JP2009175880A - Information processing apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively perform reencryption of data recorded in a data recorder. <P>SOLUTION: An encryption recorder 1 can read and write encrypted data for a data recorder 2. A cryptographic processing section 17 encrypts data to be recorded in the data recorder 2 and decodes data read from the data recorder 2, by a first or second encryption method. A use history recording section 13 records a use history of data recorded in the data recorder 2. A control section 11, regarding individual piece of data encrypted by the first encryption method and recorded in the data recorder 2, decides, order for performing processing to decode by the first encryption method and then to encrypt by the second encryption method, based on at least the use history recorded in the use history recording section 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information processing apparatus capable of writing and reading encrypted data to and from a data recording apparatus, and a program applied to the information processing apparatus.

  Conventionally, in order to ensure the safety of data recorded in a data recording device such as a hard disk, when data requested to be written from an external device is written into the data recording device, the data is encrypted by a predetermined encryption method. There is an apparatus for performing a process of recording in the data recording apparatus. Here, such a device is called an encryption recording device.

  The encryption recording device is installed between the external device and the data recording device. When data is input from the external device to the data recording device, the data is encrypted by a predetermined encryption method, and the data recording device When data is output to the external device, the data is decrypted. In this case, an external device that uses the data recording device can implement desired data writing by performing the same access as the access to the data recording device without the encryption recording device.

  The encryption method used for data encryption is determined by the encryption algorithm used for encryption and the encryption key used for encryption. As examples of encryption algorithms, AES (Advanced Encryption Standard) and DES (Data Encryption Standard), which are common key cryptosystems, are well known. For example, in the case of AES, the encryption key can be selected from random values of 128 bits, 192 bits, and 256 bits.

  When data is stored in a data recording device for a long period of time, there are cases where the encryption algorithm used for encryption is compromised and the risk of key leakage becomes a problem. For example, the DES described above has long been used as the de facto standard for cryptographic algorithms, but in recent years, its strength has been seen as a problem due to the advancement of computer technology, and it is possible to shift to next-generation cryptographic methods such as AES. It is requested. Even when the same encryption algorithm is used, it may be required to update the key frequently or to use a key having a longer key length.

  For the above reasons, there is a case where it is required to change the encryption method such as the encryption algorithm and encryption key used for encryption for the recording apparatus in which the recorded data being operated is already encrypted. When changing the encryption method, the encryption recording device needs to read the data recorded in the recording device, decrypt it with the encryption method before changing the encryption method, encrypt it with the changed encryption method, and re-record it. It becomes. This is called data re-encryption.

Patent Document 1 proposes a method of re-encrypting data when an encryption method is updated. This system is characterized in that data in the data recording apparatus can be accessed even during re-encryption.
JP 2005-303981 A

  In recent years, as data to be recorded in storage systems, not only text data but also multimedia data such as voice and images are increasing, and the capacity of storage systems is becoming increasingly larger, and terabyte and petabyte class storage systems are also increasing. Not uncommon. In the case of a large-scale storage system, the time required for re-encryption due to the change of the encryption method is enormous, and a decrease in processing efficiency becomes a problem. Also, if re-encryption takes a long time, data encrypted with the old encryption method before changing the encryption method will remain in the storage until the re-encryption is completed. There is a problem.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an information processing apparatus and program capable of effectively re-encrypting data recorded in a data recording apparatus.

  An information processing apparatus according to the present invention is an information processing apparatus capable of writing and reading encrypted data to and from a data recording apparatus, wherein the data to be recorded in the data recording apparatus is a first encryption A first encryption method recording means for recording a first encryption algorithm and a first encryption key for encryption by a method, and a second encryption method for encrypting data to be recorded in the data recording device. Using the second encryption method recording means for recording the second encryption algorithm and the second encryption key, and the first encryption algorithm and the first encryption key recorded in the first encryption method recording means, Alternatively, using the second encryption algorithm and the second encryption key recorded in the second encryption method recording means, encryption of data to be recorded in the data recording device or reading from the data recording device An encryption processing means for decrypting the recorded data; a usage history recording means for recording a usage history of the data recorded in the data recording device; and the data encrypted by the first encryption method and recorded in the data recording device The order in which individual data is decrypted by the first encryption method and then encrypted by the second encryption method is determined based on at least the usage history recorded in the usage history recording means. And a scheduling means.

