JP2002328898A - User authentication server, user authentication method, user terminal, user authentication request method, computer readable recording medium having program recorded thereon and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily take a measure against impersonation by a third person by judging user terminal side authentication logic and authenticating a keyword by using the user terminal side authentication logic regarding a user authentication server connectable to a user terminal which transmits a user side conversion keyword converted according to the user terminal side authentication logic. SOLUTION: The user side authentication logic is judged by a user ID in an authentication logic judgment part 13. In a conversion keyword verification part 18, a keyword conversion part provided with server side authentication logic corresponding to the user side authentication logic is selected from a plurality of the keyword conversion parts 19-21, a server side conversion keyword is acquired and compared with the user side conversion keyword received in a user side conversion keyword reception part 17 and the keyword is verified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a keyword shared with a user authentication server in accordance with a user terminal side authentication logic, and is connectable via a network to a user terminal transmitting the converted user side converted keyword. The present invention relates to a technique for determining a user terminal-side authentication logic, performing keyword verification using the user terminal-side authentication logic, and facilitating countermeasures against impersonation by a third party.

[0002]

2. Description of the Related Art FIG. 14 is a diagram showing a connection relationship of a user authentication server according to the prior art. In the example shown in the figure, the server administrator distributes a common program serving as a user terminal-side authentication unit to each user. It authenticates the user in cooperation with the user terminal-side authentication unit installed and operable, and the server-side authentication processing unit.

[0003] However, there is a risk that the user terminal-side authentication unit may be stolen or misused and impersonated by another person. When such a situation is discovered, it is conceivable to change the logic of the user terminal side authentication unit for security, but in practice, it is necessary to deal not only with the server but also with other user terminals. Necessary and unrealistic. In particular, prevention of spoofing in the operation of distributing the program to members is an important issue.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and an object of the present invention is to use a keyword shared with a user authentication server to authenticate a user terminal. In accordance with a user authentication server that can be connected via a network with a user terminal that transmits a converted user-side converted keyword according to logic, determines the user terminal-side authentication logic, and converts the user terminal-side authentication logic. Is used to perform keyword verification,
It is an object to facilitate measures against impersonation by a third party.

[0005]

A user authentication server according to the present invention has a user terminal side authentication logic, converts a keyword shared with the user authentication server in accordance with the user terminal side authentication logic, and converts the converted user. A user authentication server connectable via a network to a user terminal transmitting a side conversion keyword, characterized by having the following elements: (1) A plurality of keywords capable of converting keywords according to individual authentication logics Keyword conversion unit (2) Authentication logic determination unit that determines user terminal side authentication logic (3) User terminal side conversion keyword receiving unit that receives user side conversion keyword from user terminal (4) Plural keyword conversion From among the units, select a keyword conversion unit having a server-side authentication logic corresponding to the determined user-side authentication logic, Activate the selected keyword conversion unit, convert the keyword shared with the user terminal to obtain the server-side conversion keyword, and verify the keyword based on the received user-side conversion keyword and the obtained server-side conversion keyword. (5) A user authentication result determination unit that determines that the user authentication result is successful when the keyword verification result by the conversion keyword verification unit is successful.

The user authentication server further includes an authentication logic management table for associating the user terminal-side authentication logic with the user ID, and a user ID receiving unit for receiving a user ID from the user terminal. The determining unit determines the user terminal-side authentication logic according to the received user ID.

The conversion keyword verification unit selects a keyword conversion unit having the same server-side authentication logic as the user terminal-side authentication logic, and compares the received user-side conversion keyword with the obtained server-side conversion keyword. Are matched, the keyword is verified by making the result of the keyword verification successful.

The user authentication server further includes a password receiving unit that receives a password, and a password authentication processing unit that performs password authentication using the received password and the user ID received by the user ID receiving unit. The user authentication result determination unit is characterized in that if the keyword verification result is successful and the password authentication result is successful, the user authentication result is determined to be successful.

[0009] The user authentication server further includes a keyword generation unit for generating a keyword, and a keyword transmission unit for transmitting the generated keyword to the user terminal.

[0010] The user authentication server further includes a keyword receiving unit that receives a keyword from the user terminal.

