JP2007233529A - Data security system for protecting data stored in computer terminal equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the leakage of secret data due to the loss or theft of portable computer terminal equipment. <P>SOLUTION: Data are stored so that the data can not be read unless any predetermined read information exists in the computer terminal equipment, and when it is necessary to read data, a server device is notified of the information indicating that effect. In the server device, terminal equipment (allowed terminal equipment) having right to read data in the computer terminal equipment is stored in each piece of the computer terminal equipment, and when information indicating that it is necessary to read data is received, the permission from the permission terminal equipment is confirmed, and only when it is permitted, the read information is supplied to the computer terminal equipment. Thus, even when the computer terminal equipment is lost or stolen, it is possible to avoid any risk that the data stored inside are read, and secret data are leaked. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for protecting data stored in a portable computer terminal device from leakage due to loss or theft of the computer terminal device.

  A computer terminal device represented by a personal computer or the like incorporates various application programs in advance to create documents, graphs, illustrations, etc., perform various processes and calculations, and further, such as the Internet. Today, it is indispensable for work because various functions such as access to various servers (database servers, mail servers, etc.) can be realized based on addresses registered in advance in computer terminal devices by connecting to various networks. It is a tool that can not be.

  In addition, small and lightweight portable computer terminal devices (so-called notebook computers, personal digital assistants, mobile phones, etc.) have also been developed, and by carrying such computer terminal devices, for example, business trip destinations And even while on the move (especially in the case of a notebook computer, it is possible to process work in a state that is almost the same as when sitting at a desk at work).

  However, if such a portable computer terminal device is lost or stolen, it is stored in confidential data (for example, electronic data of documents and drawings relating to trade secrets, electronic address books, etc. Data such as customer names, business partners, company employees' names, telephone numbers, and email addresses) may be leaked. Therefore, in order to deal with such a fear, for example, a technique that enables locking of a lid that covers a keyboard of a notebook computer (Patent Document 1), data in a computer terminal device are stored in an encrypted state, Technology that attempts to avoid leakage of confidential data due to loss or theft of computer terminal devices by storing information necessary for decryption in a small external memory so that it cannot be decrypted without connecting the external memory Have been proposed (Patent Document 2).

JP 2004-46425 A JP 2006-18345 A

  However, in the method of locking a keyboard or the like, leakage of confidential data cannot be avoided if the lock is broken, and in the method of storing information necessary for decryption in an external memory, a computer terminal device If the external memory and the external memory are stolen at the same time, there is a problem that it becomes possible to immediately extract confidential data. In particular, an external memory is used in association with a computer terminal device, and functions only when connected to the computer terminal device. Therefore, the external memory tends to be carried in the same bag as the computer terminal device. There is a high probability of being stolen at the same time as the computer terminal device.

  The present invention has been made in response to the above-described problems in the prior art, and even if a portable computer terminal device is lost or stolen, leakage of confidential data can be easily and reliably avoided. The purpose is to provide technology that can be used.

In order to solve at least a part of the problems described above, the data security system of the present invention employs the following configuration. That is,
A data security system comprising a portable computer terminal device connectable to a communication line and a server device provided on the communication line,
The computer terminal device
Data storage means for storing data in a state in which it cannot be read without predetermined read information;
When it is necessary to read data from the data storage means, read request information output means for outputting read request information as information to the server device;
Read execution means for executing the reading of data from the data storage means using the read information after confirming that the read information necessary for reading the data is supplied from the server device. ,
The server device
Correspondence storage means for storing correspondence between the computer terminal device and a permission terminal device which is a terminal device having authority to permit reading of data in the computer terminal device;
Upon receiving the read request information from the computer terminal device, read permission confirmation means for confirming the presence or absence of permission for the read from the permission terminal device associated with the computer terminal device;
The gist of the present invention is that it comprises reading information supply means for supplying the reading information to the computer terminal device when permission from the permission terminal device is confirmed.

  In such a data security system of the present invention, data is stored in a computer terminal device in a state in which it cannot be read unless there is predetermined read information, and when it is necessary to read data, the computer terminal device transfers data to the server device. On the other hand, read request information indicating that is output. It is sufficient that the data stored in the computer terminal device is in a state where it cannot be read without reading information when the data is read, and therefore, when storing the data, It may be stored in a state of data that cannot be read, or it may be stored in the same way as normal data (that is, in a state where it can be read without reading information) and then cannot be read without reading information. It does not matter if it is converted to a state. Further, the computer terminal device may be a so-called notebook computer, PDA, mobile phone, or the like as long as it can store data in such a state. In the server device, a computer terminal device and an authorized terminal device of the computer terminal device are stored in association with each other. Here, the permitted terminal device is a terminal device having the authority to permit reading of data in the computer terminal device. When the server device receives information (read request information) indicating that data reading is necessary from the computer terminal device, the server device checks whether or not permission for the reading is obtained from the permission terminal device. If it can be confirmed that the state is obtained, read information is supplied to the computer terminal device.

  Here, the permission from the permission terminal device may be obtained before receiving the read request information from the computer terminal device, or after receiving the read request information, the permission is obtained from the permission terminal device. It may be what was made. For example, after receiving the read request information from the computer terminal device, if the read signal is supplied to the computer terminal device if the permission signal from the permission terminal device can be confirmed, the read request from the computer terminal device After receiving the information, the permission from the authorized terminal device is obtained after the fact. On the other hand, for example, if the read information is supplied if it can be confirmed that the read request information is received from the computer terminal device, the read request information from the computer terminal device is supplied. Before receiving this, permission from the authorized terminal device has already been obtained. As described above, “permission from the permitted terminal device” includes permission obtained after the read request information from the computer terminal device is output and permission obtained before receiving the read request information from the computer terminal device. include.

  Further, the read information output when the permission from the permitted terminal device can be confirmed may be stored in the server device in advance, or the read information stored in the permitted terminal device is received. good. Thus, the computer terminal apparatus reads out necessary data using the read information supplied from the server apparatus.

  As described above, in the data security system of the present invention, in order to read data with the computer terminal device, permission to read must be obtained from the permitted terminal device. For this reason, even if the computer terminal device is lost or stolen, it is possible to avoid a possibility that confidential data is leaked by reading data stored therein.

  Of course, if the computer terminal device and the permission terminal device are lost or stolen at the same time, there is a possibility that the data stored therein is read out. However, the possibility of losing them at the same time is low, and it is almost impossible to bother the authorized terminal device when stealing the computer terminal device. Therefore, it can be said that the data stored in the computer terminal device is practically read and confidential data is leaked.

  Also, if you register a terminal device that you normally carry and use frequently, such as a so-called mobile phone or personal digital assistant, as a permitted terminal device, even if the authorized terminal device is lost or stolen But you can immediately notice. For this reason, since it is possible to immediately take measures such as stopping the supply of read information from the server device, it is possible to more reliably avoid leakage of confidential data.

  In addition, when the server device of such a data security system receives the read request information from the computer terminal device, permission for the read is limited to a predetermined period (that is, within a predetermined time or until a predetermined condition is established). It is good also as accepting from a permission terminal device only in the meantime.