  An information processing apparatus according to the present invention is an information processing apparatus capable of writing and reading encrypted data to and from a data recording apparatus, and stores data to be recorded in the data recording apparatus in a first manner. A first encryption method recording means for recording a first encryption algorithm and a first encryption key for encryption using the encryption method, and data to be recorded in the data recording device is encrypted using a second encryption method. Second encryption method recording means for recording a second encryption algorithm and a second encryption key for use, and the first encryption algorithm and the first encryption key recorded in the first encryption method recording means Or using the second encryption algorithm and the second encryption key recorded in the second encryption method recording means, or encrypting data to be recorded in the data recording device, or from the data recording device An encryption processing means for decrypting the extracted data; a data importance recording means for recording the importance of the data recorded in the data recording apparatus; and the data recording apparatus encrypted by the first encryption method. The importance level recorded in at least the data importance level recording means is the order in which the recorded data is decrypted by the first encryption method and then encrypted by the second encryption method. Scheduling means for determining based on the above.

  According to the present invention, it is possible to effectively re-encrypt data recorded in a data recording apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
First, a first embodiment of the present invention will be described.

  FIG. 1 is a diagram illustrating an example of a configuration of an information processing system according to the first embodiment of the present invention. The description here applies not only to the first embodiment, but also to the second to fourth embodiments described later.

  The information processing system includes an encryption recording device 1, a data recording device 2, and an external device 3. In this information processing system, for example, the encryption recording device 1 can function as a server that uses the data recording device 2 as a database of various information, and the external device 3 can function as a client. The entire information processing system including these devices 1, 2, and 3 can be realized as one information processing device.

  The encryption recording device 1 corresponds to an information processing device such as a personal computer or a video recording / reproducing device, and is connected to the data recording device 2 and the external device 3. In response to a data write request from the external device 3, the encryption recording device 1 encrypts the data supplied from the external device 3 with a predetermined encryption method and records it in the data recording device 2, In response to a data read request from the device 3, the data recorded in the data recording device 2 can be read and decrypted by a predetermined encryption method, and the data can be supplied to the external device 3.

  In particular, the encryption recording device 1 uses the second encryption method (the DES method, for example) to record the data recorded in the data recording device 2 in the second encryption method (for example, the DES method). For example, the function of effectively updating the data encrypted by the AES method), that is, for each piece of data encrypted in the first encryption method and recorded in the data recording apparatus 2, the first And a function of effectively performing a process of re-encrypting with the second encryption method after being decrypted with this encryption method.

  The data recording device 2 corresponds to a non-volatile storage device such as a hard disk and records data encrypted by the encryption recording device 1.

  The external device 3 corresponds to an information processing device such as a personal computer, a portable information terminal, a mobile phone, and the like, and accesses the encryption recording device 1 to request writing and reading of data with respect to the data recording device 2. can do.

  The encryption recording apparatus 1 includes a control unit 11, a data input / output unit 12, a usage history recording unit 13, a data management unit 14, a policy recording unit 15, a scheduling unit 16, an encryption processing unit 17, and a first encryption method recording unit 18. (Hereinafter referred to as “encryption method 1 recording unit 18”) and a second encryption method recording unit 19 (hereinafter referred to as “encryption method 2 recording unit 19”).

  The control unit 11 controls the overall operation of the encryption recording apparatus 1 and is a function realized by a processor executing a computer program that operates under an OS (Operating System).

  The data input / output unit 12 receives a data write request to the data recording device 2 from the external device 3 and sends the data to the control unit 11, or receives a data read request from the external device 3 in the data recording device 2. The data is received and sent from the control unit 11 to the external device 3.

  The usage history recording unit 13 records a usage history of data recorded in the data recording device 2. This usage history is recorded for each physical or logical unit of data to be recorded in the data recording device 2. The physical unit is, for example, a record unit in a hard disk device, and the logical unit is, for example, a file unit. The usage history includes, for each data, general information such as the access date / time, access type, and data identification name of the data, as well as information indicating the frequency of access to the data. In the first embodiment, the access frequency is expressed as “the number of accesses to the data / the total number of accesses to the data recording device 2”.

  The data management unit 14 determines whether each piece of data recorded in the data recording device 2 is recorded by the first encryption method or whether the individual data is recorded by the second encryption method. Are recorded and managed.

  The policy recording unit 15 records a scheduling policy (information indicating which policy should be used for scheduling) required by the scheduling unit 16 in performing scheduling for determining the order of data to be re-encrypted. Is.

  Based on the usage history recorded in the usage history recording unit 13, the scheduling policy recorded in the policy recording unit 15, and the encryption method type information recorded in the data management unit 14, the scheduling unit 16 Scheduling is performed to determine the order in which re-encryption should be performed from data.