[0011] The user authentication server further includes a combination authentication logic determining unit that determines the combination authentication logic, and a combination authentication logic instruction transmitting unit that transmits a combination authentication logic instruction that specifies the determined combination authentication logic. The conversion keyword verification unit activates a second keyword conversion unit having the determined combination authentication logic, in addition to the selected keyword conversion unit, and outputs a keyword shared with the user terminal to the selected keyword conversion unit. It is characterized in that the keyword is converted by the second keyword conversion unit to obtain a server-side conversion keyword.

A user authentication method according to the present invention has a user terminal side authentication logic, converts a keyword shared with a user authentication server according to a user terminal side authentication logic, and transmits the converted user side conversion keyword. A user authentication method using a user authentication server connectable to a user terminal via a network, comprising the following elements: (1) Conversion of a plurality of keywords capable of converting keywords according to individual authentication logics Step (2) Authentication logic determination step of determining user terminal side authentication logic (3) User terminal side conversion keyword receiving step of receiving user side conversion keyword from user terminal (4) Multiple keyword conversion units From among the keyword conversion units having server-side authentication logic corresponding to the determined user-side authentication logic Select, activate the selected keyword conversion unit, convert the keyword shared with the user terminal to obtain a server-side conversion keyword, and based on the received user-side conversion keyword and the obtained server-side conversion keyword. (5) A user authentication result determining step of determining that the user authentication result is successful when the keyword verification result by the conversion keyword verification unit is successful.

A computer-readable recording medium storing a program according to the present invention has user terminal-side authentication logic, converts a keyword shared with a user authentication server according to the user terminal-side authentication logic, and converts the keyword. Computer-readable storage medium storing a program for causing a computer serving as a user authentication server connectable via a network to a user terminal transmitting a user-side conversion keyword to execute the following processing. (1) A plurality of keyword conversion processes capable of converting keywords according to individual authentication logics (2) Authentication logic determination process for determining user terminal-side authentication logic (3) User-side conversion keywords from user terminals User-side conversion keyword reception processing to be received (4) Multiple keyword conversion From the conversion units, a keyword conversion unit having a server-side authentication logic corresponding to the determined user terminal-side authentication logic is selected, the selected keyword conversion unit is activated, and a keyword shared with the user terminal is converted. A conversion keyword verification process in which a server-side conversion keyword is acquired and a keyword is verified based on the received user-side conversion keyword and the acquired server-side conversion keyword. (5) When the keyword verification result by the conversion keyword verification unit is successful And a user authentication result determination process for making the user authentication result a success.

A program according to the present invention has a user terminal-side authentication logic, converts a keyword shared with a user authentication server according to a user terminal-side authentication logic, and transmits the converted user-side converted keyword. It is a program for causing a computer serving as a user authentication server connectable to a terminal via a network to execute the following procedure. (1) A plurality of keywords capable of converting keywords according to individual authentication logics Conversion procedure (2) Authentication logic determination procedure for determining user terminal-side authentication logic (3) User-side conversion keyword receiving procedure for receiving a user-side conversion keyword from a user terminal (4) Multiple keyword conversion units From inside, a key having server-side authentication logic corresponding to the determined user terminal-side authentication logic Select the word conversion unit, activate the selected keyword conversion unit, convert the keyword shared with the user terminal to obtain the server-side conversion keyword, and receive the received user-side conversion keyword and the obtained server-side conversion keyword (5) A user authentication result determination procedure that determines that the user authentication result is successful if the keyword verification result by the conversion keyword verification unit is successful.

A user terminal according to the present invention is a user terminal connectable via a network to a user authentication server that can share a keyword, and has the following elements: (1) User authentication server (2) a user terminal-side authentication logic corresponding to the user ID and a combination authentication logic specified by the received combination authentication logic instruction. (3) A converted keyword transmitting unit that transmits the converted user-side converted keyword to the user authentication server.

A user authentication requesting method according to the present invention is a user authentication requesting method using a user authentication server that can share a keyword and a user terminal connectable via a network, and has the following elements. (1) An authentication logic instruction receiving step of receiving a combination authentication logic instruction for specifying the combination authentication logic from the user authentication server. (2) The user terminal side authentication logic and the combination authentication logic specified by the received combination authentication logic instruction. (3) A converted keyword transmitting step of transmitting the converted user-side converted keyword to the user authentication server.

