JP7776175B2 - Encryption system, encryption device, encryption method, and program - Google Patents

Description

The present disclosure relates to an encryption system, an encryption device, an encryption method, and a program.

The amount of log data generated by various types of devices is increasing due to their recent advances in functionality. Furthermore, depending on the type of device and the information handled, it may be necessary to maintain confidentiality when collecting log data.

For example, Patent Document 1 describes a log collection system that aims to collect log information without using dedicated tools or a dedicated user interface, while preventing information leakage to third parties. The log collection system includes a formatting unit, a log acquisition unit, an encryption unit, and a log writing unit. The formatting unit formats external media from and to which information can be read and written, by including a public key in the volume label. The log acquisition unit acquires log information when the external media is connected. The encryption unit encrypts the acquired log information with the public key included in the volume label. The log writing unit writes the encrypted log information to the external media.

In addition, to collect log data while maintaining confidentiality, a method of encrypting files at the file level, unlike the technology described in Patent Document 1, can be adopted. However, such a method poses the risk of monopolizing the computing resources of the device and increasing the load on the device during operation. For this reason, a method has been proposed that reduces the load on computing resources by encrypting only parts of the data.

Patent Document 2 also describes a packet communication method that is adaptable to high-speed lines by eliminating the need for processing using complex encryption algorithms, suppresses deterioration in transmission efficiency due to redundant bits, and enables data confidentiality using a simple method. The packet communication method is designed to prevent data eavesdropping and tampering during bit-synchronized data communication, and includes an insertion step, a reception disabling step, and a reception enabling step. The insertion step artificially inserts a synchronization flag sequence indicating the start and end of a frame, which is a unit of transmitted data, so that the frame length in packet communication is equal to or less than the minimum frame length. The reception disabling step causes an unauthorized receiving side to discard frames shorter than the minimum frame length as short frames, thereby disabling reception by unauthorized parties attempting to eavesdrop or tamper with the data. The reception enabling step deletes the artificially inserted synchronization flag sequence, allowing an authorized receiving side to receive frames shorter than the minimum frame length as regular frames.

Patent Document 3 describes a data encryption method that does not require adding encryption functions to existing WWW (World Wide Web) servers or WWW browsers. The data encryption method performs data processing, including encryption, on data to be encrypted, which has embedded instructions specifying a data processing method, including an encryption processing method, in accordance with the embedded instructions. The data encryption method encrypts the range specified by the encryption range specification instruction for data to be encrypted, which has embedded encryption range specification instructions specifying the range to be encrypted.

Patent Document 4 describes a log recording device that aims to achieve both user data confidentiality and fault analysis. The log recording device includes a CDB (Command Description Block) determination means, a first encryption means, and a log output means. The CDB determination means determines whether a SCSI request in the input SCSI (Small Computer System Interface) log data is related to user data or not, based on CDB determination information. The first encryption means encrypts, based on an encryption key, the portion of the SCSI request containing user data for a SCSI request determined by the CDB determination means to be related to user data. The log output means formats the SCSI request determined by the CDB determination means to be a SCSI request not related to user data and the SCSI request with the encrypted portion containing user data from the first encryption means, and outputs the resulting file as a log file for analysis.

Japanese Patent Application Laid-Open No. 2017-215853 Japanese Patent Application Publication No. 11-215190 Japanese Patent Application Publication No. 11-215122 Japanese Patent Application Laid-Open No. 2019-097028

However, with the technology described in Patent Document 2, in order to achieve data confidentiality, it is necessary to insert a synchronization flag sequence even when encrypting all of the device's log data.

Furthermore, the technology described in Patent Document 3 outputs a single encrypted file incorporating a decryption range designation command, not only when the data to be encrypted includes both encrypted and unencrypted portions, but also when it includes only encrypted portions. Therefore, even if the technology described in Patent Document 3 is applied to encrypting device log data, a single encrypted file incorporating a decryption range designation command will be output, even when all of the log data is encrypted.

Furthermore, the technology described in Patent Document 4 also outputs a file containing both encrypted and unencrypted portions as a single file, so in order to decrypt it, information indicating that it has been encrypted is required, even if the file is completely encrypted.

The present disclosure has been made to solve the above problem, and aims to provide an encryption system, etc., which, when specifying the range to be encrypted and encrypting device log data, can avoid the need for information indicating the range even when encrypting the entire range.

In a first aspect, the encryption system includes an acquisition unit that acquires log data, an encryption unit that encrypts the log data, a reception unit that receives an instruction specifying the range of encryption to be performed by the encryption unit before log data acquisition begins, a storage unit that stores the log data, and a control unit that controls, based on the range, the timing of log data acquisition by the acquisition unit, the start and end positions of encryption by the encryption unit, and the storage of log data by the storage unit. The control unit controls the encryption unit to perform encryption by inserting a start flag that indicates the start position and an end flag that indicates the end position, respectively, at the start and end positions indicated by the range. If the entire range of log data is specified as the range, the control unit controls the encryption unit to perform encryption without controlling the insertion of the start flag and the end flag. The control unit stores the encrypted data for the portion of log data that falls within the range and the plaintext data for the portion of log data that does not fall within the range in the storage unit, each as separate files.

In a second aspect, the encryption device includes an acquisition unit that acquires log data, an encryption unit that encrypts the log data, a reception unit that receives an instruction specifying the range of encryption to be performed by the encryption unit before starting to acquire the log data, a memory unit that stores the log data, and a control unit that controls, based on the range, the timing of log data acquisition by the acquisition unit, the start and end positions of encryption by the encryption unit, and the storage of log data by the memory unit. The control unit controls the encryption unit to perform encryption by inserting a start flag that indicates the start position and an end flag that indicates the end position, respectively, at the start and end positions indicated by the range. If the entire range of log data is specified as the range, the control unit controls the encryption unit to perform encryption without controlling the insertion of the start flag and the end flag. The encrypted data for the portion of log data that falls within the range and the plaintext data for the portion of log data that does not fall within the range are stored in the memory unit, each as separate files.

In a third aspect, the encryption method comprises acquiring log data, encrypting the log data, accepting an instruction specifying the range of encryption before starting to acquire the log data, storing the log data, and controlling the timing of log data acquisition, the start and end positions of encryption, and storing the log data based on the range, wherein the controlling includes inserting a start flag indicating the start position and an end flag indicating the end position at the start and end positions indicated by the range, respectively, to perform encryption; when the entire range of the log data is specified as the range, performing encryption without inserting the start flag and the end flag; and storing, as separate files, the encrypted data for the portion of the log data that falls within the range and the plaintext data for the portion of the log data that does not fall within the range.

In a fourth aspect, the program is a program for causing a computer to execute encryption processing, and the computer-readable medium stores the program. The encryption processing includes acquiring log data, encrypting the log data, accepting an instruction specifying the range of encryption before starting log data acquisition, storing the log data, and controlling the timing of log data acquisition, the start and end positions of encryption, and storing the log data based on the range. The controlling includes inserting a start flag indicating the start position and an end flag indicating the end position at the start and end positions indicated by the range, respectively, to execute encryption; if the entire range of log data is specified as the range, executing encryption without inserting the start flag and the end flag; and storing the encrypted data for the portion of log data that falls within the range and the plaintext data for the portion of log data that does not fall within the range, respectively, as separate files.

This disclosure makes it possible to provide an encryption system, etc., that can specify the range to be encrypted and encrypt the log data of a device, thereby avoiding the need for information indicating the range even when encrypting the entire range.

