JP2007148466A - Portable storage device and os - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable storage device managed so that secret files may not be stored in a user terminal or leaked out to a network, in the device connected to the user terminal to be used for editing a secret file on the user terminal. <P>SOLUTION: The portable storage device includes secret files and an OS in which an application for using the secret files, a means which restricts the storages of secret files in a device except its own device; a means which executes authentication in reference to information unique to its own device when the OS is started up; and a means which restricts the access of the OS to a network; are installed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable storage device that is managed so that stored confidential information does not leak, and in particular, a portable storage device that is connected to a user terminal and can use and edit confidential information on the user terminal. It is about.

  Conventionally, when a confidential file is stored in a secondary storage device such as a hard disk or a portable storage device such as a USB memory, the confidential file is forcibly encrypted and stored in the storage device. Therefore, it is generally performed to prevent leakage of confidential information. As a result, even if a confidential file is taken out of the local machine, it is possible to prevent leakage of confidential information because the file is encrypted.

  For example, in the system described in Patent Document 1, a data read / write request to a storage device issued from an application program to an operating system is intercepted, and an encryption key for encrypting data is written on the network at the time of the write request. To obtain data from the connected key management computer, encrypt the data with this encryption key, save it in the storage device, and read out the encrypted data from the storage device and decrypt the encrypted data when a read request is made Is obtained from the key management computer, the encrypted data is decrypted with this encryption key, and the original data taken out is passed to the application program. As a result, it is possible to prevent the data in the storage device from being seen or altered without performing a troublesome operation by the user, and it is possible to prevent the data in the storage device from being wiretapped even if the computer itself is stolen. It has become.

  Also, a technique for preventing confidential information from leaking out in plain text by performing access control to a portable storage device or printing device at the OS (operating system) level has been proposed and implemented.

JP-A-11-149414

  However, even in a system that performs automatic file encryption as described above, there is a possibility that confidential information may be leaked by the actions of a user having a certain authority. For example, a user with editing authority can copy and paste plaintext confidential information to another application or save it in an unencrypted folder while editing a confidential file. For this reason, it is difficult to say that protection of confidential information is completely realized.

  On the other hand, in the forced file encryption system at the OS level as described above, use of various applications is restricted, and there is a large aspect that convenience is lost. It is considered difficult to fully introduce the system into institutions. For example, the file encryption system described above is useful in an environment where the execution environment can be forced on each user terminal under a predetermined security policy within the company, but it is not suitable for the user terminal of a subcontractor that handles the same confidential information. Enforcing a similar execution environment is not practical, and it is difficult to achieve complete confidential information protection.

  Furthermore, even if encrypted, there is a demand to avoid storing confidential files in a storage device or a portable storage device of a local machine. In particular, a portable storage device such as a USB memory in which a confidential file is encrypted and stored can be easily taken out, and the encryption may be released by a malicious person and confidential information may be leaked. There is also.

  The present invention has been made in view of such circumstances, and is a portable storage device that is connected to a user terminal and can use and edit a confidential file on the user terminal, and the confidential file is stored on the user terminal. It is intended to provide a portable storage device managed so as not to be stored in the network or leaked to the network.

  As a result of diligent research in view of the above problems, the present inventor installs an OS and an application whose functions are restricted so as not to execute operations that may leak a confidential file while encrypting and storing the confidential file. The idea was to construct a portable storage device.

  More specifically, the present invention provides a portable storage device configured as follows.

  (1) A secret file is stored, and includes an OS in which an application for using the secret file and means for restricting the saving of the secret file outside the own apparatus are installed. Portable storage device.

  (2) A confidential file is stored, an application for using the confidential file, a means for restricting storage of the confidential file outside the own device, and authentication by referring to information unique to the own device when the OS is started A portable storage device characterized in that the means for performing includes an installed OS.

  (3) A confidential file is stored, an application for using the confidential file, a means for restricting the storage of the confidential file outside the own device, and authentication by referring to information unique to the own device when the OS is started A portable storage device comprising: an OS in which means for performing the above and means for restricting network access of the OS are installed.

