JP2010114490A - Device and method for encryption backup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for encryption backup. <P>SOLUTION: The encryption backup device prevents backup due to erroneous encryption key as follows: a cache memory 114 stores an encryption key K01 consisting of a bit sequence of predetermined unit data and a checking key K02 consisting of a bit sequence obtained by inverting the bit sequence of the encryption key K01 in advance; and when encrypted data (data 153 and 153) obtained by encrypting the predetermined unit data is recorded in a magnetic tape 150, it is determined whether the bit sequence obtained by inverting the bit of the checking key K02 matches the bit sequence of the encryption key K01 upon starting record of the encrypted data (data 153 and 153) of block unit continuing to the record of magnetic tape management information 151, upon completion of recording (timing T01-T03) or upon detecting tape finish end (timing T04); and it is determined that the encryption key K01 is broken when the bit sequences do not match. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an encryption backup device and an encryption backup method for encrypting and backing up data stored in a magnetic disk device in a computer system to a magnetic tape device, and particularly to damage of an encryption key when performing encrypted backup. The present invention relates to an encrypted backup device and an encrypted backup method that can determine and prevent backup with an erroneous encryption key.

  In recent computer systems, when data stored in a magnetic disk device is backed up to a magnetic tape device, there is a risk of theft due to the portability of a magnetic tape cartridge as a recording medium. The data is recorded on the magnetic tape of the cartridge, and the data is decrypted using the encryption key and restored to the magnetic disk device. The above-mentioned encryption is a process for changing data into another representation according to a certain rule, and making it impossible for a person who does not know the rule to know what the original is. The conversion rule is called an encryption key. The encryption key is composed of a bit string including “0” and “1”.

Incidentally, as a document describing a technique related to a backup device that encrypts data and stores it on a magnetic tape, the following Patent Document 1 is cited. In this Patent Document 1, an encryption key is stored in a data center, and a user request is issued. A technique is described in which a data center transfers an encryption key to a backup device to perform decryption and restoration.
JP 2003-208355 A

  The backup device according to the technique described in Patent Document 1 temporarily stores an encryption key in a cache memory, and executes backup on a magnetic tape while encrypting data using the encryption key stored in the cache memory. However, if the encryption key stored in the cache memory during this encryption backup is damaged due to some reason such as a program bug, the encryption backup is performed normally, but the encryption key used at the time of restoration is And the wrong encryption key at the time of encryption do not match, there is a problem that restoration cannot be performed.

  An object of the present invention is to provide an encrypted backup device and a cipher capable of preventing a backup due to an erroneous encryption key by determining damage of an encryption key temporarily stored in a cache memory of the backup device when performing encrypted backup Is to provide an integrated backup method.

In order to achieve the above object, the present invention is an encryption backup device for encrypting a predetermined unit of data using an encryption key composed of a bit string, and recording the encrypted data on a magnetic tape,
A cache memory for storing the encryption key;
A tape drive for encrypting a predetermined unit of data using an encryption key stored in the cache memory, and storing the encrypted data on the magnetic tape;
A control unit that controls encryption of data using the encryption key,
The control unit
A first step of generating a check key comprising a bit string obtained by inverting the bit string of the encryption key;
A second step of storing the check key generated in the first step in the cache memory;
A third step of encrypting the predetermined unit data using an encryption key stored in the cache memory;
When recording the encrypted data encrypted in the third step on the magnetic tape is started, the bit string of the check key stored in the cache memory is inverted, and the inverted bit string and the bit string of the encryption key are A fourth step of determining whether or not they match,
A fifth step of starting recording the encrypted data on the magnetic tape when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the fourth step;
A first feature is that, when it is determined in the fourth step that the bit string obtained by inverting the bit string of the check key does not match the bit string of the encryption key, the sixth step of determining that the encryption key is broken is a first feature. To do.

According to the present invention, in the encrypted backup device of the first feature,
The control unit is
When the encrypted data recording started in the fifth step is completed, it is determined whether the bit string obtained by inverting the bit string of the check key stored in the cache memory matches the bit string of the encryption key A seventh step;
A second feature is that, when it is determined in the seventh step that the bit string obtained by inverting the bit string of the check key does not match the bit string of the encryption key, the eighth step of determining that the encryption key is broken is a second feature. To do.