1 is a block diagram showing an example of the configuration of an encryption system according to a first embodiment. 2 is a block diagram showing an encryption device as an example of the encryption system shown in FIG. 1; FIG. 3 is a flow chart for explaining an example of an encryption method in the encryption system of FIG. 1 or the encryption device of FIG. 2. FIG. FIG. 10 is a block diagram showing an example of the configuration of an encryption system according to a second embodiment. FIG. 5 is a diagram showing an example of a log acquisition command that is accepted as an instruction in the encryption system of FIG. 4. FIG. 5 is a flow diagram for explaining an example of processing in a target device in the encryption system of FIG. 4 . FIG. 7 is a flow chart continuing from FIG. 6. FIG. 5 is a sequence diagram showing an example of the overall processing in the encryption system of FIG. 4 . FIG. 9 is a sequence diagram continuing from FIG. 8 . FIG. 11 is a flowchart illustrating an example of processing in a target device in an encryption system according to a third embodiment. FIG. 2 illustrates an example of a hardware configuration of the apparatus.

The following describes the embodiments with reference to the drawings. Note that in the embodiments, identical or equivalent elements are given the same reference numerals, and duplicate explanations may be omitted. In addition, in the following drawings, identical and similar elements are given the same reference numerals, and duplicate explanations may be omitted as necessary.

<Embodiment 1>
FIG. 1 is a block diagram showing an example of the configuration of an encryption system according to the first embodiment.
1, an encryption system 1 according to this embodiment may include an acquisition unit 1a, an encryption unit 1b, a reception unit 1c, a storage unit 1d, and a control unit 1e. The encryption system 1 includes a device from which log data is to be collected (hereinafter referred to as a target device) and a log collection device that collects logs from the target device, and collects various log data from the target device. Therefore, the encryption system 1 may be referred to as a log collection system.

The type of target device does not matter, as long as it is a device that can record logs. Furthermore, the log collection device can be installed, for example, at the same location as the target device and connected directly, or it can be installed in a remote location from the target device and connected via a network.

In the encryption system 1, the target device may be equipped with an acquisition unit 1a, encryption unit 1b, reception unit 1c, memory unit 1d, and control unit 1e, but this is not limited to this; for example, a recording medium as one element of the memory unit 1d may be provided in an external device connected to the target device. The memory unit 1d and recording medium will be described later.

The target device may also have its functions distributed across multiple devices, in which case the method of distributing the acquisition unit 1a, encryption unit 1b, reception unit 1c, storage unit 1d, and control unit 1e is not important. For example, each device may have the functions of the encryption unit 1b and storage unit 1d, and one of those devices may have the acquisition unit 1a, reception unit 1c, and control unit 1e.

The acquisition unit 1a acquires log data from the target device. The method for acquiring the log data does not matter, and it can acquire log data of a type and period that is predetermined or included in instructions described below, for example. The encryption unit 1b encrypts the log data acquired by the acquisition unit 1a. However, as described below, the encryption unit 1b encrypts a specified range of log data and does not encrypt log data outside that range. Furthermore, the encryption method used by the encryption unit 1b does not matter, as long as the encrypted data can be decrypted.

The reception unit 1c receives an instruction specifying the scope of encryption to be performed by the encryption unit 1b before the acquisition unit 1a begins acquiring log data. This instruction may be sent from a log collection device connected to the target device via a network, P2P, or the like. Therefore, the reception unit 1c may be equipped with a communication unit (not shown) that communicates with the log collection device. This communication unit may be equipped with an interface for communicating with the outside world wirelessly or via a wired connection. However, the functions of the log collection device may also be equipped in the target device; in this case, the encryption system 1 is configured in the target device, and the above instructions are also received from an operation unit or the like provided on the target device.

The memory unit 1d stores encrypted log data and plaintext log data. The memory unit 1d can be a storage device equipped with a recording medium and a writing unit that writes data to the recording medium. The type of recording medium is not important.

Based on the above range, the control unit 1e controls the timing of log data acquisition by the acquisition unit 1a, the start and end positions of encryption by the encryption unit 1b, and the storage of log data by the memory unit 1d.

The control unit 1e controls the encryption unit 1b to insert a start flag indicating the start position and an end flag indicating the end position into the start and end positions indicated by the range received by the reception unit 1c, respectively, and perform encryption. At this time, the control unit 1e also controls the acquisition unit 1a to acquire log data based on the above range. In this way, the encryption system 1 can perform partial encryption of log data.

Then, the control unit 1e stores the encrypted data for the log data portion that falls within the above range, and the plain text data for the log data portion that does not fall within the above range, each as separate files (separate log files) in the memory unit 1d.

In particular, in this embodiment, when the entire range of log data is specified as the range, the control unit 1e controls the encryption unit 1b to perform encryption without inserting a start flag and an end flag. As a result, when the entire range of log data is encrypted, the start flag and the end flag are not inserted, and a log file that does not include a start flag and an end flag is stored in the memory unit 1d.

The control unit 1e can be realized, for example, by a CPU (Central Processing Unit), working memory, and a non-volatile storage device storing a program. This program can be a program that causes the CPU to execute the processes of the acquisition unit 1a, encryption unit 1b, reception unit 1c, and writing unit of the storage unit 1d. In addition, the recording medium of the storage device provided in the control unit 1e can also be used as the recording medium of the storage unit 1d.

The target device may also include a transmission unit that, in response to an instruction received by the reception unit 1c, transmits a file (log file) stored in the memory unit 1d to the log collection device, which is the instruction device that sent the instruction. This transmission unit may utilize the communication unit provided in the reception unit 1c. In this way, the target device includes the encryption unit 1b, the reception unit 1c, the memory unit 1d, and a transmission unit that transmits the log file stored in the memory unit 1d to the log collection device, and may be a device from which log data is collected.

In this example, the log collection device is a device that transmits instructions received by the reception unit 1c to the reception unit 1c. Although not shown, the log collection device may include a control unit that controls the entire device and a communication unit that communicates with the target device. This communication unit may include an interface for communicating with the outside world wirelessly or via a wired connection. The log collection device may also be configured to receive log files stored in the memory unit 1d via the communication unit. The control unit of the log collection device may be realized, for example, by a CPU, working memory, and a non-volatile storage device that stores a program. This program may be a program that causes the CPU to execute the process of generating instructions to be sent to the reception unit 1c and the process of sending those instructions to the target device via the communication unit. The recording medium of the storage device provided in the control unit of the log collection device may also be used as a recording medium for storing the log files received in this manner.

In addition, encryption system 1 can be configured as multiple devices with distributed functions, as exemplified by the log collection device and target device, and the functions of each unit exemplified as a target device can also be distributed across multiple devices, with no restrictions on the method of distribution. When constructing encryption system 1 with distributed functions across multiple devices, each device can be equipped with a control unit, a communication unit, and, if necessary, a memory unit, etc., and the multiple devices can be connected via wireless or wired communication as necessary to work together to realize the functions of encryption system 1.

Also, as shown in FIG. 2, the encryption system 1 can be constructed as a single encryption device 2 including an acquisition unit 1a, an encryption unit 1b, a reception unit 1c, a storage unit 1d, and a control unit 1e. FIG. 2 is a block diagram showing the encryption device 2, which is an example configuration of the encryption system 1 of FIG. 1. The encryption device 2 can be a device having the functions of the target device described above, or a device having the functions of the target device and the functions of a log collection device. The encryption device 2 can be configured to include a computer device including hardware, for example, one or more processors and one or more memories. At least some of the functions of each unit within the encryption device 2 can be realized by one or more processors operating in accordance with programs read from one or more memories.

Next, an example of the processing of encryption system 1 or encryption device 2 will be described with reference to Figure 3. Figure 3 is a flow diagram for explaining an example of an encryption method in encryption system 1 or encryption device 2. Below, the encryption method in encryption system 1 will be described, but the encryption method in encryption device 2 is similar.

