JP2006237670A - Security system for database and buildup method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To build a system, whereby information leakage from within is prevented and only those people in need of the information can read required information because substantially all the information leakage originates from the people in the inside rather than by external infiltration, and to build a method thereof. <P>SOLUTION: The security system of a database in a database system is provided, wherein it is characterized in that a user A, following an initial procedure, encrypts a plain text or speech content m into an encrypted text by using a public key or a private key and stores the text to the database on the system, other user B decrypts the encrypted text by using a key possessed by the user B, the user A can decrypt the encrypted text by using the key possessed by the user A, the user B can decrypt the encrypted text by using the key possessed by the user B; and when the plain text or the speech content m are updated, the updated contents can be encrypted and stored to the database, and also the updated content can be decrypted, and the encrypted text cannot be known to third parties other than the users A, B. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention secures a database in which a public key and a private key are registered and used together with encryption and decryption of the database so that personal information other than management is not leaked to the outside through the system side. It is about building a system.

Due to recent advances in computers and network infrastructure, transactions on the Internet are growing rapidly. Along with that, a huge amount of personal information was saved on the network. In addition, as Web application development has become large-scale, the number of people involved in development and maintenance has increased, and not only in-house but also outside the company has been involved in development. It is very difficult to protect personal information, and personal information is leaked from many companies, which is a social problem. Security measures, development costs, and development time are contradictory, but it is necessary to take some security measures for risk management and make efforts to prevent information leakage.
For example, from a database storing data provided on a network, for a client that has made a search request, a method of searching data in a secret state and transmitting the data to the client in a secret state (see Patent Document 1), There is a program (see Patent Document 2) that secures a system that generates a key for data encryption and decryption based on a unique ID with a member of use.

There are two types of encryption: private key encryption and public key encryption.Private key encryption is an encryption method that uses a common key and secret key for encryption and decryption, and includes both symmetric key encryption, conventional encryption, and common key encryption. be called. Compared to public key encryption, the encryption speed is higher and the implementation size is smaller, so it is used to encrypt large amounts of data. In order to perform secret communication using the secret key cryptosystem, it is necessary that the sender and the receiver exchange the secret key through a secure route in advance. Share keys with private lines or public key methods.
There are two types of secret key ciphers: a stream cipher that sequentially generates plaintext in l-bit bits, and a block cipher that performs encryption and decryption for each fixed block. The encryption of the Plock encryption method includes a data agitation unit that converts plaintext into ciphertext and a key expansion unit that generates a key to be supplied to the data agitation unit from the encryption key. The input and output to the data agitation unit are plaintext and ciphertext, respectively. The main parts of the data agitation part and the key expansion part are both composed of a fixed stage structure. For safety reasons, auxiliary functions may be inserted before, after, or during the repetitive structure. The round key generated from the encryption key by the key expansion unit is supplied to the data agitation unit.

  In public key cryptography, how to deliver a private key between a sender and a receiver is a big problem in private key cryptography. Public key cryptography (also called asymmetric cryptography) has solved this problem of key distribution. In public key cryptography, the key for encryption and the key for decryption are different, and the key for encryption is made public and the key for decryption is kept secret. The principle of public key cryptography is as follows. Initial procedure User A generates a private key Pa and a public key Sa to be secretly managed by a predetermined method. A registers Pa in the public key book. This public key book is like a telephone directory, and the public key Pa is written instead of the telephone number corresponding to the name of A. Consider a case in which user B by encryption encrypts and transmits to A. B searches A's public key Pa using the public key book. Next, the call content m is encrypted using Pa. Here, the ciphertext c is referred to as EPa (m). A receiving the ciphertext c decrypts m = Dsa from c using a secret key Sa known only by A. Here, when m = DSA ((EPA (m)) is established, the decoding can be correctly performed.

The key generation user generates prime numbers p and q (p and q are approximately the same size), and calculates n = pq and Φ (n) = (p 1 1, q 1 1). (Φ (b): Euler function (the number of integers 1 to b that are mutually prime with b; if b = pq (p, q are prime numbers) Φ (b) = (p 1 1) (q 1 1 ) I know.))
Determine an appropriate e ∈ ZΦ (n) (GCD (e, Φ (n)) = 1), and calculate d ≡ 1 ≡ ed mod Φ (n). (GCD (a, b): a, b of the greatest common divisor, a mod b: a divided by less in b) the private key d, the public key e, n, encrypted c = m ^e mod n, decoding m = c ^d mod n, and further = m mod n where m is a digitized document (plaintext) to be encrypted, and at the same time means an integer value as its binary representation. At this time, 0 <m <n.

  In addition, the secure key length, WWW (World Wide Web), HTTP (Hyper Text Transfer Protocol), and SSL (Secure Sockets Layer) are assumed to be the interpretation of the general Internet market.

FIG. 5 shows a model diagram of general database system security as a comparison with the present invention. (A) shows that when information is transmitted to A of user 4 from B of user 4 by encryption using public key PA of A as a public key, A can be read but B cannot be read. (B) indicates that A cannot be read when B sends with B's public key PB. (C) can be read by both users A and B when encrypted using the private key K, but requires a place to store the private key K, and when placed on the database server 5, it can be viewed by a person who looks into the database server 5. It will be done.
FIG. 6 shows an example of the construction of a conventional general ordinary commerce site. In the ordinary commerce site, communication is encrypted using a security technology called SSL in order to increase security. The contents performed by the development, operation, maintenance group, and customer group 4 on the system side 1 will be described below. The development and maintenance group 2 on the system side 1 (1) summarizes the required specifications of the commercial transaction site, raises the specifications, and (2) starts up the necessary servers, Web servers or database servers. (3) (Normal) Generate a key required for SSL and create a certificate. (4) Have the certificate authority sign the certificate and save the signed certificate on the Web server. (5) Set the database according to the specifications or create a web page. On the other hand, in the operation group 3, necessary information, for example, merchandise information and the number of stocks, etc. are input to enable operation. The maintenance group monitors the server and backs up the database. Development group 2 and operation group 3 have the authority to enter the server directly. Operation group 3 and customer group 4 communicate using a Web browser and send information. The customer group 4 confirms the signed certificate, encrypts the communication by SSL communication, and sends information ((c) in the figure). In this figure, the database is not encrypted.

