JP2010287173A - Data security method, data security system, server, and client device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that data which is already received cannot be seen when the most part of resources of a server is not used for data receiving processing. <P>SOLUTION: In a security method, the server 20 monitors whether the resource utilization factor of resources of the server 20 exceeds a preset threshold during receiving data from a client device 10, and transmits a data reduction instruction to reduce data to the client device 10 when the resource utilization factor exceeds the threshold. The client device 10 reduces the data and transmits the reduced data to the server 20 when receiving the data reduction instruction from the server 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a data security method, a data security system, a server, and a client device for remotely maintaining data of a client device.

  When investigating a client device of a client remotely (for example, investigating about unauthorized access from the outside), it is necessary to conduct investigation based on the secured data while maintaining the data of the client device remotely.

  Non-Patent Document 1 discloses a method using a tool called netcat (nc) as a data maintenance method for performing data maintenance remotely.

  FIG. 4 shows a configuration of a conventional data maintenance system using netcat.

  In the data maintenance system shown in FIG. 4, the server 200 receives data transmitted from the client device 100 via the network (NW), and secures the received data of the client device 100. .

  The data security system shown in FIG. 4 operates as follows.

  First, the receiving server 200 executes the following command.

“# Nc -l -p (receive port number)> (disk save destination file name)”
As a result, when data is subsequently received at the reception port indicated by (reception port number), the server 200 saves the received data in a file indicated by (disk save destination file name).

  Next, the transmission-side client device 100 executes the following command.

“# Dd if = (file name) | nc (destination IP address) (destination port number)”
As a result, the client apparatus 100 reads data from the file indicated by (file name), and transmits the read data indicated by (destination port number) of the destination IP address indicated by (destination IP address). Send to destination port.

WATANABE Katsuhiro and Ihara Hideaki, “Unauthorized Access Investigation Guide”, ISBN 4-87311-079-3, issued April 2002, p. 299-302

  However, in the conventional data security system shown in FIG. 4, the client apparatus 100 transmits data read from the designated file, and the server 200 only saves the received data in the designated file. It is.

  Therefore, even when the user wants to view the received data using the data view function on the server 200, if most of the resources such as the CPU and memory are used for data reception processing, the data There is a problem that the view function cannot be used satisfactorily.

  Also, it is not possible to maintain another data while maintaining a large amount of data stored in an HDD or the like, even if the other data is relatively small data such as a log file. There is a problem.

  Therefore, an object of the present invention is to provide a data security method, a data security system, a server, and a client device that can solve at least one of the above-described problems.

The data security method of the present invention
A data security method by a client device and a server that receives data from the client device and secures the received data,
Monitoring whether or not the resource utilization rate of the resource of the server exceeds a preset threshold while the server receives data from the client device;
The server, when the resource utilization rate exceeds the threshold, sending a data reduction command to reduce data to the client device;
And a step of reducing the data when the client device receives the data reduction command from the server and transmitting the reduced data to the server.

In addition, the data security method of the present invention includes:
When the server receives a second data reception command while receiving the first data from the client device, the server device issues a first data suspension command to the client device to temporarily stop transmission of the first data. Sending, and
When the client device receives the first data suspension command from the server, temporarily stops transmission of the first data, and transmits a first data suspension completion report to the server;
When the server receives the first data suspension completion report from the client device, starts preparing to receive the second data;
After the server completes preparation for receiving the second data, a second data transmission command for starting transmission of the second data to the client device;
When the client device receives the second data transmission command from the server, the second data transmission completion report is sent to the server after starting the transmission of the second data and completing the transmission of the second data. Sending to
When the server receives the second data transmission completion report from the client device, starts preparing to receive the first data again;
After the server completes preparation for re-reception of the first data, a first data re-transmission command for resuming transmission of the remaining portion of the first data to the client device;
And a step of resuming transmission of the remaining portion of the first data when the client device receives the first data retransmission command from the server.

  According to the present invention, when the resource utilization rate exceeds the threshold value during reception of data from the client device, the server transmits a data reduction command to the client device to reduce the data so that the resource utilization rate becomes the threshold value. Control not to exceed.

