JP2006216146A - Hard disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an HDD capable of preventing leakage of HDD data and deleting the HDD data at a high speed. <P>SOLUTION: This hard disk drive is constructed in such a manner that a management table is provided for recording access history of a sector for each data sector unit to be accessed by an instruction from a host, write history is recorded in an area, corresponding to the writing-designated sector of the management table by a writing instruction from the host, reference is made to the reading-designated sector of the management table by a reading instruction from the host to return the data of the designated sector when writing history is set, and data, unrelated to the data of the designated sector, is made to be returned to the host, when writing history has not been set. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In order to prevent information written in a hard disk drive (hereinafter abbreviated as HDD), which is an external storage device of an information processing apparatus such as a personal computer, from leaking when being passed to a third party for reuse, Relates to a method (whitening) of erasing data.

  In recent years, due to the enforcement of laws and regulations related to the recycling of personal computers, the market for second-hand sales of personal computers has been attracting attention. At this time, a problem is to prevent important information written in the HDD from leaking to a third party. It is not enough to delete a file on the OS, and the file can be restored by using a special tool. In order to prevent this, conventionally, an operation of overwriting meaningless data in all data areas of the HDD (so-called whitening) has been performed.

  This whitening operation has a problem that it takes time because the operation writes to all data areas of the HDD. Furthermore, depending on the data to be overwritten, the file may be restored due to the residual magnetism of the media. For this reason, Patent Document 1 discloses a technique for reliably performing whitening at high speed.

Japanese Patent Laid-Open No. 2003-30801

  However, in the above prior art, data is overwritten anyway, so it takes time to delete. In particular, since the capacity of HDDs has been increasing in recent years, the larger the capacity, the longer the time, and the need for shortening the work time and improving the efficiency has become higher.

  An object of the present invention is to provide an HDD that solves the above problems, prevents data leakage, and erases data from the HDD at high speed.

  In order to solve the above-described problems, the hard disk drive of the present invention is provided with a management table for recording the access history of each sector in the data sector to be accessed by an instruction from the host. When the write history is set by referring to the area corresponding to the read-designated sector of the management table according to the read instruction from the host by recording the write history in the area corresponding to the write-designated sector of the table Returns the data of the specified sector to the host, and returns data unrelated to the data of the specified sector to the host when the write history is not set.

  Furthermore, the write history of the management table is erased when a specific operation command is designated from the host.

  According to the present invention, it is possible to instantly implement the same effect as that of erasing the entire data of the HDD. That is, since the HDD whitening work can be performed instantaneously, the HDD whitening work time associated with the reuse of the personal computer is greatly reduced and the efficiency is greatly improved.

  Embodiments of the present invention will be described below.

  Hereinafter, an operation when whitening the HDD according to an embodiment of the present invention will be described. FIG. 1 is a configuration diagram of an HDD according to the present embodiment. The HDD 1 has a disk 2 in which actual data is written and a management table 3 that is a feature of the present invention.

  The management table 3 is provided with a flag indicating whether or not data has been written in units of sectors on the disk 2. Here, it is assumed that the flag is set to 1 and the flag is not set to 0. First, it is assumed that all flags are 0 for the initial HDD. Thereafter, the sector that has written changes the corresponding flag to 1. For example, when writing to sector 1, the flag of sector 1 in management table 3 changes from 0 to 1 (FIG. 1). When reading, first, the flag of the corresponding sector in the management table 3 is checked, and if it is 1, the corresponding sector of the actual disk 2 is read and the data is transferred to the host. If 0, the disk 2 is not read, and meaningless data unrelated to the sector (for example, all 00, incremental pattern, etc.) is transferred to the host.

  For example, in the case of the HDD shown in FIG. 1, when a read command for sector 1 is received, the flag is 1, so sector 1 of disk 2 is read and the data is transferred to the host. When it comes, since the flag is 0, meaningless data unrelated to the sector is transferred to the host without going to read the disk 2.

