JPH05233459A - Data backup device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention encrypts and backs up data requiring confidentiality. [Structure] Data used for predetermined processing in an information processing system is stored in a magnetic disk 1, and all access is made to data read from the magnetic disk 1 based on access right information given in advance. The protection determination unit 3 determines whether or not the subject has a read access right to the data, and the encryption unit 4 determines whether or not at least one access subject does not have the read access right. Encrypted with magnetic tape 5
On the other hand, with respect to the data determined to have read access right to all the access subjects, this data is recorded on the magnetic tape 5 as it is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data backup device used in an information processing system having an access protection function.

[0002]

2. Description of the Related Art Recently, various information processing systems have been used, but in such systems, data is often destroyed due to a failure or an operation error.

Therefore, in the past, assuming such a situation, the data processed by the system is copied and stored, and when the data is actually destroyed, it is based on the stored data. 2. Description of the Related Art A data backup device is used that performs so-called backup to restore original data.

On the other hand, an information processing system is generally provided with an access protection function for protecting data from unauthorized access for the purpose of protecting security and privacy.

The access protection function in this case is composed of means for setting access right information and means for performing access control. Here, the access right information is information about which access subject has what right to access which data to be processed in the system, and the access subject means what to access. It depends on the system whether it is considered as an individual access subject in units of, for example, each user registered in the system is considered as an individual access subject, and each user processes each data processed in the system. There are cases in which access right information is set and access protection is performed in the form of what kind of access the user has. In addition to this, access protection is performed by considering each command in the system as an individual access entity, and each processing unit configuring the system is considered as an individual access entity and accessed by hardware. Some can realize the protection function.
Further, the access control means determines, when the access subject tries to access the data, based on the access right information, whether or not the access should be permitted, and blocks the access which should not be permitted. It is to be.

[0006]

However, when backing up data in an information processing system having such an access protection function, the following problems have occurred.

First, even if sufficient access protection can be achieved for data in the process of processing in an information processing system, it is often difficult to provide sufficient access protection for data copied and stored by backup. It is to be. For example, when a file system on a magnetic disk is backed up by a magnetic tape, the file system can generally protect access to files on the magnetic disk.
Access protection may not be possible even for files on magnetic tape.

In such a case, even if the file is on the magnetic disk, even if the file is restricted to users who have the right to read it for security protection and privacy protection,
For the one recorded by backup,
A user who does not originally have the right to read may be able to read the data. In addition, as a medium for recording a backup, a replaceable medium such as a magnetic tape is generally used, and since these media are easy to carry, they may be stolen. It was

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a data backup device capable of stably securing security protection and privacy protection for data stored by backup. To do.

[0010]

According to the present invention, in a data backup device used in an information processing system having an access protection function, a first storage medium for storing data used for predetermined processing in the information processing system. Determination means for determining whether or not the access subject has the read access right to the data based on the access right information given in advance for the data read from the first storage medium. At least one of the access subjects has an encryption means for performing encryption on data determined to have no read access right, and for the data determined by the determination means to have all access subjects have a read access right, The data is recorded as it is, and at least one access entity has read access Is constituted by a second storage medium for recording the encrypted data in the encryption means for data determined not to have.

Further, the second storage medium records the access right information previously given to the data together with the data to be recorded, and the access given to the data is read with respect to the data read from the second storage medium. Based on the authorization information, the determining means determines whether or not all the access entities have the read access right to the data, and the determining means determines that at least one access entity does not have the read access right. The decrypted data is decrypted by the decryption means, and the data determined by the determination means to have all the access entities have the read access right, the data is unchanged or the at least one access entity performs the read access. For the data determined not to have the right, the data decrypted by the decryption means is The is configured to write the first storage medium, respectively.

[0012]

As a result, according to the present invention, data for which at least one access subject does not have the read access right is encrypted and backed up as data that requires confidentiality, and all access subjects have the read access right. With respect to the data that has, the data will be backed up as it is without encryption as the data that does not require confidentiality, and the security protection and the privacy protection of the backup data can be secured.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of an operating system to which the data backup device of the embodiment is applied. In the figure, reference numeral 1 is a magnetic disk constituting a file system capable of storing a plurality of files, and the magnetic disk 1 is controlled by a disk control unit 2 to write and read files.

A protection determination section 3 is connected to the disk control section 2. The protection determination unit 3 is also connected to a tape control unit 6 described later, and the file contents read from the magnetic disk 1 or the file contents read from the magnetic tape 5 described below are preset in these files. Based on the access right information, it is determined whether all the access subjects have the read access right to the file, and the read access protection is performed.
The file contents read from the magnetic disk 1 or the file contents read from the magnetic tape 5, which will be described later, based on the result of the judgment by the protection judging unit 3, are encoded / decrypted by the magnetic tape control unit 5, the magnetic tape control unit 5, or the disk. It is given to the control unit 2. The encryption / decryption unit 4 uses the well-known D
The file data is encrypted or decrypted by using the ES method or the like.