  Therefore, if the above threshold is set to the resource usage rate according to the amount of resources used when executing the data view function, the resources used when executing the data view function are secured even during reception of a large amount of data. As a result, the user can see the already received data using the data view function.

  According to the present invention, when the server receives a second data reception command while receiving the first data, the server temporarily stops transmission of the first data and then prepares to receive the second data. After that, the client apparatus is made to start transmitting the second data. When the transmission of the second data is completed, the client apparatus prepares to receive the first data again, and then transmits the remaining portion of the first data to the client apparatus. To resume.

  Therefore, even if the first data being received by the server has a large capacity, the user can interrupt and receive the second data first, so that the user can maintain another necessary data even while maintaining the large capacity data. The effect that it can do is acquired.

It is a block diagram which shows the structure of the data maintenance system of one Embodiment of this invention. FIG. 2 is a sequence diagram illustrating an example of an operation for controlling a resource utilization rate of a server that is receiving data to a threshold value or less in the data maintenance system illustrated in FIG. 1. FIG. 2 is a sequence diagram for explaining an example of an operation for causing a client device and a server that are transmitting / receiving data to transmit / receive another data by interruption in the data maintenance system illustrated in FIG. 1. FIG. 2 is a sequence diagram for explaining an example of an operation for causing a client device and a server that are transmitting / receiving data to transmit / receive another data by interruption in the data maintenance system illustrated in FIG. 1. FIG. 2 is a sequence diagram for explaining an example of an operation for causing a client device and a server that are transmitting / receiving data to transmit / receive another data by interruption in the data maintenance system illustrated in FIG. 1. It is a block diagram which shows the example of 1 structure of the conventional data maintenance system.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to drawings.

  Referring to FIG. 1, the data security system of this embodiment includes a client device 10 and a server 20 that receives data from the client device 10 via a network (NW) and secures the received data. Yes.

  The client device 10 includes a connection unit 11, a data transmission unit 12, a command reception unit 13, a data acquisition unit 14, a data transmission amount control unit 15, a transmission data control unit 16, a transmission pause unit 17, have.

  Each unit in the client device 10 generally operates as follows.

  The connection unit 11 transmits a connection request to the server 20 and performs a connection process with the server 20.

  The data transmission unit 12 transmits data to the server 20.

  The command receiving unit 13 receives various commands from the server 20 and transmits a report to that effect to the server 20 when processing for the command is completed.

  The data acquisition unit 14 acquires data transmitted by the data transmission unit 12.

  The data transmission amount control unit 15 controls the capacity of data transmitted by the data transmission unit 12.

  The transmission data control unit 16 controls the entire client device 10 during data transmission.

  The transmission pause unit 17 performs various processes such as instructing the data transmission unit 12 to pause and resume transmission when data transmission is paused.

  The server 20 includes a connection reception unit 21, a data reception unit 22, a command transmission unit 23, a client control unit 24, a resource utilization rate monitoring unit 25, a reception data control unit 26, a reception data storage unit 27, A data view control unit 28.

  Each part in the server 20 generally operates as follows.

  When receiving a connection request from the client device 10, the connection reception unit 21 performs a connection process with the client device 10.

  The data receiving unit 22 transmits data from the client device 10.

  The command transmission unit 23 transmits various commands to the client device 10 and receives a report from the client device 10 that processing for the command is completed.

  The client control unit 24 controls the client device 10.

  The resource usage rate monitoring unit 25 monitors whether or not the resource usage rate of resources such as the CPU and memory of the server 20 exceeds a preset threshold during reception of data from the client device 10. In the present embodiment, the threshold is set to a resource usage rate that does not affect the data view function executed by the data view control unit 28, that is, a resource usage rate according to the resource amount used when the data view function is executed. Shall.

  The reception data control unit 26 controls the entire server 20 when receiving data.

  The reception data storage unit 27 stores the data received by the data reception unit 22.

  The data view control unit 28 executes a data view function.

