JPH02244926A - Method and device for secret data base communication - Google Patents

Abstract

PURPOSE:To simplify access control and to improve secrecy by allowing a data base center to form a cipher key by using the same inherent information and inherent random number as user's ones, cipher data base information, transmit the ciphered information to the user, update the inherent random number, and transmit the updated random number to the user. CONSTITUTION:A user terminal is constituted of a memory card I/O unit 2 for reading out information necessary for forming a cipher key K1 from a storage medium 1, an access control input terminal 3 for inputting an identification(ID) Number, a key former 4, a cipher coder/decoder 5, and a communication control circuit 6. A user (i) forms the necessary cipher key Ki by using at least the inherent information Ii and the inherent random number Ri out of the inherent information Ii, ID information Pi and the inherent random number Ri at the time of accessing a data base. At the time of accepting the access, a new inherent random number Ri' is obtained by using the inherent random number Ri and the inherent information Ii to update the inherent random number Ri and store the updated inherent random number Ri' and the updated inherent random number Ri' is ciphered by the cipher key Ki to transmit the ciphered ID key to the user side. Consequently, simple key control with high secrecy can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a confidential database communication method and apparatus between a user and a database center.

(Prior art) In database communication using a wireless line such as a satellite or a wired line such as a cable, when a pre-registered user (member) accesses a database, a specific user is identified via an authentication number or a password. Users can access a database center (hereinafter simply referred to as the "center") provided exclusively for the company. With wireless lines, these authentication numbers and passwords used for access can be received by other users via their respective wireless communication devices, so they can be easily misused.

Furthermore, when a specific user accesses a database and receives necessary database information, other users can also intercept the database information at the same time without permission, which poses a problem when providing database services.
Therefore, it is necessary to transmit this information using encryption.

(Problem to be solved by the invention) In confidential database communication using encryption, it is conceivable to perform independent encryption processing for access management for accessing the center from the user side and for database transmission. management becomes inevitably complex. In addition, if the authentication number, PIN number, or encryption key is copied or stolen, the same key will continue to be used for database communication without knowing that it has been misused or eavesdropped. Although there may be cases, it generally requires an enormous amount of work to recover confidentiality from such situations.

As described above, with the conventional confidential database communication system and device, it is not possible to easily manage access from the user side to the center and to perform highly confidential database communication.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and aims to provide a confidential database communication method and device that allows easy access management and highly confidential database communication. .

(Means for Solving the Problems) A first feature of the present invention is a confidential database communication method in which a plurality of users access a database in a database center and retrieve desired database information. the authentication number, unique information corresponding to the authentication number, a password, password information corresponding to the password, and a unique random number that is updated each time the user accesses the password; When a user accesses the database center, the user sends at least the authentication number and the encrypted password among the authentication number, the password, and the unique random number to the database center; The center compares the pre-stored information and the information sent from the user and accepts the user's access when they match, and the database center compares the unique information that is the same as that of the user and the information sent from the user. Create an encryption key using at least the unique information and the unique random number of the password information and the unique random number, encrypt the database information, and transmit it to the user, update the unique random number, and send it to the user. It is about transmission.

A second feature of the present invention is a confidential database communication device in which a plurality of pre-registered users access a database in a database center and retrieve desired database information, comprising: an authentication number determined for each user; Unique information corresponding to the authentication number, a password, and password information corresponding to the password.

a storage means for storing a unique random number that is updated each time the user accesses it; and an encryption key is created using at least the unique information and the unique random number among the information stored in the recording means. from a user terminal having an encryption key generation means, a decryption means for decrypting encrypted database information from the database center, and a communication control means for controlling communication between the user and the database center; It's in the way it's structured.