  In the above example, since it is SSL communication, corporate impersonation, communication wiretapping and tampering cannot be performed. However, the development and maintenance group on the system side can access the DB base. Most of the data is stored in plain text. Even if the DB base is encrypted, the decryption key is stored on the Web server, so it can be decrypted by the development and maintenance group.

  More specifically, in a general commercial transaction site, the user customer 4 can access only his / her information. On the other hand, access by the administrator 2 on the system side has the authority to access any server 5 in order to manage the system. However, you may be able to browse data that you do not need to know. Access to the operation group (customer contact) 3 is web-based, so it is only necessary to access the web server. However, it is necessary to know business information. Here, it is shown that the system-side development group 2 that does not need to know the user's personal information or the like can read the database 6 in the server 5.

Japanese Patent Application Laid-Open No. 2004-21654 JP 2004-297755 A

  Information leakage is more likely to be taken from inside rather than from outside. Therefore, how to prevent information from leaking from the inside is the key. Building a system that can be read only by the people who need it will dramatically improve security. If the inside is classified according to business, it becomes the development side, the operation side, and the maintenance side. Among these, the development side and the maintenance side do not particularly need personal information, so a system is constructed so that personal information cannot be read, and the operation side that requires personal information for business purposes can read personal information.

  In the database system, using the public key or private key, the initial procedure user A stores the plaintext and the content of the call m as ciphertext in a database on the system, and the other user B owns B. And A can be decrypted with the key owned by A, B can be decrypted with the key owned by B, and when updated, it is encrypted and stored in the database. Provided is a database security system characterized in that it can be decrypted and is not known to third parties other than A and B. In particular, in order to eliminate information leakage from the system side, the system is characterized in that it cannot obtain information more than necessary for customer management.

  The present invention has the following effects. (1) Since the data stored in the database is encrypted, it is more difficult to leak information from the development group and maintenance group than a general system. (2) Since only information that is in charge can be taken out from the operation group, a large amount of information is rarely leaked. (3) Even if information is leaked, the person who can read it is determined, so it is possible to track where the information leaked. (4) If the server-side Web page and the client program (such as Java Applet) are not modified, it can be assured that personal information can only be read by customer groups and operation groups. (5) Even if a change is made to the commerce site itself, information registered before the change cannot be read unless the key is known.

FIG. 1 shows a basic model (a) in the database safety system according to the first embodiment of the present invention. As a user side, a customer group 4 and a user side as an operation group (customer contact) side 3 are shown. , communication not encrypted, and the information itself is encrypted (EnInfo _a). Since the flowing information is encrypted internally, the contents cannot be known unless there is a key necessary for decryption. The encryption method will be described later, but the customer 4 and the customer contact 3 can browse and update information. However, the system administrator 2 can make the system incapable of knowing information.
FIG. 1 (b) shows a system model diagram in the business transaction of one embodiment. In the database system, the initial procedure user A (customer side 4) uses the public key or the secret key, and the plain text or the contents of the call m is encrypted and stored in the database 6 on the system, and other user B (customer contact 3) decrypts it with the key and ciphertext owned by B, and A is the key owned by A, B can be decrypted by the key owned by B, and when updating, it can be encrypted and stored in the database and decrypted. It is known to third parties other than A and B. The present invention relates to a database security system characterized in that it is not provided. As can be seen in this figure, the customer encrypts the plaintext (circled number 1), sends it to the server 5, and stores it in the database as it is (ciphered number 3). The operation side (customer window) 3 can decrypt information (circled number 10) with the key, and can encrypt information (circled number 11). This can be read and decrypted by the customer (circled number 6). In the figure, ● indicates ciphertext, and ○ indicates plaintext. A circled number 13 represents the system public key. By doing so, the system administrator 2 cannot read the encrypted contents of the database.

  Fig. 2 is a model diagram when one key in the system, N customers 4 as users of the initial procedure, and 1 division of customer information as information (referred to as a 1-to-N (1) system). (A) indicates that customer information segmentation consists of multiple items (name, address, telephone number, etc.) as customer information. A division of 1 means customer information rather than handling multiple items individually. Is divided into two groups: system side 1, customer 4, and operation group side 3, and the former (system side) cannot read information, and the latter (customer, operation group side) As a system that can read the information, one operational group 3 system uses a public key method, and a customer group 4 uses at least one of a public key method and a secret key method. The safety system of the database, characterized. FIG. 2 (b) shows an example of commercial transaction. Like FIG. 1 (b), the system side (development and maintenance group) can access the database, but the information is encrypted. It will not be readable.

