JP2009244955A - Encrypted file management system for mobile terminal, its method, and those devices and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance usability of file management of an encrypted file while securing its security. <P>SOLUTION: A mobile terminal which is connected with a network, and decrypts an encrypted file which is saved and requests user authentication by user operation, is provided with: a status measurement section; a user authentication information reqesting section; a recording section; and an encrypted file management section. The status measurement section measures a status of the mobile terminal and outputs the status information. The user authentication information requesting section requests a user the user authentication information according to the status information. The recording section saves the encrypted file. The encrypted file management section performs decryption of the encrypted file by the input of the user authentication information, the status information, and an approval result input from an authentication server when the user authentication information is corresponding to the status information, and when the user authentication information is approved by the authentication server. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mobile terminal encrypted file management system and method, and a device and a program thereof, particularly for managing an encrypted confidential information file in a file management function of a mobile terminal.

  Notebook PCs (Personal Computers) and PDAs (Personal Digital Assistants) have become widespread, and mobile computing that can be used by computers regardless of location has become possible. As a result of the use of these portable terminals in unspecified places, problems that have not existed in the past have arisen in the management of confidential information. For example, it may allow peeping of confidential information in public places. Or it is becoming a social problem that confidential information such as customer information leaks due to loss or theft of a mobile terminal.

  As an idea of preventing leakage of confidential information (hereinafter also referred to as “confidential file”) by restricting the use of a computer in an unspecified place, for example, one disclosed in Patent Document 1 is known. FIG. 9 shows a system configuration of the mobile terminal management system 90 of Patent Document 1 and will be briefly described. The mobile terminal management system 90 includes a mobile terminal 103, a management computer 104, and a GPS satellite 901. The mobile terminal 103 and the management computer 104 are connected to the public network via an intra-organization network.

When the confidential file in the mobile terminal 103 is used, the management computer 104 requires authentication based on the location information of the mobile terminal 103. As for the location information of the mobile terminal 103, a GPS position measurement function (not shown) provided in the mobile terminal 103 receives a positioning radio wave from the GPS satellite 901 and calculates the latitude and longitude of the location where the mobile terminal 103 is located. Desired. The management computer 104 gives permission to use the confidential file according to the position information. Therefore, the place where the confidential file can be used can be limited to a limited range such as a related office or a user (user) home. As a result, peeping of confidential information in public places can be prevented. Further, even when the mobile terminal 103 is lost or stolen, it is possible to prevent misuse of confidential files outside a specific location.
Japanese Patent Laying-Open No. 2003-256287 (FIG. 9)

  However, in the conventional method, the place where the confidential file can be used is limited, so that the flexibility is poor and the usability is poor. In the conventional example using only the GPS position measurement function, it is particularly difficult to use a positioning radio wave from a GPS satellite indoors because it is limited to the window. Although a method using RFID (Radio Frequency Identification) in combination is also conceivable, the drawback that can be used only in the range where the radio waves of the RFID exist is similar to the GPS position measurement function.

  In addition, the above-described conventional method has a problem that it is impossible to cope with theft of a portable terminal for the purpose of loosing confidential information from the beginning. A person who intends to steal confidential information takes out a recording device (such as a hard disk drive) in which the confidential file is recorded from the portable terminal and decrypts the confidential file. That is, when a portable terminal is stolen, it is a problem to leave a confidential file in the portable terminal. As described above, the method of only restricting the use of the confidential file based on the position information is insufficient for managing the confidential information.

  Loss of confidential information is very large, and in some cases, it can lead to a situation involving the survival of the company. Therefore, there is a need for a file management method for confidential files that is more strictly managed. On the other hand, simply strict management of confidential information may lead to inconvenience. Since the level of security related to confidential information required in accordance with the situation where the mobile terminal is placed (hereinafter referred to as “security strength”) also changes, a file management method that can cope with the change in security strength is required. Yes.

  The present invention has been made in view of the above points, and is an easy-to-use portable file encrypted file management system and method for securing sufficient safety according to the situation where the portable terminal is placed. An object of the present invention is to provide such a device and a program thereof.