A third feature of the present invention is a confidential database communication device in which a plurality of pre-registered users access a database in a database center and retrieve desired database information, comprising: an authentication number determined for each user; storage means for storing unique information corresponding to the authentication number, a password, password information corresponding to the password, and a unique random number that is updated each time the user accesses it; access determination means for determining whether the user is one of the plurality of users based on the access information obtained; and unique random number generation means for generating a unique random number of the user identified by the access determination means; the encryption key generating means for generating an encryption key using at least the unique random number and unique information stored in the storage means; a database storage means for storing the database information; cryptographic encoding means for cryptographically encoding the read database information and the unique random number generated by the unique random number generating means using the cryptographic key; and controlling communication of the access information etc. from the user. a center terminal equipped with a communication control means for accessing the database center based on access information sent from the user as necessary, and allowing the database center to encrypt the database information. The present invention is configured to transmit the unique random number to the user and update the unique random number.

(Principle of the Invention) The principle of the confidential database communication method according to the present invention will be explained below.

The present invention will be explained using an example in which a user member accesses a database prepared at the center and performs confidential database communication, assuming a group consisting of multiple user members who perform database communication with the center. do.

■The user side and the center side should do the following in advance as preparation.

For a specific user member i, the authentication number and password unique to the user member that are shared with the center and registered in advance are 1. (f), 1. (i), the unique information corresponding to the authentication number is II, the password information corresponding to the password is P, (here, i is the user name, and it is assumed that for user A it is 1. and for user E it is ) and a unique random number R2, and a storage means or removable external storage medium (for example, a hard disk, optical disk, magnetic card, IC card, or floppy disk) is prepared in the user's user terminal and the center side, respectively. .

■Here, when a certain user i accesses the database, he uses at least the authentication number and PIN out of the authentication number, PIN, and unique random number as access information (
However, in the following, we will explain using the authentication number, PIN number, and unique random number), in order to prevent the PIN number and unique random number from being known to a third party, or to protect the encrypted database information transmitted from the center. In order to decipher, unique information technology 5. Among the password information P and unique random number R, at least unique information 1 and unique random number R are used to create the necessary encryption key (however, in the following, unique information I4, password information P6, and unique random number R4 are used) (described below).

■Additionally, to this encryption key, the unique random number R6 encrypted using the cryptographic random number E
R, and the encrypted password E1. (i) and unencrypted authentication number 1. (i), the encrypted cryptographic unique random number ER, and the cryptographic password E I , (i) are transmitted to the center and the database is accessed.

■At the center side, the received authentication number 1. Based on (i), at least the unique information 1 registered and stored in advance, the password information P, and the unique random number R+ are read out, 1 is generated as the encryption key, and the received encrypted password E I ,
(L) and the cryptographic unique random number E R+ are decrypted to obtain the unique random number R and the password 1. (i) obtained and memorized PIN number 1. (i) and the unique random number R1, and if they are the same, the user is considered to be an official user and access is accepted.

(2) Thereafter, the database information determined based on the user's database selection control signal is encrypted using the aforementioned encryption key Kl generated on the center side and transmitted to the user side.

(2) The user side encrypts and decrypts the sent encrypted database information using the above-mentioned encryption key.

■Here, at a certain point in time, such as when access is accepted, while the encrypted database information is being transmitted, or when all the encrypted database information has been transmitted, the unique random number R1, the unique information I4. A new unique random number R1° is obtained by using at least the unique random number R1 and the unique information Il of 1 and the random number for the password information P1 and the encryption key, and thereby the unique random number R, is updated and stored. The generated unique random number R1° is used as an encryption key to encrypt and transmit the encrypted data to the user side. In addition, the encryption key used in item 0 may be either the encryption key generated using the updated unique random number R1° or the encryption key generated using the previous unique random number R1. both are fine.

■When the user receives this, it decrypts it using the aforementioned encryption key 1, updates the unique random number R, with the new unique random number Ri' obtained, and stores it for the next access. .

As described above, the present invention provides confidential database communication in which database information is encrypted and transmitted from the center side to the user side using at least a unique random number that is unique for each user and updated for each confidential database communication. Access management is easy and highly confidential database communication is possible.