First, before starting to acquire log data, the encryption system 1 receives an instruction specifying the range of encryption to be performed (step S1). Based on this instruction, the encryption system 1 acquires the log data (step S2). Next, the encryption system 1 determines whether the instruction indicates that the entire range should be encrypted (step S3).

If the answer is YES in step S3, the encryption system 1 performs encryption on the entire range of log data without inserting start and end flags, i.e., without going through step S5 described below (step S6).The encrypted log data is then stored as a single log file (step S7).

On the other hand, if the result of step S3 is NO, the log data acquired in step S2 is determined to be within the above range (step S4). Then, for the log data determined to be YES in step S4, i.e., the log data that falls within the above range, the encryption system 1 inserts a start flag and an end flag at the start and end positions, respectively, of the log data within the above range (step S5). The encryption system 1 then performs encryption (step S6). Then, similarly, the process proceeds to step S7, where the encrypted log data is stored as a single log file.

On the other hand, for log data for which the result of step S4 is NO, i.e., log data that does not fall within the above range, the encryption system 1 stores the data in plain text as a single file (step S8).

The timing of obtaining the log data in step S2 does not matter in the order shown, as long as it is obtained before encryption if the data is to be encrypted, or before storing the log file (step S8) if the data is left in plain text.

The encryptable log collection process according to this embodiment has been described. In this embodiment, the decryption method for encrypted log files is not important. Encrypted log files stored in this embodiment can be viewed by using a decryption method that corresponds to the encryption method. Also, in this embodiment, log files that are encrypted throughout their entirety do not have start and end flags, but these log files can be viewed by using a general-purpose decryption method. Furthermore, since the plaintext log files stored in this embodiment are separate files from the encrypted log files, they can be viewed as is.

As described above, according to this embodiment, when collecting logs from a target device, instead of encrypting all of the log data, partial encryption is used to hide only confidential information, and only the information that can be provided can be made public by storing it in a plaintext log file. For example, partial encryption makes it possible to immediately determine the publicly available information in the log, such as time information, making it possible to quickly check the log when a problem occurs. Furthermore, since this embodiment is configured so that it is possible to select whether or not encryption is required, logs can be collected without the hassle of decryption even when encryption is not required, such as during in-house testing or debugging.

In addition, according to this embodiment, when collecting logs from the target device, the log data can be partially encrypted, thereby shortening the time that CPU resources are occupied by encryption and reducing the load on the target device.

For example, if a failure occurs in the target device making it difficult to obtain log data remotely, it may be necessary to go to the site to collect the log data, and this work may be outsourced to a third party. Even in such a case, this embodiment can ensure confidentiality only for the necessary parts while reducing the load on the target device, making the log file unreadable by third parties and eliminating the risk of information leaks. In this way, this embodiment makes it possible to safely collect the contents of the log file without third parties being able to view it when collecting logs on-site or remotely from the target device.

In particular, according to this embodiment, when encrypting device log data by specifying the range to be encrypted, it is possible to avoid the need for information indicating the range even when encrypting the entire range. In other words, according to this embodiment, encryption is possible without a start flag or an end flag when encrypting the entire range, and the encrypted and unencrypted portions can be saved in separate files. Therefore, according to this embodiment, the amount of data can be reduced by not inserting flags when encrypting the entire range, and the necessary confidentiality can be ensured by encrypting the necessary portions even when viewing the file.

<Embodiment 2>
The second embodiment will be described with reference to Figures 4 to 9, focusing on the differences from the first embodiment, but the various examples described in the first embodiment can also be applied. First, an example configuration of an encryption system according to this embodiment will be described with reference to Figures 4 and 5. Figure 4 is a block diagram showing an example configuration of an encryption system according to the second embodiment, and Figure 5 is a diagram showing an example of a log acquisition command accepted as an instruction in this encryption system.

The encryption system shown in FIG. 4 (hereinafter referred to as the present system) may include a target device 10 that functions as the encryption device according to this embodiment, and a log collection device 20 that collects log files from the target device 10. As described in embodiment 1, the log collection device 20 may encrypt and collect log files at the installation location of the target device 10, or may perform the encryption and collection from a remotely connected target device 10.

For simplicity of explanation, an example will be given in which the system includes one target device 10. However, the system can also be configured to have multiple target devices 10 for one log collection device 20, with the log collection device 20 sending instructions to each of the multiple target devices 10 and collecting log files from each.

The log collection device 20 may include a control unit 21, an operation unit 22, a memory unit 23, and a communication unit 24. The log collection device 20 may be configured as a single or distributed device.

The control unit 21 is a control unit that controls the entire log collection device 20. The control unit 21 can be realized, for example, by a CPU, working memory, and a non-volatile storage device that stores a program. This program can include a program that causes the CPU to execute processing for log acquisition. In addition, the storage device provided in the control unit 21 can also be used as the memory unit 23, which will be described later.

The operation unit 22 accepts an operation to request a log file from the target device 10 that is the target of log collection, and passes the operation content to the control unit 21, which can then request the log file in accordance with the operation content. This request is a command that requests (instructs) the target device 10 to acquire a log, and is hereinafter referred to as a log acquisition command.

As shown in Figure 5, the log acquisition command can include information indicating the type of log to be collected, information indicating whether encryption is required, and information indicating the specified encryption range (in the case of partial encryption). These pieces of information, i.e., parameters, that can be included in the log acquisition command can be specified, for example, from the operation unit 22.

The information indicating the log type described above can be information indicating the type of log to be collected, such as the log of an application incorporated in the target device 10 or the log of a device provided in the target device 10. In the example of Figure 5, for simplicity, the information indicating the log type is described as being expressed in the name of a log acquisition command. However, each log acquisition command may contain information indicating the log type, or the target device 10 may be configured to be able to determine the log type from the log acquisition command name.

Note that, in the cases where all data is encrypted or where no encryption is performed, the explanation here is based on the assumption that the target device 10 is able to identify the log data to be collected based on the log type alone. However, as will be described later, in these cases, it is also possible to include information indicating the log acquisition range in the log acquisition command, and configure the target device 10 to identify the log data to be collected based on the log type and log acquisition range.

The information indicating whether encryption is required can be information indicating full encryption, partial encryption, or no encryption. The information indicating the encryption range is information that specifies the encryption range for a log acquisition command that specifies partial encryption, and is an invalid parameter for anything other than partial encryption. The information indicating the encryption range can be information indicating a range specified by the processing content, such as from process α to process β, for the log type indicated by the log acquisition command, or information indicating a processing period, such as from the first date and time to the second date and time. Alternatively, the information indicating the encryption range can be a combination of these. Furthermore, the range specified by the processing content can be multiple ranges, such as from process α to process β and from process γ to process δ, or multiple processing periods, such as from the first date and time to the second date and time and from the third date and time to the fourth date and time.

Operations accepted by the operation unit 22 can include an operation to input information indicating the target device 10 from which logs are to be collected. Operations accepted by the operation unit 22 can include an operation to input information included in a log acquisition command. Therefore, operations accepted can include an operation to input information indicating the log data to be acquired or the type of log data, information indicating whether encryption is to be performed, and, if encryption is to be performed, information indicating whether encryption is to be performed on all or part of the target. Furthermore, operations accepted can include an operation to input information indicating the encryption range if partial encryption is to be performed on the log data to be acquired.

Alternatively, the operation unit 22 may simply accept an operation to input information indicating the target device 10. In this case, the control unit 21 can read or generate a log acquisition command based on predetermined content regarding whether encryption is required and the encryption range specification (in the case of partial encryption).

The memory unit 23 is a storage device that stores the log file received from the target device 10 via the communication unit 24 in response to the above request. The communication unit 24 transmits the above request to the target device 10 under control of the control unit 21 and receives the log file in response. The communication unit 24 may be equipped with a wired or wireless communication interface.