  The OS described above has policy data relating to the OS operation restriction, and is configured to be restricted in operation based on the policy data. The policy data includes the OS expiration date, the OS startup frequency limit, the computer that can use the OS, the access to data or applications on the OS, the network access limit of the OS, and the user authentication. It includes setting information regarding at least one of information, usage restrictions on confidential files for each user, application usage restrictions for each user, and printing restrictions.

  The present invention also provides an OS for incorporating a portable storage device configured as follows.

  (1) An OS installed in a portable storage device and activated by a computer outside the device, storing a confidential file, an application for using the confidential file, and the portable storage of the confidential file An OS having installed therein means for restricting storage outside the apparatus.

  (2) An operating system installed in a portable storage device and activated by a computer outside the device, storing a confidential file, an application for using the confidential file, and the portable file of the confidential file An OS comprising: means for restricting storage outside a storage device; and means for performing authentication by referring to information unique to the portable storage device at startup.

  (3) An operating system installed in a portable storage device and started by a computer outside the device, and an application for using a confidential file, and saving of the confidential file outside the portable storage device are restricted. An OS comprising: means for performing authentication; means for performing authentication by referring to information unique to the portable storage device when the OS is activated; and means for restricting network access.

  The OS described above has policy data relating to the operation restriction of its own system, and is configured to restrict the operation based on the policy data. The policy data includes the OS expiration date, the OS startup frequency limit, the computer that can use the OS, the access to data or applications on the OS, the network access limit of the OS, and the user authentication. It includes setting information regarding at least one of information, usage restrictions on confidential files for each user, application usage restrictions for each user, and printing restrictions.

  As described above, in the portable storage device of the present invention, the confidential file can be stored on the user terminal while being used and edited on the user terminal connected to the user terminal. It can be managed so as not to leak on the network. Moreover, since the portable storage device of the present invention can be used by connecting to the user terminal without changing the computing environment of the existing user terminal, the convenience for the user is not impaired.

  The best mode for carrying out a portable storage device for protecting confidential information according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do.

System Configuration of Portable Storage Device and User Terminal FIG. 1 is a diagram schematically showing a system configuration of a portable storage device of the present invention and a user terminal using the same. The portable storage device referred to in the present invention is an external storage device that is detachable from the computer, and a USB memory, a semiconductor memory, a portable compact hard disk, a recording medium such as a CD, a DVD, or the like can be used.

  The portable storage device 100 includes a function-restricted OS 101 constructed in a part of a storage area, and hardware specific information 108 recorded in advance in a ROM or the like. The hardware specific information 108 is information that can uniquely identify the portable storage device 100. For example, in the case of a USB device, hardware specific information such as vendor information and serial number is recorded in a non-rewritable area for each device.

  The function-limited OS 101 has only the minimum functions necessary for the operation of the portable storage device 100 and the user terminal 109. In particular, the secondary storage device 112 of the user terminal 109, an external storage device, a USB device, It is characterized in that it does not have a device driver for a device that may be a leakage destination of a confidential file such as a floppy disk, or access is severely restricted even if it has a device driver. As an OS that can realize such a function restriction, an original OS that realizes the function restriction using a filter driver that extends the function of the device driver with respect to the existing OS, and an arbitrary device access function may be added or deleted. There is Windows XP Embedded etc. that can do.

  In FIG. 1, an OS 101 whose function is restricted includes an application 102 for using / editing a confidential file, a network monitoring module 103, a hard disk control module 104, a device authentication module 105, and a policy management module 106. The classified confidential file 107 is held.

  When the portable storage device 100 is used from the user terminal 109, the network monitoring module 103 monitors a packet that the user terminal 109 transmits and receives through the network, and a Web mail site or FTP server that may leak a confidential file Access to the website is prohibited, and control is performed so that only secure sites can be accessed. In order to ensure stronger security, a certificate-based mutual authentication function between C / S may be implemented. It is assumed that the access refusal information is held by the policy management module 106 or the like.

  The hard disk control module 104 restricts or prohibits access to the secondary storage device 112 in the user terminal 109 while the OS 101 whose function is restricted is activated from the user terminal 109. The restriction or prohibition of access can be realized by mounting a filter driver that performs access control for each drive, or by controlling so that the secondary storage device itself is not mounted when the OS 101 is activated.