  Hereinafter, the operation of the data maintenance system of this embodiment will be described.

(1) Resource Usage Rate Control Operation First, an operation for controlling the resource usage rate of the server 20 that is receiving data to be equal to or less than a threshold value will be described with reference to FIG.

  Referring to FIG. 2, in the client device 10, the data transmission unit 12 transmits data to the server 20, and in the server 20, the data reception unit 22 receives data transmitted from the data transmission unit 12. (Step S101).

  In the server 20, during data reception, the resource utilization rate monitoring unit 25 monitors whether the resource utilization rate of the server 20 exceeds a threshold value. When the resource usage rate monitoring unit 25 detects that the resource usage rate exceeds the threshold (step S102), the resource usage rate monitoring unit 25 notifies the client control unit 24 (step S103), and the client control unit 24 sends the command transmission unit 23. Then, a transmission data reduction command is transmitted to the client device 10 (step S104).

  Subsequently, in the client device 10, when the command reception unit 13 receives a transmission data reduction command, the data transmission amount control unit 15 notifies the data transmission unit 12 of a transmission data reduction preparation command (step S105). When the preparation for reducing the transmission data is completed, the data transmission unit 12 notifies the data transmission amount control unit 15 to that effect (step S106). Next, the data transmission amount control unit 15 transmits a transmission data reduction completion report to the server 20 via the command reception unit 13 (step S107), and the data transmission unit 12 reduces the data capacity of the transmission data. And transmission of the reduced transmission data is started (step S108).

  Thereafter, in the server 20, when the command transmission unit 23 receives the transmission data reduction completion report, the client control unit 24 causes the resource usage rate monitoring unit 25 to reconfirm whether the resource usage rate exceeds the threshold. (Step S109) When the resource utilization rate still exceeds the threshold (Step S110), the resource utilization rate monitoring unit 25 returns to the process of Step S103.

  As described above, in this embodiment, when the resource usage rate exceeds the threshold during reception of data from the client device 10, the server 20 transmits a transmission data reduction command to the client device 10 to reduce the transmission data. By doing so, the resource utilization rate is controlled not to exceed the threshold.

  Therefore, in the server 20, if the above threshold is set to a resource usage rate according to the amount of resources used when executing the data view function, the resources used when executing the data view function even during reception of a large amount of data. Therefore, the user can see the already received data by using the data view function.

(2) Another Data Interrupt Operation Next, an operation for causing the client device 10 and the server 20 that are transmitting / receiving data to transmit / receive another data by interrupt will be described with reference to FIGS. 3A, 3B, and 3C.

  Referring to FIG. 3A, in the client device 10, the data acquisition unit 14 acquires data 1 (step S201), and the data transmission unit 12 transmits the data 1 acquired by the data acquisition unit 14 to the server 20 ( In step S202), in the server 20, the data reception unit 22 stores the data 1 transmitted from the data transmission unit 12 in the data storage unit 27 (step S203).

  In the server 20, when the reception data control unit 26 receives a reception command for the data 2 as another data from the user during reception of the data 1 (step S <b> 204), the reception data control unit 26 receives the priority reception of the data 2. The command is notified to the client control unit 24 (step S205), and the client control unit 24 transmits a temporary stop command for data 1 to the client device 10 via the command transmission unit 23 (step S206).

  Subsequently, in the client device 10, when the instruction receiving unit 13 receives the data 1 pause command, the transmission data control unit 16 notifies the data 1 pause command to the transmission pause unit 17 (Step S1). (S207) The transmission pause unit 17 notifies the data transmission unit 12 of a data 1 transmission stop command and a stop location information return command (step S208). Next, the data transmission unit 12 stops the transmission of the data 1 (step S209), notifies the transmission suspension unit 17 of the stop location information of the data 1 (step S210), and the transmission suspension unit 17 Is stored (step S211). The stop location information of data 1 is the end address of the transmitted portion of data 1. Next, the transmission pause unit 17 notifies the transmission data control unit 16 that the transmission of data 1 has been paused (step S212), and the transmission data control unit 16 passes the command reception unit 13 through the command reception unit 13. A temporary completion report of data 1 is transmitted to the server 20 (step S213).