  An encrypted file management system for a portable terminal according to the present invention is connected to a network, requests a user authentication by a user operation, decrypts an encrypted file stored therein, an authentication server that performs user authentication, , Consisting of. The portable terminal includes a situation measurement unit, a user authentication information request unit, a recording unit, and an encrypted file management unit. The situation measurement unit measures the situation of the mobile terminal and outputs the situation information. The user authentication information request unit requests user authentication information corresponding to the situation information from the user. The recording unit stores the encrypted file. The encrypted file management unit receives the user authentication information, the status information, and the approval result input from the authentication server, and the user authentication information is appropriate for the status information and the user authentication information is approved by the authentication server. If so, the encrypted file is decrypted.

  In the encrypted file management system for a portable terminal according to the present invention, the situation measuring unit measures the situation where the portable terminal is placed and outputs the situation information. The user authentication information request unit requests user authentication information from the user according to the status information. The encrypted file management unit decrypts the encrypted file when the user authentication information matches the situation information. Therefore, it is possible to detect the change of the situation where the portable terminal is placed and manage the encrypted file with the security strength suitable for the situation, so that the safety is high. In addition, since user authentication information corresponding to the status of the mobile terminal is requested from the user, it is possible to provide a mobile terminal encrypted file management system that is flexible and easy to use.

  Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals are given to the same components in a plurality of drawings, and the description will not be repeated.

  FIG. 1 shows a system configuration of an encrypted file management system 10 for a portable terminal which is an example of the present invention. In the portable file encrypted file management system 10, an authentication server 12 and a portable terminal 16 are connected via a network (hereinafter referred to as “NW”) 14. The authentication server 12 authenticates the user. The portable terminal 16 requests authentication from the authentication server 12 by a user operation.

  The authentication server 12 includes a communication interface unit 121, a user authentication unit 122, and a control unit 124. The portable terminal 16 includes a communication interface 161, an encrypted file management unit 162, a recording unit 163, a user authentication information request unit 164, and a situation measurement unit 165. FIG. 2 shows an operation sequence of the authentication server 12 and the mobile terminal 16. The situation measuring unit 165 of the portable terminal 16 measures the situation where the portable terminal 16 is placed and outputs the situation information (step S165). As the situation information, for example, in addition to the latitude and longitude information of the place where the mobile terminal is placed by the GPS position measurement function as in the conventional example, acceleration information, use of RFID, etc. (details will be described later) are considered. It is done. The user authentication information request unit 164 requests the user authentication information corresponding to the situation information from the user, and performs user authentication such as OTP (One Time Password), biometric recognition information by a fingerprint sensor or a retina sensor from a keyboard or the like (not shown). Information is obtained (step S164). The encrypted file management unit 162 sends the obtained user authentication information to the authentication server 12 connected to the end of the NW 14 via the communication interface unit 161 and requests authentication (step S30). The user authentication unit 122 of the authentication server 12 authenticates the user authentication information obtained via the communication interface unit 121 of the authentication server 12, and transmits the authentication result to the mobile terminal 16 (step S31). The encrypted file management unit 162 of the portable terminal 16 receives the authentication result from the authentication server 12, the user authentication information from the user authentication information request unit 164, and the situation information from the situation measurement unit 165, and the user authentication information is received. If it matches the situation information and if the authentication result is approved, the encrypted file 163a recorded in the recording unit 163 is decrypted to be editable (step S162).

  The portable terminal 16 and the authentication server 12 are realized by a predetermined program being read into a computer configured by, for example, a ROM, a RAM, and a CPU, and the CPU executing the program. Each control unit 166, 124 controls the operation of each unit according to the respective program in the above-described process. As a result, an easy-to-use encrypted file management system for a mobile terminal can be realized while ensuring sufficient safety according to the situation where the mobile terminal 16 is placed.

  Next, the operation will be described in more detail by showing more specific configuration examples of the encrypted file management unit 162, the user authentication information request unit 164, and the situation measurement unit 165. The operation flow of the portable terminal 16 and the authentication server 12 is shown in FIGS. As illustrated in FIG. 1, the encrypted file management unit 162 includes a status authentication information determination unit 1621, an authentication server cooperation unit 1622 including an encryption key temporary recording unit 1623, a file management unit 1624, and an encryption unit 1625. And a decoding unit 1626.

