JPH04245368A - Electronic file cabinet system - Google Patents

Abstract

PURPOSE:To facilitate the control and improve the safety by controlling log-in control and access control centrally and performing a ciphering process. CONSTITUTION:A user-side terminal 1 sends the user ID to a host computer when accessing an electronic file cabinet 29 on the side of the host computer 2. Then the user-side terminal obtains an open key and a password to generate a key by a 1st key generating means 16 and a ciphering means 17 ciphers the user ID. The host computer 2 receives the user ID and reads out respective IC codes corresponding to respective user IDs and a 2nd key generating means 24 generates a key to decipher the ciphered user ID, thereby allowing the terminal to log in when the user ID is proper. Consequently, the log-in control and access control are centralized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic file cabinet using an ID-based file encryption key management system.

0002

2. Description of the Related Art In distributed processing systems, host computers are required to store data from workstations, personal computers, etc., that is, to serve as an electronic file cabinet.

On the other hand, if data is stored on a host computer that is accessed by many people, there is a risk that the data may be accessed by a third party, and in order to protect this data, encryption and access Control technology is required.

A conventional electronic file cabinet management system using access control is shown in FIG. In the figure, 100
110 is a host computer that manages the electronic file cabinet, and 110 is a terminal such as a workstation or a personal computer in this system.

The operation of the system of FIG. A will now be described. When the user ID is sent from the terminal 110, the host computer 100 searches the password file 101 for the password PW corresponding to this user ID and outputs it.

[0006] This password PW is compared with the password PW sent from the terminal following the user ID in the comparison means 103.
If they match, you will be allowed to log in to the system.

[0007] Access to the electronic file cabinet is managed separately from host login. Terminal 110
When a command including the name of the cabinet to be accessed is sent from , the means for controlling access 104 searches the access management table 105 using the user ID that has permitted login and the specified cabinet name.

[0008] Since each user ID is granted permission to read, write, rewrite, etc. for each cabinet, predetermined access is permitted based on the result of searching the access management table 105.

[0009]

SUMMARY OF THE INVENTION The above conventional system has the following problems. ■There is a risk that your password will be stolen by wiretapping.

[0010] ■The password file must be kept strictly. ■Access control tables must be stored securely. ■Since the file is not encrypted, there is a risk of it being intercepted.

[0011] In order to solve these problems, line encryption and file encryption are required. Also, file encryption can be considered as protection against reading, but
For protection against rewriting, it is necessary to rely on access control.

[0012] Regarding these techniques, mutually independent ones have been realized. For example, regarding access control,
The technology for creating and managing keys for encrypting/decrypting files was published in Japanese Patent Application No. 01-184715 by the applicant.
It is proposed in the issue.

[0013] However, in the electronic file cabinet system, login control and access control are managed separately, and the system is extremely complicated. The present invention
The purpose of the present invention is to provide an electronic file cabinet system that simplifies management and is highly secure by centrally managing login control and access control in the electronic file cabinet system.

[0014]

[Means for Solving the Problems] The electronic file cabinet system of the present invention, which has been made to solve the above problems, includes a user terminal 1 and a host computer 2 based on a request sent from the terminal 1. In the system for accessing the electronic file cabinet 29, the terminal 1 side includes means 1 for inputting user identification information for identifying the user and sending it to the host computer 2 side.
1, a means 12 for inputting a public key created including the user's secret information and file identification information for identifying the electronic file cabinet as constituent elements; and means 12 for inputting the public key and the secret information input by the user. means 16 for generating a first secret key based on the inputted file access command; means 17 for encrypting the input authentication information using the private key and sending it to the host computer 2; means 18 for encrypting the encrypted data using a first secret key and transmitting the encrypted data to the host computer 2;
The host computer 2 has a user profile 21 in which file identification information of files to which access authority is granted for each user identification information is stored, and a second secret based on the identification information read from the user profile 21. means 22, 23, 24 for generating keys; means 25 for decrypting the encrypted authentication information using the second private key; means 26 for permitting/disallowing login;
means 27 for decrypting the encrypted command using the second private key; and means 27 for referring to the user profile 21 based on the decrypted command to confirm access authority and accessing the electronic file cabinet 29. It is characterized by having an access control means 28 for accessing.