The target device 10 is an example of the encryption device 2 in Figure 2. The target device 10 can be equipped with a main control unit 11 that controls the entire device, and a communication unit 12 that communicates with the outside. Under the control of the main control unit 11, functional units (not shown) that realize the original functions of the target device 10 can be made to function.

Furthermore, the target device 10 can be equipped with the following components in order to function as an encryption device. That is, the target device 10 can be equipped with a log acquisition unit 15 and buffer unit 16, encryption unit 17, writing unit 18 and recording medium 19, and generation control unit 14, which are examples of the acquisition unit 1a, encryption unit 1b, memory unit 1d, and control unit 1e of FIG. 2, respectively. Furthermore, the communication unit 12 has the function of the reception unit 1c of FIG. 2 as well as the function of transferring log files to the log collection device 20. The log acquisition unit 15 and buffer unit 16, encryption unit 17, writing unit 18 and recording medium 19, and generation control unit 14 can function as a log generation unit 13 in which each unit works together to generate logs. The target device 10 can be configured as a single device or a distributed device.

The main control unit 11 is a control unit that controls the entire target device 10. The main control unit 11 can be realized, for example, by a CPU, working memory, and a non-volatile storage device that stores a program. This program can be a program that causes the CPU to execute processing in the above-mentioned functional units, as well as processing that instructs the generation control unit 14 of the log generation unit 13 to perform processing related to log acquisition for functioning as an encryption device. The storage device provided in the main control unit 11 can also be used as a recording medium 19. The communication unit 12 receives log acquisition commands from the log collection device 20 and transmits log files in response. The communication unit 12 can be provided with a wired or wireless communication interface.

The log generation unit 13 generates log files under control of the main control unit 11. Specifically, the log generation unit 13 receives a log acquisition command from the main control unit 11, which has been received by the communication unit 12, and thereby links the components included in the log generation unit 13, such as the generation control unit 14. Then, through this linkage, the log generation unit 13 generates log files and transmits the log files via the communication unit 12, as described below.

The generation control unit 14 is a control unit that controls the entire log generation unit 13 under control of the main control unit 11. Upon receiving a log acquisition command from the main control unit 11 via the communication unit 12, the generation control unit 14 generates a log file in accordance with the log acquisition command and transmits the log file via the communication unit 12. As described above, this log acquisition command can include whether encryption is required and the specified encryption range if partial encryption is required. Of course, if the log acquisition command only includes the encryption range, it implicitly includes whether encryption is required, and therefore it can be said that the generation control unit 14 can know whether encryption is required and whether full encryption or partial encryption is required.

Based on the log acquisition command, the generation control unit 14 controls the timing of log data acquisition by the log acquisition unit 15, the start and end positions of encryption by the encryption unit 17, and the writing of log data to the recording medium 19 by the writing unit 18.

In other words, the generation control unit 14 controls the start of log collection in accordance with the contents of the log acquisition command received from the main control unit 11. This control includes control over the log acquisition unit 15, encryption unit 17, and writing unit 18, causing them to respectively acquire log data, encrypt the log data, file the log data, and write the file. Furthermore, the generation control unit 14 returns the written file, that is, the log file, to the log collection device 20 that sent the log acquisition command via the communication unit 12.

As part of the above encryption process, the generation control unit 14 controls the encryption unit 17 to perform encryption by inserting an encryption start flag indicating the start position and an encryption end flag indicating the end position at the start and end positions indicated by the encryption range, respectively.

However, if the entire range of log data is specified as the encryption range, the generation control unit 14 controls the encryption unit 17 to perform encryption without inserting the encryption start flag and encryption end flag. As a result, when the entire range of log data is encrypted, the encryption start flag and encryption end flag are not inserted, and a log file that does not include the encryption start flag and encryption end flag is stored on the recording medium 19.

To file the log data and write the files, the generation control unit 14 performs the following control: That is, the generation control unit 14 controls the writing unit 18 to store, as separate log files, the encrypted data for the log data portion that falls within the encryption range, and the plain text data for the log data portion that does not fall within the encryption range.

In particular, in this embodiment, when a partial range of log data is specified as the encryption range in a log acquisition command, the log acquisition command is configured to include an instruction to specify a partial encryption log acquisition range that includes but is larger than the encryption range. In other words, the operation unit 22 of the log collection device 20 accepts an operation to specify information indicating the partial encryption log acquisition range, and the control unit 21 controls the log acquisition command to include this information and transmit it to the target device 10 via the communication unit 24. This allows the target device 10 to know the range of log data to be acquired in plain text from the partial encryption log acquisition range and encryption range.

Then, the generation control unit 14 controls the writing unit 18 to store the encrypted data obtained in the partial encryption log acquisition range together as a single log file 19a. Furthermore, the generation control unit 14 controls the writing unit 18 to store the plaintext data obtained in the portion (range) of the partial encryption log acquisition range excluding the encryption range together as a single log file 19b. By this control, even if the partial encryption log acquisition range includes multiple encryption ranges, all encrypted data for these encryption ranges is stored together as a single log file 19a, and all plaintext data for the remaining ranges is stored together as a single log file 19b.

For example, if a certain log acquisition command specifies the encryption range to be from process α to process β and from process γ to process δ out of the partial encrypted log acquisition range, one encrypted log file 19a and one plain text log file 19b will be stored.

The same concept can be applied when the encryption range is specified for multiple processing periods, such as from the first date and time to the second date and time and from the third date and time to the fourth date and time. Here, the first date and time, second date and time, third date and time, and fourth date and time are described as being closer to the present, in that order. In this case, the encrypted log data from the first date and time to the second date and time and the encrypted log data from the third date and time to the fourth date and time are stored as a single log file. The plaintext log data from the second date and time to the third date and time, the plaintext log data from the start date and time of the partial encryption log acquisition range to the first date and time, and the plaintext log data from the fourth date and time to the end date and time of the partial encryption log acquisition range are stored as a single log file. However, if the start date and time of the partial encryption log acquisition range are the same as the first date and time, no corresponding plaintext log data exists. Conversely, if the end date and time of the partial encryption log acquisition range are the same as the fourth date and time, no corresponding plaintext log data exists.

The log acquisition unit 15, under the control of the generation control unit 14, acquires log data from the target device 10 as instructed by the log acquisition command and temporarily stores it in the buffer unit 16. The buffer unit 16 is a temporary storage buffer for the log data acquired by the log acquisition unit 15, and the temporarily stored log data is used when the encryption unit 17 encrypts it or when the writing unit 18 writes it.

The encryption unit 17 encrypts the log data acquired by the log acquisition unit 15 within the range (encryption range) specified in the log acquisition command. The encryption method used by the encryption unit 17 does not matter, as long as the encrypted data can be decrypted. The encryption unit 17 also sets an encryption start flag at the start point indicated by the encryption range, and an encryption end flag at the encryption end point indicated by the encryption range. The encryption start flag and encryption end flag can be set by inserting the encryption start flag and encryption end flag, respectively.

Furthermore, the encryption unit 17 encrypts the plaintext log data to be encrypted, temporarily stored in the buffer unit 16, using, for example, a byte array and a set encryption method and password. The encryption unit 17 also allows for setting the encryption method, and the encryption method can be set via an operation unit (not shown) of the target device 10 or according to the contents described in the log acquisition command. The password can be set according to the contents described in the log acquisition command, but is not limited to this. Furthermore, any encryption method can be used by the encryption unit 17, such as public key encryption, Transport Layer Security (TLS), or Secure Socket Layer (SSL) instead of a password. The encryption unit 17 can temporarily store the encrypted log data in the buffer unit 16. However, the encrypted log data can also be temporarily stored in a buffer unit provided within the encryption unit 17.

