JP2000029792A - Secret information storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the confidentiality by storing information on a user, information showing the storage destination of secret information, and an encoding key characteristic of the user on a small-capacity medium and generating and storing a key characteristic of the device on a hard disk. SOLUTION: At incorporating, a key B105 characteristic of the device is generated and stored on an external storage device 102. Then the user actuates an encoding control mechanism 103 to register information 108 on the user. The contents of the information 108 of the user consist of a user ID, a password, and the encoding key A109 characteristic of the user. Then the user specifies desired secret information 110 to be concealed. An encoding control mechanism 103 reads the secret information 110 out and encodes it with a key A109 characteristic of the user. Consequently, a file obtained by further encoding the obtained file with the encoding key 105 characteristic of the device is written to a location such that the user specifies on the external storage device of the device. The location that the user specifies is written as a storage location 112 of the confidential information to an IC card 106.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing confidential information of a computer, and more particularly, to a relatively small-capacity portable medium (such as an IC card) for storing confidential information and a relatively large capacity. The present invention relates to a method for securely storing and storing confidential information by using a medium (such as a hard disk).

[0002]

2. Description of the Related Art In a conventional method, user information (user ID, password, etc.) is stored in a relatively small-capacity transportable medium such as an IC card or a floppy disk, and is compared with user information input by a user. By performing the check, the access to the confidential information is restricted by making the confidential information stored in the medium accessible. Alternatively, it is possible to access the confidential information by extracting the encryption key stored in the medium and decrypting the confidential information by the same method.

As another method, a part of user information (such as a password) is stored in another computer connected to a network to prevent the entire user information from being stolen. On such an open network, the danger of eavesdropping by a malicious third party during communication cannot be avoided, so that it is necessary to use an encryption technique or the like to prevent eavesdropping.

[0004]

The conventional method has the following problems. That is, in the conventional method, since the user information and the confidential information are stored on the same medium, there is no consideration of the danger of the medium being stolen by a malicious third party. Or the key to access confidential information is stolen. A method to prevent all the user information from being stolen by giving a part of the user information (such as a password) to another computer connected via a network, while communicating on an open network such as the Internet. The risk of eavesdropping by a malicious third party cannot be avoided. In order to prevent eavesdropping, it is necessary to use an encryption technology in a communication protocol.

[0005]

According to the present invention, user information (user ID, password) and confidential information are stored in a relatively small-capacity and easily transportable medium A (eg, IC card, floppy disk). By storing the information indicating the destination, the user-specific encryption key A, and generating and holding the device-specific key in the hard disk, the medium A stored by the user and the information input by the user Only when all of the machine-specific key in the hard disk and the encrypted confidential information in the hard disk are valid, the confidential information can be accessed (viewed, used, and changed).

[0006] First, a user (or, in the case of pre-installation, a maker of a shipping source) creates an encryption key B unique to the device during the procedure of installing software and stores it on a hard disk. The method of creating a device-specific key is performed by using a built-in date and time, hardware-specific address information, or a random number in a manner that can determine that the possibility of being the same as another device is sufficiently small.

Next, in a procedure for registering user information, a key A unique to the user is created and stored together with the user information in a medium A having excellent portability. The method of creating a user-specific key is a method that can be used to judge that the possibility of being the same as another device is sufficiently small using the time when the user is registered, a part of the user information (password), or a random number. Do.

[0008] Using these two keys, the confidential information is double encrypted and stored. As an encryption procedure, encryption with a user-specific key A and encryption with a device-specific key B are performed in this order. The reason for this is that when encrypted only with the user's key, the file of confidential information in the hard disk is copied, and another device in which the same software as that in the device is installed is brute-force. It considers that confidential information can be accessed by a practical method.

Further, in consideration of the failure of the hard disk, it is necessary to copy the confidential information to another medium. However, only when the user information is correctly input using the medium A, the key B is decrypted. The function to store the output file on the copy destination medium is provided. To store from the copy destination medium to the hard disk of another device, after registering the user using the medium A, when the user inputs the medium A and the legitimate input, the user must first encrypt with the device-specific key. It is realized by the function of storing in the hard disk.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A specific method for carrying out the present invention will be described below.