A computer-readable recording medium on which the program according to the present invention is recorded is a computer-readable recording medium for allowing a computer serving as a user terminal connectable via a network to a user authentication server capable of sharing a keyword to execute the following processing. It is a computer-readable recording medium on which a program is recorded. (1) Authentication logic instruction receiving processing for receiving a combination authentication logic instruction for specifying a combination authentication logic from a user authentication server (2) User terminal side User-side keyword conversion processing for converting a keyword in accordance with the authentication logic and the combination authentication logic specified by the received combination authentication logic instruction (3) Sending a converted keyword that sends the converted user-side conversion keyword to the user authentication server processing.

[0018] The program according to the present invention is a program for causing a computer as a user terminal connectable via a network to a user authentication server capable of sharing a keyword to execute the following procedure. 1) An authentication logic instruction receiving procedure for receiving a combination authentication logic instruction specifying the combination authentication logic from the user authentication server. (2) According to the user terminal side authentication logic and the combination authentication logic specified by the received combination authentication logic instruction. (3) A conversion keyword transmission procedure for transmitting the converted user conversion keyword to the user authentication server.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a diagram showing a connection relationship of a user authentication server according to the present invention. Each of the user terminals 2 and 3 has an individual authentication logic, and the user authentication server 1 has all of these authentication logics. The authentication logic of the distributed program serving as the user terminal-side authentication unit is stored in the user authentication server 1 in association with the user or the user terminal.

FIG. 2 is a diagram showing a configuration of the user authentication server according to the first embodiment. 10 is a user authentication screen processing unit, 11 is a password authentication processing unit, 12 is a password management table, 13 is an authentication logic determination unit for keyword authentication, 14 is an authentication logic management table,
5 is a keyword generation unit, 16 is a keyword transmission unit,
17 is a user-side converted keyword receiving unit, 18 is a converted keyword verifying unit, 19 to 21 are keyword converting units,
22, a user authentication result determining unit; 23, a user authentication result output unit; and 30, a server-side keyword authentication processing unit. Note that the user authentication screen processing unit 10 is an example of a password receiving unit, and is also an example of a user ID receiving unit. The keyword converters 19 to 21 are usually stored in a storage medium as a program, and are loaded into a memory and operated when activated. However, it may be resident as a process. Further, the keyword conversion units 19 to 21 may be configured by a combination of functions that incorporate and use a plurality of functions (or subroutines) in one program.

FIG. 3 is a diagram showing a configuration example of the password management table. User ID 301 and password 302
Are stored in association with each other.

FIG. 4 is a diagram showing a configuration example of the authentication logic management table. User ID 401 and authentication logic 4
02 are stored in association with each other.

FIG. 5 is a diagram showing a configuration example of the first user terminal according to the first embodiment. The first user terminal is
Keyword receiving unit 41, user side keyword conversion unit A4
2. A user-side keyword authentication processing unit 50 including a conversion keyword transmission unit 43 is provided. Note that the first user terminal is a terminal used by a user whose user ID is “U0001”.

FIG. 6 is a diagram showing a configuration example of the second user terminal according to the first embodiment. The second user terminal is
Keyword receiving unit 41, user side keyword conversion unit B4
4. A user-side keyword authentication processing unit 50 including a conversion keyword transmission unit 43 is provided. Note that the first user terminal is a terminal used by a user whose user ID is “U0002”. As shown in the figure, the first user terminal and the second user terminal have different user terminal side authentication logics.

Next, the operation will be described. The user authentication screen processing unit 10 transmits the user authentication screen to the user terminals 2 and 3 and receives the user ID and the password. The password authentication processing unit 11 sets the combination of the user ID 401 and the authentication logic 402 of the password management table 12. Is determined, and if they match, the user authentication result is determined to be successful. If they do not match, the user authentication result is regarded as failure.

Authentication logic determination unit 13 for keyword authentication
If the user authentication result is successful, the user ID is acquired, and the authentication logic associated with the acquired user ID in the authentication logic management table 14 is determined as the user terminal-side authentication logic.

The keyword generation unit 15 generates a keyword shared by the user authentication server 1 and the user terminals 2 and 3. For example, a random number is used.

The keyword transmitting section 16 transmits the generated keywords to the user terminals 2 and 3.

On the other hand, in the user terminals 2 and 3, the keyword is received by the keyword receiving section 41, and the keyword is converted according to the user terminal side authentication logic provided in each user side keyword conversion section. A conversion keyword is generated and transmitted to the user authentication server 1 by the conversion keyword transmission unit 43.