The writing unit 18 controls the file creation and writing of the encrypted log data and plaintext log data temporarily stored in the buffer unit 16 to the recording medium 19. As a result, the recording medium 19 stores at least one of a log file for encrypted flagged log data, a log file for encrypted ungated log data, and a log file for plaintext log data.

The recording medium 19 may be of any type, such as a hard disk drive, solid state drive, or portable recording medium. The recording medium 19 may also be a storage device used by the target device 10 to perform its intended functions.

Furthermore, the generation control unit 14 and the log acquisition unit 15 can be configured as subprograms that cause the CPU of the main control unit 11 to respectively generate logs and return log files via the communication unit 12, and acquire log data. The encryption unit 17 and the writing unit 18 can be configured as subprograms that cause the CPU of the main control unit 11 to respectively encrypt log data and file and write log data. However, these components are not limited to being configured as subprograms; for example, the encryption unit 17 can also be configured as hardware that performs encryption.

Next, an example of processing in the target device 10 in this system will be described with reference to Figures 6 and 7. Figure 6 is a flow diagram for explaining an example of processing in the log generation unit 13 of the target device 10 in this system, and Figure 7 is a flow diagram following Figure 6.

Figures 6 and 7 illustrate an example of processing for a certain log acquisition command, but if there are multiple log acquisition commands for the target device 10, the following processing is performed for each log acquisition command.

In the log generation unit 13, when the generation control unit 14 receives a log acquisition command from the log collection device 20, it first checks the information (parameters) described in the log acquisition command (step S11). Next, the generation control unit 14 determines whether encryption is necessary based on the check results (step S12).

If encryption is not required, i.e., if the answer is NO in step S12, the generation control unit 14 causes the log acquisition unit 15 to acquire (collect) the log data and temporarily store the collected log data in plain text in the buffer unit 16 (step S13). Next, the generation control unit 14 controls the writing unit 18 to convert the plain text log data temporarily stored in the buffer unit 16 into a file and write it to the recording medium 19 (step S14), thereby ending the process.

If encryption is required, i.e., if the answer is YES in step S12, the generation control unit 14 determines whether partial encryption (whether all encryption) is required based on the check result in step S11 (step S15). If all encryption is required, i.e., if the answer is NO in step S15, the generation control unit 14 causes the log acquisition unit 15 to acquire (collect) log data and temporarily stores the collected log data in plain text in the buffer unit 16 (step S16).

Then, the generation control unit 14 causes the encryption unit 17 to encrypt the log data temporarily stored in the buffer unit 16 and temporarily store the encrypted log data in the buffer unit 16 (step S17). The encryption unit 17 stores, for example, plaintext log data in a byte array, specifies an encryption method and password, and performs encryption. The encryption method and password may be specified in the log acquisition command or may be predetermined.

Next, the generation control unit 14 controls the writing unit 18 to convert the encrypted log data temporarily stored in the buffer unit 16 into a file and write it to the recording medium 19 (step S18), thereby completing the processing.

If partial encryption is performed, i.e., if the answer is YES in step S15, the generation control unit 14 executes a loop process from the start of the loop (step S21s) to the end of the loop (step S21e) until the log acquisition command is completed.

When partial encryption is performed, the encryption start position is specified by the encryption range in one of the partial encryption log acquisition ranges. Therefore, the generation control unit 14 first determines whether the encryption start position indicated by the check result in step S11 is the encryption start position based on the current acquisition status of the log data (step S22). Note that at the beginning of the loop processing, if the start position of the partial encryption log acquisition range and the encryption start position match, the answer is YES in step S22; otherwise, that is, if there is an unencrypted range at the beginning, the answer is NO in step S22.

If the answer is NO in step S22, the generation control unit 14 causes the log acquisition unit 15 to acquire (collect) log data and temporarily stores the collected log data in plain text in the buffer unit 16 (step S23). Next, similar to step S22, the generation control unit 14 determines whether the current acquisition status of the log data indicates the encryption start position (step S24). If the answer is NO in step S24, the processing of step S23 continues.

The generation control unit 14 continues the processing of step S23 until the sequence advances to the encryption start position (until step S24 becomes YES). When the sequence advances to the encryption start position, i.e., when step S24 becomes YES, the generation control unit 14 controls the writing unit 18 to write the plaintext log data temporarily stored in the buffer unit 16 up to that point to the first file, which is a file for plaintext (step S25).

In step S25, in the first loop in which the first file has not yet been generated, the generation control unit 14 controls the writing unit 18 to generate the first file by converting the temporarily stored plaintext log data into a file and writes it to the recording medium 19. In the next and subsequent loop processes, in step S25, the generation control unit 14 causes the writing unit 18 to append the temporarily stored plaintext log data to the first file stored in the recording medium 19. After step S25 is completed, the process moves to the next loop process.

On the other hand, if step S22 returns YES, the generation control unit 14 causes the encryption unit 17 to insert an encryption start flag (step S26). At this stage, log data containing only the encryption start flag for that encryption section can be temporarily stored in the buffer unit 16. Following step S26, the generation control unit 14 causes the log acquisition unit 15 to acquire (collect) log data, temporarily stores the collected log data in plain text in the buffer unit 16 (step S27), and determines whether the encryption end position has been reached (step S28). If step S28 returns NO, the generation control unit 14 continues processing in step S27.

If the encryption end position is reached, i.e., if the answer is YES in step S28, the generation control unit 14 controls the encryption unit 17 to insert an encryption end flag at the end of the temporarily stored log data, and causes the encryption unit 17 to perform the insertion (step S29).

Next, the generation control unit 14 causes the encryption unit 17 to encrypt the flagged log data temporarily stored in the buffer unit 16, and causes the encrypted log data to be temporarily stored in the buffer unit 16 (step S30). Here too, the encryption unit 17 stores, for example, plaintext log data in a byte array, specifies an encryption method and password, and performs encryption. The encryption method and password may be specified in the log acquisition command or may be predetermined.

The generation control unit 14 controls the writing unit 18 to write the encrypted log data that has been temporarily stored in the buffer unit 16 to a second file, which is a file for encryption (step S31).

In step S31, in the first loop in which the second file has not yet been generated, the generation control unit 14 controls the writing unit 18 to generate a second file by converting the temporarily stored encrypted log data into a file and writing it to the recording medium 19. In the next and subsequent loop processes, in step S31, the generation control unit 14 causes the writing unit 18 to append the temporarily stored encrypted log data to the second file stored on the recording medium 19. After step S31 is completed, the process moves to the next loop process.

Next, an example of processing by the log collection device 20 and the target device 10 will be described with reference to Figures 8 and 9. Figure 8 is a sequence diagram showing an example of the overall processing in this system, and Figure 9 is a sequence diagram following Figure 8.

First, the log collection device 20 sends a log acquisition request, which is a log acquisition command, to the target device 10, which is received by the generation control unit 14 (step S100). While it has been explained that the log acquisition command can be specified from the operation unit 22 of the log collection device 20, etc., the contents set in the log acquisition command can be predetermined, i.e., they cannot be changed by the user of the log collection device 20.

Next, the generation control unit 14 checks the parameters set in the received log acquisition command (step S101). A loop process is executed as many times as the number of received log acquisition commands. In this loop process, one of the following processes will be executed depending on the check result for the target log acquisition command: no encryption process, full encryption process, or partial encryption process.