(Embodiment) Next, a confidential database communication device for realizing confidential database communication of the present invention will be described.

1 and 2 are configuration diagrams of a user terminal and a center terminal according to the present invention.

First, a user terminal according to the present invention will be explained.

In FIG. 1, the user terminal of the present invention uses an encryption key K.

A memory card input/output device 2 for reading the information necessary to generate the . Access control input terminal 3 for entering the PIN number
, a key generator 4, a cryptographic encoder/decoder 5, and a communication control circuit 6. The user's password and unique random number are input to the cryptographic encoder/decoder 5 via the switch 23 and the cryptographic encoding input terminal 7, and are cryptographically encoded using the key generated by the key generator 4, together with the authentication number. It is transmitted to the center via the communication control circuit 6. Thereafter, when access is accepted, a database selection control signal is sent to the center via switch 23. Further, the encrypted database information received from the center via the communication control circuit 6 is decoded by the encryption encoder/decoder 5 and output as database information from the encryption/decryption output terminal 8 via the switch 24. be done.

On the other hand, the center terminal in FIG. 2 includes a communication control circuit 9, a key generator lO5 for generating an encryption key Kl, an encryption decoder 11, a unique random number generator 12 for updating a new unique random number, and the necessary A cryptographic encoding input terminal 13 for encrypting information, a decoding output terminal 14 for obtaining decrypted passwords and unique random numbers, a database storage unit 15 for storing database information, and a terminal for each user. Access management information storage unit 16 for storing unique random numbers, authentication numbers, passwords, unique information, password information, etc. When necessary, this output is also a unique random number in order to perform randomization from when generating unique random numbers. A random number generator 17 for adding as an input to the generator 12, an access acceptance determiner 18 for determining whether the access from the user is legitimate, and a unique database for the requested database and update if the access is legitimate. The random number is sent to the cryptographic encoder/decoder 11 via the terminal 13.
．． Switches 19 and 20.21 are controlled based on the judgment result of the access acceptance judgment unit 18, and 22 is a switch controlled based on the cryptographically encoded database selection control signal sent from the user terminal. It consists of a database control section that controls reading of databases.

Based on the above configuration, the operation when user A accesses the center and performs confidential database communication will be specifically explained.

■User A uses storage medium 1 (for example, I
C card) into the card reader 2 of the user terminal, and enter the PIN number 1 from the access control input terminal 3. (
Enter a).

■According to this, user A's authentication number I, (a) and password 1. Based on (a), unique information stored in user A's card 1. , password information P, and unique random number R are read out through the memory card input/output device 2 and input into the key generation circuit 4.

(2) Using this information, the key generator 4 generates an encryption key according to a predetermined rule (G).

Here, the unique random number R8 changes each time the database is accessed, and is determined and sent by the unique random number generator 11 at the center at the time of the previous database access.

■Furthermore, using 1 as this encryption key, the encryption encoder decoder 6
The PIN number and the unique random number R1 are encrypted via the PIN code E, (a) and the cipher specific random number ER, are generated and transmitted to the center via the communication control circuit 5 along with the authentication number I-(a). .

As mentioned above, the minimum access information required to access the center is the authentication number I, (a)
and PIN number 1. (a). At that time, the PIN number engineer. If (a) is transmitted as is, there is a possibility that it will be misused by a third party who is intercepting it, so at least the PIN number 1. It is necessary to encrypt (a) and send it to the center.

However, if the unique random number R1, which is updated every time communication is used, is used as the PIN r, (a), it is not necessarily necessary to encrypt and transmit it, and the unique random number R1 can be transmitted as is, or to further increase the security. The encryption-specific random number ER may be encrypted and transmitted. Incidentally, in a state where confidentiality is enhanced, a password may be input to the access control input terminal 3 simply for controlling reading of the contents of the storage medium 1.