  The situation measurement unit 165 has, for example, a GPS position measurement function, receives a positioning radio wave from a GPS satellite, and outputs the position information of the mobile terminal 16 to the encrypted file management unit 162 as situation information (step S1651, see FIG. 3). ). The status information is input to the user authentication information request unit 164 via the encrypted file management unit 162. The situation determination unit 1641 of the user authentication information request unit 164 determines the situation where the mobile terminal 16 is placed from the situation information (step S1641a). When it is determined from the situation information that an emergency situation (details will be described later) is made (Y in step S1641b), in this example, the file lock or file is deleted so that the encrypted file 163a cannot be used (step S1624). When the situation determination unit 1641 determines that the security strength is to be raised from the situation information (step S1641c), the user information request unit 1642 requests the user authentication information corresponding to the situation from the user (step S1642a). As a situation where it is not necessary to increase the security strength, for example, a case where the portable terminal 16 is used in the office can be considered. In this case, for example, user authentication is performed using only the user ID and password.

  A situation where the security strength is increased may be, for example, a situation where the mobile terminal is used outside the company. In that case, in addition to the normal user ID and password, an identification code indicating that the upper manager's permission is obtained is requested. In response to the request, the user who operates the portable terminal 16 inputs the user ID, password, and identification code to the user authentication information request unit 164 using an input means such as a keyboard (step S1642b). The user authentication information input to the user authentication information request unit 164 is input to the encrypted file management unit 162. The status authentication information determination unit 1621 of the encrypted file management unit 162 determines whether the user authentication information matches the status information input from the status measurement unit 165 (step S1621). When the user authentication information matches the situation information, the situation authentication information determination unit 1621 instructs the authentication server cooperation unit 1622 to transmit the user authentication information to the authentication server 12. The situation authentication information determination unit 1621 makes an authentication request to the authentication server 12 in accordance with the instruction (step S1622a). If the user authentication information does not match the situation information, in this example, the file management unit 1624 locks the file so that the encrypted file 163a cannot be used, as in the case of the emergency described above (Y in step S1641b). Alternatively, the file is deleted (step S1624).

  The user authentication unit 122 of the authentication server 12 receives user authentication information from the mobile terminal 16 (step S1221, see FIG. 4). Then, the user authentication information is authenticated (step S1222). If the user authentication information is valid and the user can be approved (Y in step S1223), the user authentication unit 122 uses the authentication result indicating the approved result and the common key for decrypting the encrypted file 163a as the portable terminal. 16 (step S1225). When the user is denied (step S1223N), only the authentication result representing the denied result is transmitted to the portable terminal 16 (step S1224).

  The authentication server cooperation part 1622 of the portable terminal 16 receives the authentication result of the authentication server 12 (step S1622b). When the authentication result is approved, the authentication server cooperation unit 1622 records the common key in the encryption key temporary recording unit 1623 and instructs the file management unit 1624 to decrypt the encrypted file 163a. The decryption unit 1626 reads the common key from the encryption key temporary recording unit 1623 and decrypts the encrypted file 163a (step S1626). If the authentication result is denied, the file management unit 1624 deletes the file lock or file so that the encrypted file 163a cannot be used (step S1624), as in the case of the emergency described above. Although omitted in the operation flow of FIG. 3, the encryption unit 1625 re-encrypts the file that has been decrypted and edited and records it in the recording unit 163.

  Here, the emergency situation will be described using the situation measuring unit 165 shown in FIG. An emergency situation is a situation in which, for example, the portable terminal 16 is stolen and the encrypted file 163a is roughly taken. As the assumed situation information, for example, when excessive acceleration is applied to the portable terminal 16 or when the casing of the portable terminal 16 is opened for the purpose of removing the hard disk drive (hereinafter referred to as “HDD”). Conceivable. Of course, even with the GPS position measurement function described above, an emergency may be determined when the measured location is a specific location. However, judging an emergency situation based only on the position information of the GPS position measuring function is dangerous because of the high possibility of misjudgment. Therefore, a method of increasing the accuracy of emergency determination by using another type of situation measuring unit 165 as shown in FIG.