  The encryption processing unit 17 encrypts data to be recorded in the data recording device 2 or decrypts data read from the data recording device 2 by the first encryption method or the second encryption method.

  The encryption method 1 recording unit 18 records a first encryption algorithm (program) for encrypting data to be recorded in the data recording device 2 by the first encryption method and a first encryption key used for this. It is.

  The encryption method 2 recording unit 19 records a second encryption algorithm (program) for encrypting data to be recorded in the data recording device 2 by the second encryption method, and a second encryption key used for the second encryption algorithm (program). It is.

  Here, for the sake of convenience, the encryption method 1 recording unit 18 and the encryption method 2 recording unit 19 are separated, but the encryption algorithm is common among the encryption algorithms and encryption keys that determine the respective encryption methods. Can have one storage area for recording the encryption algorithm.

  Next, a normal use state and a re-encryption state in the encryption recording apparatus 1 will be described with reference to FIG. The description here applies not only to the first embodiment, but also to the second to fifth embodiments described later.

  During operation, the encryption recording apparatus 1 takes one of a normal use state and a re-encryption state. In the normal use state, the first encryption algorithm and the first encryption key corresponding to the first encryption method are recorded in the encryption method 1 recording unit 18, and all the data recorded in the data recording device 2 is stored. It is in a state of being encrypted by the first encryption method. At this time, the second encryption algorithm corresponding to the second encryption method and the second encryption key are not yet recorded in the encryption method 2 recording unit 19.

  A second encryption algorithm and a second encryption key corresponding to the second encryption method used for re-encryption are input from, for example, the external device 3 via the data input / output unit 12, and the control unit 11 performs the encryption method 2 When recorded in the recording unit 19, the encrypted recording device 1 shifts to a re-encrypted state. When all the data recorded in the data recording device 2 is re-encrypted by the second encryption method in the re-encryption state, the state is again shifted to the normal use state. At this time, the first encryption algorithm and the first encryption key recorded in the encryption method 1 recording unit 18 are erased by the control unit 11, and the second encryption algorithm and the recording method stored in the encryption method 2 recording unit 19 The second encryption key is transferred to the encryption method 1 recording unit 18 by the control unit 11.

  Next, referring to FIG. 3 to FIG. 5, which encryption method type information is managed by the data management unit 14 as the encryption recording apparatus 1 shifts from the normal use state to the re-encryption state data management unit 14. Explain how it will change. The description here applies not only to the first embodiment, but also to the second to fifth embodiments described later. In the following description, for the sake of convenience, the first encryption method is referred to as “encryption method 1”, and the second encryption method is referred to as “encryption method 2”.

  When the encryption recording apparatus 1 is in a normal use state including a re-encryption start state, all data (for example, data A, data B, data C, data D, data E) in the encryption recording apparatus 1 are It is encrypted with the encryption method 1. At this time, as shown in FIG. 3, the encryption method type information managed by the data management unit 14 is that data A, data B, data C, data D, and data E are each encrypted by the encryption method 1. Indicates a state.

  When the encryption recording device 1 is being re-encrypted, that is, in the re-encryption state, the data encrypted by the encryption method 1 and the data encrypted by the encryption method 2 are stored in the encryption recording device 1. Are mixed. At this time, as shown in FIG. 4, the encryption method type information managed by the data management unit 14 is, for example, in a state where the data A and data C are still encrypted by the encryption method 1, while the data It shows that B, data D, and data E are re-encrypted by the encryption method 2.

  When the encryption recording apparatus 1 finishes re-encryption, all data A, data B, data C, data D, and data E in the encryption recording apparatus 1 are encrypted by the encryption method 2. At this time, as shown in FIG. 5, the encryption method type information managed by the data management unit 14 is that data A, data B, data C, data D, and data E are encrypted by the encryption method 2, respectively. Indicates a state.

  Next, an example of scheduling according to the first embodiment will be described with reference to FIG.

  In the first embodiment, a scheduling policy indicating that “re-encryption is performed in order from data with lower access frequency” is recorded in the policy recording unit 15. Therefore, the scheduling unit 16 performs scheduling for performing re-encryption in order from data with a low access frequency according to the scheduling policy. The contents of the scheduling policy can be changed through an input device (not shown).