Reference numeral 5 is a magnetic tape for storing a plurality of backup files, and the magnetic tape 5 is controlled by a magnetic tape controller 6 to write and read files.

Reference numeral 7 denotes a control unit, which controls the disk control unit 2, the protection determination unit 3, the encryption / decryption unit 4, and the magnetic tape control unit 6, and controls these circuits. And outputs a control command. Next, the operation of the embodiment configured as described above will be described.

In this case, in the file system of the operating system to be backed up in this embodiment, three attributes U, G and P are given as access right information to each file stored in the magnetic disk 1. To be done. And such an operating system is a system used by multiple users,
A user group can be defined as a set of users.

The attribute U given to each file holds the identifier of the user who owns the file. The attribute G holds the identifier of the user group to which the file belongs. Further, the attribute P is a 6-bit binary integer value indicating which user has what access right to the file,
The 0th bit indicates whether or not the user indicated by the U attribute has the right to read the file, and the 1st bit indicates whether or not the user indicated by the U attribute has the right to write to the file. Indicates whether or not a user who is not the user indicated by the U attribute but belongs to the user group indicated by the G attribute has the right to read the file. The third bit is not the user indicated by the U attribute but the G attribute. Whether or not the user belonging to the user group shown in (4) has the right to write to the file is determined by the user whose 4th bit is neither the U attribute nor the G attribute. Whether the user has the right to read the file, whether the fifth bit is not the user indicated by the U attribute and does not belong to the user group indicated by the G attribute has the right to write to the file Either that indicates (either bit indicates that the value is entitled when 1, indicates that no time 0.).

In such backup recording in the operating system, the operation of the magnetic disk 1 in the file system is periodically stopped, and all files existing in the magnetic disk 1 during that period are
This is done by copying the contents onto the magnetic tape 6. In this case, the operating system provides a command to record the backup. From this state, data recording for backup is executed according to the processing flow shown in FIG. 2 by a command instructing backup. In this case, the disk control unit 2 reads the file to be backed up from the magnetic disk 1 (step S21).

Next, the file thus read is given to the protection judging section 3 and read access protection judgment is made based on the attribute value of the file (step S22). In this case, whether or not all users have the right to read the contents of the file depends on whether the P attribute of the file is 0th, 2nd, or 4th.
It is determined by whether the bits are all 1's. That is, the 0th, 2nd, and 4th bits of the P attribute are set to p0,
Expressed as p2 and p4, the read access protection determination result c is calculated by c = p0 ^ p2 ^ p4. (^ Means AND)

When the value of c is 1 as a result of the judgment here, it is judged that the file encryption is unnecessary (step S23), and the file is directly given to the magnetic tape control unit 6 and the magnetic tape 5 is supplied. Is written in (step S2
5).

On the other hand, when the value of c is 0 as the judgment result of the protection judging unit 3, it is judged that the file needs to be encrypted (step S23), and the file is given to the encryption / decryption unit 4 (step S23). S24). In the encryption / decryption unit 4,
The file data determined to be encrypted is encrypted using the well-known DES method or the like. Then, the contents of the encrypted file are given to the magnetic tape control unit 6 and written on the magnetic tape 5 (step S25). In this case, the U attribute given to the file,
The respective values of the G attribute and the P attribute are also written on the tape. Thereafter, the backup process is similarly performed for all the files stored in the magnetic disk 1.

Therefore, in this way, data for which at least one access subject does not have the read access right is encrypted and backed up as data that requires confidentiality, and all access subjects have the read access right. Data can be backed up as it is without the need for confidentiality without encryption, so efficient confidentiality can be obtained for the data saved by the backup, and the security and privacy of the backup data is violated. It is possible to eliminate the risk of being caused and stably secure these security protection and privacy protection.

Next, the restoration of the backup data recorded on the magnetic tape 5 in this way is executed according to the processing flow shown in FIG. 3 by the command for instructing the restoration of the backup.

In this case, the magnetic tape controller 6 reads the file to be restored from the magnetic tape 5 (step S31). In this case, the U attribute, G attribute, P recorded on the magnetic tape 5 at the time of the backup recording described above.
It also reads each value of the attribute.

Next, the file thus read is given to the protection judging section 3 and read access protection judgment is made based on the attribute value of the file (step S32). In this case, based on the value of the P attribute restored from the magnetic tape 5, it is performed in the same manner as the read access protection determination made at the time of recording described above. That is, if the 0th, 2nd, and 4th bits of the P attribute restored from the magnetic tape 5 are expressed as p0 ', p2', and p4 ', the read access protection determination result c is c = p0''p2''. Calculated by p4 '. (^ Means AND)

When the value of c is 1 as a result of the judgment here, it is judged that the file decryption is unnecessary (step S33), and the file is directly given to the disk control unit 2 and is applied to the magnetic disk 1. It is written (step S3
5).