■The communication control circuit 5 has an encryption password EI engineering (a) and an authentication number 1. Communication control such as transmission path error correction is performed between the communication control circuit 9 on the other side so that (a) and the cryptographic random number ER are correctly received by the center side, and after that, the database selection control signal, the cryptographic database information, Control is performed so that the encryption-specific random numbers ER' and ER' sent from the center for updating can be received correctly.

(2) Further, when the center terminal accepts the access from the user, the user encrypts and sends a database selection control signal to select necessary database information.

When the cryptographic database information selected by the user is sent via the communication control circuit 6, the cryptographic encoder/decoder 5 performs the cryptographic decoding process using the aforementioned cryptographic key Kl.
Database information is sent from the encryption/decryption output terminal 7.

■Also, at a predetermined time point such as when database communication starts or ends, the cryptographically unique random number ER' sent from the center is decoded by the cryptographic encoder/decoder 6 to generate a new unique random number R'. , and update R with this and store it in the recording medium 1.

Next, the operation on the center side will be explained.

■At the center terminal, the authentication number 1 received via the communication control circuit 9. By (a), it is known that the accessor is user A, and in order to generate the encryption key, user A's unique information In, password information p, which are stored in advance, are used.
and unique random number R1 are extracted from the access management information storage unit 16 and input into the key generator 10, and an encryption key is generated according to the above-mentioned rule (G).

■Furthermore, the generated cryptographic key is sent to a cryptographic encoder/decoder l.
0, and decrypts the cryptographic password E I (a) and the cryptographic unique random number ER received via the communication control circuit 9, respectively.

(2) Each of the decrypted information is input to the access acceptance determination device 18 via the switch 21, and the password 1. (a) and the unique random number R, and if they match, access is accepted.

■If access is accepted, switch 19 and 2
0 is operated, and the switch 21 is used to control the connection between the encryption encoder 11 and the database control unit 22, and the database information requested based on the database selection control signal from the user A is stored in the database. Part 1
Pull out from 5.

(2) The retrieved database information is encrypted by the cryptographic encoder/decoder 11 using the cryptographic key KI, and sent to the user A via the communication control circuit 9 as cryptographic database information.

■When access is accepted, during the requested database communication, or when it is completed, the encryption key used and unique information 1. , the password information P, and the unique random number R1, as well as the output of the random number generator 17 as necessary, are input to the unique random number generator 12 to generate a new unique random number R'a, and the unique random number R, This is access management information storage unit 1 for updating.
6 as a unique random number.

■Furthermore, this updated unique random number R'a is sent to the switch 20.
The data is input to the encryption encoder/decoder 11 via the encryption key Kl, encrypted using the encryption key Kl, and transmitted to the user A via the communication control circuit 9. Note that if the access is not considered legitimate, the switches 19 and 20 are closed, and the switch 21 closes the database control unit 22 and the cryptographic encoder/decoder 11.
The database information and unique random numbers will not be updated or sent.

Table 1 shows an example of the contents stored in the external storage medium 1 when each of users A, B, and C uses the external storage medium 1 for database access in the present invention. Further, Table 2 shows an example of the configuration of information stored for access management at the center.

(Leaving space below) Table 1 Example of configuration of encryption key generation information in user's external storage medium Table 2 Contents in access management information storage unit of database center As an example of rule (G) for key generators 4 and 9 mentioned above, ,
This can be realized by taking a bit-by-bit exclusive OR of at least the input unique random number R, the unique information 1, and the password information P, and inputting it to the block cipher. In addition,
The minimum required parameter for the encryption key is the unique random number R.
1 and the unique information (2) are sufficient, and to further enhance confidentiality, the password information P and the previously used encryption key may also be used at the same time.

In addition, as an example of the rule (H) of Unique Random Number Generator]1, input unique information 1. and the password information P, the encryption key used is 1, the unique random number RI, and the random number are taken for each bit exclusive OR, and it is input into a block cipher, or a random number generator is used for initialization. This can be achieved by using it as a value.