  Subsequently, in the server 20, when the command transmission unit 23 receives the temporary completion report of the data 1, the client control unit 24 notifies the reception data control unit 26 of a data 2 reception preparation command (step S214). ). Next, the reception data control unit 26 notifies the reception data storage unit 27 of a reply command of the stop location information of the data 1 (step S215), and the reception data storage unit 27 receives the stop location information of the data 1 through the reception data control. It returns to the part 26 (step S216). The stop location information of data 1 is the end address of the received portion of data 1. Next, the reception data control unit 26 notifies the reception data storage unit 27 of an instruction to secure the storage location of the data 2 (step S217), and the reception data storage unit 27 secures the storage location of the data 2 (step S218). ), And notifies the reception data control unit 26 of the fact and the storage location information of the data 2 (step S219). The data 2 storage location information is an area for storing the data 2 on the received data storage unit 27.

  Referring to FIG. 3B, subsequently, in the server 20, the received data control unit 26 notifies the data receiving unit 22 of a received data storage location switching command and data 2 storage location information (step S220). The receiving unit 22 switches the storage location of the received data based on the storage location information of the data 2 (step S221), and notifies the reception data control unit 26 to that effect (step S222). Next, the reception data control unit 26 notifies the client control unit 24 that preparation for reception of data 2 has been completed (step S223), and the client control unit 24 transmits the data 2 via the command transmission unit 23. The command is transmitted to the client device 10 (step S224).

  Subsequently, in the client device 10, when the transmission command for data 2 is received by the command receiving unit 13, the transmission data control unit 16 notifies the data transmission unit 12 of a transmission preparation command for data 2 (step S225). When the preparation for transmission of data 2 is completed, the data transmission unit 12 notifies the transmission data control unit 16 to that effect (step S226). Next, the transmission data control unit 16 notifies the data acquisition unit 14 of an acquisition and transmission command for the data 2 (step S227).

  Thereby, in the client device 10, thereafter, the data acquisition unit 14 starts acquiring data 2 (step S 228), and the data transmission unit 12 transmits the data 2 acquired by the data acquisition unit 14 to the server 20. In the server 20, the data receiving unit 22 starts storing the data 2 transmitted from the data transmitting unit 12 in the received data storing unit 27 (step S230).

  Subsequently, in the client device 10, when the data acquisition unit 14 completes the acquisition and transmission of the data 2, the data acquisition unit 14 notifies the transmission data control unit 16 to that effect (step S <b> 231). The transmission completion report of data 2 is transmitted to the server 20 via 13 (step S232).

  Subsequently, in the server 20, when the transmission completion report of the data 2 is received by the command transmission unit 23, the client control unit 24 receives the fact that the reception of the data 2 is completed and the re-reception preparation command for the data 1 The data control unit 26 is notified (step S233).

  Referring to FIG. 3C, subsequently, in the server 20, the reception data control unit 26 notifies the reception data storage unit 27 of an instruction to secure the storage location of the data 1 and stop location information of the data 1 (step S 234). The reception data storage unit 27 secures the storage location of the data 1 based on the stop location information of the data 1 (step S235), and notifies the reception data control unit 26 of the fact and the storage location information of the data 1 (step S235). S236). At this time, the received data storage unit 27 sets the storage location of the data 1 as the end address of the data 1 indicated by the stop location information, and stores the remaining portion of the data 1 behind the end address. Next, the received data control unit 26 notifies the data receiving unit 22 of the received data storage location switching command, the data 1 storage location information, and the data 1 stop location information (step S237). Switches the storage location of the received data based on the storage location information of data 1 (step S238), and notifies the reception data control unit 26 to that effect (step S239). Next, the reception data control unit 26 notifies the client control unit 24 that preparation for re-reception of the data 1 is completed (step S240), and the client control unit 24 transmits the data 1 via the command transmission unit 23. A retransmission command is transmitted to the client device 10 (step S241).