The user-side converted keyword receiving section 17 receives the user-side converted keyword. The conversion keyword verification unit 18 selects a keyword conversion unit having a server-side authentication logic corresponding to the user terminal-side authentication logic according to the user terminal-side authentication logic acquired from the keyword authentication authentication logic determination unit 13. In this example, the authentication logic having the same logic itself is referred to as “corresponding server-side authentication logic”. The selected keyword conversion unit is activated, and the keyword generated by the keyword generation unit 15 is converted to obtain a server-side conversion keyword. Keyword verification is performed based on the received user-side conversion keyword and the acquired server-side conversion keyword. In this example, if the two match, the keyword verification result is determined to be successful, and if not, the keyword verification is determined to be unsuccessful. However, the corresponding authentication logic is not always the same logic,
In the keyword verification, it is sufficient that the result can determine the validity of the keyword.

If both the keyword verification result and the password authentication result are successful, the user authentication result determination unit 22
The user authentication result is regarded as success. User authentication result output unit 2
3 outputs a user authentication result. The user authentication result is
It is transmitted to the user terminals 2 and 3 and can be used in a server process of the user authentication server 1 or the like.

Embodiment 2 In the present embodiment, a description will be given of a mode in which a shared keyword is generated in the user terminals 2 and 3 and transmitted to the user authentication server 1. FIG. 7 is a diagram illustrating a configuration of a user authentication server according to the second embodiment. A keyword receiving unit 24 is provided instead of the keyword generating unit 15 and the keyword transmitting unit 16. Further, instead of the keyword generated by the keyword generation unit 15, the keyword reception unit 24 requests the user terminals 2, 3 and performs the processing of the conversion keyword verification unit 18 using the received keyword.

FIG. 8 is a diagram showing a configuration example of a first user terminal according to the second embodiment. Keyword receiving unit 41
, The keyword generation unit 45 and the keyword transmission unit 4
6. The keyword generation unit 45 generates a keyword in response to a request from the user authentication server 1, and transmits the keyword from the keyword transmission unit 46 to the user authentication server 1. FIG. 9 is a diagram illustrating a configuration example of a second user terminal according to the second embodiment. The configuration example of the second user terminal is also
This is the same except that the logic of the user-side keyword conversion unit B is different.

Other configurations and operations are described in the first embodiment.
Is the same as

Embodiment 3 FIG. A description will be given of an embodiment in which keyword verification is performed using the combination authentication logic. FIG.
13 is a diagram illustrating a configuration of a user authentication server according to Embodiment 3. FIG. User authentication screen processing unit 10, password authentication processing unit 11, password management table 12, authentication logic determination unit 13 for keyword authentication, authentication logic management table 14, keyword generation unit 15, keyword transmission unit 16, keyword conversion units 19 to 21, The configuration and operation of the user authentication result determination unit 22 and the user authentication result output unit 23 are as follows.
This is the same as in the first embodiment. In the present embodiment, a combination authentication logic determination unit 25, a combination authentication logic instruction transmission unit 26, and keyword conversion units 27 to 29 are provided. The keyword converters 27 to 29 are also usually stored in a storage medium as a program, and are loaded into a memory and operated when activated. However, it may be resident as a process. Also, a combination of functions that incorporates and uses multiple functions (or subroutines) in one program,
The keyword conversion units 27 to 29 may be configured.

FIG. 11 is a diagram showing a configuration example of a user terminal according to the third embodiment. A combination authentication logic instruction receiving unit 47 and keyword converting units 48, 49, 51 are added. The keyword converters 48, 49, and 51 also usually
It is stored in a storage medium as a program, and when it is activated, it is loaded into a memory and operated. However, it may be resident as a process. A plurality of functions (or subroutines) are incorporated in one program, and a combination of functions used and used is a keyword conversion unit 48, 49, 51.
May be configured.

Next, the characteristic operation will be described.
The combination authentication logic determination unit 25 determines the keyword conversion unit to be used in combination among the held keyword conversion units 27 to 29 using the combination authentication logic. The combination authentication logic instruction transmission unit 26 transmits an instruction to use the combination authentication logic to the user terminals 2 and 3.