According to the present invention, in the encrypted backup device of the second feature,
The control unit is
A ninth step of determining whether or not the next unit data to be backed up exists when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the seventh step;
A third feature is that, when it is determined in the ninth step that the next unit of data to be backed up does not exist, the tenth step of determining that the encrypted backup is successful is executed.

Further, the present invention provides an encrypted backup device according to the third feature,
The control unit is
A fourth feature is that when it is determined in the ninth step that there is a next unit of data to be backed up, an eleventh step is executed in which the third to eighth steps are executed.

Moreover, the present invention provides the encrypted backup device having the third or fourth feature,
The control unit is
A fifth feature is that, when it is determined in the tenth step that the encrypted backup is successful, a twelfth step of deleting the encryption key and the check key stored in the cache memory is executed.

Furthermore, the present invention provides a cache memory that stores an encryption key composed of a bit string of data of a predetermined unit, and encrypts the predetermined unit of data using the encryption key stored in the cache memory, and the encrypted data is magnetically stored. A tape drive that stores data on the tape; and a control unit that controls encryption of data using the encryption key, encrypting the predetermined unit data using an encryption key, and storing the encrypted data in a magnetic tape A backup method of an encrypted backup device for recording in
In the control unit,
A first step of generating a check key comprising a bit string obtained by inverting the bit string of the encryption key;
A second step of storing the check key generated in the first step in the cache memory;
A third step of encrypting the predetermined unit data using an encryption key stored in the cache memory;
When recording the encrypted data encrypted in the third step on the magnetic tape is started, the bit string of the check key stored in the cache memory is inverted, and the inverted bit string and the bit string of the encryption key are A fourth step of determining whether or not they match,
A fifth step of starting recording the encrypted data on the magnetic tape when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the fourth step;
A sixth feature is that when it is determined in the fourth step that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key do not match, the sixth step of determining that the encryption key is damaged is executed. To do.

According to the present invention, in the encrypted backup method of the first feature,
In the control unit,
When the encrypted data recording started in the fifth step is completed, it is determined whether or not the bit string obtained by inverting the bit string of the check key stored in the cache memory matches the bit string of the encryption key A seventh step;
A seventh feature is that when it is determined in the seventh step that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key do not match, the eighth step of determining that the encryption key is damaged is executed. To do.

The present invention also provides an encrypted backup method according to the seventh feature,
In the control unit,
A ninth step of determining whether or not the next unit data to be backed up exists when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the seventh step;
An eighth feature is that when it is determined that there is no next unit of data to be backed up in the ninth step, the tenth step of determining that the encrypted backup is successful is executed.

The present invention also provides an encrypted backup method according to the eighth feature,
In the control unit,
A ninth feature is that when it is determined in the ninth step that the next unit of data to be backed up exists, an eleventh step is executed that executes the third to eighth steps.

According to the present invention, in the backup method of the eighth or ninth feature,
In the control unit,
A tenth feature is that when the encrypted backup is determined to be successful in the tenth step, a twelfth step of deleting the encryption key and the check key stored in the cache memory is executed.

  In the backup method and apparatus according to the present invention, a check key comprising a bit string obtained by bit-inversion of an encryption key stored in a cache memory is stored in the cache memory, and a predetermined unit of data is encrypted on a magnetic tape. By determining whether the bit string obtained by bit-inversion of the check key matches the bit string of the encryption key at the start and end of recording, the encryption key is damaged for each encrypted backup of a predetermined unit of data. Therefore, it is possible to prevent backup with an erroneous encryption key.

  Hereinafter, an encrypted backup apparatus and an encrypted backup method according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a computer system including an encrypted backup device 100 according to the present embodiment, FIG. 2 is a diagram for explaining the concept of an encrypted backup method according to the present embodiment, and FIG. 3 is a magnetic tape according to the present embodiment. FIG. 4 is a flow diagram of the encryption backup method according to the present embodiment.