  As described above, the usage history of data in the usage history recording unit 13 is recorded for each physical or logical unit of data to be recorded in the data recording device 2. In the example of FIG. 6, the identification names of the data in the data usage history are represented as data A, data B, data C,. Below each data, the access frequency to each data is shown in a fraction. The denominator of the fraction indicates the total number of accesses to the data recording device 2 after the data is recorded in the data recording device 2, and the numerator indicates the number of times the data is accessed.

  In the example of FIG. 6, data is arranged in descending order of access frequency from the left side. The data on the right side has a lower access frequency and is less likely to be accessed during re-encryption, so the priority for re-encryption is higher.

  For example, in state 1, there have been 10 accesses to the data recording apparatus 2 so far, of which 4 times are data B, 3 times are data A, 2 times are data D, and 1 time is access to data C. It is shown that.

  Here, when an access such as a write request for data E occurs and the information of data E is added to the data usage history, a transition is made as in state 2. In state 2, there is no change in the access frequency to data A, data B, data C, and data D, and data E is added. The access frequency of data E is 1/1.

  Next, when an access such as a read request for data C occurs, the state transits to state 3. In state 3, the total number of accesses of the denominator is incremented by 1 for each data, and only 1 is added to data C for the numerator.

  Next, when an access such as a read request for data B occurs, the state transits to state 4. In state 4, the total number of accesses in the denominator is incremented by 1 for each data, and only 1 for data B is incremented for the numerator. That is, since the access frequency of the data B is greater than the access frequency of the data E, the data B and the data E are switched in order.

  When the access frequency is expressed as a fraction in this way, for example, “1/2” and “5/10”, even if the ratio is the same, the number of accesses to each data and the total number of accesses are different. It may occur. In that case, the statistical result based on the larger number of accesses is reflected in “5/10” than in “1/2”, and when the next access to the data recording apparatus 2 is made. Since the access frequency of the data does not fluctuate greatly, it can be considered that the reliability and accuracy are high. On the other hand, in the case of “1/2”, the access frequency is calculated in a situation where the total number of accesses to the data recording device 2 is only two times, and the next access to the data recording device 2 is made In addition, since the access frequency of the data varies greatly, it can be considered that the reliability and accuracy are low. In such a case, it is desirable that scheduling is performed such that data having an access frequency of “5/10” is pre-encrypted more preferentially than data having an access frequency of “1/2”.

  Next, a basic operation when the encryption recording apparatus 1 is in a normal use state will be described with reference to FIG. The description here applies not only to the first embodiment, but also to the second to fifth embodiments described later.

  First, with reference to FIG. 7A, an operation when a data read request is made will be described.

  When there is a data read request from the external device 3, the control unit 11 reads the data requested to be read from the data storage unit 2 (step S11), and the encryption processing unit 17 decrypts the data with the encryption method 1 (step S11). S12). The decrypted data is output to the external device 3 (step S13), the data reading history is added to the usage history in the usage history recording unit 13 and updated (step S14), and the data reading process is completed.

  Next, with reference to FIG. 7B, an operation when there is a data write request will be described.

  When there is a data write request from the external device 3, the control unit 11 encrypts the write-requested data by the encryption processing unit 17 using the encryption method 1 (step S15). The encrypted data is written to the data storage unit 2 (step S16), the data writing history is added to the usage history in the usage history recording unit 13 and updated, and the data is stored in the data management unit 14 using an encryption method. 1 is registered (step S17), and the data writing process is completed.

  Next, the re-encryption operation when the encryption recording apparatus 1 is in the re-encryption state will be described with reference to FIG. The description here applies not only to the first embodiment, but also to a second embodiment and a third embodiment described later.

  When the control unit 11 records the encryption algorithm and the encryption key corresponding to the new encryption method in the encryption method 2 recording unit 19, the encryption recording device 1 shifts from the normal use state to the re-encryption state, and the data recording device 2 Re-encryption processing is started to effectively change the encryption method of all recorded data to a new encryption method.

  Since there is a possibility that a data read request or a data write request from the external device 3 may occur even during the data encryption method change, the control unit 11 monitors whether or not there is such a request (step S21).

  The operation when a data write request is generated is the same as the operation in the normal use state described with reference to FIG. However, in the normal use state, the data is encrypted by the encryption method 1 in step S15, but in the re-encryption state, the data is encrypted by the encryption method 2.

  When there is a data read request from the external device 3 (in the case of “read request” in step S22), the control unit 11 reads the data requested to be read from the data recording device 2 (step S23), and the data management unit 14 determines whether the data is encrypted by encryption method 1 or encryption method 2 (step S24).