  In this way, in order to read the data in the computer terminal device, the signal indicating that the reading is permitted from the permitted terminal device to the server device within a predetermined period after the data is read by the computer terminal device ( Permission signal) must be transmitted. This is impossible unless the operator of the computer terminal device and the operator of the permission terminal device are the same person or at least communicate with each other. Therefore, even if the computer terminal device is transferred to a third party due to loss or theft, there is no possibility that confidential data is leaked by reading data stored therein.

  Alternatively, in the server device of the data security system described above, it is possible to store a setting state as to whether or not reading of data in the computer terminal device is permitted, and to set the reading in the computer terminal device to a permitted state. When the permission signal is received from the permitted terminal device, this setting state may be set for a predetermined time in a state where permission from the permitted terminal device is obtained.

  In this way, in order to read the data in the computer terminal device, the reading is permitted from the permitted terminal device to the server device within a predetermined period immediately before the data is read by the computer terminal device. A permission signal must be transmitted. This is impossible if the computer terminal device and the permission terminal device are operated by the same person, or at least the operators of the respective devices are not in contact. For example, even if a third party who has stolen a computer terminal device tries to read data, a permission signal cannot be output from the permission terminal device to the server device within a predetermined period immediately before the data. Since no read information is obtained from the data, it is impossible to read data. Therefore, even when the computer terminal device is in the hands of a third party, it is possible to avoid reading data stored therein.

  In addition, when the server device can store the setting state described above (that is, the setting state regarding whether or not data reading in the computer terminal device is permitted), the setting state is transmitted from the permission terminal device. It may be changed by operation.

  In this way, in a normal state, the data in the computer terminal device can be read out without operating the permitted terminal device one by one by setting the data reading in a permitted state. On the other hand, if the computer terminal device is lost or stolen, the data in the computer terminal device can be read out by operating the permission terminal device and changing the data reading to a non-permitted state. However, it is possible to make it impossible to read data without obtaining read information from the server device. In the end, this makes it possible to avoid leakage of confidential data without sacrificing the operability of the computer terminal device.

  Further, in the above-described computer terminal device of the data security system, the read information received from the server device can be stored, and this read information is stored when the power is turned off or every predetermined period (for example, every predetermined time or a predetermined condition is satisfied). It may be deleted every time. Then, when it is necessary to read data, it is determined whether or not read information is stored. If not, read request information may be output to the server device. .

  In this way, when data is read continuously within a predetermined period, the data can be read using the stored read information without being connected to the server device, so that the data can be read quickly. It becomes. Nevertheless, the stored read information is erased when the power is turned off or every predetermined period. Therefore, if the computer terminal device is lost or stolen, the data stored inside is deleted. Cannot be read. For this reason, it is possible to avoid leaking confidential data while enabling the data stored in the computer terminal device to be read quickly.

Further, in the above-described data security system of the present invention, in order to avoid data leakage, a computer terminal device that receives read information from a server device and reads data is required. Therefore, if attention is paid to this point, the present invention can be grasped as the following computer terminal device. That is, the computer terminal device of the present invention is
A portable computer terminal device connectable to a communication line,
Data storage means for storing data in a state in which it cannot be read without predetermined read information;
When it is necessary to read data from the data storage means, read request information output means for outputting read request information as information to the server device provided on the communication line;
And a read execution means for executing a read from the data storage means using the read information after confirming that the read information necessary for reading the data is supplied from the server device. The gist.

  In such a computer terminal device of the present invention, it is impossible to read data unless reading information is received from the server device. For this reason, even if the computer terminal device is lost or stolen, it is possible to avoid a situation where confidential data is leaked by reading data stored therein.

Alternatively, in the above-described data security system of the present invention, in order to avoid data leakage, a server device that receives communication from the computer terminal device and supplies read information is required. Therefore, if attention is paid to this point, the present invention can be grasped as a server device as follows. That is, the server device of the present invention
A server device to which a portable computer terminal device is connected via a communication line,
Stores the correspondence between the computer terminal device that stores data in a state in which data cannot be read if there is no predetermined read information, and the permitted terminal device that is an authorized terminal device that has permission to read data in the computer terminal device Corresponding correspondence storage means,
When reading request information, which is information indicating that data reading is necessary, is received from the computer terminal device, a read permission for confirming the permission of the reading from the permission terminal device associated with the computer terminal device Confirmation means;
The gist of the present invention is to provide read information supply means for supplying the read information to the computer terminal device when permission from the permission terminal device is confirmed.

  In such a server device of the present invention, when reading request information is received from a computer terminal device, only when reading permission is obtained from the permission terminal device registered for the computer terminal device, Read information is supplied. In other words, since read information is not supplied unless permitted from the authorized terminal device, it is possible to avoid reading confidential internal data even if the computer terminal device is lost or stolen. It becomes possible.

The computer terminal device or server device of the present invention described above can also be realized by causing a computer to read a predetermined program and exhibit necessary functions. Therefore, paying attention to this point, the present invention can be grasped as a program for causing a computer to perform various functions. That is, the program of the present invention corresponding to the computer terminal device of the present invention described above is
A program for realizing a process of reading data stored in a portable computer terminal device connectable to a communication line using a computer,
A first function for storing data that cannot be read if there is no predetermined read information;
When it is necessary to read data from the data storage unit, a second function of outputting read request information as information to the server device provided on the communication line;
And a third function of performing a read operation using the read information after confirming that the read information necessary for reading the data is supplied from the server device. To do.

  If such a program is read by a computer and the various functions described above are realized, even if the computer terminal device is lost or stolen, it is possible to avoid reading data stored therein. Is possible.

  In the above-described program, the function of detecting that the data needs to be read may be realized as follows. That is, an operating system is running on the computer terminal device, and when data is read from the storage device mounted on the computer terminal device, the data is transferred from the operating system to the driver program that controls the operation of the storage device. By outputting a command instructing execution of reading, it is possible to detect that it is necessary to read data by receiving this command instead of the driver program. Furthermore, the function of reading data using the read information supplied from the server device may be realized as follows. In other words, a read instruction received from the operating system may be supplied to the driver program, so that the read data may be read and then the read data may be supplied to the operating system.

  In this way, even when data stored in the computer terminal device is directly read from the operating system, read request information directed to the server device can be output by detecting this. As a result, it is possible to reliably avoid leakage of confidential data.

The program of the present invention corresponding to the server device of the present invention described above is
A program for realizing a process of supplying information to a portable computer terminal device connected via a communication line using a computer,
Stores the correspondence between the computer terminal device that stores data in a state in which data cannot be read if there is no predetermined read information, and the permitted terminal device that is an authorized terminal device that has permission to read data in the computer terminal device Function (A) to keep,
A function of confirming whether or not permission for the reading from the permission terminal device associated with the computer terminal device is received from the computer terminal device when reading request information as information indicating that data reading is necessary ( B) and
When the permission from the permission terminal device is confirmed, the gist is to realize the function (C) for supplying the read information to the computer terminal device using a computer.