[Constitution]
The encrypted backup apparatus 100 according to the present embodiment is connected to a business server 1 corresponding to an upper host via a network 2 as shown in FIG. 1 and stored in a magnetic disk device (HDD) of the business server 1. A tape library device 140 including a magnetic tape as a recording medium, and a plurality of magnetic disk devices 120a to 120n for temporarily storing business data of the business server 1; A control unit 110 that controls backup of business data from the business server 1 to the magnetic disk devices 120a to 120n and encrypted backup and restoration from the magnetic disk devices 120a to 120n to the tape library device 140, and the control unit 110 FC to switch between and the tape library device 140 Composed of Fiber Channel) switch 130..

  The controller 110 includes a plurality of host ports 111a to 111n connected to the HBA (host bus adapter) of the business server 1 via the network 2, and a plurality of ports connected to the magnetic disk devices 120a to 120n. Disk ports 116a to 116n, a plurality of library ports 117a to 117n connected to the FC switch 130, host ports 111a to 111n, disk ports 116a to 116n, disk ports 116a to 116n, and library A data transfer controller 112 for controlling data transfer between the ports 117a to 117n, a cache memory 114 for temporarily storing an encryption key used when recording and reproducing data on the magnetic tape, and the data transfer controller 112 By day A memory 115 for storing a control program for controlling the transmission and encryption / decryption, and a CPU113 Metropolitan for performing data transfer and encryption / decryption using a control program stored in the memory 115.

  The tape library device 140 includes a tape storage shelf 145 for storing a plurality of magnetic tapes (cartridges) 150 as recording media, a plurality of tape drives 142a to 142n for recording / reproducing data on the magnetic tape 150, and the tape storage. It comprises a transport mechanism 141 that is a robot that transports an arbitrary magnetic tape 150 stored in a shelf 145 to and from any tape drive 142a to 142n.

  The computer system configured in this way temporarily stores business data stored in the magnetic disk device of the business server 1 in the magnetic disk devices 120a to 120n of the encrypted backup device 100 through the network 2, and then stores the magnetic disk. It operates to encrypt the data of the devices 120a to 120n and back them up to the magnetic tape 150. The reason why the encrypted backup device temporarily stores the business data in the magnetic disk device is that the backup to the magnetic tape takes a relatively long time compared to the case where the magnetic disk is used as the recording medium, and the business server stores the data. This is because the time that can be spent for backup is limited to the short time of the business server's business stop time (such as midnight), and the data migration from the business server to the backup device and the migration to magnetic tape must be performed asynchronously. .

[Operation]
Next, the operation principle of the encryption backup method in the computer system configured as described above will be described with reference to FIG. As shown in FIG. 2, the encrypted backup method according to the present embodiment activates an encrypted backup of data 30 by activating a control program TRM (Tape Replication Manager) 20 of the encrypted backup apparatus 100, and a plurality of the encrypted backup methods are activated by this activation. A command processing S21 to generate an encryption key K01 composed of a bit string and a check key K02 for checking by inverting the bit string ("0""1") of the encryption key K01, and the generated encryption key A process 22 for storing K01 and the check key K02 in the cache memory 114; and a process 23 for transferring the encryption key K01, the check key K02 and the data stored in the cache memory 114 to the tape library device 140; This tape library The device 140 encrypts the data 30 using the encryption key K01 and records it on the magnetic tape 150, and performs a tape drive control step 24 for determining whether or not the encryption key K01 is damaged by the processing described later. It can be confirmed whether or not the encryption key is damaged.

  As shown in FIG. 4, the determination as to whether or not the encryption key is damaged is performed as a procedure for recording data on the magnetic tape 150 from the head side (left side in the figure) of the magnetic tape itself. A step of recording management information 151 (non-encrypted) such as date / number of times of recording is compared with a bit string obtained by inverting the bit string of the encryption key K01 and the check key K02 (determining whether or not they are the same) ) To check whether or not the encryption key is destroyed at the timing T01 before the recording block start point, and record the encrypted backup data [1] obtained by encrypting the backup target data using the encryption key K01. Whether or not the encryption key is destroyed by comparing the process and the bit string obtained by inverting the bit string of the check key K02 in the same manner as the timing T1 At the timing T02 after the end of the recording block, at the timing T03 whether or not the encryption key is destroyed at any time, and at the timing T4 when all data recording is completed. Performing a step of checking whether or not the key has been destroyed.