  FIG. 2 shows an algorithm showing the specific operation to be performed in the above operation at the time of reading and at the time of writing. Up to this point, the conventional HDD and the HDD 1 incorporating the method of the present invention operate differently as a normal HDD because there is no difference in movement as viewed from the host, although the operation of the HDD itself is different.

  Next, the operation when whitening is performed will be described. The HDD 1 has a function of returning all the flags of the management table 2 to 0 when a special command is issued. The whitening process is completed by running a program that issues this special command. Since only the flag of the management table 3 is returned, it is executed instantaneously. At this point, the user data is still written on the disc 2.

  Further, a case where a malicious person attempts to read data in the HDD using a special tool or the like after performing the above whitening operation will be described. Although user data is written on the disk 2, even if a read command is issued to the HDD 1, the flags of the management table 3 are all 0, so the HDD 1 does not read the data written on the disk 2 and reads the data. Insignificant data unrelated to the sector is transferred. Therefore, user data cannot be read. Since this appears to be the same operation as the HDD whitened with the complete erasure software when viewed from the host side, the effect is equivalent and effective even with the whitening according to the method of the present invention.

Next, an example will be shown in which another function is used to return all the flags of the management table 2 to 0, which are used when whitening is performed.
As shown in FIG. 3, a physical switch 4 is provided on the control board of the HDD 1 and all the flags of the management table 2 are returned to 0 when the switch 4 is turned on. Since whitening can be performed simply by turning on the switch, it is not necessary to prepare a program that issues a special command. There is no worry about data loss. In addition, it is possible to make this switch a short jumper, etc. so that ordinary users do not notice it. It is also possible to disclose and use the function.

  In the two embodiments described so far, only the HDD, such as preparing a program for issuing a special command when whitening, or operating a switch that can be executed only by a person whose function is disclosed, It was a special function that the vendor had. On the other hand, the example which implements this invention as a standard function is shown.

  In recent years, ATA interface HDDs used for personal computers and the like have increased the number of functions that support the HDD password function as an added function. Among the security function related commands, there is a security erase unit command. This command is a command to release the lock and return the HDD to a state in which no password is set, on condition that all the internal data is erased, since the HDD has been locked due to forgetting the password.

  Since the execution content of this command is the same as that of whitening, the whitening of the HDD can be performed using this command. However, the execution contents of this command also overwrite meaningless data in all data areas of the HDD, and are merely doing the same thing as complete erasure software. Therefore, the execution time becomes enormous. If the present invention is applied to this command, the command can be executed instantaneously. In other words, when the Security Erase Unit command is issued, the function of resetting all the flags of the management table 2 to 0 can be executed, so that the operation of erasing all data areas can be replaced.

  In this embodiment, a command defined in the ATA standard is used, and since this is not a vendor-unique method, any HDD using the present invention can instantly execute whitening in the same manner regardless of the vendor. Increased versatility.

It is a figure showing the composition of HDD showing the relation between the flag management table and the data written on the disk. It is the flowchart which showed the operation | movement algorithm at the time of read and write. It is a HDD external view explaining the method of erasing data with a physical switch.

Explanation of symbols

1 ... HDD, 2 ... disk, 3 ... management table, 4 ... switch

Claims (2)

In a hard disk drive that performs read / write in units of sectors according to instructions from the host,
Provide a management table that records the access history of the sector for each data sector to be accessed according to an instruction from the host,
In accordance with a write instruction from the host, a write history is recorded in an area corresponding to the sector specified for writing in the management table,
When the write history is set by referring to the area corresponding to the read-designated sector of the management table by the read instruction from the host, the data of the specified sector is returned to the host, and the write history is not set In some cases, the hard disk drive is characterized by returning data unrelated to the specified sector data to the host. 2. The hard disk drive according to claim 1, wherein when a specific operation command is designated by the host, the write history of the management table is erased.

Images