For encryption processing in the 1: N (l) system, a program called Java Applet that runs on a Web browser is used. This program is stored on the web server and loaded into the client when the page is loaded. Therefore, if the development and maintenance group incorporates a mechanism into the program, it is possible to steal the customer key. However, since a signed program can be created, it can be confirmed from the outside whether the program has been modified. The key can be obtained by changing the Web page itself and sending personal information in plain text, but it is necessary to confirm whether the Web page has been changed by the operation group.
Here, the system is divided into two groups, “Development group and maintenance group” and “Customer group and operation group”. The former group cannot read information and the latter group can read information. The customer group may use either a public key method or a secret key method.

Table 1 shows the encryption notation.

The procedure for building a 1: N (l) system is as follows.
As a commerce site in this system, the system side development group,
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) A process of inputting information necessary for operation and maintaining it in an operable state,
(4) The process of extracting the information by combining the parts corresponding to the customer's personal information,
Customer group
(1) Checking SSL (security) signed certificate and system key K signed certificate,
(2) generating a customer key Ka;
(3) The process of encrypting only the portion corresponding to personal information and sending the information by SSL (security) communication,
Set the construction method consisting of

The system procedure will be described in the order of (1) initial setting, (2) information encryption and transmission, and (3) safety confirmation.
(1) In the initial setting procedure, the operation group creates a system key K. Since K is a public key method,
K = (S, P)
S: K's secret key, S = (d, n) (dεZ, n = pq (p and q are prime numbers))
P: K public key, P = (e, n) (e∈Z)
It is. The public key P is made public.
Then the customer a (collective customer group 1) to create a key K _a. If the customer key is the public key system _{K a K a = (S a} , P a)
S _a : K _a private key, S _a = (d _a , n _a ) (d _a ∈Z, n _a = p _a q _a (p _a and q _a are prime numbers))
P _a : Public key of K _a , P _a = (e _a , n _a ) (e _a εZ)
The public key _Pa is made public.
Customer key is to simply secret key K _a is the case of the secret key system. It is also assumed that the system key is longer than the customer key.
(2) In the information encryption and transmission procedure, information known at this time is put together,
1) When key customer group is the public key system, the development group, maintenance group: P, Pa, operations groups: S, P, P _a, customer _a: P, P a, the S _a.
2) When the key customer group is the secret key system, the development group, maintenance group: P, operation group: S, P, customer a: P, the K _a.
To send information info _a , customer a sends the following encrypted information EnInfo _a .
1) If the key customer group is the public key system, information send EnInfo _a is _{EnInfo a = (En (info a} , P a), En (S a, P))
Two encrypted information pair or _{EnInfo a ≡En, (info a,} P a) mod n a
EnInfo _a ≡En (S _a , P) mod n
EnInfo _a may be used.
2) If the key customer group is the secret key system, information send EnInfo _a is _{EnInfo a = (En (info a} , K a), En (K a, P))
The two pairs of encrypted information are:
(3) In verifying safety,
1) The known information of customer a is
a) In the case of the customer key is public-key method, which is a _{P a, S a, P,} Enlnfo a.
Info _a can be found from the first term of Enlnfo _a and S _a .
De (EnInfo _a , S _a ) ⇒De (En (info _a , P _a ), S _a = info _a
Thus, customer a can read the information.
b) customer key is the case K _a, P, Enlnfo _a secret key system.
Info _a can be found from the first term of Enlnfo _a and S _a .
_{De (Enlnfo a, K a)} ⇒ De (En (info a, K a), K a) = Info a
Thus, customer a can read the information.
2) The known information of the operation group is
a) When customer key is public key system: S, P, Pa, EnInfo _a . From the second term of Enlnfo _a and S
_{De (EnInfo a, S) ⇒De} (En (S a, P), S) = S a next, Sa can get.
Thus the 1) as well as retrieve information info _a. Also, since S _a is known, it can be updated.
b) When the customer key is a secret key system: S, P, Enlnfo _a . Enlnfo 2 nd term and S from De (EnInfo _a, S) of _{a ⇒De (En (K a,} P), S) = K a next, K _a can get.
Thus the 1) as well as retrieve information info _a. In addition, it is also updated in was found K _a.
3) Development group, maintenance group, known information of customers other than a a) Customer key is public key method
P, P _a , Enlnfo _a .
Since Enlnfo _a = (En (info _a , Pa), En (Sa, P), the two terms cannot be decoded.
Therefore, information cannot be extracted.
b) When the customer key is a private key method
P, Enlnfo _a .
Since Enlnfo _a = (En (info _a , K _a ), En (K _a , P)), the two terms cannot be decoded. Therefore, information cannot be extracted.
From the above, safety was verified.

Fig. 3 is a model diagram (a) showing an M-to-N (1) system. When there are M keys in the system, N customers, and 1 division of customer information, the system has multiple keys. As a result, multiple groups can be grouped to set up a group in a tree shape, create the original system key K, create the system key K _A , system key K _B from it, further system keys K _AA , K _BB the creation possible and then, was safe system mode of the database, characterized in that decoding with the original K the encrypted information K _a. (B) This is an example of a commercial transaction site, and the response by a plurality of operation groups is examined.
The procedure is as follows:
As a commercial transaction site in claim 3, the system side development group is:
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) Operation A generates a system key K _A = (S _A , P _A ) and creates a certificate;
(4) The operation A receives a certificate from the administrator of the operation group and holds it in the server;
(5) A step of repeating the steps (3) and (4),
(6) A process of inputting information necessary for operation and maintaining it in an operable state,
(7) The process of extracting the information by combining the portion corresponding to the customer's personal information,
Consists of
Customer group
(1) Checking the SSL (security) signed certificate and the system key K signed certificate, and the system key K _A , K _B ,.
(2) a step of generating a customer key K _A,
(3) The process of encrypting only the portion corresponding to personal information and sending the information by SSL (security) communication,
A database security system construction method characterized by comprising:

である。公開鍵である P は公開しておく。そして、運用グループ A はシステム鍵Ｋ_Aを生成する。公開鍵方式であるので、

である。公開鍵である P_A は公開しておく。ここで、運用グループ A は En ( S_A 、 P ) を公開しておく。これは運用管理者の長が運用グループ A の情報を読み取るのに使用する。以下同様に運用グループ B 、運用グループ C 、、、がK_B、K_C、、、、を作成し、
Ｐ_B、P_C、、、Ｅｎ（Ｓ_B，Ｐ）、Ｅｎ（Ｓ_C、Ｐ）、、、を公開する。更に運用グループからも同様に作ることができる。運用グループＡ＿Ａ、Ｂ＿Ｂ、、、がＫ_AA、Ｋ_AB、、、を作成し、Ｐ_AA、Ｐ_AB、、、Ｅｎ（Ｓ_AA、Ｐ_A）、Ｅｎ（Ｓ_AB、Ｐ_A）、、、を公開する。以上 K 、Ｋ_A、Ｋ_AA、、、Ｋ_B、Ｋ_BA、、、の個数が合計 M になる。
顧客グループの鍵の設定をする。顧客 a (集合 顧客グループの１）が鍵 Ka を生成する。顧客鍵が公開鍵方式の場合は、

とし、公開鍵である Pa は公開しておく。顧客鍵が秘密鍵方式の場合は単に秘密鍵 Ka とする顧客鍵よりもシステム鍵のほうが長いものとする。
（２）情報の暗号化、送信
顧客 a が情報 ＥｎＩｎｆｏ_a を運用グループ A に送るには以下の暗号化した情報ＥｎＩｎｆｏ_aを送る。
１）顧客グループの鍵が公開鍵方式の場合、送る情報ＥｎＩｎｆｏ_aは、

からなるＥｎＩｎｆｏａでよい。
２）顧客グループの鍵が秘密鍵方式の場合、送る情報ＥｎＩｎｆｏ_aは、

の 2 つの暗号化された情報のペアとする。 (1) Initial settings, (2) Information encryption and transmission, and (3) Safety verification were verified in the same manner as in the previous system.
(1) Initial setting procedure Consider grouping operation groups. Since there are M system keys, the operation group can be divided into M groups. First, the person who manages the original system key K and the operation manager (operation group 1) are determined, and the system key K is set. Since the system key K is a public key method,

It is. Public key P is made public. Then, the operation group A generates a system key K _A. Since it is a public key method,

It is. Is a public key P _A is made public. Here, the operation group A discloses En (S _A , P). This is used by the operations manager's head to read the information in operation group A. Similarly, operation group B, operation group C,, create K _B , K _C ,,
P _B , P _C ,, En (S _B , P), En (S _C , P), are disclosed. Furthermore, it can be made from the operation group in the same manner. The operation groups A_A, B_B,, create K _AA , K _AB ,, and create P _AA , P _AB ,, En (S _AA , P _A ), En (S _AB , P _A ), Publish. The total number of K, K _A , K _AA ,, K _B , K _BA , and so on is M.
Set the customer group key. Customer a (1 of the group customer group) generates the key Ka. If the customer key is public key,

The public key Pa is made public. If the customer key is a private key method, the system key is longer than the customer key that is simply the private key Ka.
(2) Information encryption and transmission The customer a sends the following encrypted information EnInfo _a to send the information EnInfo _a to the operation group A.
1) When the key of the customer group is a public key method, the information EnInfo _{a to be} sent is

EnInfo consisting of
2) When the key of the customer group is a secret key system, the information EnInfo _{a to be} sent is

Let's say that the two pairs of encrypted information.

よって、顧客ａは情報を読み取れる。
（ｂ）顧客鍵が秘密鍵方式の場合、顧客ａは
Ka 、Ｅｎｌｎｆｏ_aを知っているので、Ｅｎｌｎｆｏ_aのーつ目の項と Sa からｉｎｆｏ_a が分かる。

よって、顧客ａは情報を読み取れる。
２）運用グループＡの情報読み取りについて、
（ａ）顧客鍵が公開鍵方式の場合、運用グループＡは
S_A 、 P_A 、 P_a 、Ｅｎｌｎｆｏ_a知っているので、Ｅｎｌｎｆｏ_aの 2 つ目の項と S_A から

となり Sa が取得出来る。よって上記 １ ) と同様に情報ｉｎｆｏ_aを取り出せる。また、Ｓａがわかったので、更新もできる。
（ｂ）顧客鍵が秘密鍵方式の場合、運用グループＡは
S_A 、 P_A 、 Ｅｎｌｎｆｏ_aである。 Ｅｎｌｎｆｏ_aの 2 つ目の項と S_A から

となり、Ｋ_aが取得できる。よって、上記１）と同様に情報ｉｎｆｏ_a を取り出せる。また、Ｋ_aが分かったので、更新もできる。
３）運用管理者の長（アドミニストレイタ）の情報読み取りについて、
（ａ）顧客鍵が公開鍵方式の場合、運用管理者の長は
Ｓ、 P 、 P_a 、En ( SA 、 P ）、Ｅｎｌｎｆｏ_aを知っているので、En ( SA 、 P ）とＳから

となり、Ｓ_Aを取得できる。この時点で上記 ２ ）の場合と同様に情報 ｉｎｆｏ_a の読み取り、更新が可能である。
（ｂ）顧客鍵が秘密鍵方式の場合、運用管理者の長は
Ｓ_A、 P_A 、En ( S_A 、 P ）、Ｅｎｌｎｆｏ_a知っているので、 En ( S_A 、 P ）とＳから

となり、 S_A を取得出来る。この時点で上記 ２ ）の場合と同様に情報 ｉｎｆｏ_a の読み取り、更新が可能である。 (3) Verification of safety 1) About the information of customer a
(A) When customer key is public key method, customer a
Since we know Sa and Enlnfo _a, we can know info _a from the first term of Enlnfo _a and Sa.