  If such a program is read by a computer and the various functions described above are realized, read information is not supplied to the computer terminal device unless permission is obtained from the authorized terminal device. . For this reason, even if the computer terminal device is lost or stolen, it is possible to avoid reading data stored in the computer terminal device.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. Summary of Examples:
B. Device configuration:
C. First embodiment:
C-1. Data read processing:
C-2. Read information transmission processing:
D. Second embodiment:
E. Third embodiment:
F. Fourth embodiment:

A. Summary of Examples:
Various embodiments exist in the data security system of the present invention. For the sake of convenience of understanding, an outline common to each embodiment will be briefly described first. FIG. 1 is an explanatory diagram showing an outline of the data security system of this embodiment. As shown in the figure, the data security system of this embodiment includes a server device 200 connected to a communication line such as the Internet 500 and a portable computer terminal device 100 (so-called notebook computer, which can be connected to the Internet 500). And a terminal device 300 (for example, a mobile phone 300a, a portable information terminal 300b, a notebook computer 300c, etc.) that can be connected to the Internet 500.

  As is well known, the computer terminal device 100 and the server device 200 are equipped with an arithmetic circuit mainly composed of a so-called CPU and an internal storage device such as a hard disk drive (so-called HDD) and stored in the internal storage device. It is possible to read out the stored data and perform various processes by the CPU. The computer terminal device 100 is also equipped with a network interface card (so-called NIC), and can be connected to the Internet 500 by communicating with the router 502 in a wired or wireless manner. Furthermore, in response to recent advances in computer-related technology, a large amount of data is stored and carried in the internal storage device of the portable computer terminal device 100, and the data can be read out as needed while on a business trip or on the go. Processing can be performed.

  However, since a large amount of data is stored in the internal storage device, if the computer terminal device 100 is lost or stolen, there is a risk that the stored confidential data is leaked to the outside. In view of these points, in the data security system of the present embodiment, it is possible to avoid leakage of confidential data by adopting the following configuration.

  First, in the internal storage device of the computer terminal device 100, at least confidential data is stored in a state in which it cannot be read if there is no predetermined read information. Further, a terminal device 300 (hereinafter, “permitted terminal device”) having authority to permit reading of confidential data in the computer terminal device 100 is determined in advance, and the computer terminal device 100 and the permitted terminal device of the computer terminal device 100 are Are registered in the server device 200 in advance. FIG. 1 conceptually shows how the correspondence between the computer terminal device 100 and the permitted terminal device is stored in the server device 200. In the example shown in the drawing, for the computer terminal device 100 (hereinafter referred to as computer terminal device A) displayed as “A” in the drawing, the mobile phone 300a (shown as “B” in the drawing) In the following, mobile phone B) is registered as a permitted terminal device. In addition, for a computer terminal device (hereinafter referred to as a computer terminal device D) displayed as “D” in the figure, a computer terminal device A, a mobile phone B, and a portable information terminal displayed as “C” A state in which 300b (hereinafter, portable information terminal C) is registered as a permitted terminal device is shown.

  When the computer terminal device 100 needs to read data, the computer terminal device 100 outputs information (read request information) to the server device 200 via the Internet 500. When the server device 200 receives the read request information from the computer terminal device 100, the server device 200 checks whether or not permission for reading is obtained from the permission terminal device registered for the computer terminal device 100, and permits Is obtained, the read information necessary for reading the data is supplied to the computer terminal device 100. Here, the permission for the data reading may be transmitted from the computer terminal apparatus 100 to the server apparatus 200 after the read request information is output to the server apparatus 200, or Before the read request information is output from the computer terminal device 100 (before the data needs to be read by the computer terminal device 100), the read permission is transmitted from the permission terminal device to the server device 200 in advance. It is also good.

  The arrow indicated by the alternate long and short dash line in FIG. 1 schematically shows a state in which the mobile phone B transmits to the server device 200 to permit the computer terminal device A to read data. is there. The mobile phone B is connected to the Internet 500 via a wireless base station 504 installed by a mobile phone company. As described above, since the fact that mobile phone B is a permitted terminal device of computer terminal device A is registered in server device 200, permission from mobile phone B is accepted by server device 200 and server Read information is supplied from the apparatus 200 toward the computer terminal apparatus A. The arrows indicated by broken lines in the figure schematically show how the read information is supplied from the server device 200 toward the computer terminal device A. When the computer terminal device A receives the read information supplied from the server device 200 in this way, the computer terminal device A reads necessary data using the read information.

  As described above, in the data security system of the present embodiment, even if data is to be read from the internal storage device of the computer terminal device 100, the data is read if permission from the permission terminal device of the computer terminal device 100 is not obtained. I can't do that. Therefore, even if the computer terminal device 100 is lost or stolen, it is possible to avoid leakage of confidential data stored in the internal storage device of the computer terminal device 100. Of course, if the computer terminal device 100 and the authorized terminal device of the computer terminal device 100 are lost or stolen at the same time, there is no possibility of leakage of confidential data. Since it is extremely unlikely that the authorized terminal device is lost or stolen at the same time, it is practically possible to reliably prevent leakage of confidential data from the computer terminal device 100. Such a data security system of the present embodiment can be realized in various modes, and each of these embodiments will be described in detail below.

B. Device configuration :
FIG. 2 is an explanatory diagram showing a rough configuration of the computer terminal device 100 according to the present embodiment. The configuration of the server device 200 is the same as that of the computer terminal device 100 shown in FIG. Therefore, the configuration of the computer terminal device 100 and the server device 200 will be described below with reference to FIG.

  The computer terminal apparatus 100 mainly includes a main body 110, a display unit 150 such as a liquid crystal screen, and an input operation unit 160 such as a keyboard. In the main body 110, a CPU 112 that executes various arithmetic processes, a ROM 122 that stores data and programs in a nonvolatile manner, a RAM 124 that stores data in a volatile manner, and a large amount of data are stored. A hard disk drive (hereinafter referred to as HDD) 116 that is stored in a nonvolatile manner is connected to the bus 118 so as to exchange data with each other. In addition, a video interface (hereinafter referred to as “VIF”) 114 for exchanging data with the display unit 150, a keyboard interface (hereinafter referred to as “KIF”) 126 for receiving data from the input operation unit 160, a wired connection to the bus 118. Alternatively, a network interface card (hereinafter referred to as NIC) 128 for wirelessly connecting to a network and a peripheral device interface (hereinafter referred to as PIF) 120 for exchanging data with peripheral devices are also connected.

  When the computer terminal device 100 (and server device 200) having the above configuration is powered on, a special program called BIOS stored in the ROM 122 is executed, and then a program called OS is read from the HDD 116. Executed. Various processes performed thereafter are executed by reading various programs stored in the HDD 116 under the control of the OS. Further, in the computer terminal device 100 (and server device 200) of this embodiment, a security program for preventing leakage of confidential data is also stored in the HDD 116, and this security program is executed after the OS is started up. It is possible to reliably and easily avoid leakage of confidential data stored in an internal storage device (HDD 116, RAM 124, ROM 122, etc.) of the computer terminal device 100. Below, the process performed by this security program is demonstrated in detail.

C. First Example:
As a preparation for explaining the processing performed by the security program, first, the relationship between the security program and the OS will be briefly explained. As described above with reference to FIG. 1, the data security system according to the present embodiment includes the computer terminal device 100, the server device 200, and the like. The computer terminal device 100 and the server device 200 have a special OS called an OS. The program is running. Each of the computer terminal device 100 and the server device 200 stores a dedicated security program, and when each OS is activated, the security program is read from the OS and executed.

  Among these, the security program executed by the server device 200 is executed by using the functions provided from the OS for all the basic functions such as data reading and writing as in the case of general application programs. It has become. Therefore, when the security program of the server device 200 exchanges data with the HDD, PIF, NIC, or the like, it exchanges via the OS (using the function of the OS).