If the log acquisition command is an unencrypted log acquisition command, the generation control unit 14 executes the log acquisition command, which initiates temporary storage (buffering) of the log data in the buffer unit 16 (step S102). The generation control unit 14 then requests the writing unit 18 to convert the log data into a file (step S103), and the writing unit 18 executes the file conversion and stores the plaintext log file on the recording medium 19 (step S104). The writing unit 18 then notifies the generation control unit 14 in response to the request that the file conversion has been completed (step S105). Upon receiving this notification, the generation control unit 14 transmits (transfers) the plaintext log file stored on the recording medium 19 to the log collection device 20 via the communication unit 12 (step S106), thereby terminating the process.

If the log acquisition command is to encrypt all data, the generation control unit 14 executes the log acquisition command, which initiates temporary storage of the log data in the buffer unit 16 (step S107). Next, the generation control unit 14 sends an encryption request to the encryption unit 17 (step S108), and the encryption unit 17 responds to the request, encrypts the temporarily stored log data (step S109), and notifies the generation control unit 14 of the completion of encryption (step S110).

Upon receiving this notification, the generation control unit 14 requests the writing unit 18 to file the log data (step S111), and the writing unit 18 executes the file creation and stores the encrypted log file on the recording medium 19 (step S112). Next, in response to the request, the writing unit 18 notifies the generation control unit 14 that the file creation has been completed (step S113). Next, the generation control unit 14 transmits (transfers) the encrypted log file stored on the recording medium 19 to the log collection device 20 via the communication unit 12 (step S114), and the process ends.

If the log acquisition command is partially encrypted, a loop process is executed in which one of the following is performed until the log acquisition command ends: processing at the encryption start point, processing at the encryption end point, or processing in the non-encrypted area.

The encryption start position is not necessarily the beginning of the log data. Therefore, the generation control unit 14 executes a log acquisition command, which temporarily stores the log data in the buffer unit 16 as processing in a non-encrypted section until the encryption start position is reached (step S126). The generation control unit 14 then requests the writing unit 18 to file the log data (step S127), and the writing unit 18 executes the file creation and stores the plaintext log file on the recording medium 19 (step S128). Next, in response to the request, the writing unit 18 notifies the generation control unit 14 that the file creation in this non-encrypted range has been completed (step S129). If there is a next non-encrypted range, in step S127, the plaintext log data may be appended to the plaintext log file stored on the recording medium 19.

An example of processing at the encryption start position will be described. When the encryption start position is reached, the generation control unit 14 executes a log acquisition command, thereby starting temporary storage of the log data in the buffer unit 16 (step S115). Next, the generation control unit 14 sends an encryption start request to the encryption unit 17 (step S116). Upon receiving the encryption start request, the encryption unit 17 inserts an encryption start flag at the encryption start position of the pre-encryption log data temporarily stored in step S115 (step S117), and returns an encryption start response to the generation control unit 14 (step S118).

An example of processing at the encryption end position will be described below. When processing reaches the encryption end position, the generation control unit 14 sends an encryption end request to the encryption unit 17 (step S119). The encryption unit 17 inserts an encryption end flag at the end of the log data that was continuously and temporarily saved in step S115 (step S120), and performs encryption of the section delimited by the encryption start flag and encryption end flag (step S121). The encryption unit 17 then returns an encryption end response to the generation control unit 14 (step S122).

Then, the generation control unit 14 requests the writing unit 18 to file the encrypted log data for that section (step S123). Upon receiving this request, the writing unit 18 executes the file creation and stores the encrypted log file on the recording medium 19 (step S124). Next, in response to the request, the writing unit 18 notifies the generation control unit 14 that file creation for this encryption range has been completed (step S125). If there is a next encryption range, the encrypted log data may be added to the encrypted log file stored on the recording medium 19 in step S124.

In this way, once the log data has been acquired, partially encrypted, and filed using the target log acquisition command, the partial encryption loop process ends. The generation control unit 14 then transmits (transfers) one plaintext log file and one encrypted log file stored on the recording medium 19 to the log collection device 20 via the communication unit 12 (step S130), and the process ends.

As described above, according to this embodiment, in addition to the effects of embodiment 1, even if the log acquisition command includes multiple encryption ranges, the multiple encryption ranges can be combined and obtained as a single encrypted log file. Furthermore, according to this embodiment, even if the log acquisition command includes one or more encryption ranges, which results in the inclusion of multiple non-encrypted ranges, the multiple non-encrypted ranges can be combined and obtained as a single plaintext log file.

Furthermore, in this embodiment, it has been described that log acquisition commands that perform partial encryption include information indicating the partial encryption log acquisition range. However, it is also possible to include information indicating the log acquisition range for both log acquisition commands that perform full encryption and log acquisition commands that do not perform encryption. This allows the target device 10 to identify the log data to be collected for these two types of log acquisition commands based on the log type and log acquisition range included in the log acquisition command.

Furthermore, as illustrated in the sequence diagrams of Figures 8 and 9, the generation control unit 14 in this embodiment has the function of determining the insertion positions of the encryption start flag and encryption end flag during execution of the log acquisition command, and switching between non-encryption, partial encryption (partial encryption), and full encryption. By having such a function, it is possible to switch processing in response to any of these three types of requests from the log collection device 20, generate a log file, and transfer that log file to the log collection device 20.

Finally, we will briefly explain how to use the encryption start flag and encryption end flag when viewing (decrypting) a log file when partial encryption is performed. In this case, the encryption start flag and encryption end flag are not used; decryption of the encrypted log file is possible by ignoring these flags. However, these flags can be used when viewing log files for a single log acquisition command in sequence. For example, decryption of the encrypted log file can be performed first, and the encrypted and non-encrypted ranges can be presented in order. Whether the encrypted or non-encrypted range comes first is known after the log acquisition command is generated by the log collection device 20, and can be determined by referencing the log acquisition command. For example, after the encryption end flag, the next non-encrypted range in the plaintext log file can be read and presented, and once the presentation of the non-encrypted range in the plaintext log file has finished, the next encrypted range indicated by the next encryption start flag can be read and presented.

<Embodiment 3>
The third embodiment will be described with reference to Fig. 10 etc., focusing on the differences from the second embodiment, but the various application examples described in the first and second embodiments are also applicable to the third embodiment. As the configuration example of the encryption system in Fig. 4 can be applied to the third embodiment as well, with the exception of some processes, the description will be based on the configuration example in Fig. 4.

In embodiment 2, when a log acquisition command includes multiple encryption ranges, the multiple encryption ranges are combined into a single encrypted log file, and the multiple non-encrypted ranges are combined into a single plaintext log file.

In contrast, in this embodiment, the generation control unit 14 stores the encrypted log data as a single file on the recording medium 19 each time the encryption range is separated by the start and end positions indicated by the encryption range, and stores the plaintext log data as a single file on the recording medium 19. In other words, in this embodiment, when the encryption range is divided into multiple parts, it is possible to store a log file each time the encryption range is separated in processing order, and to transmit each stored log file to the log collection device 20.

A specific example of how files are stored is given below. If the log acquisition command specifies processes α through β and processes γ through δ as the encryption range, the following two encrypted log files will be stored: one for processes α through β and one for processes γ through δ. Furthermore, consecutive log data other than these processes can each be stored as a plaintext log file. For example, the log data for a series of processes from after process β to before process γ is stored as a single plaintext log file. Furthermore, if there is a series of processes before process α, the log data for that series of processes will be stored as a single plaintext log file, and if there is a series of processes after process δ, the log data for that series of processes will be stored as a single plaintext log file. In this example, there will be a maximum of three plaintext log files.

The same concept can be applied when the encryption range is specified for multiple processing periods, such as from the first date and time to the second date and time and from the third date and time to the fourth date and time. Here, the first date and time, second date and time, third date and time, and fourth date and time are described as being closer to the present in that order. In this case, an encrypted log file from the first date and time to the second date and time and an encrypted log file from the third date and time to the fourth date and time are stored. Also, a plaintext log file from the second date and time to the third date and time, a plaintext log file from the start date and time of the partial encryption log acquisition range to the first date and time, and a plaintext log file from the fourth date and time to the end date and time of the partial encryption log acquisition range are stored. However, if the start date and time of the partial encryption log acquisition range are the same as the first date and time, no corresponding plaintext log file exists, and if the end date and time of the partial encryption log acquisition range are the same as the fourth date and time, no corresponding plaintext log file exists.