Therefore, the customer a can read the information.
(B) If the customer key is a private key method, customer a
Since Ka and Enlnfo _a are known, info _a can be found from the first term of Enlnfo _a and Sa.

Therefore, the customer a can read the information.
2) About reading information of operation group A
(A) When customer key is public key method, operation group A
S _A , P _A , P _a , Enlnfo _a know, so from the second term of Enlnfo _a and S _A

And Sa can be acquired. Thus the 1) as well as retrieve information info _a. Also, since Sa is known, it can be updated.
(B) When the customer key is a private key method, the operation group A
S _A , P _A , Enlnfo _a . From the second term of Enlnfo _a and S _A

And K _a can be acquired. Therefore, the 1) as well as retrieve information info _a. Also, since K _a is known, it can be updated.
3) About reading the information of the manager (administrator)
(A) In the case of customer key is the public key system, long S of the operations _{manager, P, P a, En (} SA, P), so you know the _{Enlnfo a, En (SA, P} ) from S

And S _A can be acquired. Reading the same manner as in the case information info _a above 2) At this point, updates are available.
(B) If the customer key is a secret key method, the head of the operation manager knows S _A , P _A , En (S _A , P), Ennfo _a , so from En (S _A , P) and S

And S _A can be acquired. Reading the same manner as in the case information info _a above 2) At this point, updates are available.

となり、Ｓ_Aを取得できる。Ｓ_AとＥｎｌｎｆｏ_aの２項目から

よってＳ_aを取得できた。
ここでＥｎ（Ｓ_a、Ｐ_B）を計算し、これをＥｎＩｎｆｏ_aの２項目に変更すると、

となる。よって上記２）と同様に運用グループＢは読み取り、更新できるようになった。
（b）顧客鍵が秘密鍵方式の場合、運用管理者の長は
Ｓ、 P 、Ｐ_A、Ｐ_B、En ( S_A 、 P ）、Ｅｎ（Ｓ_B、P）、Ｅｎｌｎｆｏ_a
知っているので、Ｅｎ（Ｓ_A、Ｐ）とＳから

となり、Ｓ_Aを取得できる。Ｓ_AとＥｎｌｎｆｏ_aの２項目から

よってＫａを取得できた。
ここでＥｎ（Ｋ_a、Ｐ_B）を計算し、これをＥｎＩｎｆｏ_aの２項目に変更すると

となる。よって上記２）と同様に運用グループＢは読み取り、更新できるようになった。運用グループが読めるようになっても、もし運用グループＡが（ａ）Ｓ_a（ｂ）Ｋ_aを保持していると、情報を集めてしまうので、顧客ａに鍵の変更を促すか、システム鍵で顧客ａの鍵を変更して顧客ａに伝える必要がある。
５）開発グループ、保守グループ、ａ以外の顧客に情報が読み取られる可能性について、
（ａ）顧客鍵が公開鍵方式の場合

であり、開発グループ、保守グループ、ａ以外の顧客Ｓａ，Ｓ_Aを知らないので、２項とも復号化できない。よって情報は取り出せない。
（ｂ）顧客鍵が秘密鍵方式の場合

であり、開発グループ、保守グループ、ａ以外の顧客はＫ_a，Ｓ_Aを知らないので２項とも復号化できない。よって情報は取り出せない。
以上安全性が検証できた。 4) Regarding the possibility that the manager of the operation manager can change from operation group A to operation group B,
(A) When the customer key is a public key method, the head of the operation manager is S, P, Pa, P _A , P _B , En (S _A , P), En (S _B , P), Enlnfo _a
Because I know, from En (S _A , P) and S

And S _A can be acquired. From two items: S _A and Enlnfo _a

Therefore, _Sa was able to be acquired.
Here, when calculating En (S _a , P _B ) and changing it to two items of EnInfo _a ,

It becomes. Therefore, operation group B can be read and updated as in 2) above.
(B) When the customer key is a secret key method, the operation manager head is S, P, P _A , P _B , En (S _A , P), En (S _B , P), Enlnfo _a
Because I know, from En (S _A , P) and S

And S _A can be acquired. From two items: S _A and Enlnfo _a

Therefore, Ka was able to be acquired.
Here, when En (K _a , P _B ) is calculated and changed to two items of EnInfo _a

It becomes. Therefore, operation group B can be read and updated as in 2) above. Even so operations group can read, if the operations group A is holding the _{(a) S a (b)} K a, so will collect the information, or prompt the change of the key to customer a, system It is necessary to change the key of the customer a with the key and notify the customer a.
5) Regarding the possibility of information being read by customers other than the development group, maintenance group, and a.
(A) When customer key is public key method

, And the development group, maintenance group, customer Sa other than a, because it does not know the S _A, with two terms can not be decoded. Therefore, information cannot be extracted.
(B) When the customer key is a secret key method

Since customers other than the development group, maintenance group, and a do not know K _a and S _A , neither of the two terms can be decrypted. Therefore, information cannot be extracted.
The safety has been verified.