On the other hand, when the value of c is 0 as the judgment result of the protection judgment unit 3, it is judged that the file needs to be decrypted (step S33), and the file is given to the encryption / decryption unit 4 (step S33). S34). In the encryption / decryption unit 4,
Decrypt the file data that is determined to require decryption. Then, the contents of the decrypted file are given to the magnetic disk controller 2 and written on the magnetic disk 1 (step S35). Thereafter, all files stored in the magnetic tape 5 for backup are similarly restored to the magnetic disk 1.

Therefore, even in this way, with respect to the data backed up, at least one of the access subjects does not have the read access right, is decrypted and restored as data requiring confidentiality, and all the access subjects are restored. For data that has read access to
Since it becomes possible to restore data without decryption without decrypting it, efficient data confidentiality can be obtained even when restoring the data saved by backup, and the security and privacy of the restored data can be obtained. The risk of being compromised can be eliminated, and these security protection and privacy protection can be stably ensured. As another embodiment, the present invention can be applied to backup of communication contents in an electronic mail system.

In this case, there are two types of mail in the electronic mail system, namely, a postcard format and a sealed letter format. Of these, the postcard format mail is provided at a relatively low cost, and the content is within a certain fixed size. Although restricted and content confidential is not guaranteed, enveloped mail is offered at a relatively high price, content size is not limited, and content confidentiality is guaranteed.

Therefore, for the mail of the postcard type, the read access and the write access by the sender of the mail and the read access of all the users are permitted, and for the mail of the envelope type, the sender of the mail is permitted. Only read and write access and read access by the recipient of the mail are allowed. In other words, whether the mail type is a postcard or a sealed letter is used as the access right information.

For backup in this mail system, two floppy disk devices F0 and F1 are used.
This is realized by recording the contents of the mail in F0 for the postcard type mail and F1 for the envelope type mail when the user requests the mail transmission.

In this case, as shown in the flowchart of FIG. 4, first, read access protection determination is performed (step S
41). Here, whether or not the contents of the mail can be read by all users is equivalent to whether or not the mail is of a postcard type. Therefore, the read access protection judgment is the backup target. Find out what the type of mail is.

When it is determined that the mail is in the postcard format as a result of the determination here (step S42), the contents are recorded in F0 without being encrypted (step S43). On the other hand, if it is determined in step S42 that the mail is in the envelope format,
The contents of the mail are encrypted (step S44) and recorded in F1 (step S45).

Therefore, even in the electronic mail system,
In the same way as when backing up as described above,
Efficient confidentiality can be obtained for the mail stored by the backup, the risk of the security and privacy of the backup mail being violated can be eliminated, and these security protection and privacy protection can be stably secured. The present invention is not limited to the above-mentioned embodiments, and can be carried out by appropriately modifying it without departing from the scope of the invention.

[0037]

As described above, according to the present invention, with respect to data that needs confidentiality in data backup, the risk of data security and privacy infringement through backup is eliminated, and security protection and privacy protection are stably secured. can do. In addition, backup is performed only by encrypting and decrypting confidential data, so data can be efficiently backed up without the need for unnecessary encryption / decryption calculations. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment shown in FIG.

3 is a flowchart for explaining the operation of the embodiment of FIG.

FIG. 4 is a flowchart for explaining another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic disk, 2 ... Disk control part, 3 ... Protection determination part, 4 ... Encryption / decryption part, 5 ... Magnetic tape, 6 ... Tape control part, 7 ... Control part.

Claims (2)

[Claims] 1. A data backup device used in an information processing system having an access protection function, comprising: a first storage medium for storing data used for a predetermined process in the information processing system; Determining means for determining whether or not the access subject has a read access right to the data based on the access right information given in advance for the data read from the medium; and at least one access subject by the determining means. Of the data determined to have no read access right, the encryption means for performing encryption on the data, and the data determined to be read access right by all the access subjects by the determination means It is recorded as it is, and the at least one access subject has a read access right. For non judged data is data backup apparatus characterized by comprising a second storage medium for recording the encrypted data in the encryption means. 2. The second storage medium records, together with the data to be recorded, access right information previously given to the data, and the data read from the second storage medium is given to the data. Based on the access right information, the determining means determines whether the access subject has the read access right to the data, and the determining means determines that at least one access subject does not have the read access right. The data is decrypted by the decryption unit, and the data determined by the determination unit to have all the read access rights is the data, or the at least one access entity has the read access right. For the data determined not to have the respective data decrypted by the decryption means The data backup device according to claim 1, wherein the data backup is written in the first storage medium.