  When the data is encrypted with the encryption method 1 (in the case of “encrypted with the encryption method 1” in step S25), the control unit 11 decrypts the data with the encryption method 1 by the encryption processing unit 17. (Step S26). Next, the control unit 11 encrypts the decrypted data by the encryption processing unit 17 using the encryption method 2 (step S27), and writes it back to the data recording device 2 (that is, replaces the corresponding data in the data recording device 2). (Step S28) The fact that the data is recorded in the encryption method 2 is recorded in the data management unit 14 (that is, the fact that the data is changed from the encryption method 1 to the encryption method 2) (step S29). Further, the control unit 11 outputs the data decoded in step S26 to the external device 3 through the data input / output unit 12 (step S31). The process in step S31 may be performed immediately after the process in step S26.

  On the other hand, when the data is encrypted by the encryption method 2 (in the case of “encrypted by the encryption method 2” in step S25), the control unit 11 uses the encryption processing unit 17 to transmit the data by the encryption method 2. The data is decrypted (step S30) and output to the external device 3 through the data input / output unit 12 (step S31).

  In step S22 described above, when there is no data read request or write request from the external device 3 (in the case of “no read request” in step S22), the control unit 11 records in the usage history recording unit 13 through the scheduling unit 16. Based on the usage history of the data, the data is acquired in order from the least frequently accessed (step S32), and the data management unit 14 determines whether the data is encrypted using the encryption method 1 or encryption method 2. (Step S33).

  When the data is encrypted by the encryption method 1 (in the case of “encrypted by the encryption method 1” in step S34), the control unit 11 reads the data from the data recording device 2 (step S35), The read data is decrypted by the encryption processing unit 17 by the encryption method 1 (step S36), the decrypted data is encrypted by the encryption processing unit 17 by the encryption method 2 (step S37), and the encrypted data is recorded as data. Write back to the device 2 (that is, replace the corresponding data in the data recording device 2) (step S38), and record that the data is recorded in the encryption method 2 in the data management unit 14 (that is, the encryption method). The fact that the mode has been changed from 1 to the encryption method 2 is recorded) (step S39).

  On the other hand, when the data is encrypted by the encryption method 2 (in the case of “encrypted by the encryption method 2” in step S34), it is not necessary to encrypt the data again by the encryption method 2.

  After performing such a series of processes, the control unit 11 determines whether the data management unit 14 has data information encrypted by the encryption method 1 (step S41). If it exists (“Yes” in step S41), the processing from step S21 described above is repeated, and if it does not exist (“No” in step S41), the control unit 11 is recorded in the encryption method 2 recording unit 19. The second encryption algorithm and the second encryption key are moved to the encryption method 1 recording unit 18, and the first encryption algorithm and the first encryption key in the encryption method 1 recording unit 18 are transferred to the second encryption algorithm and the second encryption algorithm. (Step S42), and a transition is made to a normal use state in which no change in the encryption method has occurred.

  As described above, according to the first embodiment, re-encryption can be performed more efficiently than when data in the data recording device 2 is re-encrypted sequentially from the beginning. That is, there is a high possibility that a read request will be generated from the external device 3 even during re-encryption of data in the data recording device 2 for data that is frequently accessed. Therefore, at that time, by subsequently encrypting the decrypted data with the encryption method 2, as a whole, the encryption method can be changed more efficiently than when the encryption method is changed sequentially from the beginning of the data. Can do.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In addition, description of the part which is common in 1st Embodiment mentioned above is abbreviate | omitted, and a different part is demonstrated.

  The configuration and operation of the information processing system according to the second embodiment of the present invention are basically the same as the configuration and operation of the information processing system according to the first embodiment. However, the definition of the access frequency for each data recorded as a part of the usage history in the usage history recording unit 13 is different from that in the first embodiment.

  That is, the access frequency in the first embodiment is expressed by “the number of accesses to the data / the total number of accesses to the data recording device 2”, whereas the access frequency in the second embodiment is simply “the number of accesses to the data”. Expressed as “number of accesses”.

  Since the definition of the access frequency is thus different, the scheduling method according to the second embodiment is different from the scheduling method according to the first embodiment shown in FIG.

  FIG. 9 shows an example of scheduling according to the second embodiment.

  In the example of FIG. 9 as well, data is arranged in descending order of access frequency from the left side. The data on the right side has a lower access frequency and a higher priority for re-encryption. However, the access frequency here is expressed by the number of accesses.

  For example, state 1 indicates that data C has been accessed once, data D has been accessed twice, data A has been accessed 3 times, and data B has been accessed 4 times.