FIG. 1 shows an apparatus to which the present invention is applied and its configuration. Hereinafter, a medium having a relatively small capacity and excellent in portability will be described as an IC card, and an external storage device fixedly connected to the apparatus main body will be described as a hard disk. In the present invention, the encryption control mechanism 103
One external storage device 102 is included in the application program 104 and incorporated. For example, an application program may be an electronic commerce client that requires an electronic certificate, and confidential information may be an electronic certificate.

At the time of installation, a key B105 unique to the apparatus is used.
Is created and stored in the external storage device 102. The method of creating the device-specific key B105 is performed by using a built-in date and time, hardware-specific address information, or a random number in a method that can determine that the possibility of being the same as another device is sufficiently small.

Next, the user activates the encryption control mechanism 103 and registers the user information. At this time, the encryption control mechanism 1
03 writes the user information 108 into the initialized IC card 106 by the IC card reader / writer 107. The contents of the user information 108 are a user ID / password and a user-specific encryption key A109. Next, the user specifies the confidential information 110 to be hidden.

This is often read by the external medium 112. The encryption control mechanism 103 reads the confidential information 110 and encrypts the confidential information 110 with the key A109 unique to the user. As a result, the obtained file is further transferred to the device-specific encryption key 105.
And writes the file obtained as a result of the encryption in a location specified by the user in the external storage device of the device. The location specified by the user is the storage location 1 of confidential information in the IC card.
Written as 12.

The details of each process will be described below.
FIG. 2 shows a flow of an installation process of the application program 104. When the installation of the program is started, the program is incorporated 201 as in the case of the normal installation. 201 includes creation of necessary directories, compression and decompression and copying of necessary program files, setting of environment variables for program operation, setting of registry, and the like.

After 201 is completed, the encryption key B unique to the device
Is generated 202 and the key B is stored 203 in the hard disk, and the installation process ends. FIG. 3 shows the flow of the user registration process. First, reading of user information (user ID) 301, reading of user information (password) 3
02 is performed. These are implemented by a method of reading a screen input by a user.

Next, the IC card is read 303, and if the data already exists, the user is determined whether or not to initialize (304, 307). Thereafter, a user-specific encryption key A is generated 305, and the user information and the encryption key A are stored in an IC.
Write on the card. FIG. 4 shows confidential information storage processing 1. The confidential information storage process 1 is a process from the state in which confidential information is not encrypted at all until it is encrypted and stored on the hard disk.

First, user information and reading of an IC card (4
01, 402) It is determined whether the user input is correct and 40
3. If correct, read 404 confidential information, extract 405 the encryption key A from the IC card, and encrypt 406 the confidential information with the encryption key A.

Next, an encryption key B unique to the apparatus is extracted from the hard disk, and the secret information encrypted with the key A is further encrypted 408 with the encryption key B. Finally, the user is inquired 409 of the storage location of the encrypted confidential information, writes 410 the designated storage location information to the IC card, and stores 411 the encrypted confidential information in the designated storage location. If the input of the user information is incorrect and there is an erroneous input exceeding the specified number of times, the processing is stopped (412, 4).
13).

FIG. 5 and FIG. 6 show, via a medium, a hard disk of another apparatus in which the same function as the procedure of copying the encrypted confidential information stored above to another medium is installed. Show how to store confidential information. In the copying process shown in FIG. 5, first, the user information is read 501 and the IC card is read 502, and the input is correct 503
Reads 504 the storage location information from the IC card, and reads 50 the encrypted confidential information stored in the storage location.
5. Extract encryption key B 506, encryption key B for confidential information
Decoding 507 is performed. Next, the user inputs the position of the copy destination on the screen 508, and stores 509 the secret information (encrypted with the key A) combined with the key B in the medium designated as the copy destination. The input error of the user information is the same as in FIG. 4 (510, 511).

In the confidential information storage processing 2 (storage processing to another device) in FIG. 6, first, user information reading 601 and IC
When the card is read 602 and the user input is correct 603, the user is required to input the position information of the input source file 604, and the confidential information decrypted with the encryption key B (encrypted with the encryption key A) Is read from the position of the input source file 605, an encryption key B 'is taken out 606 (key B': different from the key B because it is another device), and encryption 607 is performed using the key B '. I do.

Next, the user is prompted to input the location of the storage location.
8. The storage location information of the confidential information in the IC card is rewritten 610 together with 609 of storing the encrypted confidential information in the designated storage destination. The error in the input of the user information is the same as the description of FIG. 4 (611, 612).