  The device authentication module 105 refers to the hardware specific information 108 in the portable storage device 100 when the OS 101 whose function is restricted is activated, and authenticates whether the device 101 is a pre-registered proper device. The activation of the OS 101 is permitted only when it is recognized that it is activated on an appropriate device. It is assumed that the authentication information is held by the policy management module 106 or the like. This prevents the OS 101 from being copied to an inappropriate storage device and booted.

  The policy management module 106 manages policies related to the use of the OS 101 whose functions are restricted. For example, the expiration date and the number of times that the OS 101 can be activated, the authentication information for the user terminal 109, the address list of machines on the network that permit access to the user terminal 109, the authority to use the OS 101 and the confidential file 107 for each user, the printing rejection, etc. Various policies can be set in advance.

  The user terminal 109 includes a CPU 110, a main storage device 111, and a secondary storage device 112. The secondary storage device stores an OS 113, an existing application 114, and existing data 115 that are normally used in the user terminal 109. Has been. These are existing computing environments installed in the user terminal 109 in advance. The portable storage device of the present invention provides a secure computing environment in which a confidential file can be used and edited without damaging the existing computing environment.

Usage Form of Portable Storage Device by User Terminal FIG. 2 is a flowchart showing a flow of processing when the portable storage device 100 of the present invention is connected to the user terminal 109 and the OS 101 whose function is restricted is activated. In FIG. 2, first, when the user terminal 109 connected to the portable storage device 100 is turned on (step 200), the BIOS of the user terminal 109 boots the OS 101 whose function is limited in the portable storage device 100 ( Step 201). It is assumed that the BIOS is set in advance to give priority to booting from an externally connected storage device. Next, the portable storage device 101 is authenticated by the device authentication module 105 installed in the OS 101 (step 202). In this authentication, the hardware specific information 108 of the portable storage device 100 is acquired and checked against a policy held by the OS 101 to determine whether the portable storage device 101 is an appropriate device (step 203). . If the authentication is successful, a logon screen is displayed and the user is allowed to log on (step 204). The user logs on and uses the application 102 on the OS 101 whose function is restricted, and the confidential information in the portable storage device 101 is stored. The file 107 can be used / edited (step 205). If the authentication fails, an authentication failure message is displayed (step 206), and the activation of the OS 101 is interrupted.

  FIG. 3 is a flowchart showing a flow of processing when the user terminal 109 uses / edits the encrypted confidential file 107 stored in the portable storage device 100 of the present invention. In FIG. 3, when the application 102 accesses the encrypted confidential file 107 (step 300), the hard disk control module 104 decrypts the confidential file 107 and transmits it to the application (step 301). Thus, the user can use / edit the confidential file 107 decrypted on the application 102 (step 302). When saving the confidential file 107 edited on the application 102, the application 102 executes file saving processing (step 303). At this time, the hard disk control module 104 checks the storage destination of the confidential file 107 (step 304). If the storage destination is a storage area in the portable storage device 100, the hard disk control module 104 encrypts and records the confidential file 107 (step 305). If the storage destination is other than the portable storage device 100, the hard disk control module 104 forcibly cancels the storage process (step 306). In this way, since the storage destination of the confidential file 107 used / edited by the user is limited only to the portable storage device 100, the confidential file 107 can be prevented from being leaked.

System Construction of Portable Storage Device FIG. 4 is a diagram schematically showing a system configuration of a management terminal for installing the OS 101 whose function is restricted in the portable storage device 100. In FIG. 4, a management application 401 and an OS configuration tool 404 are installed on the management terminal 400. The OS configuration tool 404 is a tool for configuring the OS 101 with limited functions installed in the portable storage device 100. The management application 401 includes a policy setting module 402 and an encrypted data writing / extracting module 403. The policy setting module 402 is a module for creating policy data that defines the operation of the OS 101 whose function is restricted. The policy data created by the policy setting module 402 is incorporated into the OS 101 whose function is restricted, and the policy management module 106 installed in the OS 101 performs operations such as function restriction of the OS 101 based on this policy data. Become. The encrypted data writing / extracting module 403 is a module for performing writing and reading processing of the encrypted confidential file 107 stored in the portable storage device 100.