  Here, when an access such as a write request for data E occurs and the information of data E is added to the data usage history, a transition is made as in state 2. In state 2, there is no change in the access frequency to data A, data B, data C, and data D, and data E is added. The access frequency of data E is 0.

  Next, when an access such as a read request for data C occurs, the state transits to state 3. In state 3, only 1 is added to data C.

  Next, when an access such as a read request for data B occurs, the state transits to state 4. In the state 4, only 1 is added to the data B.

  As described above, according to the second embodiment, even when the access frequency is simply expressed by “the number of accesses to the data”, the same effect as that of the first embodiment can be obtained.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In addition, description of the part which is common in 1st Embodiment and 2nd Embodiment mentioned above is abbreviate | omitted, and a different part is demonstrated.

  The configuration and operation of the information processing system according to the third embodiment of the present invention are basically the same as the configuration and operation of the information processing system according to the first embodiment and the second embodiment. However, the definition of the access frequency for each data recorded as a part of the usage history in the usage history recording unit 13 is different from the case of the first embodiment or the second embodiment.

  That is, the access frequency in the third embodiment is expressed as “access order” (order in which the elapsed time after the access is short). This access order can be determined based on information such as the access date and time for each data recorded in the usage history recording unit 13 as part of the usage history. Since the definition of the access frequency is thus different, the scheduling method according to the third embodiment is the same as the scheduling method according to the first embodiment shown in FIG. 6 or the second method shown in FIG. This is different from the scheduling method according to the form.

  FIG. 10 shows an example of scheduling according to the third embodiment.

  In the example of FIG. 10, the data on the left side indicates that the most recent read access was made. The data on the right side is less likely to be accessed, and the priority for re-encryption is higher.

  For example, state 1 indicates that data C, data D, data A, and data B are accessed in this order.

  Here, when an access such as a write request for data E occurs and the information of data E is added to the data usage history, a transition is made as in state 2.

  Next, when an access such as a read request for data C occurs, the state transits to state 3.

  Next, when an access such as a read request for data B occurs, the state transits to state 4.

  As described above, according to the third embodiment, even when the access frequency is expressed in the “access order”, the same effects as those of the first embodiment and the second embodiment can be obtained.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. In addition, description of the part which is common in 1st Embodiment and 2nd Embodiment mentioned above is abbreviate | omitted, and a different part is demonstrated.

  The configuration and operation of the information processing system according to the fourth embodiment of the present invention are the same as the configuration and operation of the information processing system according to the first to third embodiments, except for the portion related to scheduling. is there. As the definition of the access frequency in the fourth embodiment, any of the access frequency definitions described in the first to third embodiments may be adopted.

  The difference from the first to third embodiments is the content of the scheduling policy recorded in the policy recording unit 15 and the content of the processing of the scheduling unit 16 that uses this.

  In the first to third embodiments, the scheduling policy indicates that “re-encryption is performed in order from the data with the lowest access frequency”. In the third embodiment, the scheduling policy Indicates that “re-encryption is performed in order from the data with the highest access frequency”. Therefore, the scheduling unit 16 performs scheduling for performing re-encryption in order from the data with the highest access frequency according to the scheduling policy.

  The scheduling policy according to the fourth embodiment is based on the idea that data with high access frequency is often used and therefore the importance of the data is high. When the encryption method 1 before the change of the encryption method is compromised and it becomes necessary to change to the encryption method 2, it is desirable to re-encrypt important data with the new encryption method 2 as soon as possible. In that case, by performing re-encryption in order from the data with the highest access frequency, the purpose of re-encrypting important data as soon as possible can be effectively achieved.

  Next, the re-encryption operation when the encryption recording apparatus 1 is in the re-encryption state will be described with reference to FIG.

  The operation shown in FIG. 11 is the same as the operation shown in FIG. 8 except for step S32A. That is, in the first to third embodiments, data is acquired in order from the lowest access frequency based on the usage history of the data recorded in the usage history recording unit 13 in step S32 in FIG. In the fourth embodiment, in step S32A in FIG. 11, data is acquired in descending order of access frequency based on the usage history of data recorded in the usage history recording unit 13.

  As described above, according to the fourth embodiment, by performing re-encryption in order from the data with the highest access frequency, when the weakness is found in the encryption method or when the encryption method becomes old and the encryption strength is insufficient, Compromise can be dealt with immediately, and important data can be changed to a new cryptosystem as soon as possible.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. In addition, description of the part which is common in 4th Embodiment mentioned above is abbreviate | omitted, and a different part is demonstrated.