  The situation measuring unit 165 shown in FIG. 5A includes an acceleration detecting unit 50 and an AD converting unit 51. The acceleration detection unit 50 includes an acceleration sensor formed of, for example, a piezoelectric element, and generates a voltage value proportional to the acceleration applied to the acceleration sensor. The AD conversion unit 51 converts the voltage value generated by the acceleration detection unit 50 into a digital value to obtain status information.

  Since portable terminals are composed of components that are vulnerable to impact such as liquid crystal panels and HDDs, they are generally handled with care. However, when the mobile terminal is stolen, it is possible to assume a situation where excessive acceleration is applied such that the mobile terminal is handled in a messy manner and is not normally applied to the mobile terminal. The situation measuring unit 165 shown in FIG. 5A detects the excessive acceleration.

  The state measurement unit 165 ′ shown in FIG. 5B is composed of a housing open detection switch 52 and a resistor 53. One end of the chassis open detection switch 52 is connected to the positive power source of the portable terminal, the other end is connected to one end of the resistor 53, and the other end of the resistor 53 is connected to the negative power source of the portable terminal. A connection point between the other end of the chassis open detection switch 52 and one end of the resistor 53 is an output terminal for status information. The housing of a portable terminal is not normally disassembled. In a state where the housing is not disassembled, the housing open detection switch 52 is in a closed state, and current flows from the positive power source of the mobile terminal toward the negative power source. Therefore, the status information at one end of the resistor 53 is the voltage value of the positive power source. Become. When a malicious third party disassembles the mobile terminal housing, the housing open detection switch 52 is opened, and the status information changes to the voltage value of the negative power supply. When the status authentication information determination unit 1621 of the encrypted file management unit 162 detects this change in status information, the file management unit 1624 immediately deletes the encrypted file 163a. At the same time, if the common key is recorded in the encryption key temporary recording unit 1623, the common key is also deleted. In this way, it is possible to prevent the encrypted file 163a from passing over to a third party.

  In addition, when the chassis open detection switch 52 is in an open state, it is considered that an emergency can be determined based only on the information. On the other hand, in the case of acceleration detection, since it is easily assumed that excessive acceleration is given to the mobile terminal by dropping the mobile terminal by mistake, it is dangerous to use it alone.

  Therefore, as shown in FIG. 6, a method of using a plurality of situation measuring units in combination is conceivable. The situation measurement unit 60 shown in FIG. 6 includes a GPS position measurement function 61, an acceleration detection function 62, a chassis open detection switch 63, an RFID 64, and a loss prevention sensor 65. The GPS position measurement function 61 is the same as that described above. The acceleration detection function unit 62 is also the same as the situation measurement unit 165 described with reference to FIG. The chassis open detection switch 63 is also the same as the situation measuring unit 165 ′ already described with reference to FIG. The RFID 64 can use, for example, a radio wave type active tag, and obtains limited position information of a specific conference room or the like. The loss prevention sensor 65, for example, connects the portable terminal and the user wirelessly with weak radio waves, and measures the physical distance between the portable terminal and the user depending on whether the electric field strength is a certain value or more. Is. Thus, each of the GPS position measurement function 61 to the loss prevention sensor 65 constitutes a situation measurement unit. Since the encrypted file management unit 162 and the user authentication information requesting unit 164 process the status information output from each status measurement unit in parallel to determine the status, the accuracy of the status determination can be improved. For example, when the situation information of the loss prevention sensor 65 represents a state in which the distance between the mobile terminal and the user is far away, if the acceleration detection function unit 62 detects excessive acceleration, it is determined as an emergency situation. Can be considered. Thus, the effect of improving the accuracy of situation determination can be expected by using a plurality of situation measurement units in combination.

  As described above, according to the encrypted file management system 10 for a mobile terminal, when the mobile terminal 16 is used in-house, for example, user authentication is performed using only a normal user ID and password. When the portable terminal 16 is used outside the company, user authentication is performed using an identification code, a user ID, and a password, for example, indicating that an upper manager's permission has been obtained. In this way, encrypted files can be managed according to the level of security strength that changes depending on the situation. Furthermore, in the case of an emergency situation, the encrypted file is locked or erased, so that misuse of confidential information by a third party can be completely prevented. In addition, even when the user authentication information corresponding to the situation information is not obtained, the example has been described in which the encrypted file is locked or deleted in the same manner as in an emergency, but in that case, impersonation is difficult, such as biometric information The user authentication information may be requested from the user again.

