiment of this invention. It is a block diagram which shows an example of a structure of the initial vector supply part shown in FIG. It is a flowchart which shows an example of operation | movement of the initial vector supply part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard disk drive apparatus 2 Encryption / decryption apparatus 3 Hard disk drive 4 Memory 5 Encryption part 6 Decryption part 7 Initial vector supply part 8 Host controller 9 Encryption key memory | storage part 71 Command determination part 72 Sector address calculation part 73 Initial vector generation part 73 74 Information table I Command number IV Initial vector LBA Sector address addr Memory address

Claims (4)

An encryption / decryption device for a hard disk drive for queuing a plurality of commands for requesting data transfer to and from a memory and determining an execution order of the queued commands,
Corresponding to a plurality of commands queued to the hard disk drive, sector address information indicating a sector address of the hard disk drive specified by each command and an address range of data requesting the transfer in the memory An information table to be stored,
A control unit that receives an access request from the hard disk drive and outputs an address for accessing the memory;
A sector address acquisition unit that searches the address range including the address output from the control unit with reference to the information table, and acquires a sector address based on sector address information corresponding to the found address range;
An initial vector generation unit that generates the initial vector based on the sector address acquired by the sector address acquisition unit;
When encrypting data in units of blocks, the initial vector generated by the initial vector generation unit is used when encrypting the top data, and the data immediately before the data is used for data other than the top data An encryption unit that encrypts data transferred from the memory to the hard disk drive by a block encryption method that performs encryption.
A decryption unit that decrypts the data encrypted by the block encryption method when transferred from the hard disk drive to the memory using the initial vector generated by the initial vector generation unit ;
The information table is
Storing the address range of the data as the start address of the data requesting the transfer in the memory and the size of the data requesting the transfer;
The sector address acquisition unit
The address output from the control unit is greater than or equal to the start address and searches for an address range that satisfies a condition that does not satisfy the address obtained by adding the start address and the data size,
The information table is
Further, as the sector address information, the head of the sector address specified by each command is stored,
The sector address acquisition unit
A value obtained by dividing the difference between the address output from the control unit and the head address stored in association with the address range found in the information table by the sector size of the hard disk drive, An encryption / decryption device for a hard disk drive , wherein the sector address is calculated by adding to the sector address information stored in association with the found address range . The hard disk drive is
SATA (Serial Advanced Technology Attachment) of NCQ encryption decoding apparatus for a hard disk drive of claim 1, wherein the corresponding (Native Command Queuing). The block encryption method is:
The encryption / decryption device for a hard disk drive according to claim 1 or 2 , wherein the encryption / decryption device is a CBC (Cipher Block Chaining) mode of AES (Advanced Encryption Standard). An encryption / decryption device for a hard disk drive according to any one of claims 1 to 3 ,
Memory,
A hard disk drive device comprising: a hard disk drive that queues a plurality of commands for requesting data transfer to and from the memory and determines an execution order of the queued commands.

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