As described above, in the present invention, a user can receive the authentication number 1 of another user via a wireless line. It is possible to know (i), but the password 1. (a) and the unique random number R are encrypted, and because the unique random number R1 changes each time it is accessed, it is extremely difficult to decipher these contents. Moreover, the encryption key generated each time database communication is performed is always different, and it is almost impossible to obtain correct database information even if the encryption database information is intercepted. Furthermore, the authentication number I-(i) and the password I-(a) between the accessing user and the center are
If the content of Rt and the unique random number Rt are not the same, the access will not be accepted, and once the access is accepted, the unique random number will be updated each time. It has the feature of being able to simultaneously implement security measures for authentication and measures against interception of database information.

In addition, in the present invention, in normal use, the user simply enters the password 1. Just by specifying (a), the same cipher WaK as the center is automatically generated, allowing confidential database communication. Furthermore, when comparing the unique random number R stored by the user and the unique random number R stored in the center, if they are different from each other, the confidentiality of access information between the user and the center is broken. It is clear that someone else completely copied the internal information on the card and accessed the database without permission. Here, by resetting only the unique random number in the storage medium 1 of the user and the corresponding unique random number of the center, confidentiality can be easily restored again, and the effect of the copied access information becomes invalid.

In addition, members who require a particularly high level of confidentiality should perform the above access communication process to the center one or more times in a row when performing confidential database communication, forcefully and quickly update the RI, and then try again to actually perform the actual communication. By starting confidential database communication at It can be made into something. In addition, the copied storage medium 1
If there is likely to be an eavesdropper who is constantly monitoring database information using a similar database communication system, eavesdropping can be prevented by forcibly updating the unique random numbers using other means.

Therefore, by allowing each member to individually perform such operations with the center in a timely manner, it is possible to maintain a high level of confidentiality at all times without having to simultaneously update large-scale information regarding key generation for security protection. Furthermore, for periodic maintenance of the security protection capability to maintain complete confidentiality, a new storage medium with only the unique random numbers rewritten as described above may be transferred to another 1,890. , and use it to perform confidential database communication.

In this embodiment, when providing an independent confidential database service to a group consisting of completely different user members, the management of the authentication number at the center, the unique information processing in the IC card, and the bit configuration of the unique random number R3 are required. If the group is changed, keys generated by members other than that specific group will always be authenticated unlike official ones, and will not be able to access databases of other groups. Therefore, on a confidential database communication system with such a configuration, communication of multiple confidential databases belonging only to a specific group can be realized, and even within the same group, members can be divided into classes by dividing the databases that can be accessed. It is.

In addition, if the information related to the generation of an encryption key is stored only in an external storage medium such as an IC card, and the composition of unique information and unique random numbers is changed for each group, and the above access information is managed at the center, each The database access management communication system and access terminal system can be shared not only within the group but also with other groups.

DES is the encryption algorithm for the encryption encoder/decoder.
or other existing methods may also be used.

(Effects of the Invention) As described above, the present invention allows users to securely keep information confidential without being intercepted by other members within a group specified by a simple access operation in which the user simply specifies a PIN number. In addition to being able to receive database services,
Since the encryption key is automatically changed using a unique random number R1 that is updated every time there is an access, an individual encryption key can be used for each user, and high confidentiality can be achieved, as well as simple key management.

In addition, if the information related to generation is copied to the encryption key in the removable external storage medium 1 such as an IC card, or even after it has actually been misused, it is possible to detect the fact of abuse and recover the encryption key Ki. Confidentiality can be easily restored, and highly reliable confidential database communication can be maintained without frequent updating of encryption keys as explained above.

Furthermore, by simply changing a part of the storage information in the storage medium 1, other groups can independently perform confidential database communication using the same hardware, making it possible to realize an extremely economical circuit configuration. .