Next, the detailed operation of the backup method according to the present embodiment will be described with reference to the flowchart shown in FIG.
In this processing procedure, the business server 1 starts backup software (TRM) for magnetic tape to the backup device 100, and the backup device 100 uses the encryption key (bit string) when the business server 1 performs encryption. To the control unit 110 and stored in the cache memory 114, step S403 for generating a check key K02 obtained by inverting the bit string of the encryption key K01 and storing it in the cache memory 114, and the control unit 110 Step S404 for inverting the bit string of the check key K02 stored in the memory 114 determines whether or not the bit string of the encryption key K01 matches the bit string inverted in the step S404, and when it is determined that they do not match The step of reporting the encryption key breakage to the business server To perform the step S405 to migrate to flop S420.

  Next, when it is determined in step S405 that the processing matches, step S406 of writing the management information 151 described above to the magnetic tape 150 and the encryption key K01 stored in the cache memory 114 of the control unit 110 are stored in the tape library device 140. Step S407 set in the control unit (not shown) and the magnetic head in the encrypted backup process are positioned at the beginning or end of the area (“encryption unit” in FIG. 3) in which the magnetic tape is encrypted and recorded. When it is determined that the magnetic head is located, step S409 proceeds to step S415, which will be described later, and it is determined in step S409 that the magnetic head is located at the beginning or end of the encryption unit. When the control unit 110 inverts the bit string of the check key K02 in the cache memory 114 That the step S410, the bit string of the bit string and the encryption key K01 inverted at the step S410 is inverted or identical or not, executes the step S411 to shift to the step S420 when it is determined that not the same.

  Next, when it is determined in step S411 that the processing is the same, step S415 for encrypting the specified data and performing backup recording on the magnetic tape, and whether or not the backup of the data in step S415 has ended. Step S416 that returns to step S409 when it is determined that the process is not finished, and step S417 that cancels (deletes from the cache memory) the encryption key setting of the tape library device 140 when it is judged that the process is finished in step S416. Then, step S418 for rewinding the magnetic tape and step S419 for reporting the normal end of the encrypted backup to the business server 1 are executed.

  Through the series of processing steps, the encryption backup apparatus and method according to the present embodiment enables the control unit 110 to store the encryption key K01 and the check key K02 obtained by inverting the bit string of the encryption key K01 in the same cache memory 114. When the encrypted data is recorded on the magnetic tape 150 and stored, the encryption key K01 stored in the cache memory 114 is stored at the start or end of writing in the backup unit (for example, the volume unit of the magnetic disk device). It is verified that it is not damaged using the check key K02, and when it is determined that the key is damaged, the encryption key is reported to the business server, and when it is determined that the key is not damaged, the encrypted backup is completed normally. Report to the backup server's cache memory. The restoration of data due to damage of the encryption key can be prevented to become disabled.

  In the above-described embodiment, as described with reference to FIG. 3, an example in which the validity of the encryption key is determined immediately after the management information 151 is recorded and before and after recording of the backup unit of the encrypted data has been described. However, the timing of the check according to the present invention is not limited to the above example, and may be executed at other timings, for example, just after the management information 151 is recorded and immediately after the last encrypted backup data is recorded. You may comprise so that it may verify, or just after recording of the management information 151, and only after the recording of all the encryption backup data is complete | finished.

1 is a diagram showing a computer system including a magnetic tape storage device which is an encrypted backup device according to an embodiment of the present invention. The figure for demonstrating the concept of the encryption backup method by this embodiment. The figure for demonstrating the recording to the magnetic tape by this embodiment. The flowchart of the encryption backup method by this embodiment.

Explanation of symbols

  1: Business server, 2: Network network, 30: Data, 100: Encrypted backup device, 110: Control unit, 111a to 111n: Host port, 116a to 116n: Disk port, 117a to 117n: Library port 120a to 120n: magnetic disk device, 142a to 142n: tape drive, 112: data transfer controller, 114: cache memory, 115: memory, 130: FC switch, 140: tape library device, 141: transport mechanism, 145: tape storage Shelf, 150: magnetic tape, 151: management information.