[0015] Furthermore, the public key is a data value obtained by raising a predetermined integer to a power, and the power term includes a term that is the product of the reciprocal of the secret information and the reciprocal of the identification information. The first key generation means 16 generates the first private key by deleting the reciprocal term of the private information from the public key using the input private information, and The key generation means 22, 23, and 24 generate a reciprocal of each of the identification information using the center secret information 23, and perform a power calculation of the predetermined integer using the obtained reciprocal of each identification information as a term. The second private key may be generated by doing so.

Furthermore, the host computer 2 provides update information in each identification information section in the user profile 21 indicating whether or not the identification information has been updated;
A changed identification information holding means 41 is provided that stores the correspondence relationship between the updated identification information and the identification information before being updated, and when each piece of identification information is read from the user profile 21 using the received user identification information, the updated identification information is stored. Check the information, and if it has been updated, read out the changed identification information holding means 41 to create public key generation information including the new identification information, and use this public key generation information as the second secret. The terminal 1 is configured to encrypt the encrypted data using a key and send it to a terminal that is permitted to log in, and then rewrite the section of the identification information to be updated in the user profile 21 with new identification information. The public key generation information may be decrypted using the first private key to update the public key.

[0017]

[Operation] In the electronic file cabinet system of the present invention, first, for each user, the secret information (password) of the user, the identification information (ID code) for each user, and the identification of the electronic file cabinet to which access authority has been given. A public key created using the information (ID code) is supplied.

When this user accesses the electronic file cabinet on the host computer side, he first inputs his user ID. This is sent to the host computer 2.

Next, enter the public key and password. As a result, the first key generation means 16 removes the term based on the password from the public key and creates a first private key. After that, when the user inputs the authentication number (center ID), the encryption means 17 encrypts this identification number using the first secret key and sends it to the host computer 2.

On the other hand, when the host computer 2 receives the user ID, it reads each ID code corresponding to this user ID. Next, a second secret key is generated using each read ID code.

[0021] Here, since the first secret key and the second secret key are generated according to a formula decided in advance by the center, they have the same ID.
If a code is used, it will have the same value. In other words,
The user generates a second private key (by host computer 2) by inputting an ID code, while generating a first private key from the public key by inputting a password.

Furthermore, the encrypted authentication number received by the host computer 2 is decrypted using a second secret key. This encryption/decryption method is also agreed upon, so
If the first private key and second private key match, the same authentication number will be obtained.

[0023] If this authentication number is valid, the host computer 2 allows the terminal 1 to log in. Furthermore, when the user who is permitted to log in inputs a command to access the cabinet, the encryption means 18 encrypts the command using the first secret key and sends it to the host computer 2.

[0024] Upon receiving this command, the decryption means 27 on the host computer 2 side decrypts the command using the second secret key. (As described above, the first private key and the second private key match.) Based on this command, the access control means 28 refers to the user profile 21 and checks whether access authority is granted. , cabinet 2
Permit access to 9.

[0025] Furthermore, when changing the key of a cabinet, the identification information of the cabinet is changed, so it is necessary to change the user's public key based on the change. Therefore, a flag or the like is provided for each piece of identification information in the user profile 21 to indicate that the identification information is to be updated, and this flag is referenced at the time of login. The identification information to be updated is read out from the changed identification information holding means 31, new public key generation information including this identification information is created, encrypted, and sent to the terminal 1 currently permitted to log in.

[0026] The terminal 1 decrypts the received public key generation information and thereby updates the public key.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

[0028] Reference numeral 1 is a terminal, and reference numeral 2 is a host computer located at the center and managing the electronic file cabinet. The terminal 1 includes a user ID input means 11 for inputting the user's personal ID and sending it to the host computer 2, and a user ID input means 11 for inputting the user's personal ID and sending it to the host computer 2, and the reciprocal of the ID such as the user's department ID, department ID, and project ID in which the user is engaged, and the reciprocal of the password. means 12 for inputting the public key generated by , means 13 for inputting the password, means 1 for inputting the center ID, date and time, and random numbers.
4. Command input means 15 for instructing access to the electronic cabinet on the host computer 2 side; private key generation means 16 for generating a first private key from the public key sent from the public key input means and the input password; Center I
D, means 17 for encrypting date, time, and random numbers using a first secret key; and means 18 for encrypting commands using the first secret key.