[0023]

As described above, according to the present invention, the confidential information of the user stored in the apparatus is taken out if the input by a legitimate user and an easily transportable medium such as an IC card are not prepared. In addition, it is possible to provide a means for preventing the copying of the confidential information by another unauthorized user while allowing the user to easily copy the confidential information to another medium in case of a device failure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus in which a confidential information storage device of the present invention operates.

FIG. 2 is a specific flowchart of software installation processing of the present invention.

FIG. 3 is a specific flowchart of a user registration process in the software of the present invention.

FIG. 4 is a specific flowchart diagram of confidential information storage processing 1 of the present invention.

FIG. 5 is a specific flowchart of the confidential information copying process of the present invention.

FIG. 6 is a specific flowchart of confidential information storage processing 2 of the present invention.

[Explanation of symbols]

101: Computer device on which the software of the present invention operates 102: External storage device connected to the device, 103
... An encryption / decryption control mechanism serving as a function of the present invention;
5: Device-specific encryption key B, 106: IC card for storing user information, etc., 107: IC card reader / writer, 108: User-specific information stored in the IC card, 109: User-specific Encryption key A, 110 ...
Confidential information to be concealed, 111: encrypted and stored confidential information, 112: storage position information of confidential information, 113: input / output medium (FD, DAT, etc.), 200: start of program installation processing, 201: installation of program,
202: Device-specific key B generation processing, 203: Key B storage on the hard disk, 300: User registration processing start, 301: User information reading (user ID), 30
2 ... Reading of user information (password), 303 ... IC
Card reading, 304: determination of whether or not there is registered data in the IC card, 305: generation of an encryption key A, 3
06: writing user information and encryption key A to the IC card; 307: determining whether to initialize the IC card;
00: start of confidential information storage processing 1, 401: reading of user information, 402: reading of IC card, 40
3: determination of correctness of user input; 404: reading of confidential information; 405: encryption key A from IC card
Reading, 406... Encryption processing using the encryption key A, 40
7 ... Extraction of encryption key B from hard disk, 408 ...
Encryption processing using the encryption key B, 409... Input reading of storage location information from a user, 410... IC of storage location information
Writing to a card, 411 ... Storing encrypted confidential information in a storage position, 412 ... Process of adding 1 to an error counter, 413 ... Counter count determination, 500 ... Start of confidential information storage process 1, 501 ... User Read information,
502: Read IC card; 503: Determine whether user input is correct; 504: Read storage location information from IC card; 505: Read encrypted confidential information; 506: Encryption key B from hard disk Take out,
507: decryption processing using the encryption key B, 508: input reading of copy destination information from the user, 509: storage of confidential information (encrypted with the key A) decrypted with the encryption key B in the copy destination 510: Processing for adding 1 to the error counter, 511: Counter number judgment, 600:
Start of confidential information storage processing 1, 601: Read user information, 602: Read IC card, 603 ...
Judgment as to whether the user's input is correct, 604... Reading the input from the input source information from the user, 605... From the input source of the confidential information decrypted with the encryption key B (encrypted with the key A) Reading, 606: taking out the encryption key B 'from the hard disk, 607: encryption processing using the encryption key B', 608: inputting and reading the storage location information from the user,
609: Rewriting of the storage position information of the IC card, 610 ...
Storing the encrypted confidential information in the storage location, 611... Adding 1 to the error counter, 612...

Claims (3)

[Claims] A means for generating and storing an apparatus-specific key; a key stored in a small-capacity medium only when user authentication is normally performed; a means for extracting an apparatus-specific key; A confidential information storage device comprising means for double encrypting confidential information using a key and storing it in an external storage device, and a mechanism for controlling these means to enhance confidentiality. Means for generating and storing a device-specific key; means for storing a key stored in a small-capacity medium only when user authentication is normally performed; means for extracting a device-specific key; A confidential information storage device characterized in that means for decrypting confidential information in an external storage device that has been double-encrypted using a key and a mechanism for controlling these means are provided to increase confidentiality. 3. In addition to the above, means for extracting and decrypting a device-specific key only when user authentication using a small-capacity medium is normally performed, and confidential information (user Means for writing the confidential information encrypted with the key) to the medium, and confidential information encrypted with the user's key written on the medium only when the user has been successfully authenticated. 2. The apparatus according to claim 1, further comprising means for encrypting (the confidential information combined with the device-specific key) with the device-specific key and storing the encrypted confidential information in an external storage device. Or the confidential information storage device according to 2.