FIG. 4 is a model diagram (a) of the M to N (L) system in the present invention. If there are M keys in the system, N customers, and L division of customer information, by dividing the customer information into multiple pieces, instead of thinking about multiple items at once, individual items A safety system method for a database characterized in that a group in charge of each item is set and individual information of customer a information info, info a 2, etc. can be read for each group in charge of the operation group About. (B) is a model diagram of an example of a commercial transaction. As described above, the information is divided and the access to necessary information differs depending on the person in charge, thereby preventing leakage.
The procedure is as follows.
As an example commerce site, the system side development group is
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) Operation A generates a system key K _A = (S _A , P _A ) and creates a certificate;
(4) The operation A receives the certificate from the administrator of the operation group and stores it in the server;
(5) A step of repeating the steps (3) and (4),
(6) A process of inputting information necessary for operation and maintaining it in an operable state,
(7) The process of extracting the information by combining the portion corresponding to the customer's personal information,
Consists of
Customer group
(1) Checking the SSL (security) signed certificate and the system key K signed certificate, and the system key K _A , K _B ,.
(2) generating a customer key K _a (S _a , P _a );
(3) generating Ka1, Ka2, ..., KaL = (En (Ka1, Pa) ..., En (KaL, Pa)),
(4) Registering Ka1, Ka2,..., KaL with the server,
(5) A process of encrypting only the portion corresponding to personal information and sending information by SSL (security) communication,
A database security system construction method characterized by comprising:

である。公開鍵であるＰは公開しておく。そして、運用グループ A はシステム鍵Ｋ_Aを生成する。公開鍵方式であるので、

である。公開鍵であるＰ_Aは公開しておく。
ここで、運用グループＡは Ｅｎ（Ｓ_A、Ｐ）を公開しておく。これは運用管理者の長が運用グループＡの情報を読み取るのに使用する。
以下同様に運用グループＢ、運用グループＣ、、、がＫ_B、Ｋ_C、、、を作成し、Ｐ_B，Ｐ_C、、、Ｅｎ（Ｓ_B、Ｐ）、Ｅｎ（Ｓ_C、Ｐ）、、、を公開する。
さらに、運用グループ A からも同様に作ることが出来る。
運用グループ A ＿ A 、 A＿B 、、、がK_AA 、 K_AB 、、、を作成し、P_AA、Ｐ_AB、、
Ｅｎ（Ｓ_AA、Ｐ_A）、Ｅｎ（Ｓ_AB、Ｐ_A）、、、を公開する。
以上K 、Ｋ_A、 K_AA 、、 K_B 、Ｋ_BA、、、の個数が合計 M になる。
顧客グループの鍵の設定をする。
顧客 a (∈顧客グループ）が鍵 Ka を生成する。
顧客鍵は公開鍵方式を使用し、

とし、公開鍵であるＰ_aは公開しておく。
顧客 a は ｉｎｆｏ_al 、 ｉｎｆｏ_a2 、、、 ｉｎｆｏ_aL をそれぞれ暗号化して送る。暗号化には秘密鍵方式を用いる。それぞれの情報は以下の対応付けられた鍵を用いて暗号化する。

顧客 a は自身で復号化するときの為に

を公開しておく。ここで送る情報と担当運用グループの対応付けを以下のようにする。

それぞれの運用グループが読み取れるように

を公開しておく。
（２）情報の暗号化、送信
顧客 a が ｉｎｆｏ_al 、 ｉｎｆｏ_a2、、、 ｉｎｆｏ_aL を運用グループ A 、B、、、に情報を送るには以下の暗号化した情報 Ｅｎｌｎｆｏ_a を送る。

（３）安全性の検証
１）顧客ａが情報ｉｎｆｏａ１、ｉｎｆｏａ２を読み取れることの可能性について、
顧客ａは、Ｓ_a、Ｋ_a1・・・_L、ＥｎＩｎｆｏ_a を知っているので、Ｋ_a1・・・_Lの
１つ目の項とＳ_aより

Ｋ_a1を取得できる。よってＥｎＩｎｆｏ_aの１つ目の項とＫ_a1より

となり、ｉｎｆｏ_a1 、ｉｎｆｏ_a2 が取得できる。
２）運用グループＡの情報ｉｎｆｏ_a1の読み取り可能性、更新可能性について
運用グループＢは情報ｉｎｆｏ_a2を読み取れるかどうか、更新できるかどうか。
運用グループＡは Ｅｎ（Ｋ_a1、Ｐ_A）、ＥｎＩｎｆｏ_a、Ｓ_A 知っているので、
Ｅｎ（Ｋ_a1、Ｐ_A）、ＳＡより

より、Ｋ_a1を取得できる。あとは、上記１）と同様に情報が読み取れる。更新も
Ｋ_a1が取得できているので、顧客ａが情報を送るときと同じように情報を暗号化すれ ば更新できる。
運用グループＢについても同様に、Ｅｎ（Ｋ_a2、Ｐ_B）、ＥｎＩｎｆｏ_a、Ｓ_B から Ｋ_a2を取得できるので、情報を読み取り、更新ができる。
３）運用管理者の長による情報の読み取り可能性、更新の可能性について、
運用管理者の長は、Ｅｎ（Ｋ_a1、Ｐ_A）、Ｅｎ（Ｋ_a2、Ｐ_B）、ＥｎＩ ｎｆｏ_a、
Ｅｎ（Ｓ_A、Ｐ）、Ｅｎ（Ｓ_B、Ｐ）、Ｓ を知っている。Ｓ、Ｅｎ（Ｓ_A、Ｐ）から