Therefore, the present invention applies not only to wired lines such as cables, but also to wired lines such as cables.
It can be applied to various database systems that use wireless lines such as satellites that can be easily intercepted, and its effects are extremely large.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a user terminal according to the present invention, and FIG. 2 is a block diagram of a center terminal according to the present invention. External storage medium, memory card input/output device, access control input terminal, key generator, encryption encoder/decoder, communication control circuit, 7 ・ ・ ・ 8 ・ ・ ・ 9 ・ ・ ・ 10 ・ ・ 11 ・ ・12・ ・ ・ 13・ ・ ・ 14・ ・ 15・ ・ 16・ ・ ・ 17・ ・ 18・ ・ ・ 19, 20° 22・ ・ ・ Encryption encoding input terminal, encryption decoding output terminal, communication control circuit, cryptographic key generator, cryptographic encoding/decoding device, unique random number generator, cryptographic encoding input terminal, cryptographic decoding output terminal, database storage section, access management information storage section, random number generator, access acceptance determination device, 21, 23.24...Switch circuit. Database control unit.

Claims (7)

[Claims] (1) In a confidential database communication method in which multiple users access a database in a database center and retrieve desired database information, an authentication number determined for each of the multiple users and unique information corresponding to the authentication number. , a password, password information corresponding to the password, and a unique random number that is updated each time the user accesses the database center, and when the user accesses the database center, the user sends at least the authentication number and the encrypted password among the authentication number, the password, and the unique random number to the database center, and the database center collects the pre-stored information and the user's information. The user's access is accepted when the transmitted information is compared and they match, and the database center selects at least the unique information of the unique information, the password information, and the unique random number that are the same as the user's information. and the unique random number to create an encryption key to encrypt the database information and transmit it to the user, and also update the unique random number and transmit it to the user. (2) In a confidential database communication device in which a plurality of pre-registered users access a database in a database center and retrieve desired database information, an authentication number determined for each user and a corresponding authentication number are provided. Storage means for storing unique information, a password, password information corresponding to the password, and a unique random number that is updated each time the user accesses the information; and information stored in the recording means. an encryption key generation means for generating an encryption key using at least the unique information and the unique random number; a decryption means for decrypting encrypted cryptographic database information from the database center; and the user and the database. 1. A confidential database communication device comprising a user terminal having communication control means for controlling communication with a center. (3) In a confidential database communication device in which a plurality of pre-registered users access a database in a database center and retrieve desired database information, an authentication number determined for each user and an authentication number corresponding to the authentication number are provided. storage means for storing unique information, a PIN number, PIN information corresponding to the PIN number, and a unique random number that is updated each time the user accesses the information; access determination means for determining whether the user is one of the plurality of users; unique random number generation means for generating a unique random number of the user identified by the access determination means; and at least the unique random number and the the encryption key creation means for creating an encryption key using the unique information stored in the storage means; the database storage means for storing the database information; and the database information read from at least the database storage means. and a unique random number generated by the unique random number generating means using the cryptographic key; and a communication control means for controlling communication of the access information etc. from the user. accesses the database center based on access information sent from the user as needed, and the database center encrypts the database information and transmits it to the user; A confidential database communication device characterized by being configured to update a unique random number. (4) The confidential database communication device according to claim 2, wherein the user terminal includes cryptographic encoding means for encrypting the access information with the encryption key. (5) The security according to claim 3, wherein the center terminal is configured to encrypt the database using a different encryption key for each user when transmitting the database to the user. Database communication device. (6) Without directly transmitting the encryption key between the user and the database center, the unique random number that changes for each access necessary to generate the encryption key is encrypted and transmitted, used for authentication, and used for each 4. The confidential database communication device according to claim 2, wherein the confidential database communication device is configured to generate a cryptographic key and perform cryptographic encoding and decoding. (7) The center terminal receives any information including the unique random number, the unique information, the password information, the encryption key, and the random number at the time when the access is accepted, the time when the database has been transmitted, or at a certain point in time. 4. The system according to claim 3, wherein the unique random number is newly generated and updated using the combination, and further encrypted and transmitted to the user for updating, and used for the next database access. Confidential database communication device.