On the other hand, for example, in the second user terminal 2, the combination authentication logic instruction receiving section 47 receives the combination authentication logic instruction. User side keyword conversion unit B44
Selects the keyword conversion unit Y49 according to the combination authentication logic instruction, and performs keyword conversion by combining the keyword conversion units. In this example, first, conversion is performed by the keyword conversion unit Y49 having combination conversion logic, and then conversion is performed by the user-side keyword conversion unit B44.
The order of conversion may be determined in advance between the user authentication server 1 and the user terminals 2 and 3, or may be included in the above-described combination authentication logic instruction and controlled by the user-side keyword conversion unit.

The user authentication server 1 receives the notification of the combination authentication logic from the combination authentication logic determination unit 25 in the process of the conversion keyword verification unit 18 and selects the keyword conversion unit Y28 in accordance with the notification to convert the keyword by combination. Do. In this example, first, conversion is performed by the keyword conversion unit Y28 having combination conversion logic, and then, keyword conversion is performed by the user terminal-side authentication logic determined by the authentication logic determination unit 13 for keyword authentication. The order of conversion may be determined in advance between the user authentication server 1 and the user terminals 2 and 3, and may be included in the notification of the combination authentication logic described above.
Control may be performed by the conversion keyword verification unit 18.

Embodiment 4 FIG. FIG. 12 is a diagram illustrating a configuration of a user authentication server according to the fourth embodiment. FIG.
FIG. 17 is a diagram illustrating a configuration example of a user terminal according to Embodiment 4. This is a mode in which a configuration relating to combination authentication of the third embodiment is added to the configuration of the second embodiment in which keywords are generated by the user terminals 2 and 3. The operation of each component is the same as in the second and fourth embodiments.

User authentication server 1 and user terminals 2, 3
Is a computer, and each element can execute processing by a program. Further, the program can be stored in a storage medium, and can be read by the computer from the storage medium.

[0042]

According to the present invention, the user terminal-side authentication logic is determined, and a keyword conversion unit having a server-side authentication logic corresponding to the determined user terminal-side authentication logic is selected to perform keyword verification. Spoofing access from an unauthorized device other than the user terminal can be eliminated.
Also, with regard to the specific user terminal side authentication logic, if an access by impersonation occurs by a third party who has intercepted the communication record, other user terminals using authentication logic other than the user terminal side authentication logic There is no danger for user authentication. Therefore, it is not necessary to deal with the other user terminals (for example, change the authentication logic).

Since the authentication logic of the user terminal is determined according to the received user ID, the authentication logic of the user terminal can be easily specified.

Using the result converted by the keyword conversion unit having the same server-side authentication logic as the user terminal-side authentication logic, if the comparison result matches, the keyword verification result is successful. Dependency of terminal side authentication logic becomes clear.

When the result of the keyword verification is successful and the result of the password authentication is also successful, the user authentication is determined to be successful. Therefore, it is possible to confirm that the user is the user in addition to the access from the user terminal.

Since the keyword is generated and transmitted, the keyword can be surely shared with the user terminal.

Since the keyword is received, the keyword can be surely shared with the user terminal.

Since the combination authentication logic, which is changed every time, is converted into a keyword and verified, even if a communication record is intercepted, it cannot be spoofed by simply reproducing the communication record as it is.

[Brief description of the drawings]

FIG. 1 is a diagram showing a connection relationship of a user authentication server according to the present invention.

FIG. 2 is a diagram showing a configuration of a user authentication server according to the first embodiment.

FIG. 3 is a diagram illustrating a configuration example of a password management table.

FIG. 4 is a diagram illustrating a configuration example of an authentication logic management table.

FIG. 5 is a diagram showing a configuration example of a first user terminal according to the first embodiment.

FIG. 6 is a diagram illustrating a configuration example of a second user terminal according to the first embodiment.

FIG. 7 is a diagram showing a configuration of a user authentication server according to a second embodiment.

FIG. 8 is a diagram showing a configuration example of a first user terminal according to the second embodiment.

FIG. 9 is a diagram illustrating a configuration example of a second user terminal according to the second embodiment.

FIG. 10 is a diagram showing a configuration of a user authentication server according to a third embodiment.

11 is a diagram illustrating a configuration example of a user terminal according to Embodiment 3. FIG.

FIG. 12 is a diagram showing a configuration of a user authentication server according to a fourth embodiment.