  In the fourth embodiment, based on the idea that data having a higher access frequency has a higher importance level, information on the access frequency included in the usage history in the usage history recording unit 13 is used to re-start the data in order from the data with the highest access frequency. In the fifth embodiment, the scheduling for performing encryption has been described. However, in the fifth embodiment, information on access frequency is not used, and instead, each data recorded in the data recording device 2 is set in advance. Scheduling for re-encryption is performed in order from the most important data using the importance information.

  FIG. 12 is a diagram illustrating an example of a configuration of an information processing system according to the fifth embodiment of the present invention. In the first to fourth embodiments, the usage history recording unit 13 is provided as shown in FIG. 1, but in the fifth embodiment, data importance management is performed instead of the usage history recording unit 13. A part 20 is provided. The data importance management unit 20 records the importance of each data recorded in the data recording device 2. In this case, the scheduling unit 16 includes the importance for each data recorded in the data importance management unit 20, the scheduling policy recorded in the policy recording unit 15, and the encryption method type information recorded in the data management unit 14. Based on this, scheduling is performed to determine an order indicating which data should be re-encrypted at the time of re-encryption.

  The importance of data is determined in advance and recorded in the data importance management 20. The importance of data may be set manually for each data each time a data unit is added, but the following methods are conceivable.

  As a first method, importance is set in advance for each use of data, and when data is added, a preset degree of importance is applied. For example, the importance level is set for each area such as an area used by the database and an area used by the OS.

  As a second method, the importance is set for each type of data. For example, the importance is set in advance for each type of text file, image file, database file, etc., and when data is added, the importance is set as the importance of the added data.

  Next, the re-encryption operation when the encryption recording apparatus 1 is in the re-encryption state will be described with reference to FIG.

  The operation shown in FIG. 13 is the same as the operation shown in FIG. 11 except for step S32B. That is, in the fourth embodiment, in step S32A in FIG. 11, data is acquired in descending order of access frequency based on the usage history of data recorded in the usage history recording unit 13. In the embodiment, in step S32B in FIG. 13, data is acquired in descending order of importance based on the importance of data recorded in the data importance management unit 20.

  As described above, according to the fifth embodiment, the same effect as that of the fourth embodiment can be obtained even when the preset importance of data is used instead of the data access frequency. it can.

  Note that the method described in the above embodiment includes a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), an optical disk (CD-ROM, DVD, etc.), a magneto-optical disk (MO) as programs that can be executed by a computer. ), And can be distributed in a storage medium such as a semiconductor memory.

  In addition, as long as the storage medium can store a program and can be read by a computer, the storage format may be any form.

  In addition, an OS (operating system) running on a computer based on an instruction of a program installed in the computer from a storage medium, MW (middleware) such as database management software, network software, and the like realize the above-described embodiment. A part of each process may be executed.

  Furthermore, the storage medium in the present invention is not limited to a medium independent of a computer, but also includes a storage medium in which a program transmitted via a LAN or the Internet is downloaded and stored or temporarily stored.

  Further, the number of storage media is not limited to one, and the case where the processing in the above embodiment is executed from a plurality of media is also included in the storage media in the present invention, and the media configuration may be any configuration.

  The computer according to the present invention executes each process in the above-described embodiment based on a program stored in a storage medium, and includes a single device such as a personal computer or a system in which a plurality of devices are connected to a network. Any configuration may be used.

  In addition, the computer in the present invention is not limited to a personal computer, but includes an arithmetic processing device, a microcomputer, and the like included in an information processing device, and is a generic term for devices and devices that can realize the functions of the present invention by a program. .