Note that here too, as in embodiment 2, a partial encryption log acquisition range is specified. Also, in this embodiment, information indicating the log acquisition range may be included in the log acquisition command for full encryption and the log acquisition command for no encryption.

Next, an example of processing in the log generation unit 13 of the target device 10 in this embodiment will be described with reference to Figure 10. Figure 10 is a flow diagram for explaining an example of processing in the log generation unit 13 of the target device 10 in an encryption system relating to embodiment 3, and is a flow diagram for explaining another example of processing following Figure 6.

Figures 6 and 10 also explain an example of processing for a certain log acquisition command, but if there are multiple log acquisition commands for the target device 10, the following processing is executed for each log acquisition command. Note that explanations using sequence diagrams such as those shown in Figures 8 and 9 will be omitted.

In this embodiment, the processing is similar when there is no encryption or when all data is encrypted, and the processing example in Figure 6 can be applied. In this embodiment, as shown in Figure 10, when a log acquisition command is partially encrypted, a loop process is executed in which one of the following processes is executed until the end of the log acquisition command: processing at the encryption start position, processing at the encryption end position, and processing in the non-encrypted section. In this loop process, in this embodiment, the processes of steps S25 and S31 in Figure 7 are changed to steps S25a and S31a, respectively.

In step S25a, if the answer is YES in step S24, the generation control unit 14 controls the writing unit 18 to write the plain text log data that is the target of the loop processing at that time and that is temporarily stored in the buffer unit 16 to the first file, which is a file for plain text.

In step S25a, the generation control unit 14 controls the writing unit 18 to file the temporarily stored plain text log data to generate a first file, which is then written to the recording medium 19. The first file here becomes a first file for each target section. Therefore, the first file will be stored as a first file for each target section for the number of loop processes for which step S24 returned YES. After step S25a is completed, the process moves to the next loop process.

In step S31a, the generation control unit 14 controls the writing unit 18 to write the encrypted log data temporarily stored in the buffer unit 16, i.e., the encrypted log data that has not been filed, to a second file, which is a file for encryption.

In step S31a, the generation control unit 14 controls the writing unit 18 to file the temporarily stored encrypted log data, i.e., the encrypted log data that has not been filed, to generate a second file and write it to the recording medium 19. The second file here is a second file for each target section. Therefore, the second file will be stored as a second file for each target section for the number of loop processes for which step S28 returned YES. After step S31a is completed, the process moves to the next loop process.

As described above, according to this embodiment, in addition to the effects of embodiment 1, even if the log acquisition command contains multiple encryption ranges, one encrypted log file can be obtained for each encryption range, and one plaintext log file can be obtained for each non-encryption range.

Here, we briefly explain how to use the encryption start flag and encryption end flag when viewing (decrypting) a log file when partial encryption is performed. In this case, the encryption start flag and encryption end flag are not used; decryption of the encrypted log file is possible by ignoring these flags. However, these flags can be used when viewing encrypted log files for a single log acquisition command in sequence. For example, the encrypted log file can be decrypted first, and the encrypted and non-encrypted ranges can be presented in order. This order is known after the log acquisition command is generated by the log collection device 20, so it can be obtained by referencing the log acquisition command. Alternatively, the order can be determined by the last saved date and time of the log file. For example, after the encryption end flag, the next non-encrypted range in the plaintext log file can be read and presented, and once the presentation of the non-encrypted range in the plaintext log file has finished, the next encrypted range indicated by the next encryption start flag can be read and presented.

In addition, the target device 10 may be provided with a function to switch between processing in embodiment 2 and processing in embodiment 3, and the log acquisition command sent by the log collection device 20 may include information indicating which processing to apply.

<Other Embodiments>
[a]
In each embodiment, the functions of the encryption system, encryption device, target device, log collection device, and devices that can be included in the encryption system have been described, but each device is not limited to the configuration example shown in the figure, and it is sufficient if each device can realize these functions.

[b]
Each of the devices described in the first to third embodiments may have the following hardware configuration. Fig. 11 is a diagram showing an example of the hardware configuration of the device. The same applies to the other embodiment [a] above.

The device 100 shown in FIG. 11 may include a processor 101, memory 102, and a communication interface (I/F) 103. The processor 101 may be, for example, a microprocessor, an MPU (Micro Processor Unit), or a CPU. The processor 101 may include multiple processors. The memory 102 is configured, for example, by a combination of volatile memory and non-volatile memory. The functions of each device described in embodiments 1 to 3 are realized by the processor 101 reading and executing a program stored in the memory 102. In this case, information can be sent and received with other devices via the communication interface 103 or an input/output interface (not shown).

In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

Note that this disclosure is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the disclosure. Furthermore, this disclosure may be implemented by combining the respective embodiments as appropriate.

Some or all of the above embodiments may also be described as, but are not limited to, the following notes:

(Appendix 1)
an acquisition unit that acquires log data;
an encryption unit that encrypts the log data;
a reception unit that receives an instruction to specify a range to be encrypted by the encryption unit before starting acquisition of log data;
a storage unit that stores log data;
a control unit that controls, based on the range, the timing of acquisition of log data by the acquisition unit, the start and end positions of encryption by the encryption unit, and storage of log data by the storage unit;
Equipped with
The control unit
controlling the encryption unit to insert a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then perform encryption;
When the entire range of the log data is designated as the range, the encryption unit is controlled to perform encryption without inserting the start flag and the end flag;
The encrypted data for the log data corresponding to the range and the plaintext data for the log data not corresponding to the range are stored in the storage unit as separate files.
Encryption system.
(Appendix 2)
when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit collectively stores the encrypted data obtained in the partial encryption log acquisition range as a single file in the storage unit, and collectively stores the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the range as a single file in the storage unit.
2. The encryption system of claim 1.
(Appendix 3)
when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit stores the encrypted data as one file in the storage unit and stores the plaintext data as one file in the storage unit each time the range is delimited by a start position and an end position indicated by the range.
2. The encryption system of claim 1.
(Appendix 4)
an instruction device that transmits an instruction to the reception unit to be received by the reception unit;
a target device that is a target for collecting log data, the target device including the encryption unit, the reception unit, the storage unit, and a transmission unit that transmits the file stored in the storage unit to the instruction device;
Equipped with
4. The encryption system according to any one of claims 1 to 3.
(Appendix 5)
an acquisition unit that acquires log data;
an encryption unit that encrypts the log data;
a reception unit that receives an instruction to specify a range to be encrypted by the encryption unit before starting acquisition of log data;
a storage unit that stores log data;
a control unit that controls, based on the range, the timing of acquisition of log data by the acquisition unit, the start and end positions of encryption by the encryption unit, and storage of log data by the storage unit;
Equipped with
The control unit
controlling the encryption unit to insert a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then perform encryption;
When the entire range of the log data is designated as the range, the encryption unit is controlled to perform encryption without inserting the start flag and the end flag;
The encrypted data for the log data corresponding to the range and the plaintext data for the log data not corresponding to the range are stored in the storage unit as separate files.
Encryption device.
(Appendix 6)
when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit collectively stores the encrypted data obtained in the partial encryption log acquisition range as a single file in the storage unit, and collectively stores the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the range as a single file in the storage unit.
6. The encryption device of claim 5.
(Appendix 7)
when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit stores the encrypted data as one file in the storage unit and stores the plaintext data as one file in the storage unit each time the range is delimited by a start position and an end position indicated by the range.
6. The encryption device of claim 5.
(Appendix 8)
a transmitting unit that, in response to the instruction received by the receiving unit, transmits the file stored in the storage unit to an instruction device that transmitted the instruction;
8. The encryption device according to any one of appendices 5 to 7.
(Appendix 9)
Obtaining log data;
Encrypting log data;
receiving an instruction to specify a range to be encrypted before starting acquisition of log data;
storing the log data; and
Controlling the timing of acquiring log data, the start and end positions of encryption, and storage of log data based on the range;
Equipped with
The controlling comprises:
inserting a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then performing encryption;
When the entire range of the log data is designated as the range, encryption is performed without inserting the start flag and the end flag; and
storing the encrypted data for the log data that falls within the range and the plaintext data for the log data that does not fall within the range in separate files;
encryption methods, including
(Appendix 10)
When a partial range of log data is specified as the range, the receiving includes receiving an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
The controlling includes collectively storing the encrypted data obtained in the partial encryption log acquisition range as a single file, and collectively storing the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the partial encryption log acquisition range as a single file.
10. The encryption method of claim 9.
(Appendix 11)
When a partial range of log data is specified as the range, the receiving includes receiving an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
The controlling includes storing the encrypted data as one file and storing the plaintext data as one file each time the range is delimited by a start position and an end position indicated by the range.
10. The encryption method of claim 9.
(Appendix 12)
12. The encryption method of claim 9, further comprising: in response to the instruction received by the receiving, transmitting the stored file to the instruction device that sent the instruction.
(Appendix 13)
Obtaining log data;
Encrypting log data;
receiving an instruction to specify a range to be encrypted before starting acquisition of log data;
storing the log data; and
Controlling the timing of acquiring log data, the start and end positions of encryption, and storage of log data based on the range;
Including,
The controlling comprises:
inserting a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then performing encryption;
When the entire range of the log data is designated as the range, encryption is performed without inserting the start flag and the end flag; and
storing the encrypted data for the log data that falls within the range and the plaintext data for the log data that does not fall within the range in separate files;
Including,
A computer-readable medium that stores a program for causing a computer to execute an encryption process.
(Appendix 14)
When a partial range of log data is specified as the range, the receiving includes receiving an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
The controlling includes collectively storing the encrypted data obtained in the partial encryption log acquisition range as a single file, and collectively storing the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the partial encryption log acquisition range as a single file.
14. The computer-readable medium of claim 13.
(Appendix 15)
When a partial range of log data is specified as the range, the receiving includes receiving an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
The controlling includes storing the encrypted data as one file and storing the plaintext data as one file each time the range is delimited by a start position and an end position indicated by the range.
14. The computer-readable medium of claim 13.
(Appendix 16)
the encryption process includes, in response to the instruction received by the receiving, transmitting the stored file to a device that sent the instruction.
16. The computer-readable medium of any one of claims 13 to 15.

The present invention has been described above with reference to embodiments, but the present invention is not limited to the above. Various modifications that would be understood by a person skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

1 Encryption system 1a Acquisition unit 1b Encryption unit 1c Reception unit 1d Memory unit 1e Control unit 2 Encryption device 10 Target device 11 Main control unit 12 Communication unit 13 Log generation unit 14 Generation control unit 15 Log acquisition unit 16 Buffer unit 17 Encryption unit 18 Writing unit 19 Recording medium 19a Encrypted log file 19b Plain text log file 20 Log collection device 21 Control unit 22 Operation unit 23 Memory unit 24 Communication unit 100 Device 101 Processor 102 Memory 103 Communication interface

Claims (10)

an acquisition unit that acquires log data;
an encryption unit that encrypts the log data;
a reception unit that receives an instruction to specify a range to be encrypted by the encryption unit before starting acquisition of log data;
a storage unit that stores log data;
a control unit that controls, based on the range, the timing of acquisition of log data by the acquisition unit, the start and end positions of encryption by the encryption unit, and storage of log data by the storage unit;
Equipped with
The control unit
controlling the encryption unit to insert a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then perform encryption;
When the entire range of the log data is designated as the range, the encryption unit is controlled to perform encryption without inserting the start flag and the end flag;
The encrypted data for the log data corresponding to the range and the plaintext data for the log data not corresponding to the range are stored in the storage unit as separate files.
Encryption system. when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit collectively stores the encrypted data obtained in the partial encryption log acquisition range as a single file in the storage unit, and collectively stores the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the range as a single file in the storage unit.
The encryption system of claim 1 . when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit stores the encrypted data as one file in the storage unit and stores the plaintext data as one file in the storage unit each time the range is delimited by a start position and an end position indicated by the range.
The encryption system of claim 1 . an instruction device that transmits an instruction to the reception unit to be received by the reception unit;
a target device that is a target for collecting log data, the target device including the encryption unit, the reception unit, the storage unit, and a transmission unit that transmits the file stored in the storage unit to the instruction device;
Equipped with
The encryption system according to any one of claims 1 to 3. an acquisition unit that acquires log data;
an encryption unit that encrypts the log data;
a reception unit that receives an instruction to specify a range to be encrypted by the encryption unit before starting acquisition of log data;
a storage unit that stores log data;
a control unit that controls, based on the range, the timing of acquisition of log data by the acquisition unit, the start and end positions of encryption by the encryption unit, and storage of log data by the storage unit;
Equipped with
The control unit
controlling the encryption unit to insert a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then perform encryption;
When the entire range of the log data is designated as the range, the encryption unit is controlled to perform encryption without inserting the start flag and the end flag;
The encrypted data for the log data corresponding to the range and the plaintext data for the log data not corresponding to the range are stored in the storage unit as separate files.
Encryption device. when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit collectively stores the encrypted data obtained in the partial encryption log acquisition range as a single file in the storage unit, and collectively stores the plaintext data obtained in the portion of the partial encryption log acquisition range excluding the range as a single file in the storage unit.
The encryption device according to claim 5 . when a partial range of log data is specified as the range, the reception unit receives an instruction to specify a partial encrypted log acquisition range that is a log acquisition range that includes the range and is larger than the range;
the control unit stores the encrypted data as one file in the storage unit and stores the plaintext data as one file in the storage unit each time the range is delimited by a start position and an end position indicated by the range.
The encryption device according to claim 5 . a transmitting unit that, in response to the instruction received by the receiving unit, transmits the file stored in the storage unit to an instruction device that transmitted the instruction;
The encryption device according to any one of claims 5 to 7. The computer
Obtaining log data;
Encrypting log data;
receiving an instruction to specify a range to be encrypted before starting acquisition of log data;
storing the log data; and
Controlling the timing of acquiring log data, the start and end positions of encryption, and storage of log data based on the range;
performs an encryption process including
The controlling comprises:
inserting a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then performing encryption;
When the entire range of the log data is designated as the range, encryption is performed without inserting the start flag and the end flag; and
storing the encrypted data for the log data that falls within the range and the plaintext data for the log data that does not fall within the range in separate files;
encryption methods, including Obtaining log data;
Encrypting log data;
receiving an instruction to specify a range to be encrypted before starting acquisition of log data;
storing the log data; and
Controlling the timing of acquiring log data, the start and end positions of encryption, and storage of log data based on the range;
Including,
The controlling comprises:
inserting a start flag indicating the start position and an end flag indicating the end position into the start position and the end position indicated by the range, respectively, and then performing encryption;
When the entire range of the log data is designated as the range, encryption is performed without inserting the start flag and the end flag; and
storing the encrypted data for the log data that falls within the range and the plaintext data for the log data that does not fall within the range in separate files;
Including,
A program that causes a computer to perform encryption processing.