  On the other hand, the security program executed by the computer terminal device 100 is read from the OS and executed, and the security in the server device 200 is that most of the basic functions are realized by using the functions of the OS. It is the same as the program. However, when the security program exchanges data with the HDD 116 (or the RAM 124 or the like), at least a part of the data is in a state where the security program is interposed between the OS and the driver of the HDD 116.

  FIG. 3 is an explanatory diagram conceptually showing the relationship between the OS and the security program when the computer terminal device 100 reads data from the HDD. Focusing on the case where the computer terminal device 100 reads data from the HDD 116, as shown in the figure, the security program of the computer terminal device 100 is interposed between the HD driver that directly controls the operation of the HDD 116 and the OS. The instruction that the OS instructs the HD driver to read data is transmitted to the HD driver via the security program. For this reason, when the OS tries to read data from the HDD 116, the security program of the computer terminal device 100 can always detect this.

C-1. Data read processing:
FIG. 4 is a flowchart showing a flow of processing (data reading processing) executed by the security program when the computer terminal device 100 reads data from the HDD 116. Hereinafter, a case where data is read from the HDD 116 will be described. However, the present invention is similarly applied to a case where data is read from the RAM 124 or the like as long as it is a storage device built in the computer terminal device 100. be able to.

  As shown in the figure, when the data reading process is started, first, it is determined whether or not a request for reading data in the HDD 116 has been received from the OS of the computer terminal apparatus 100 (step S100). After the security program of the computer terminal device 100 is activated, as described above with reference to FIG. 3, when the OS tries to read data from the HDD 116, the request is transmitted to the HD driver via the security program. It becomes like this. Therefore, if there is a data read request from the OS, the security program can immediately detect this.

  When a read request from the OS is detected (step S100: yes), it is determined whether or not the data to be read is confidential data (step S102). Such a determination can be made by various methods. For example, the following determination may be made. First, a dedicated storage area for storing confidential data is provided in the HDD 116. This can be realized by a method such as partitioning the HDD 116 by partitions. If the OS is to read data from the dedicated storage area, it can be determined that the confidential data is to be read. Alternatively, for data stored in the HDD 116, an attribute indicating whether the data is confidential data is set, and when a data read request is received from the OS, the attribute of the requested data is referred to. It is also possible to determine whether it is confidential data.

  By the method as described above, it is determined whether or not the data to be read by the OS is confidential data (step S102). If it is determined that the data is not confidential data (step S102: no), the OS The read request received from is transferred to the HD driver (step S110). On the other hand, when it is determined that the data to be read is confidential data (step S102: yes), information indicating that there is a data read request from the OS (read request information) is stored in the server. Processing to output to the apparatus 200 is performed (step S104). As described above, the NIC 128 is mounted on the computer terminal device 100 and can be connected to the server device 200 via the NIC 128. In step S <b> 104, the security program of the computer terminal device 100 performs a process of outputting the read request information to the server device 200 by driving the NIC 128 using the function of the OS. Note that all the data in the HDD 116 may be regarded as confidential data, and the process of step S104 may be performed immediately without performing the process of step S102.

  As described above, when the security program outputs the read request information to the server device 200, the security program then determines whether or not the read information is received from the server device 200 (step S106). Here, the read information is information necessary for reading confidential data stored in the HDD 116. That is, the computer terminal device 100 according to the present embodiment stores confidential data in the HDD 116 in a state in which it cannot be read unless there is read information. When it is necessary to read the confidential data, read request information indicating that fact is stored. Is output to the server apparatus 200. In response to this request, it is confirmed whether or not information necessary for reading data is supplied from the server device 200.

  It should be noted that the state where data is stored in an unreadable manner can be realized in various ways. For example, it may be in a state where it is rejected even if it tries to read data, or it can be in a state where data can be read but encrypted but cannot be discriminated. The state in which reading is rejected can be realized by, for example, rejecting reading unless a password is input. In addition, a table called FAT (File Allocation Table) is encrypted. This can also be realized. That is, the data stored in the HDD 116 is stored in a state of being divided into small data (called clusters) having a predetermined size, but the FAT stores the order of the clusters and the clusters stored on the HDD 116. It is used to manage the location. Therefore, if the FAT is encrypted, data cannot be read from the HDD 116, so that it is possible to realize a state in which reading is substantially rejected.

  In this embodiment, it is assumed that the confidential data cannot be read by encrypting the FAT. Therefore, in the present embodiment, the data for decrypting the encrypted FAT is “read information necessary for reading the confidential data”. Since FAT has a small data size, encryption and decryption can be performed in a very short time. In addition, by encrypting only the confidential data portion instead of encrypting the entire FAT, it is possible to read data other than the confidential data as usual.

  If the read information is not received from the server device 200 (step S106: no), the security program of the computer terminal device 100 is in a standby state until the read information is received. When the read information is received from the server device 200 (step S106: yes), the received read information is used to convert the state of the HDD 116 from a state where confidential data cannot be read to a state where it can be read (step S108). . As described above, in the present embodiment, since the confidential data is made unreadable by encrypting the FAT, in step S108, the encrypted FAT is decrypted using the read information. Processing is performed.

  When the FAT decryption is thus completed, the confidential data can be read out in the same manner as normal data. Therefore, the security program transfers the data read request received from the OS to the HD driver (step S110), and ends the data read processing shown in FIG. In the HD driver, in accordance with the data read request transferred from the security program as described above, the process of reading the data stored in the HDD 116 is performed. In the process of step S106 described above, the time waiting until the read information is received from the server device 200 is counted, and the data cannot be read when the standby time reaches a predetermined time. May be displayed and the data reading process shown in FIG. 4 may be interrupted.

  As described above, in the computer terminal device 100 according to the first embodiment, when the confidential data is to be read, the read request information indicating that fact is output to the server device 200. If the read information necessary for reading the confidential data is not supplied from the server device 200, it is impossible to read the confidential data. That is, whether or not data can be read in the computer terminal device 100 depends on whether or not read information is supplied from the server device 200, and whether or not read information is supplied is determined on the server device 200 side. The following process is executed by the security program. Hereinafter, processing performed by the security program on the server device 200 side when the read information is transmitted from the server device 200 toward the computer terminal device 100 will be described.

C-2. Read information transmission processing:
FIG. 5 is a flowchart showing a flow of processing (read information transmission processing) executed when the security program of the server device 200 transmits read information to the computer terminal device 100. Such processing is also processing executed when the OS of the server apparatus 200 starts a security program.

  When the read information transmission process is started in the server device 200, first, read request information (that is, information indicating that it is necessary to read data in the HDD 116) is received from the computer terminal device 100. Is determined (step S200). As described above with reference to FIG. 4, the security program of the computer terminal device 100 monitors a read request for data output from the OS to the HD driver, and when the OS tries to read confidential data from the HDD 116, Is detected, and read request information indicating that is output to the server device 200 (step S104 in FIG. 4). If such read request information has not been received from the computer terminal device 100 (step S200: no in FIG. 5), the computer is in a standby state until it is received.