Claims (10)

An encryption backup device that encrypts a predetermined unit of data using an encryption key composed of a bit string, and records the encrypted data on a magnetic tape,
A cache memory for storing the encryption key;
A tape drive for encrypting a predetermined unit of data using an encryption key stored in the cache memory, and storing the encrypted data on the magnetic tape;
A control unit that controls encryption of data using the encryption key,
The control unit
A first step of generating a check key comprising a bit string obtained by inverting the bit string of the encryption key;
A second step of storing the check key generated in the first step in the cache memory;
A third step of encrypting the predetermined unit data using an encryption key stored in the cache memory;
When recording the encrypted data encrypted in the third step on the magnetic tape is started, the bit string of the check key stored in the cache memory is inverted, and the inverted bit string and the bit string of the encryption key are A fourth step of determining whether or not they match,
A fifth step of starting recording the encrypted data on the magnetic tape when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the fourth step;
An encryption backup apparatus that executes a sixth step of determining that the encryption key is damaged when it is determined that the bit string obtained by inverting the bit string of the check key in the fourth step does not match the bit string of the encryption key. The control unit is
When the encrypted data recording started in the fifth step is completed, it is determined whether or not the bit string obtained by inverting the bit string of the check key stored in the cache memory matches the bit string of the encryption key A seventh step;
The encryption according to claim 1, wherein when the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key are determined not to match in the seventh step, the eighth step of determining that the encryption key is broken is executed. Backup device. The control unit is
A ninth step of determining whether or not the next unit data to be backed up exists when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the seventh step;
3. The encrypted backup device according to claim 2, wherein when it is determined that there is no next unit of data to be backed up in the ninth step, the tenth step of determining that the encrypted backup is successful is executed. The control unit is
4. The encrypted backup apparatus according to claim 3, wherein when it is determined that there is a next unit of data to be backed up in the ninth step, an eleventh step of executing the third step to the eighth step is executed. The control unit is
The encrypted backup device according to claim 3 or 4, wherein when it is determined in the tenth step that the encrypted backup is successful, a twelfth step of erasing the encryption key and the check key stored in the cache memory is executed. A cache memory for storing an encryption key comprising a bit string of data of a predetermined unit, and a tape for encrypting the predetermined unit of data using the encryption key stored in the cache memory and storing the encrypted data on the magnetic tape An encryption unit comprising: a drive; and a control unit configured to control encryption of data using the encryption key, wherein the predetermined unit data is encrypted using an encryption key, and the encrypted data is recorded on a magnetic tape. A backup device backup method comprising:
In the control unit,
A first step of generating a check key comprising a bit string obtained by inverting the bit string of the encryption key;
A second step of storing the check key generated in the first step in the cache memory;
A third step of encrypting the predetermined unit data using an encryption key stored in the cache memory;
When recording the encrypted data encrypted in the third step onto the magnetic tape is started, the bit string of the check key stored in the cache memory is inverted, and the inverted bit string and the bit string of the encryption key are A fourth step of determining whether or not they match,
A fifth step of starting recording the encrypted data on the magnetic tape when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the fourth step;
An encryption backup method for executing a sixth step of determining that the encryption key is damaged when it is determined in the fourth step that the bit string obtained by inverting the bit string of the check key does not match the bit string of the encryption key. In the control unit,
When the encrypted data recording started in the fifth step is completed, it is determined whether or not the bit string obtained by inverting the bit string of the check key stored in the cache memory matches the bit string of the encryption key A seventh step;
The encryption according to claim 6, wherein when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key do not match in the seventh step, the eighth step of determining that the encryption key is broken is executed. Backup method. In the control unit,
A ninth step of determining whether or not the next unit data to be backed up exists when it is determined that the bit string obtained by inverting the bit string of the check key and the bit string of the encryption key match in the seventh step;
8. The encrypted backup method according to claim 7, wherein when it is determined that there is no next unit of data to be backed up in the ninth step, the tenth step of determining that the encrypted backup is successful is executed. In the control unit,
9. The encrypted backup method according to claim 8, wherein when it is determined that there is a next unit of data to be backed up in the ninth step, the eleventh step of executing the third step to the eighth step is executed. In the control unit,
10. The encrypted backup method according to claim 8 or 9, wherein when it is determined that the encrypted backup is successful in the tenth step, a twelfth step of deleting the encryption key and the check key stored in the cache memory is executed.

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