  As a second embodiment of the encrypted file management system for a portable terminal according to the present invention, a configuration in which an authentication status data recording unit 125 is provided on the authentication server 12 side will be described. In the second embodiment, the status information of the portable terminal is also determined on the authentication server 12 side. The authentication status data recording unit 125 is indicated by a broken line in FIG. The configuration and operation on the portable terminal 16 side are basically the same as those in the first embodiment, except that status information is transmitted to the authentication server 12 in addition to user authentication information when an authentication request is made. The operation flow of the authentication server 12 according to the second embodiment will be described with reference to FIG.

  The operation flow up to user authentication in step S1223 is the same as that in the first embodiment, except that the reception of status information (step S1226) is added. The user authentication unit 122 of the authentication server 12 performs status authentication with reference to the authentication status data recording unit 125 based on the status information transmitted from the mobile terminal 16 (step S1227). When the status of the mobile terminal is authenticated (Y in step S1228), the user authentication unit 122 transmits an authentication result indicating that the result of user authentication and status authentication has been approved and a common key to the mobile terminal (step S1224). ). If the status of the portable terminal is denied (N in step S1228), the denial result is transmitted to the portable terminal 16 (step S1225).

  As described above, when the status of the portable terminal 16 is also determined on the authentication server 12 side, the encrypted file management system for portable terminals can be made easier to use. For example, when the user uses the mobile terminal 16 outside the company as in the above-described example, there may be a case where the use permission of the superior cannot be obtained in advance on a sudden outing or a business trip. In such a case, the portable terminal cannot be used outside the company by the method of determining the situation information only on the portable terminal 16 side shown in the first embodiment. With the configuration of the second embodiment, the mobile terminal can be used even after going out. In other words, it is only necessary to ask the senior manager for permission to use from the outside by e-mail or telephone, and to have the usage permission information written in the authentication status data recording unit 124 of the authentication server 12 from the senior manager PC connected to the NW 14. . As described above, by providing the authentication status data recording unit 125 in the authentication server 12 and authenticating the status of the mobile terminal on the authentication server 12 side as well, the usability of the encrypted file management system for the mobile terminal is improved. Is possible.

  Also, the authentication server 12 side can take the initiative and manage the encrypted files of the mobile terminal more actively. For example, when there is an authentication request from the stolen portable terminal 16 to the authentication server 12, information on the stolen portable terminal is written in the authentication status data recording unit 125 in advance, so that the encryption of the portable terminal 16 is immediately performed. It is also possible to control the portable terminal 16 so as to delete the conversion file 163a.

  As a third embodiment of the portable file encrypted file management system of the present invention, a configuration example in which a situation data recording unit 166 that records only situation information is provided in the portable terminal 16 is shown. The description of the first and second embodiments has been made on the assumption that the situation measuring unit 165 operates only when using the mobile terminal. For example, the latitude / longitude information of the place where the mobile terminal 16 is used is measured each time by the GPS position measurement function. When a history of such status information is necessary, it is recorded in, for example, the RAM forming the control unit 166 or the recording unit 163 (HDD) in which the encrypted file 163a is recorded.

  Since the history of the situation information is important information, it is necessary to prevent the malicious third party from tampering. However, if it is recorded in the RAM or HDD of a normal PC, there is a risk that it will be easily found and altered by a third party. The amount of status information is smaller than that of the encrypted file 163a, etc., so that it can be difficult to discover from a third party by recording it separately in a small-capacity flash memory. . Further, by configuring the status data recording unit 166 with a tamper-resistant chip, it is possible to make it more difficult for a third party to tamper with the status information. Tamper resistance refers to resistance to reading internal information physically and logically.