13 is a diagram illustrating a configuration example of a user terminal according to Embodiment 4. FIG.

FIG. 14 is a diagram showing a connection relationship of a user authentication server according to the related art.

[Explanation of symbols]

1 user authentication server, 2 user terminals, 3 user terminals, 10 user authentication screen processing unit, 11 password authentication processing unit, 12 password management table, 13 keyword authentication authentication logic determination unit, 14 authentication logic management table, 15 keywords Generation unit, 16 keyword transmission unit, 17 user-side conversion keyword reception unit, 1
8 conversion keyword verification unit, 19 keyword conversion unit A, 20 keyword conversion unit B, 21 keyword conversion unit C, 22 user authentication result determination unit, 23 user authentication result output unit, 24 keyword reception unit, 30 server-side keyword authentication processing unit , 41 keyword receiving unit, 42
User-side keyword conversion unit A, 43 conversion keyword transmission unit, 44 user-side keyword conversion unit B, 45 keyword generation unit, 46 keyword transmission unit, 47 combination authentication logic instruction reception unit, 48 conversion keyword transmission unit X, 49 conversion Keyword transmission unit Y, 50 user-side keyword authentication processing unit, 51 converted keyword transmission unit Z.

Claims (14)

[Claims] 1. A user terminal having an authentication logic which converts a keyword shared with a user authentication server in accordance with the authentication logic of a user terminal and transmits the converted user-side converted keyword to a user terminal via a network. (1) a plurality of keyword conversion units capable of converting keywords according to individual authentication logics (2) user terminal side Authentication logic determination unit that determines authentication logic (3) User terminal-side conversion keyword receiving unit that receives user-side conversion keywords from user terminals (4) User side that has been determined from among a plurality of keyword conversion units Select the keyword conversion unit having the server-side authentication logic corresponding to the authentication logic, and activate the selected keyword conversion unit A conversion keyword verification unit that converts a keyword shared with the user terminal to obtain a server-side conversion keyword, and verifies a keyword based on the received user-side conversion keyword and the obtained server-side conversion keyword (5) A user authentication result determination unit that determines that the user authentication result is successful when the keyword verification result by the conversion keyword verification unit is successful. 2. The user authentication server further includes an authentication logic management table for associating the user terminal-side authentication logic with the user ID, and a user ID receiving unit that receives a user ID from the user terminal. The user authentication server according to claim 1, wherein the authentication logic determination unit determines the user terminal side authentication logic according to the received user ID. 3. The conversion keyword verification unit selects a keyword conversion unit having the same server-side authentication logic as the user terminal-side authentication logic, and compares the received user-side conversion keyword with the acquired server-side conversion keyword. 2. The user authentication server according to claim 1, wherein when the results match, the keyword verification result is successful. 4. The user authentication server further includes a password receiving unit that receives a password, and a password authentication processing unit that performs password authentication using the received password and the user ID received by the user ID receiving unit. 3. The user authentication server according to claim 2, wherein the user authentication result determination unit sets the user authentication result to success if the keyword verification result is successful and the password authentication result is successful. 5. The user according to claim 1, wherein the user authentication server further includes a keyword generation unit that generates a keyword, and a keyword transmission unit that transmits the generated keyword to a user terminal. Authentication server. 6. The user authentication server according to claim 1, wherein the user authentication server further includes a keyword receiving unit that receives a keyword from a user terminal. 7. The user authentication server further includes a combination authentication logic determination unit that determines combination authentication logic, and a combination authentication logic instruction transmission unit that transmits a combination authentication logic instruction that specifies the determined combination authentication logic. The conversion keyword verification unit activates the second keyword conversion unit having the determined combination authentication logic in addition to the selected keyword conversion unit, and converts the keyword shared with the user terminal into the selected keyword conversion unit. The user authentication server according to claim 1, wherein the server-side conversion keyword is obtained by converting the keyword with a second keyword conversion unit. 8. A user terminal having an authentication logic, converting a keyword shared with a user authentication server in accordance with the authentication logic of the user terminal, and transmitting the converted user-side converted keyword to a user terminal via a network. (1) a plurality of keyword conversion steps capable of converting keywords according to individual authentication logics (2) Authentication logic determination step of determining user terminal side authentication logic (3) User terminal side conversion keyword receiving step of receiving user side conversion keyword from user terminal (4) Judgment from among a plurality of keyword conversion units Select the keyword conversion unit that has the server-side authentication logic corresponding to the user-side authentication logic A conversion that activates a keyword conversion unit, converts a keyword shared with a user terminal, obtains a server-side conversion keyword, and performs keyword verification based on the received user-side conversion keyword and the obtained server-side conversion keyword. Keyword Verification Step (5) A user authentication result determination step of making the user authentication result successful if the keyword verification result by the conversion keyword verification unit is successful. 