The host computer 2 is a user's personal I
D and corresponding department ID, department ID, project I
A user profile 21 which is a table in which D and the like are stored, an ID reciprocal generation means 22 that generates an inverse of an ID code from an ID code read from the user profile 21 and secret information 23 possessed by the center, and each generated ID. key generation means 24 for generating a second private key using the reciprocal of
A decoding means 25 for decoding the encrypted center ID etc. sent from the terminal using the second private key, a means 26 for checking the validity of the decrypted center ID, and a second private key. The decryption means 27 decrypts the encrypted command using the decryption means 27, and the access authority is checked based on the user profile 21 based on the decrypted command, and the electronic file cabinet 2 checks the access authority based on the user profile 21 for the decrypted command.
9 and a means 29 for controlling access.

[0030] The public key input means 12 is, for example, a magnetic card or IC on which a public key is recorded from the center to each user.
Cards, etc. are distributed, and the system is configured so that input can be made using this medium. Further, the user ID input means 11, the password input means 13, the center ID input means 14, and the command input means 15 are actually the same input device such as a keyboard, and the same encryption means 17 and 18 are used. Similarly, the same decoding means 25 and 27 of the host computer 2 are used.

[0031] For example, the following public keys are used as public keys supplied in advance from the center.

[0032]

[Math 1]

This is to calculate the power of a constant M determined by the center using the product of the reciprocal of the password PW and the reciprocal of each ID data. In addition, the following private key is used.

[0034]

[Math 2]

This is generated on the terminal 1 side by using the input password PW and removing the reciprocal of the password from the power term of the public key. On the other hand, on the host computer 2 side, the reciprocal of each ID stored in the user profile 21 is generated, and the product of the reciprocals of each ID is used to perform a power calculation of the M.

As for the method of generating this reciprocal number, for example, prime numbers p and q are prepared using center secret information, and the reciprocal number generating means is as follows.

[
0037

[Math 3]

It is determined using the following relationship. Note that mod means remainder calculation, and LCM means calculation for finding the least common multiple. Further, each of the encryption means 17, 18 and the decryption means 25, 27 uses DES, FE, which are known encryption methods.
It uses AL etc.

Next, the operation of the embodiment shown in FIG. 1 will be explained. ■The user on the terminal 1 side sends a user ID to the host computer 2 using the user ID input means 11, and generates a key using the public key from the public key input means 12 and the password from the password input means 13. Means 16 generate a first private key.

[0040] The host computer 2 refers to the user profile 21 based on the sent user ID. The reciprocal number of each ID, such as the department ID written in this user's profile, is generated by the reciprocal number generation means 22 using the center secret information.

[0041] Using the reciprocal of each ID, the key generation means 24
generates a second private key. ■When the user inputs the center ID, date and time, and a predetermined random number using the input means 14, the encryption means 17 of the terminal 1 encrypts (center code + date and time + random number) using the first secret key 16, and the host computer Send to 2.

■The decryption means 25 of the host computer 2 decrypts the encrypted (center code + date and time + random number) using the second private key generated by the key generation means 24,
The checking means 26 checks the validity of this code, and if a valid center code is obtained, login is permitted.

[0043] Since the terminal 1 is notified by means (not shown) that login has been permitted, the user receives this and inputs a command using the input means 15. This command specifies the type of access to be performed (read, write, etc.) and the name of the cabinet to be accessed.

The command is encrypted by the encryption means 18 using the first secret key and sent to the host computer 2. (2) When the host computer 2 receives this encrypted command, it decrypts it using the decryption means 27 using the second secret key to obtain the command. The access control means 28 refers to the user profile 21 and checks whether the access authority specified by the command is granted.

[0045] Once the access authority is confirmed by the access control means, access to the cabinet 29 becomes possible. Next, a second embodiment of the present invention will be described using FIG. 2.

This embodiment relates to a method for changing IDs in an electronic file cabinet system. This system basically uses the same system as the first embodiment shown in FIG. 1, but parts not directly related to this embodiment are omitted in FIG.

[0047] When changing the cabinet key, it is necessary to change the cabinet ID. However, even if the cabinet ID is changed on the system side, the public key on the user side is created based on the information of this ID code, so it is necessary to change this public key.