  On the other hand, when the read request information is received from the computer terminal device 100 (step S200: yes), the security program of the server device 200 specifies the computer terminal device 100 that has output the read request information, and then further includes the computer terminal. The permitted terminal device for the device 100 is specified (step S202). The computer terminal device 100 that has output the read request information can be identified most simply as follows. First, when the computer terminal apparatus 100 outputs read request information to the server apparatus 200, a unique identification number (for example, a MAC address) assigned to the computer terminal apparatus 100 itself is also output. In this way, the server device 200 can specify the computer terminal device 100 that has output the read request information based on the identification number received together with the read request information. Here, the MAC address is a unique number assigned in advance to all devices connectable to the network. Alternatively, when the read request information is received from the computer terminal apparatus 100, the computer terminal apparatus 100 that has output the read request information may be specified by analyzing the header information of the received read request information.

  Further, as described above, the permitted terminal device is a terminal device registered in advance as having the authority to permit reading to the computer terminal device 100 that has notified that reading of data is necessary. 300. As the permitted terminal device, any device that can be connected to a network, such as a mobile phone, a portable information terminal such as a so-called PDA, or a notebook computer, can be registered. In the server device 200, the computer terminal device 100 and the permitted terminal device of the computer terminal device 100 are stored in association with each other in advance.

  FIG. 6 is an explanatory diagram conceptually showing a state in which the computer terminal device 100 and the permitted terminal device are stored in the server device 200 in association with each other. For example, for the computer terminal device “A”, three terminal devices 300 (“B”, “C”, “D”) are registered as permitted terminal devices. For the computer terminal device “D”, only the terminal device “F” is registered as a permitted terminal device. As described above, a plurality of permitted terminal devices can be registered in one computer terminal device 100. In addition, when registering permitted terminal devices, an identification number unique to each terminal device (for example, a telephone number for a mobile phone, a MAC address for a portable information terminal, a notebook computer, etc.) can be registered. That's fine.

  Note that it is also possible to register a certain computer terminal device 100 as a permitted terminal device of another computer terminal device 100, such as the computer terminal device “D” shown in FIG. Therefore, such a device is not only the computer terminal device 100 but also a permission terminal device for other computer terminal devices 100. In step S202 of FIG. 5, when the read request information is received from the computer terminal device 100, a process of identifying the authorized terminal for the computer terminal device 100 that has output the information by referring to the correspondence relationship as shown in FIG. I do.

  When the security program of the server device 200 identifies the permitted terminal device in this way, this time, after setting the timer to a predetermined time (step S204), a signal (permitted signal) for permitting reading from the identified permitted terminal device. Is determined (step S206). As described above, the permission terminal device is the terminal device 300 that can be connected to the network, and by connecting to the server device 200 via the network, a read permission signal can be transmitted. In step S206, it is determined whether or not such a read permission signal has been received from the permitted terminal device. If the read permission signal has not been received (step S206: no), the predetermined time set in the timer is determined. It is determined whether or not it has elapsed (step S208). If the predetermined time has not elapsed (step S208: no), it is determined again whether or not a read permission signal is received from the permitted terminal device (step S206).

  In the server device 200, such a determination is repeated until a read permission signal is received from the permitted terminal device or until a predetermined time set in the timer elapses. When the read permission signal is received (step S206: yes) Read information (here, data for decrypting the encrypted FAT) is transmitted to the computer terminal device 100 (step S210). In the present embodiment, it is assumed that the read information is stored in advance in the server device 200 in a state associated with the computer terminal device 100 as shown in FIG. Accordingly, in step S <b> 210, a process of reading out read information stored corresponding to the computer terminal device 100 and transmitting it to the computer terminal device 100 is performed.

  When a plurality of terminal devices 300 are set as permitted terminal devices as in the computer terminal device “A” shown in the correspondence relationship in FIG. 6, the permission signal is received from any one of the terminal devices 300. If so, the read information may be transmitted assuming that read permission has been obtained. Alternatively, if the permission information is received from all the terminal devices 300 and the read information is transmitted assuming that the permission to read is obtained, the difficulty of acquiring confidential data in the HDD 116 can be further increased. it can.

  Further, in the present embodiment, it has been described that the read information is stored in advance in the server device 200 for each computer terminal device 100. However, it is not always necessary to store the read information in the server device 200 in advance. For example, when transmitting a permission signal permitting data reading from the permission terminal device to the server device 200 or after transmitting a permission signal, read information is transmitted from the permission terminal device, and the read information is transmitted to the computer. It may be transferred to the terminal device 100.

  On the other hand, if a predetermined time has passed without receiving a read permission signal from the permitted terminal device (step S208: yes), the fact that the read permission cannot be obtained is transmitted to the computer terminal device 100 (step S212). ), The read information transmission process shown in FIG.

  In the above description, when the read request information is received from the computer terminal device 100, the read information is output when the permission signal is obtained before the predetermined time elapses. However, when the permission signal is obtained not before the predetermined time but before the predetermined condition is satisfied, the read information may be output.

  FIG. 7 is an explanatory diagram conceptually showing a state in which read information is returned from the server apparatus 200 in response to output of data read request information from the computer terminal apparatus 100. As described above with reference to FIG. 4, when the confidential data needs to be read out by the computer terminal device 100, read request information indicating that fact is transmitted to the server device 200 (see step S104 in FIG. 4), and the server device 200. Then, a reception period of a predetermined time is set (see step S204 in FIG. 5). Then, when a read permission signal is received from the permitted terminal device during this acceptance period, read information is transmitted from the server device 200 toward the computer terminal device 100. The computer terminal apparatus 100 can read data by receiving the read information transmitted in this way.

  As described above, in the data security system according to the first embodiment, even if it is necessary to read data by the computer terminal device 100, the read information necessary for reading is obtained if the read permission is not obtained from the authorized terminal device. Therefore, data cannot be read out. Further, only the terminal device 300 registered in advance as the permitted terminal device of the computer terminal device 100 can give permission for reading. For this reason, even if the computer terminal device 100 is lost or stolen, it is possible to reliably and relatively easily avoid leakage of confidential data stored in the internal HDD 116 to the outside. It becomes possible. Further, read information from the server device 200 is input from the network interface of the computer terminal device 100 and cannot be input from the input operation unit 160 such as a keyboard. For this reason, since the person who stole the computer terminal device 100 cannot release the lock state of the HDD 116 (the state in which data cannot be read) from the input operation unit 160, it is extremely difficult to obtain confidential data.

  Of course, if the authorized terminal device is lost or stolen at the same time as the computer terminal device 100, there is a risk of leakage of confidential data inside. However, it is unlikely that the authorized terminal device will be lost or stolen at the same time as the computer terminal device 100, and such a risk can be virtually ignored.

  Furthermore, even if the computer terminal device 100 and the permission terminal device are lost or stolen at the same time, a device that is normally carried and frequently used, such as a mobile phone or a personal digital assistant, is registered as the permission terminal device. By doing so, even if the computer terminal device 100 and the permission terminal device are lost or stolen at the same time, it is possible to immediately recognize that the permission terminal device has been lost or stolen. For this reason, when the authorized terminal device is lost or stolen, the administrator of the server device 200 is contacted by telephone, or the website that manages the server device 200 is accessed through the network, and the computer device is connected from the server device 200 to the computer terminal. It is also possible for the server device 200 to take measures for preventing leakage of confidential data, such as stopping transmission of read information to the device 100.