を取得できる。よって、上記２）と同様にｉｎｆｏ_a1を読み取り、更新もできる。
また、ｉｎｆｏ_a2についても同様にＳ、Ｅｎ（Ｓ_B、Ｐ）から

を取得できる。よって、上記２）と同様にｉｎｆｏ_a2を読み取り、更新もできる。
４）運用管理者の長はによる運用グループＡから運用グループＢへの変更可能につい て、
運用管理者の長は、Ｅｎ（Ｋ_a1、Ｐ_A）、Ｅｎ（Ｋ_a2、Ｐ_B）、ＥｎＩ ｎｆｏ_a、
Ｅｎ（Ｓ_A、Ｐ）、Ｅｎ（Ｓ_B、Ｐ）、Ｓ を知っている。Ｅｎ（Ｓ_A、Ｐ）、Ｓから

を取得できる。Ｅｎ（Ｋ_a1、Ｐ_A）とＳ_Aから

Ｋ_a1を取得する。
ここで、Ｅｎ（Ｋ_a1、Ｐ_A）をＥｎ（Ｋ_a2、Ｐ_B）として更新すると、運用グループＡは情報ｉｎｆｏ_a1が読めなくなり、運用グループＢは情報ｉｎｆｏ_a1が読めるようになる。運用グループＢが情報ｉｎｆｏ_a1が読めるようになっても、もし、運用グループＡがＫ_a1 を保存していると、情報を読めてしまうので、顧客ａに鍵の変更を促すか、システム鍵で顧客ａの鍵を変更して顧客ａに伝える必要がある。
５）開発グループ、保守グループ、ａ以外の顧客に情報が読み取られる可能性について、

であり、開発グループ、保守グループ、ａ以外の顧客はＫ_a1、Ｋ_a2が分からないので２項とも復号化できない。よって情報は取り出せない。
以上安全性が検証できた。 (1) Initial settings, (2) Information encryption, transmission, and (3) Safety verification were verified in the same manner as the M to N (l) system described above, and the security was verified.
(1) Initial setting Similar to the above, consider grouping operation groups. Since there are M system keys, the operation group can be divided into M groups. First, the person who manages the original system key K, the length of the operation manager (∈ operation group) are determined, and the system key K is set. Since the system key K is a public key method,

It is. The public key P is made public. Then, the operation group A generates a system key K _A. Since it is a public key method,

It is. Is a public key P _A is made public.
Here, the operation group A discloses En (S _A , P). This is used by the manager of the operation manager to read the information of the operation group A.
Similarly, operation group B, operation group C, and so on create K _B , K _C ,, and P _B , P _C , En (S _B , P), En (S _C , P), ,, Is published.
In addition, it can be created from Operation Group A as well.
Operation Group A _ A, create A_B ,,, is K _AA, the _{K AB ,,,, P AA, P} AB ,,
En (S _AA , P _A ), En (S _AB , P _A ), are disclosed.
The total number of K 1, K _A , K _AA , K _B , K _BA , and so on is M.
Set the customer group key.
Customer a (∈ Customer group) generates key Ka.
Customer key uses public key method,

The public key _Pa is made public.
Customer a send info _al, info _a2 ,,, info _aL each encrypted. A secret key method is used for encryption. Each piece of information is encrypted using the following associated key.

Customer a wants to decrypt

Is open to the public. The correspondence between the information sent here and the responsible operation group is as follows.

So that each operation group can read

Is open to the public.
(2) encryption of information, send send customers a is info _al, info _a2 ,,, info _aL an Operation Group A, is to send the information to B ,,, the following encrypted information Enlnfo _a.

(3) Safety verification 1) Regarding the possibility that customer a can read information infoa1 and infoa2,
Customer a will, than S _a, K _a1 ··· _L, so you know the EnInfo _a, 1 one eye of the term of the K _a1 ··· _L and S _a

K _a1 can be acquired. Therefore, from the first term of EnInfo _a and K _a1

Next, info _a1, info _a2 can be obtained.
2) Readability and updateability of operation group A information info _a1 Whether operation group B can read and update information info _a2 .
Operation group A knows En (K _a1 , P _A ), EnInfo _a , S _A ,
_{En (K a1, P A)} , than SA

Thus, K _a1 can be acquired. Thereafter, the information can be read in the same manner as in 1) above. Since K _a1 has been acquired, it can be updated if the information is encrypted in the same way as when customer a sends the information.
Similarly, the operation group _{B, En (K a2, P} B), EnInfo a, it is possible to acquire the K _a2 from S _B, read information can be updated.
3) Regarding the possibility of reading and updating information by the head of the operation manager,
The head of the operations manager is En (K _a1 , P _A ), En (K _a2 , P _B ), EnI nfo _a ,
We know En (S _A , P), En (S _B , P), S 2. From S, En (S _A , P)

Can be obtained. Therefore, info _a1 can be read and updated in the same manner as in 2) above.
Similarly for info _a2 , from S and En (S _B , P)

Can be obtained. Therefore, it is possible to read and update info _a2 as in 2) above.
4) The manager of the operation manager can change from operation group A to operation group B.
The head of the operations manager is En (K _a1 , P _A ), En (K _a2 , P _B ), EnI nfo _a ,
We know En (S _A , P), En (S _B , P), S 2. From En (S _A , P), S

Can be obtained. From En (K _a1 , P _A ) and S _A

Obtain K _a1 .
Here, when you update En the (K _a1, P _A) as the _{En (K a2, P B)} , Operation Group A is no longer read the information info _a1, operations group B is as information info _a1 can be read. Even if the operation group B can read the information info _a1 , if the operation group A stores the K _a1 , the information can be read. It is necessary to change the key of the customer a and notify the customer a.
5) Regarding the possibility of information being read by customers other than the development group, maintenance group, and a.