  Subsequently, in the client device 10, when the command receiving unit 13 receives the data 1 retransmission command, the transmission data control unit 16 notifies the data temporary retransmission unit 17 of the data 1 retransmission preparation command ( In step S242), the transmission pause unit 17 notifies the data transmission unit 12 of the data 1 retransmission preparation instruction and the data 1 stop location information (step S243), and the data transmission unit 12 retransmits the data 1. When the preparation is completed, this is notified to the transmission pause unit 17 (step S244). Next, the transmission pause unit 17 notifies the data acquisition unit 14 of an acquisition preparation instruction from the stop location of the data 1 and the stop location information of the data 1 (step S245). When the preparation for acquisition from the stop point is completed, the transmission suspension unit 17 is notified of this (step S245), and the transmission suspension unit 17 notifies the transmission data control unit 16 that preparation for retransmission of data 1 is completed. Notification is made (step S247). Next, the transmission data control unit 16 notifies the data acquisition unit 14 of an acquisition and transmission command from the stop position of the data 1 (step S248).

  Thereby, in the client device 10, thereafter, the data acquisition unit 14 resumes acquisition of the data 1 from the stop position (step S249), and the data transmission unit 12 stops the data 1 acquired by the data acquisition unit 14 The transmission from the location to the server 20 is resumed (step S250). In the server 20, the data reception unit 22 sends the data 1 transmitted from the data transmission unit 12 to the received data storage unit 27 from the stop location. Is saved again (step S251).

  Although not shown in FIGS. 3A, 3B, and 3C, the server 20 determines whether or not the resource utilization rate of the server 20 has exceeded a threshold during reception of data 1 or data 2. If the resource utilization rate exceeds the threshold value, the processing after step S103 in FIG. 2 is performed.

  As described above, in this embodiment, when the server 20 receives another data 2 reception command during reception of the data 1, the server 20 temporarily stops the transmission of the data 1 after the client device 10 temporarily stops transmission of the data 2. Preparation for reception is performed, and then transmission of data 2 is started by the client device 10. When transmission of data 2 is completed, preparation for re-reception of data 1 is made, and then transmission of the remaining portion of data 1 is performed by the client device 10. To resume.

  Therefore, even if the data 1 being received by the server 20 has a large capacity, it is possible to receive another data 2 first by interrupting it. The effect that it can maintain is acquired.

DESCRIPTION OF SYMBOLS 10 Client apparatus 11 Connection part 12 Data transmission part 13 Command reception part 14 Data acquisition part 15 Data transmission amount control part 16 Transmission data control part 17 Transmission temporary stop part 20 Server 21 Connection reception part 22 Data reception part 23 Command transmission part 24 Client Control unit 25 Resource utilization rate monitoring unit 26 Received data control unit 27 Received data storage unit 28 Data view control unit

Claims (8)