  Further, as shown in FIG. 7, the server apparatus 200 of this embodiment receives the read request information from the computer terminal apparatus 100 and then permits the read permission from the permitted terminal apparatus for a predetermined time (or a predetermined period). Can be accepted. In order for the server device 200 to accept read permission under such restrictions, the computer terminal device 100 and the permitted terminal device are operated by the same person, or at least the operator of the computer terminal device 100 and the permitted terminal device. Need to communicate with each other. This is because only the operator of the computer terminal device 100 can know the timing at which the read request information is output from the computer terminal device 100 to the server device 200. Therefore, the operator of the computer terminal device 100 can contact the operator. This is because it is impossible for the operator of the permitted terminal device to perform an operation of permitting reading to the server device 200 within the reception period unless it is received. For this reason, in the data security system of the first embodiment, it is possible to reliably avoid leakage of confidential data stored in the built-in HDD 116 even if the computer terminal device 100 is lost or stolen. ing.

D. Second embodiment:
In the data security system of the first embodiment described above, the server device 200 receives the read request information from the computer terminal device 100 and then receives the read permission from the permitted terminal device within a predetermined period. In the above description, the read information is transmitted to the computer terminal device 100. However, whether or not permission is obtained from the permission terminal device is set in the server device 200 in advance, and if permission is set, it is not necessary to operate from the permission terminal device. Alternatively, read information can be transmitted to the computer terminal device 100. The data security system according to the second embodiment will be described below.

  FIG. 8 is an explanatory diagram showing a state in which presence / absence of permission obtained from the permitted terminal device is stored in the server device 200 of the second embodiment. In the illustrated example, similar to the first embodiment described above, the permitted terminal device and the read information are stored for each computer terminal device 100. In addition, in the server device 200 of the second embodiment, the authorized terminal is used. Whether or not permission from the device is obtained is set for each computer terminal device 100. For example, for the computer terminal device “A”, in addition to the three permitted terminal devices and read information, it is set that data read permission is obtained from the permitted terminal device. For the computer terminal device “D”, in addition to the permitted terminal device and the read information, it is set that data read permission is not obtained. Further, in the second embodiment, such permission to read data can be changed at any time by connecting to the server device 200 from the permitted terminal device.

  FIG. 9 is a flowchart illustrating a flow of read information transmission processing performed by the server device 200 according to the second embodiment. Such processing is also processing executed when a security program is started from the OS of the server device 200.

  Also in the read information transmission process of the second embodiment, when the process is started as in the process of the first embodiment described above, first, whether or not read request information has been received from the computer terminal device 100. Is determined (step S300). If the read request information from the computer terminal device 100 has not been received (step S300: no), the standby state is maintained until it is received.

  When the read request information is received from the computer terminal device 100 (step S300: yes), the computer terminal device 100 that has output the read request information is specified (step S302). The process of specifying the computer terminal device 100 can be performed in the same manner as the server device 200 of the first embodiment shown in FIG.

  Next, it is determined whether or not read permission is obtained for the specified computer terminal device 100 (step S304). As described above with reference to FIG. 8, in the data security system according to the second embodiment, the server apparatus 200 can store the setting state as to whether or not the read permission is obtained for each computer terminal. By referring to this setting state, it is possible to immediately determine whether or not read permission has been obtained. Then, when the setting state is a state in which read permission from the permitted terminal device is obtained (step S304: yes), the stored read information is transmitted to the computer terminal device 100 (step S306). Of course, the read information may be transferred to the computer terminal device 100 instead of storing the read information.

  On the other hand, when the setting state in the server device 200 is a state in which the read permission from the permitted terminal device is not obtained (step S304: no), the computer indicates that the read permission is not obtained. After transmission to the terminal device 100 (step S308), the read information transmission process of the second embodiment shown in FIG. 9 is terminated.

  In the data security system of the second embodiment described above, the setting state regarding whether or not data can be read by the computer terminal device 100 is set in the server device 200 in advance. For this reason, every time the read request information from the computer terminal device 100 is received, even if the permission from the permission terminal device is not obtained, if the fact that the permission is obtained is set in the server device 200, the read information is immediately obtained. Can be transmitted toward the computer terminal device 100. As a result, the computer terminal device 100 can quickly receive read information and start reading data.

  Of course, the setting state in the server device 200 can be changed at any time by connecting to the server device 200 from the permitted terminal device. For this reason, when the computer terminal device 100 is lost or stolen, it is only necessary to connect the permission terminal device to the server device 200 and change the read permission setting to the permission “none” state. In this way, even if the read request information is output from the computer terminal apparatus 100, the read information is not output from the server apparatus 200. That is, since the read request from the computer terminal device 100 is rejected on the server device 200 side, it is possible to avoid leakage of confidential data stored in the computer terminal device 100.

E. Third embodiment:
In the data security system of the second embodiment described above, when read permission is obtained from the permitted terminal device, the data security system is held in the permitted state in the server device 200 unless it is further revoked from the permitted terminal device. As explained. However, the permission obtained from the permission terminal device may be held in the server device 200 for a predetermined time. The data security system according to the third embodiment will be described below.

  FIG. 10 is a flowchart illustrating a flow of a permission state setting process performed by the server device 200 according to the third embodiment to set a state as to whether or not reading of the computer terminal device 100 is permitted. Such a process is a process executed by a security program executed on the server device 200. Hereinafter, processing for setting a read permission state will be described with reference to a flowchart.

  In the permission state setting process, first, it is determined whether or not a permission signal for permitting reading by the computer terminal device 100 is received from the terminal device 300 such as a mobile phone or a portable information terminal (step S400). . When the permission signal is received (step S400: yes), it is determined whether or not the terminal device 300 that has transmitted the permission signal is registered as the permission terminal device (step S402). Similarly to the second embodiment described above, in the third embodiment as well, in the server device 200, as shown in FIG. 8, the permission terminal device and the presence / absence of read permission are associated with each computer terminal device 100. Is set. In step S402, it is determined whether or not the terminal device 300 is registered as a permitted terminal device by referring to the correspondence relationship.

  If it is determined that the terminal device that has transmitted a signal permitting reading by the computer terminal device 100 is not registered as a permitted terminal device (step S402: no), the permission signal is not accepted. Then, the permission state setting process shown in FIG. On the other hand, when it is confirmed that the terminal device 300 that has transmitted the permission signal is registered as the permitted terminal device (step S402: yes), after setting a timer for a predetermined time (step S404), the terminal device Read permission for the computer terminal device 100 for which 300 is set as the permitted terminal device is set to a permission “present” state (step S406).

  Next, it is determined whether or not a predetermined time set in the timer has elapsed (step S408). If not (step S408: no), the process waits until the predetermined time elapses. When it is confirmed that the predetermined time has passed (step S408: yes), the permission state of the computer terminal device 100 in which the read permission is set to “present” is returned to the permission “none” state again. After (step S410), the permission state setting process in FIG. 10 is terminated.