  By making it impossible to easily tamper the history of situation information, it is conceivable to actively use the history of situation information as situation information. For example, whether the history of latitude / longitude information of the mobile terminal matches the business trip plan is a criterion for determining valid status information. In addition, more effective situation information can be obtained by operating the situation measuring unit 165 and the situation data recording unit 166 when the user does not use the portable terminal. For example, the state measurement unit using the acceleration detection function described above can obtain more accurate information about how the mobile terminal 16 is handled by enabling the mobile terminal 16 to continuously measure even when the mobile terminal 16 is not used. Is possible.

  By providing the situation data recording unit 166 in the portable terminal in this way, it is possible to prevent the malicious third party from easily tampering and to effectively use the history of situation information.

  If the method for judging the status information of the mobile terminal by looking at the matching between the business trip plan and the history of the location information of the mobile terminal is, for example, the state transition method, other risk score methods and rule methods are conceivable. . In the case of using a plurality of situation measuring units described in FIG. 6 with the risk score method, a point is assigned to each piece of situation information output from each situation measuring unit, and the situation of the mobile terminal is determined by the total of the points. It is a method to judge. For example, when the chassis open switch 63 is opened, 100 points, 40 points when the user is away from the mobile terminal 16, and 60 points when excessive acceleration is applied to the mobile terminal 16 in that state. This is an emergency situation when the total reaches 100 points. In the rule method, a rule according to the situation is determined in advance, for example, when a mobile terminal is used outside the company as in the above-described example, permission from the senior manager is required. Note that the situation of the mobile terminal may be determined using a combination of these methods.

  In addition, as an example of a method for determining an emergency situation, the situation measuring unit 165 has described only an example in which a state is detected by hardware. However, there is a method for determining an emergency situation by processing user authentication information using software. . For example, it is not normally considered that the user ID, which is basic information for user authentication, is mistaken a plurality of times, or that authentication requests are repeatedly made with a nonexistent user ID. Such an abnormal situation may be detected by software and determined as an emergency. Also, a situation measuring unit that categorizes the type of network to which the mobile terminal 16 is connected by PSID or the like and logically determines the position of the mobile terminal 16 with software is also conceivable. The situation measurement unit is indicated by a broken line in FIG. 6 as a logical position detection unit 66.

  As described above, the encrypted file management system for a portable terminal according to the present invention is designed to detect a change in the situation in which the portable terminal is placed and perform file management with a security strength corresponding to the situation change. The encrypted file management system and method for mobile terminals based on the technical idea of the present invention, and their devices are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. is there. For example, the portable terminal 16 has been described as an example assuming a notebook PC, but the functions of only the encrypted file management unit 162 and the recording unit 163 are configured in the form of a USB memory directly inserted into a USB port, for example. Also good. In this case, the functions of the user authentication information request unit 164, the situation measurement unit 165, and the control unit 166 use, for example, those on the notebook PC side where the portable terminal of the present invention having the USB memory shape is inserted. . Thus, the form of the portable terminal is not limited to one notebook PC.

  Moreover, although the above-mentioned Example demonstrated the case where the portable terminal 16 and the authentication server 12 were online, naturally the portable terminal 16 can also be used offline. FIG. 8 shows an operation flow of the portable terminal 16 in that case. The online operation flow is different from FIG. 3 only in that there is no partial step S1622a to step S1622c of the exchange with the authentication server 12. As described above, even when the mobile terminal is used offline, it is possible to decrypt the encrypted file while ensuring sufficient safety according to the situation where the mobile terminal is placed.

  Note that the processing described in the above-described method and apparatus is not only executed in time series in the order described, but is also executed in parallel or individually as required by the processing capability of the apparatus that executes the processing. Also good.

  Further, when the processing means in the above apparatus is realized by a computer, the processing contents of functions that each apparatus should have are described by a program. Then, by executing this program on the computer, the processing means in each apparatus is realized on the computer.

  The program describing the processing contents can be recorded on a computer-readable recording medium. As the computer-readable recording medium, for example, any recording medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory may be used. Specifically, for example, as a magnetic recording device, a hard disk device, a flexible disk, a magnetic tape, etc., and as an optical disk, a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only) Memory), CD-R (Recordable) / RW (ReWritable), etc. can be used as magneto-optical recording media, MO (Magneto Optical disc) can be used, and flash memory can be used as semiconductor memory.