Since customers other than the development group, the maintenance group, and a do not know K _a1 and K _a2 , neither of the two terms can be decrypted. Therefore, information cannot be extracted.
The safety has been verified.

The above is only a basic example, and as another example, it can be used for the Basic Resident Register network. In that case, the system side becomes the government, the customer becomes the resident, the operation group becomes the city hall, etc., and basically the M to N (L) system is used.

  INDUSTRIAL APPLICABILITY The present invention can be used for industries that handle information in databases such as commercial transactions using the Internet and Basic Resident Register.

The basic system model figure (a) in this invention 1 example database and the model figure (b) of a commerce site are shown. The basic model figure (a) of 1 to N (1) system in this invention, and the model figure of a commerce site are shown. The basic model figure (a) of the M to N (1) system in this invention, and the model figure of a commerce site are shown. The basic model figure (a) of the M to N (L) system in this invention, and the model figure of a commerce site are shown. System model diagrams (a), (b), and (c) in a system for comparison with the present invention are shown. It is a model figure of a general normal commerce site.

Explanation of symbols

1 System side 2 Development group (may include maintenance group)
3 Operation group 4 User (customer)
5 Server 6 Database

Claims (8)

  In the database system, using the public key or private key, the initial procedure user A stores the plaintext and the content of the call m as ciphertext in a database on the system, and the other user B owns B. And A can be decrypted with the key owned by A, B can be decrypted with the key owned by B, and when updated, it is encrypted and stored in the database. A database security system characterized in that it can be decrypted and is not known to third parties other than A and B.   In the database security system of claim 1, if one key in the system, multiple N customers as users of the initial procedure, and division of customer information as information is 1, what is division of customer information? It consists of multiple items as customer information, and a division of 1 means that the system side, the customer, and the operation group side are required on the condition that the customer information is handled as a group rather than handling multiple items individually. As a system that can be divided into groups and the former (system side) cannot read information and the latter (customer, operation group side) can read information, one operation group system uses a public key method and the customer group is open to the public. A database security system using at least one of a key method and a secret key method. In the database security system according to claim 1, when there are M keys in the system, N customers, and division of customer information is 1, it is possible to divide multiple groups by using multiple system keys. Set a group in the form of a tree, create the original system key K, create the system key K _A and system key K _B from it, further enable the system keys K _AA and K _BB , and decrypt with K _A This is a database safety system characterized in that it can decrypt information that can be converted with the original K.   In the database security system according to claim 1, when the number of keys in the system is M, the number of customers is N, and the division of customer information is L division, multiple items can be obtained by dividing customer information into multiple divisions. Instead of thinking all at once, set up a group in charge for each item so that the individual information of customer a information info, info a 2, etc. can be read for each group in charge of the operation group A database safety system characterized by that. As a commerce site in claim 2, the system side development group is:
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) A process of inputting information necessary for operation and maintaining it in an operable state,
(4) The process of extracting the information by combining the parts corresponding to the customer's personal information,
Customer group
(1) Checking SSL (security) signed certificate and system key K signed certificate,
(2) generating a customer key Ka;
(3) The process of encrypting only the portion corresponding to personal information and sending the information by SSL (security) communication,
A database security system construction method characterized by comprising: As a commercial transaction site in claim 3, the system side development group is:
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) Operation A generates a system key K _A = (S _A , P _A ) and creates a certificate;
(4) The operation A receives a certificate from the administrator of the operation group and holds it in the server;
(5) A step of repeating the steps (3) and (4),
(6) A process of inputting information necessary for operation and maintaining it in an operable state,
(7) The process of extracting the information by combining the portion corresponding to the customer's personal information,
Consists of
Customer group
(1) Checking the SSL (security) signed certificate and the system key K signed certificate, and the system key K _A , K _B ,.
(2) a step of generating a customer key K _A,
(3) The process of encrypting only the portion corresponding to personal information and sending the information by SSL (security) communication,
A database security system construction method characterized by comprising: As a commercial transaction site in claim 4, the system side development group is:
(1) The process of creating requirements specifications for a commercial transaction site,
(2) The process of starting up the necessary servers,
(3) A process of generating a key necessary for SSL (security) and creating a certificate,
(4) receiving the certificate from a certificate authority and storing the signed certificate in a server;
(5) A process of setting a database according to use and creating a web page;
Consists of
The system side operation group
(1) generating a system key K = (S, P) and creating a certificate;
(2) receiving a certificate signature from a certificate authority and storing the signed certificate in a server;
(3) Operation A generates a system key K _A = (S _A , P _A ) and creates a certificate;
(4) The operation A receives the certificate from the administrator of the operation group and stores it in the server;
(5) A step of repeating the steps (3) and (4),
(6) A process of inputting information necessary for operation and maintaining it in an operable state,
(7) The process of extracting the information by combining the portion corresponding to the customer's personal information,
Consists of
Customer group
(1) Checking the SSL (security) signed certificate and the system key K signed certificate, and the system key K _A , K _B ,.
(2) a step of generating a customer key Ka (Sa, Pa),
(3) generating Ka1, Ka2, ..., KaL = (En (Ka1, Pa) ..., En (KaL, Pa)),
(4) Registering Ka1, Ka2,..., KaL with the server,
(5) A process of encrypting only the portion corresponding to personal information and sending information by SSL (security) communication,
A database security system construction method characterized by comprising:   8. The database security system construction method according to claim 5, further comprising a step of monitoring the server and backing up the database as a system-side maintenance group.

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