  FIG. 11 is an explanatory diagram conceptually showing a state in which read information is transmitted from the server device 200 to the computer terminal device 100 and data is read out by the computer terminal device 100 in the data security system of the third embodiment. It is. As described above with reference to FIG. 10, when a permission signal indicating permission of data reading is transmitted from the permission terminal device to the server device 200, the server device 200 supports the corresponding computer terminal only for a predetermined time. It is set to a state where permission to read data in the apparatus 100 is obtained (permission “permitted” state). Then, the read information is supplied from the server device 200 only when the data read request information is received from the computer terminal device 100 within the period set in the permission “present” state in the server device 200. The confidential data can be read by the computer terminal device 100.

  As described above, in the data security system according to the third embodiment, the computer terminal apparatus 100 receives the read information and can read the data immediately before the data needs to be read (at least for a predetermined time). (1), the permission terminal device must transmit a permission signal to the server device 200, and the read permission setting must be changed to a permission “present” state. However, this is because the computer terminal device 100 and the permission terminal device are operated by the same person, or at least the operator of the computer terminal device 100 and the operator of the permission terminal device must communicate with each other. It is virtually impossible. Accordingly, in the data security system of the third embodiment, as in the above-described various data security systems, even if the computer terminal device 100 is lost or stolen, the confidential information stored in the built-in HDD 116 (or RAM 124). It is possible to reliably avoid data leakage.

  Of course, in the data security system of the third embodiment, unlike the system of the second embodiment described above, a permission signal is transmitted from the permission terminal device to change the setting state in the server device 200 to a state where permission is obtained. Even if it is set, it returns to the state of no permission after a predetermined time. For this reason, in order to read data with the computer terminal device 100, it is necessary to connect to the server device 200 from the permission terminal device and set the permission “present” state, which is complicated. However, if a device that is normally carried and used, such as a mobile phone or a personal digital assistant, is set as a permitted terminal device, these permitted terminal devices can be used immediately even when the computer terminal device 100 is operated. Since it is considered to be carried, such complications can be reduced to a minimum.

  As shown in FIG. 6 or FIG. 8, the number of stored computer terminal devices 100 associated with the permitted terminal device is not necessarily one. Therefore, when the server apparatus 200 receives a request from the permitted terminal apparatus, a plurality of computer terminal apparatuses 100 may be applicable. In such a case, the server device 200 may set the read permission to the permission “present” state for all the computer terminal devices 100 that are applicable. Of course, in practice, there is only one computer terminal device 100 that needs to read data, and therefore, even for a computer terminal device 100 that is not intended by the operator of the permitted terminal device. The data reading is permitted. However, as described above, in the data security system according to the third embodiment, even when the read permission state is set to “permitted”, the permission is again returned to the “not permitted” state after a predetermined time has elapsed. For this reason, even if the computer terminal device 100 that is not necessary is set in a state where data can be read, there is no possibility that confidential data will be leaked. In addition, the processing content in the server device 200 can be simplified by doing in this way.

  In the above description, it has been described that the server apparatus 200 returns to the unauthorized state after a predetermined time has elapsed even if it receives the permission signal from the permitted terminal apparatus. However, when the predetermined condition is satisfied after the permission signal is received, not when the predetermined time has elapsed, the setting in the server device 200 may be returned to the state of no permission.

F. Fourth embodiment:
In the various embodiments described above, it has been described that the read request information is always output to the server device 200 when it is necessary to read the confidential data in the computer terminal device 100. However, the confidential data may be read from the computer terminal device 100 by storing the read information necessary for reading the confidential data in the computer terminal device 100. Even in this case, the security performance of the data is not impaired by the following way. The data security system according to the fourth embodiment will be described below.

  FIG. 12 is a flowchart showing a flow of processing (data reading processing) executed by the security program when the computer terminal device 100 reads data in the data security system of the fourth embodiment. In this process, in contrast to the data read process of the first embodiment described above with reference to FIG. 4, is the read information stored before the information indicating that the read of the confidential data has occurred is output to the server apparatus 200? The point to confirm whether or not is greatly different. Hereinafter, the data reading process of the fourth embodiment will be described with a focus on such differences.

  Also in the data read process of the fourth embodiment, as in the case of the first embodiment, when the process is started, first, a request for reading data in the HDD 116 is received from the OS of the computer terminal device 100. Is determined (step S500). If a read request from the OS is detected (step S500: yes), it is determined whether or not the data to be read is confidential data (step S502). As a result, when it is determined that the data to be read by the OS is not confidential data (step S502: no), the read request received from the OS is transferred to the HD driver (step S512).

  On the other hand, when it is determined that the data to be read is confidential data (step S502: yes), it is confirmed whether or not read information necessary for reading the confidential data is stored (step S504). . That is, in the data reading process of the first embodiment described above with reference to FIG. 4, when it is determined that the data to be read is confidential data, the read request information is immediately output to the server device 200. However, in the computer terminal device 100 of the fourth embodiment, when the read information supplied from the server device 200 is stored in the RAM 124 or the like in the memory such as the HDD 116, it is necessary to read the confidential data next. The data is read using the stored read information. Also, the stored read information is not held in the memory indefinitely, but when the computer terminal device 100 is turned off or regularly every predetermined time (and a predetermined condition is satisfied) Every time). Therefore, when it is determined that the data to be read is confidential data (step S502: yes), it is confirmed whether the read information already received from the server device 200 remains in the memory.

  If the read information remains in the memory (step S504: yes), the read information is used to convert the state of the HDD 116 from a state where the confidential data cannot be read to a state where the confidential data can be read (step S510). . As in the first embodiment described above, here, since the confidential data is made unreadable by encrypting the FAT, in step S510, the encrypted FAT is decrypted using the read information. Processing is performed.

  On the other hand, when it is determined that the previously received read information is not stored (that is, the read information has never been received or the received read information has been erased and does not remain in the memory) (Step S504: no), read request information indicating that it is necessary to read data is output to the server device 200 (step S506). Since the subsequent processing is the same as the processing of the first embodiment described above with reference to FIG. 4, in brief description, it is determined whether read information has been transmitted from the server device 200 (step S508). If it has not been transmitted yet, it is in a standby state until read information is received. When the read information is received from the server device 200 (step S508: yes), the received read information is used to convert the state of the HDD 116 from a state where confidential data cannot be read to a state where the confidential data can be read (step S508). Step S510).

  When the security program of the computer terminal device 100 converts the confidential data into a readable state, the security program of the computer terminal device 100 transfers the data read request received from the OS to the HD driver (step S512), and the fourth program shown in FIG. The data reading process of the embodiment is finished. In the HD driver, in accordance with the data read request transferred from the security program as described above, the process of reading the data stored in the HDD 116 is performed.

  In the computer terminal device 100 according to the fourth embodiment described above, the received read information is stored for a while after the read information is received from the server device 200. For this reason, when it becomes necessary to read out the confidential data again, it becomes possible to read out the confidential data immediately by using the stored read information. In addition, since the read information received from the server device 200 is deleted when the computer terminal device 100 is turned off or periodically (or when a predetermined condition is satisfied), the read information is stored in the computer terminal device 100 indefinitely. It is not held in memory. For this reason, even if the computer terminal device 100 is lost or stolen, it is possible to prevent leakage of stored confidential data.

  While various embodiments of the present invention have been described above, the present invention is not limited thereto, and is not limited to the wording of each claim unless it departs from the scope described in each claim. Improvements based on the knowledge that a person skilled in the art normally has can also be added as appropriate to the extent that those skilled in the art can easily replace them.