[0048] Here, an example will be explained in which the key of a project cabinet is changed. (2) Log in to the host computer 2 in the same way as in the first embodiment.

[0049] If the host computer 2 side has information on changes to the user profile information for the logged-in ID, new key generation information 44 is generated from the new project ID and other IDs. For example, by setting an update flag in the user profile 21,
Using this value, the change identification information holding means 31 is searched to find that project ID2 has become ID3, and the result is output. Then, the key generation means 32 generates a new ID and another ID.
New public key generation information is created using the user password held on the system side.

(2) The public key generation means is encrypted by the decryption means 33 using the second private key, and transmitted to the terminal 1. ■
In the terminal 1, this is decrypted by the decryption means 41 to obtain public key generation information. Then, the public key generation means 42 rewrites the current public key recorded on a medium such as a magnetic card with a new public key.

[0051] The host computer rewrites the part of the accessed user profile related to the project ID with a new ID.

[0052]

[Effects of the Invention] As explained above, according to the electronic file cabinet system of the present invention, it is possible to manage keys to a cabinet that can be accessed by multiple users.
Furthermore, since login control, access control, etc. can be established on the same mechanism, security is high and management is easy.

[Brief explanation of the drawing]

FIG. 1 is a first embodiment of an electronic file cabinet system of the present invention.

FIG. 2 is a second embodiment of the electronic file cabinet system of the present invention.

FIG. 3 is a diagram showing an example of a conventional electronic file cabinet system.

[Explanation of symbols]

1 User terminal 2 Host computer 11 User identification information input means 16 First key generation means 17, 18 Encryption means 21 User profile 22, 23, 24 Second key generation means 25, 27
Decoding means 28 Access control means 29 Electronic file cabinet 31 Change identification information holding means

Claims (3)

[Claims] Claim 1: A user terminal (1) and a host computer (2) based on a request sent from the terminal (1).
In a system in which a user accesses an electronic file cabinet (29), the terminal (1) side includes means (11) for inputting user identification information for identifying the user and sending it to the host computer (2) side. , means (12) for inputting a public key created including user's secret information and file identification information for identifying the electronic file cabinet as constituent elements; and means (12) for inputting the public key and the secret information input by the user. means (16) for generating a first secret key based on the above information;
); and means (18) for encrypting an input file access command using the first private key and sending it to the host computer (2); (2) is a user profile (21) in which file identification information of files to which access authority is granted for each user identification information is stored.
and means (22, 2) for creating a second private key based on the identification information read from the user profile (21).
3, 24), a means (25) for decrypting the encrypted authentication information using the second private key, and a means (25) for checking the validity of the decrypted authentication information and logging in the terminal (1). means (26) for permitting/disapproving; and means (26) for decrypting the encrypted command using the second private key;
27), and access control means (28) for accessing the electronic file cabinet (29) by referring to the user profile (21) and confirming access authority based on the decrypted command. Electronic file cabinet system. 2. The public key is a data value obtained by raising a predetermined integer to a power, and the power term includes a product term of the reciprocal of the secret information and the reciprocal of the identification information. The first key generation means (16) generates the first private key by erasing the reciprocal term of the private information from the public key using the input private information, and The second key generation means (22, 23, 24) includes center secret information (23
) to generate a reciprocal of each of the identification information, and perform a power operation of the predetermined integer using the obtained reciprocal of each identification information as a term to generate a second secret key. The electronic file cabinet system according to claim 1. 3. The host computer (2) provides update information indicating whether or not the identification information has been updated in each identification information section in the user profile (21), and also updates the updated identification information. A changed identification information storage means (31) is provided for storing the correspondence relationship between the information and the identification information before being updated, and when each identification information is read from the user profile (21) using the received user identification information, the updated information is stored. If the updated identification information has been updated, create public key generation information including the new identification information obtained by reading the changed identification information holding means (31), and transfer this public key generation information to the second The device is configured to encrypt it using a private key and send it to a terminal that is permitted to log in, and then rewrite the section of the identification information to be updated in the user profile (21) with new identification information, and the terminal (1) 2. The electronic file cabinet system according to claim 1, wherein the electronic file cabinet system is configured to update the public key by decrypting the encrypted public key generation information using the first private key.