A data security method by a client device and a server that receives data from the client device and secures the received data,
Monitoring whether or not the resource utilization rate of the resource of the server exceeds a preset threshold while the server receives data from the client device;
The server, when the resource utilization rate exceeds the threshold, sending a data reduction command to reduce data to the client device;
When the client device receives the data reduction command from the server, the client device reduces the data, and transmits the reduced data to the server. When the server receives a second data reception command while receiving the first data from the client device, the server device issues a first data suspension command to the client device to temporarily stop transmission of the first data. Sending, and
When the client device receives the first data suspension command from the server, temporarily stops transmission of the first data, and transmits a first data suspension completion report to the server;
When the server receives the first data suspension completion report from the client device, starts preparing to receive the second data;
After the server completes preparation for receiving the second data, a second data transmission command for starting transmission of the second data to the client device;
When the client device receives the second data transmission command from the server, the second data transmission completion report is sent to the server after starting the transmission of the second data and completing the transmission of the second data. Sending to
When the server receives the second data transmission completion report from the client device, starts preparing to receive the first data again;
After the server completes preparation for re-reception of the first data, a first data re-transmission command for resuming transmission of the remaining portion of the first data to the client device;
The data security method according to claim 1, further comprising a step of resuming transmission of the remaining portion of the first data when the client device receives the first data retransmission command from the server. A data maintenance system comprising a client device and a server that receives data from the client device and maintains the received data,
The server
A data receiving unit for receiving data from the client device;
A resource utilization rate monitoring unit that monitors whether a resource utilization rate of the resource of the server exceeds a preset threshold during reception of data from the client device;
A client control unit that transmits a data reduction command to reduce the data to the client device when the resource utilization rate exceeds the threshold;
The client device is
A data maintenance system comprising: a data transmission unit configured to reduce data and transmit the reduced data to the server when the data reduction command is received from the server. The server
A reception data storage unit for storing data received from the client device;
The client control unit
When receiving a second data reception command while receiving the first data from the client device,
Transmitting a first data pause command to pause the transmission of the first data to the client device;
When receiving a first data suspension completion report indicating that the transmission of the first data has been suspended from the client device, preparation for receiving the second data by the data receiving unit and the received data storage unit is started. Let
After completing the preparation for receiving the second data, a second data transmission command for starting transmission of the second data is transmitted to the client device,
When receiving a second data transmission completion report indicating that the transmission of the second data is completed from the client device, the data reception unit and the reception data storage unit start preparation for re-reception of the first data. ,
After completing preparation for re-reception of the first data, a first data re-transmission command for resuming transmission of the remaining portion of the first data is transmitted to the client device;
The client device is
When the first data suspension instruction is received from the server, the transmission of the first data is suspended in the data transmission unit,
When the second data transmission command is received from the server, the data transmission unit starts transmission of the second data,
A transmission pause unit that, when receiving the first data retransmission command from the server, causes the data transmission unit to resume transmission of the remaining portion of the first data;
After the suspension of transmission of the first data by the data transmission unit is completed, the first data suspension completion report is transmitted to the server,
The data maintenance system according to claim 3, further comprising: a transmission data control unit configured to transmit the second data completion report to the server after the transmission of the second data by the data transmission unit is completed. A server that receives data from a client device and maintains the received data,
A data receiving unit for receiving data from the client device;
A resource utilization rate monitoring unit that monitors whether a resource utilization rate of the resource of the server exceeds a preset threshold during reception of data from the client device;
A client control unit that transmits an instruction to reduce data to the client device when the resource utilization rate exceeds the threshold; A reception data storage unit for storing data received from the client device;
The client control unit
When receiving a second data reception command while receiving the first data from the client device,
Sending an instruction to pause the transmission of the first data to the client device;
When receiving a report indicating that the transmission of the first data has been suspended from the client device, the data reception unit and the reception data storage unit start preparing to receive the second data,
After completing the preparation for receiving the second data, a command to start transmission of the second data is transmitted to the client device,
When receiving a report indicating that the transmission of the second data is completed from the client device, the preparation for re-reception of the first data by the data receiving unit and the received data storage unit is started,
The server according to claim 5, wherein after completing preparation for re-reception of the first data, an instruction to resume transmission of the remaining portion of the first data is transmitted to the client device. A client device that transmits data to be maintained to a server,
A client device having a data transmission unit that, when receiving an instruction to reduce data from the server, reduces the data and transmits the reduced data to the server. During the transmission of the first data by the data transmission unit, when receiving an instruction from the server to suspend the transmission of the first data, the data transmission unit suspends the transmission of the first data,
When receiving an instruction to start transmission of second data from the server, the data transmission unit starts transmission of the second data,
A transmission pause unit that causes the data transmission unit to resume transmission of the remaining portion of the first data when receiving an instruction from the server to resume transmission of the remaining portion of the first data;
After the suspension of transmission of the first data by the data transmission unit is completed, a report to the effect that the transmission of the first data has been suspended is transmitted to the server,
The client according to claim 7, further comprising: a transmission data control unit that transmits a report to the server that the transmission of the second data is completed after the transmission of the second data by the data transmission unit is completed. apparatus.

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