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

The figure which shows an example of a structure of the information processing system which concerns on 1st Embodiment-4th Embodiment of this invention. The figure for demonstrating the normal use state and re-encryption state in the encryption recording device 1. FIG. The figure which shows an example of the state of the encryption system classification information managed by the data management part 14 when the encryption recording device 1 is in a normal use state. The figure which shows an example of the state of the encryption system classification information managed by the data management part 14 when the encryption recording device 1 is in the state under re-encryption. The figure which shows an example of the state of the encryption system classification information managed by the data management part 14 when the encryption recording device 1 is in the state of completion | finish of re-encryption. The figure which shows an example of the scheduling which concerns on the 1st Embodiment of this invention. The figure which shows basic operation | movement when the encryption recording device 1 is in a normal use state. The figure which shows the operation | movement of re-encryption when the encryption recording device 1 which concerns on the 1st Embodiment of this invention-3rd Embodiment is in a re-encryption state. The figure which shows an example of the scheduling which concerns on the 2nd Embodiment of this invention. The figure which shows an example of the scheduling which concerns on the 3rd Embodiment of this invention. The figure which shows the operation | movement of re-encryption when the encryption recording device 1 which concerns on the 4th Embodiment of this invention is in a re-encryption state. The figure which shows an example of a structure of the information processing system which concerns on the 5th Embodiment of this invention. The figure which shows operation | movement of the re-encryption when the encryption recording device 1 which concerns on the 5th Embodiment of this invention is in a re-encryption state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Encryption recording device, 2 ... Data recording device, 3 ... External device, 11 ... Control part, 12 ... Data input / output part, 13 ... Usage history recording part, 14 ... Data management part, 15 ... Policy recording part, 16 ... Scheduling unit, 17 ... Encryption processing unit, 18 ... Encryption method 1 recording unit, 19 ... Encryption method 2 recording unit, 20 ... Data importance management unit.

Claims (6)

An information processing apparatus capable of writing and reading encrypted data to and from a data recording apparatus,
A first encryption method recording means for recording a first encryption algorithm and a first encryption key for encrypting data to be recorded in the data recording device with a first encryption method;
A second encryption method recording means for recording a second encryption algorithm and a second encryption key for encrypting data to be recorded in the data recording device by a second encryption method;
Using the first encryption algorithm and the first encryption key recorded in the first encryption method recording means, or the second encryption algorithm and the second encryption recorded in the second encryption method recording means Encryption processing means for encrypting data to be recorded in the data recording device or decrypting data read from the data recording device using a key;
Usage history recording means for recording a usage history of data recorded in the data recording device;
The order in which individual data encrypted by the first encryption method and recorded in the data recording apparatus is decrypted by the first encryption method and then encrypted by the second encryption method An information processing apparatus comprising: a scheduling unit that determines at least a usage history recorded in the usage history recording unit. An information processing apparatus capable of writing and reading encrypted data to and from a data recording apparatus,
A first encryption method recording means for recording a first encryption algorithm and a first encryption key for encrypting data to be recorded in the data recording device with a first encryption method;
A second encryption method recording means for recording a second encryption algorithm and a second encryption key for encrypting data to be recorded in the data recording device by a second encryption method;
Using the first encryption algorithm and the first encryption key recorded in the first encryption method recording means, or the second encryption algorithm and the second encryption recorded in the second encryption method recording means Encryption processing means for encrypting data to be recorded in the data recording device or decrypting data read from the data recording device using a key;
Data importance recording means for recording the importance of data recorded in the data recording device;
The individual data encrypted by the first encryption method and recorded in the data recording device is decrypted by the first encryption method and then encrypted by the second encryption method. An information processing apparatus comprising: scheduling means for determining an order based on at least the importance recorded in the data importance recording means.   According to the order determined by the scheduling means, data is read from the data recording device, the read data is decrypted by the encryption processing means by the first encryption method and then encrypted by the second encryption method, The information processing apparatus according to claim 1, further comprising means for performing processing for writing back the encrypted data to the data recording apparatus.   In response to a read request for data recorded in the data recording device from an external device, if the data requested to be read is encrypted by the first encryption method, the data is recorded in the data recording device. The read data is decrypted by the encryption processing means by the first encryption method and then output to the external device and encrypted by the second encryption method. The encrypted data is stored in the data recording 4. The information processing apparatus according to claim 3, further comprising means for performing a process of writing back to the apparatus. A program applied to a computer capable of writing and reading encrypted data to and from a data recording device,
A function of performing encryption of data recorded in the data recording device or decryption of data read from the data recording device by the first encryption method or the second encryption method;
A function of recording a usage history of data recorded in the data recording device in a usage history recording means;
The individual data encrypted by the first encryption method and recorded in the data recording device is decrypted by the first encryption method and then encrypted by the second encryption method. A program for causing a computer to realize a function of determining an order based on at least the usage history recorded in the usage history recording means. A program applied to a computer capable of writing and reading encrypted data to and from a data recording device,
A function of performing encryption of data recorded in the data recording device or decryption of data read from the data recording device by the first encryption method or the second encryption method;
A function of recording the importance of data recorded in the data recording device in a data importance recording means;
The individual data encrypted by the first encryption method and recorded in the data recording device is decrypted by the first encryption method and then encrypted by the second encryption method. A program for causing a computer to realize a function of determining an order based on at least the importance recorded in the data importance recording means.

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