  For example, in the various embodiments described above, the permission terminal device functions as a remote control device for the computer terminal device 100 using the network as a communication path, and is associated with the permission terminal device based on the operation of the permission terminal device. The data reading prohibition state of the HDD 116 of the computer terminal device 100 is canceled via the server device 200 on the network. On the contrary, based on the operation of the permitted terminal device, the data readable state of the HDD 116 of the computer terminal device 100 associated with the permitted terminal device is canceled via the server device 200 on the network (the HDD 116 is deleted). A configuration in which data reading is prohibited is also possible. The present invention can be grasped as a hard disk access control system if it is configured to freely switch the data read prohibition state and the read enable state of the HDD 116 via the network by operating the permission terminal device.

  Further, in order to fully cope with simultaneous loss or theft of the computer terminal device 100 and the permission terminal device, the server device 200 prior to receiving the permission signal from the permission terminal device, the permission terminal device or the computer terminal device 100. (For example, authentication using ID or password, biometric authentication, authentication by inputting voice data representing the voice of the owner of the device, etc. to the permission terminal device or the computer terminal device 100) It is also good.

It is explanatory drawing which showed the outline | summary of the data security system of a present Example. It is explanatory drawing which showed the rough structure of the computer terminal device of a present Example. It is explanatory drawing which showed notionally the relationship between OS and a security program at the time of reading data from the memory | storage device (HDD) of a computer terminal device. It is the flowchart which showed the flow of the data reading process performed when the computer terminal device in the data security system of 1st Example reads data. It is a flowchart which shows the flow of the read information transmission process performed when the server apparatus in the data security system of 1st Example transmits read information toward a computer terminal device. It is explanatory drawing which showed notionally the mode that the computer terminal device and the permission terminal device were matched and memorize | stored in the server apparatus. It is explanatory drawing which showed notably the mode that reading information was transmitted from a server apparatus according to the data reading request | requirement from a computer terminal device. It is explanatory drawing which showed notionally the mode that the presence or absence of the data read permission was memorize | stored in the server apparatus in the data security system of 2nd Example. It is a flowchart which shows the flow of the read information transmission process performed when the server apparatus in the data security system of 2nd Example transmits read information toward a computer terminal device. It is a flowchart which shows the flow of the permission state setting process which the server apparatus in the data security system of 2nd Example performs in order to set the read permission state of a computer terminal device. In the data security system of 3rd Example, it is explanatory drawing which showed notionally that a computer terminal device received reading information from a server apparatus, and read data. It is a flowchart which shows the flow of the data reading process performed when the computer terminal device in the data security system of 4th Example reads data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Computer terminal device, 110 ... Main-body part, 112 ... CPU,
116 ... HDD, 118 ... bus, 122 ... ROM, 124 ... RAM,
150 ... display unit, 160 ... input operation unit, 200 ... server device,
300 ... a terminal device, 300a ... a mobile phone, 300b ... a portable information terminal,
300c ... notebook computer, 500 ... internet,
502 ... Router, 504 ... Radio base station

Claims (10)

A data security system comprising a portable computer terminal device connectable to a communication line and a server device provided on the communication line,
The computer terminal device
Data storage means for storing data in a state in which it cannot be read without predetermined read information;
When it is necessary to read data from the data storage means, read request information output means for outputting read request information as information to the server device;
Read execution means for executing the reading of data from the data storage means using the read information after confirming that the read information necessary for reading the data is supplied from the server device. ,
The server device
Correspondence storage means for storing correspondence between the computer terminal device and a permission terminal device which is a terminal device having authority to permit reading of data in the computer terminal device;
Upon receiving the read request information from the computer terminal device, read permission confirmation means for confirming the presence or absence of permission for the read from the permission terminal device associated with the computer terminal device;
A data security system comprising: read information supply means for supplying the read information to the computer terminal device when permission from the permission terminal device is confirmed. The data security system according to claim 1,
The server device
A data security system comprising: a read permission signal receiving unit that receives a read permission signal from the permission terminal device associated with the computer terminal device for a predetermined period when the read request information is received from the computer terminal device. The data security system according to claim 1,
The server device
A setting state storage means for storing a setting state as to whether or not reading of data in the computer terminal device is permitted;
When the permission signal indicating permission of the reading is received from the permission terminal device, the setting state of the computer terminal device associated with the permission terminal device is set to a state where reading is permitted for a predetermined period. A data security system comprising: permission state setting means. The data security system according to claim 1,
The server device
A setting state storage means for storing a setting state as to whether or not reading of data in the computer terminal device is permitted;
A data security system comprising: setting state changing means for changing the stored setting state by an operation from the permitted terminal device. A data security system according to any one of claims 1 to 4,
The computer terminal device
Read information storage means for storing the read information;
Read information erasing means for erasing the stored read information at power-off or at predetermined intervals,
When the read request information output means needs to read data from the data storage means, the read request information output means determines whether or not the read information necessary for the read is stored. A data security system as means for outputting read request information to the server device. A portable computer terminal device connectable to a communication line,
Data storage means for storing data in a state in which it cannot be read without predetermined read information;
When it is necessary to read data from the data storage means, read request information output means for outputting read request information as information to the server device provided on the communication line;
A computer terminal comprising: a read execution unit configured to execute reading from the data storage unit using the read information after confirming that the read information necessary for reading the data is supplied from the server device apparatus. A server device to which a portable computer terminal device is connected via a communication line,
Stores the correspondence between the computer terminal device that stores data in a state in which data cannot be read if there is no predetermined read information, and the permitted terminal device that is an authorized terminal device that has permission to read data in the computer terminal device Corresponding correspondence storage means,
When reading request information, which is information indicating that data reading is necessary, is received from the computer terminal device, a read permission for confirming the permission of the reading from the permission terminal device associated with the computer terminal device Confirmation means;
A server device comprising: read information supply means for supplying the read information to the computer terminal device when permission from the permission terminal device is confirmed. A program for realizing a process of reading data stored in a portable computer terminal device connectable to a communication line using a computer,
A first function for storing data that cannot be read if there is no predetermined read information;
When it is necessary to read data from the data storage unit, a second function of outputting read request information as information to the server device provided on the communication line;
A program for realizing, using a computer, a third function of executing reading using the read information after confirming that the read information necessary for reading the data is supplied from the server device. The program according to claim 8, wherein
The second function instructs the operating system running on the computer terminal device to read and execute data issued to a driver program that controls the operation of the storage device mounted on the computer terminal device. A function of receiving an instruction on behalf of the driver program, detecting that it is necessary to read data, and outputting the read request information to the server device;
The third function supplies an instruction to the read execution received from the operating system to the driver program and executes read using the read information, and then reads the read data to the operating system. A program that is a function to be supplied. A program for realizing a process of supplying information to a portable computer terminal device connected via a communication line using a computer,
Stores the correspondence between the computer terminal device that stores data in a state in which data cannot be read if there is no predetermined read information, and the permitted terminal device that is an authorized terminal device that has permission to read data in the computer terminal device Function (A) to keep,
A function of confirming whether or not permission for the reading from the permission terminal device associated with the computer terminal device is received from the computer terminal device when reading request information as information indicating that data reading is necessary ( B) and
A program for realizing, using a computer, a function (C) for supplying the read information to the computer terminal device when permission from the permission terminal device is confirmed.

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