  FIG. 5 is a flowchart showing the flow of processing when installing the OS 101 whose function is restricted to the portable storage device 100 by the management terminal 400. In FIG. 5, the management terminal 400 first configures the OS 101 whose function is restricted on the portable storage device 100 by the OS configuration tool 404 (step 500). Subsequently, necessary applications (at least those shown in FIG. 1) are installed on the OS 101 whose functions are restricted (step 501). Thereafter, the management application 401 acquires the hardware specific information 108 of the portable storage device 100 (step 502), creates policy data including the hardware specific information 108, and incorporates it into the OS 101 (step 503). Finally, the configured OS is copied to the storage area of the portable storage device 100 (step 504).

  As described above, the portable storage device for protecting confidential information according to the present invention has been described with specific embodiments, but the present invention is not limited thereto. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention.

It is a figure which shows roughly the system configuration | structure of the portable storage device of this invention, and the user terminal using this. It is a flowchart which shows the flow of a process at the time of connecting the portable memory | storage device of this invention to a user terminal, and starting OS with a function restriction | limiting. It is a flowchart which shows the flow of a process at the time of using / editing the encrypted confidential file stored in the portable storage device of this invention in a user terminal. It is a figure which shows roughly the system configuration | structure of the management terminal for installing OS in which the function restriction | limiting was carried out to the portable storage device of this invention. FIG. 5 is a flowchart showing a flow of processing when an OS whose function is restricted is installed in the portable storage device of the present invention by the management terminal shown in FIG. 4. FIG.

Explanation of symbols

101 portable storage device
102 Application
103 Network monitoring module
104 Hard disk control module
105 Device authentication module
106 Policy management module
107 Confidential file
108 Hardware specific information
109 User terminal
110 CPU
111 Main memory
112 Secondary storage device
113 User terminal OS
114 Existing applications
115 Existing data
400 management terminal
401 management application
402 Policy setting module
403 Encrypted data writing and extracting module
404 Configuration Tool

Claims (10)

Contains sensitive files,
An application for using confidential files;
A portable storage device comprising: an OS installed with means for restricting storage of confidential files outside the device. Contains sensitive files,
An application for using confidential files;
Means for restricting the storage of confidential files outside the device;
A portable storage device comprising: an OS installed with a means for performing authentication by referring to information unique to the own device when the OS is started. Contains sensitive files,
An application for using confidential files;
Means for restricting the storage of confidential files outside the device;
Means for performing authentication by referring to information unique to the own device when the OS is started;
A portable storage device comprising: an installed OS, and means for restricting network access of the OS.   4. The system according to claim 1, wherein the OS includes policy data relating to operation restrictions of the OS, and is configured to be restricted in operation based on the policy data. 5. The portable storage device described.   The policy data includes the OS expiration date, the OS startup frequency limit, the computer that can use the OS, the access to data or applications on the OS, the network access limit of the OS, and the user authentication. 5. The portable storage device according to claim 4, comprising setting information related to at least one of information, use restriction of a confidential file for each user, use restriction of an application for each user, and restriction of printing. An OS installed in a portable storage device and activated by a computer outside the device,
Contains sensitive files,
An application for using confidential files;
An OS, which is installed with means for restricting storage of confidential files outside the portable storage device. An operating system installed in a portable storage device and started by a computer outside the device,
Contains sensitive files,
An application for using confidential files;
Means for restricting storage of confidential files outside the portable storage device;
An OS installed with a means for performing authentication by referring to information unique to the portable storage device at the time of startup. An operating system installed in a portable storage device and started by a computer outside the device,
An application for using confidential files;
Means for restricting storage of confidential files outside the portable storage device;
Means for performing authentication by referring to information unique to the portable storage device at its startup;
An OS having installed therein means for restricting its own network access.   The OS according to any one of claims 6 to 8, wherein the OS has policy data relating to operation restriction of the own system, and is configured to be restricted in operation based on the policy data.   The policy data includes the OS expiration date, the OS startup frequency limit, the computer that can use the OS, the access to data or applications on the OS, the network access limit of the OS, and the user authentication. 10. The OS according to claim 9, further comprising setting information related to at least one of information, usage restrictions on confidential files for each user, usage restrictions on applications for each user, and printing restrictions.

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