  The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Further, the program may be distributed by storing the program in a recording device of a server computer and transferring the program from the server computer to another computer via a network.

  Each means may be configured by executing a predetermined program on a computer, or at least a part of these processing contents may be realized by hardware.

The figure which shows the system configuration | structure of the encryption file management system 10 for portable terminals of this invention. The figure which shows the operation | movement sequence of the authentication server 12 and the portable terminal 16 in the encryption file management system 10 for portable terminals. The figure which shows the operation | movement flow of the portable terminal 16. FIG. The figure which shows the operation | movement flow of the authentication server 12. It is a figure which shows an example of the condition measurement part 165, (a) shows an acceleration detection part, (b) shows the condition measurement part comprised by a housing open switch. The figure which shows the method of using a several situation measurement part together. The figure which shows the operation | movement flow of the authentication server of Example 2. FIG. The figure which shows the operation | movement flow in case the portable terminal 16 operate | moves offline. The figure which shows the system configuration | structure of the mobile terminal management system disclosed by patent document 1. FIG.

Claims (10)

A mobile terminal connected to a network, requesting user authentication by a user operation, and decrypting a stored encrypted file;
An authentication server for performing the user authentication;
In an encrypted file management system for mobile terminals comprising:
The mobile device
A status measurement unit that measures the status of the mobile terminal and outputs status information;
A user authentication information requesting unit that requests the user for user authentication information corresponding to the situation information;
A recording unit for storing the encrypted file;
When the user authentication information, the status information, and the authentication result input from the authentication server are input, and the user authentication information matches the status information, and the authentication result is approved, An encrypted file management unit for decrypting encrypted files;
Encrypted file management system for mobile terminals equipped with. In the portable file encrypted file management system according to claim 1,
The authentication server includes an authentication status data recording unit,
The encrypted file management unit sends the status information and the user authentication information to the authentication server to request authentication,
The said authentication server authenticates a user with reference to the said authentication status data recording part with respect to the said authentication request | requirement, The encryption file management system for portable terminals characterized by the above-mentioned. In the portable file encrypted file management system according to claim 1 or 2,
The portable terminal further includes a situation data recording unit,
The situation measurement unit operates even when the portable terminal is not used, measures the situation of the portable terminal, and records the measurement result in the situation data recording unit. system. The authentication server includes an authentication process for authenticating user authentication information transmitted from the mobile terminal,
The mobile device
A situation measurement process that measures the situation of the mobile terminal and outputs situation information;
A user authentication information request process for requesting user authentication information corresponding to the situation information to the user;
When the user authentication information and the situation information are input, and the user authentication information matches the situation information, and the result of the authentication process is approved, the encrypted file is decrypted. The process of managing encrypted files,
A method for managing an encrypted file for mobile terminals, comprising: In the encryption file management method for portable terminals according to claim 4,
The encrypted file management method for a portable terminal, wherein the authentication process is a process of inputting the status information and the user authentication information and authenticating a user with reference to an authentication status data recording unit. The encrypted file management method for mobile terminals according to claim 4 or 5,
The situation measuring process is a process of measuring the situation of the portable terminal even when the portable terminal is not used, and recording the measurement result in the situation data recording unit. File management method. When connected to the network, the mobile terminal device requests user authentication from the authentication server, and when not connected to the network, the mobile terminal device authenticates the user with the mobile terminal alone,
A status measurement unit that measures the status of the mobile terminal and outputs status information;
A user authentication unit that requests user authentication information corresponding to the situation information and authenticates the user;
A recording unit for storing the encrypted file;
In the case of the user authentication information corresponding to the situation information, using the user authentication information and the situation information as input, an encrypted file management unit that decrypts the encrypted file;
A mobile terminal device. In the portable terminal device according to claim 7,
A portable terminal device further comprising a situation data recording unit for recording a result measured by the situation measuring unit. An authentication server device for authenticating a user connected to a network,
The authentication server device includes an authentication status data recording unit, and authenticates a user by referring to the authentication status data recording unit in response to an authentication request.   An apparatus program for causing a computer to function as each apparatus according to claim 7.

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