9. A user terminal having an authentication logic, converting a keyword shared with a user authentication server in accordance with the authentication logic of the user terminal, and transmitting the converted user-side converted keyword to the user terminal via a network. A computer-readable recording medium that records a program for causing a computer serving as a user authentication server that can be connected to the computer to execute the following processing: (1) Plural keyword conversion processing capable of converting keywords according to individual authentication logics ( 2) Authentication logic determination processing for determining user terminal-side authentication logic (3) User-side conversion keyword reception processing for receiving a user-side conversion keyword from a user terminal (4) From a plurality of keyword conversion units, Keyword having server-side authentication logic corresponding to the determined user terminal-side authentication logic Select the keyword conversion unit, activate the selected keyword conversion unit, convert the keyword shared with the user terminal to obtain the server-side conversion keyword, and receive the received user-side conversion keyword and the obtained server-side conversion keyword (5) A user authentication result determination process in which the user authentication result is successful when the keyword verification result by the conversion keyword verification unit is successful. 10. A user terminal-side authentication logic, which converts a keyword shared with a user authentication server according to the user terminal-side authentication logic, and transmits the converted user-side converted keyword to a user terminal via a network. (1) A plurality of keyword conversion procedures capable of converting keywords according to individual authentication logics (2) User-side terminal authentication logic (3) User-side conversion keyword receiving procedure for receiving a user-side conversion keyword from a user terminal (4) From a plurality of keyword conversion units, to the determined user terminal-side authentication logic Select the keyword conversion unit having the corresponding server-side authentication logic, and select the selected keyword conversion To convert a keyword shared with the user terminal to obtain a server-side conversion keyword, and to perform keyword verification based on the received user-side conversion keyword and the obtained server-side conversion keyword (5) A user authentication result determination procedure for determining that the user authentication result is successful when the keyword verification result by the conversion keyword verification unit is successful. 11. A user terminal connectable via a network to a user authentication server capable of sharing a keyword, the user terminal having the following elements: (1) Combined authentication from the user authentication server Authentication logic instruction receiving unit that receives a combination authentication logic instruction that specifies a logic (2) Converts a keyword according to the user terminal side authentication logic corresponding to the user ID and the combination authentication logic specified by the received combination authentication logic instruction (3) A conversion keyword transmitting unit that transmits the converted user-side conversion keyword to the user authentication server. 12. A user authentication request method using a user authentication server capable of sharing a keyword and a user terminal connectable via a network, the method comprising the following elements: (1) User An authentication logic instruction receiving step of receiving a combination authentication logic instruction specifying the combination authentication logic from the authentication server. (2) According to the user terminal side authentication logic and the combination authentication logic specified by the received combination authentication logic instruction, a keyword is input. Conversion step of user-side keyword to be converted (3) A conversion keyword transmission step of transmitting the converted user-side conversion keyword to the user authentication server. 13. A computer-readable recording medium in which a program for causing a computer serving as a user terminal connectable via a network to a user authentication server capable of sharing a keyword to execute the following processing is recorded. Authentication logic instruction reception processing for receiving a combination authentication logic instruction specifying a combination authentication logic from the authentication server (2) According to the user terminal side authentication logic and the combination authentication logic specified by the received combination authentication logic instruction, a keyword is input. User-side keyword conversion processing for conversion (3) Conversion-keyword transmission processing for transmitting the converted user-side conversion keyword to the user authentication server. 14. A program for causing a computer as a user terminal connectable via a network to a user authentication server capable of sharing a keyword to execute the following procedure: (1) Specify combination authentication logic from the user authentication server (2) User terminal side authentication logic and user side keyword conversion procedure for converting a keyword according to the combination authentication logic specified by the received combination authentication logic instruction 3) A conversion keyword transmission procedure for transmitting the converted user-side conversion keyword to the user authentication server.