JP2000224162A - Client authentication method using irreversible function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for exchanging information with security in an enterprise information system. SOLUTION: In a network system, where a client and a business server can exchange communication, a client authentication method using an irreversible function makes it possible to exchange the authentication information with security when the method is provided with a means that converts security information of the client, so that the information cannot be extracted by converting authentication information of the client by an irreversible function and a means that revises authentication information each time by using a value generated by the server and different each time, so as to prevent other person to pretend to be the client through interception. Or the client or a 3rd device generates different values each time and the authentication is generated on the basis of the values to exchange the authentication information with security.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a conventional business system, a user inputs a user ID and a password from a client terminal to be authenticated by a business server as a correct user, and then logs in to the business server.

However, in general, a user ID and a password are not encrypted, and communication via a public network such as the Internet always involves a risk of password leakage due to eavesdropping.

[0003] The present invention is directed to a user authentication method for securely exchanging authentication information between a client and a business server.

[0004]

2. Description of the Related Art In communication between a WWW server and a browser, a typical login method is called basic authentication. When a user accesses a homepage that requires authentication, a login screen pops up and prompts the user to enter a user ID and password. When the user is registered in advance and the password is correct, the requested home page can be referred to for the first time.

At this time, the user ID and the password input by the user are encoded by the BASE64 encoding method and sent to the WWW server. However, this encoding method uses a reversible function and the password is easily leaked. There was a problem.

In the prior art relating to password registration, authentication, and update methods (Japanese Patent Laid-Open No. 9-330298), a one-way function (irreversible function) is applied to a password and the password is compared with a registered hashed password. The purpose is to use multiple passwords during authentication, and the overhead of managing multiple passwords is not considered. Therefore, it is difficult to apply to the login method when browsing the homepage.

Japanese Patent Application Laid-Open No. 9-81523 has been proposed as a mutual authentication method based on public key encryption. Such an authentication method is also applicable to a specific page of communication between a WWW server and a browser. Not suitable for user authentication during access.

Although there is PPP CHAP (RFC1994) as user authentication using a random number and a password, CHAP is a means for authenticating a client-server host and has a problem in that it cannot authenticate an end user. . For this reason, the login screen is not displayed to the user, and the server / client needs to have a definition file in advance and automatically respond using a predetermined password. In addition, CHAP continues mutual authentication between server and client, and also continues authentication during work with a certain time.
A system configuration that does not need to worry about switching telephone lines would be over-implemented.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to prevent a password from being leaked in a user authentication sequence even in a network such as the Internet to which an unspecified number of users are connected, and to identify a malicious third party. To prevent impersonation of a user with

[0010]

SUMMARY OF THE INVENTION In a client / server system, in order for a server to grant access to the client, the server needs to make sure that the client is being used by a pre-registered correct user. In general, in order to confirm that the user is the correct user, the user inputs a password and performs authentication based on whether the password matches the content registered in the server. Therefore, it is necessary to transmit the password information input by the user from the client to the server. In public networks such as the Internet, the transmission of this password is at risk of eavesdropping.

Therefore, the password is converted by an irreversible function instead of a reversible function as in the prior art, so that the password cannot be restored even if it is eavesdropped on a network. The irreversible function used here has a feature that different results are always output when different input values are given, and such irreversible functions as SHA-1 and MD5 are known.

Even if the password cannot be restored as described above, there is a risk that the authentication data converted by using the irreversible function is intercepted and transmitted to the server as false authentication data. Therefore, the server generates a different numerical value for each authentication, connects the numerical value and the password, and then uses the irreversible function. As a result, different authentication information is used every time, and impersonation by eavesdropping becomes impossible, and even if a third party accesses the server and obtains the numerical value generated by the server, the correct authentication information cannot be generated because the password is unknown. Login fails.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a client-server using the present authentication method of the present embodiment. The authentication client 8 and the business server 6 are connected via a wide area network such as the Internet. The authentication client 8
The client control device includes a display device, a keyboard, and a client control device.

An irreversible conversion device 310 also exists in a server control device that is a part of the business server 6. The characteristics of the irreversible conversion device 310 have been described with reference to FIG. The business server 6 includes a password DB 30 and manages user IDs and password information of users who can use the business server 6.

When the user 11 inputs the user ID 22 and the password 100 from the authentication client 8, the user 1
The password 100 input by the user 1 is converted to an irreversible conversion device 310.
And transmitted as authentication information to the business server 6 via the network.

FIG. 2 shows an authentication sequence when the present invention is used.

In this figure, it is assumed that the authentication client is a PC and the business server is a PC or a workstation.

The user 11 requests connection to the business server 6 using the authentication client 8 (2001). The authentication client displays a login screen for inputting a user ID and a password to the user 11 (2002). Here user 1
1 inputs a user ID 22 and a password 100 (200
3). The authentication client 8 transmits the user ID 22 input by the user 11 to the business server 6 (2004), and the business server generates different numerical challenge data 101 every time (200).
5) Reply to the authentication client (2006). The authentication client concatenates the password 100 previously input by the user 11 and the challenge data 101 returned from the server, performs irreversible conversion, calculates a hash value 102 (2007), and transmits it to the business server 6 (2008).

The business server 6 retrieves the password 31 of the user 11 from the password DB (2009), connects the previously generated challenge data 101, performs the same irreversible conversion as the authentication client, and calculates the hash value 103 (2).
010). The hash value 103 is compared with the hash value 102 transmitted from the client (2011), and if they do not match, the user using the authentication client is not authenticated and the login request is failed (2012). If they match, authenticate as an authorized user and accept the login request (201
3).

FIG. 3 shows an authentication method using a conventional reversible conversion device.

In this case, the authentication information (3003) such as a password input by the user is converted by a reversible conversion device such as BASE64 (3004) and transmitted to the business server 6 (3005).
For this reason, there is a danger that password information will be leaked if wiretapping is performed on a network.

FIG. 4 shows the characteristics of data conversion using a reversible conversion device. The input data 200 is a reversible conversion device 3
00 is converted to output data 201. Output data 20
1 is again converted by the reversible conversion device 300, so that output data 202 is obtained. At this time, the input data 200 and the output data 202 are equal. As such a conversion method, BAS
The E64 conversion is known, and processing 3004 and processing 3006 in FIG.
Corresponding to

FIG. 5 shows the characteristics of data conversion using an irreversible conversion device. The input data 210 is converted by the irreversible conversion device 310 into output data 211. The output data 211 is obtained by converting the output data 211 again by the irreversible conversion device 310. At this time, the input data 210 and the output data 212 do not match. SHA-1 and MD5 conversion are known as such conversion methods, and correspond to the processing 2007 and the processing 2010 in FIG.

[0025]

As described above, according to the present invention, authentication information can be transmitted safely through a public network, and leakage of a password can be prevented. Also, by using different authentication information every time, it is possible to prevent impersonation due to eavesdropping.

In this method, since no encryption technique is used, there is no need to manage certificates and keys. For this reason, it is a method that can be easily applied overseas.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an apparatus when the present invention is implemented.

FIG. 2 is a diagram showing an authentication sequence when the present invention is implemented.

FIG. 3 is a diagram showing a conventional authentication sequence.

FIG. 4 is a diagram illustrating characteristics of conversion by a reversible conversion device.

FIG. 5 is a diagram illustrating characteristics of conversion by an irreversible conversion device.

[Explanation of symbols]

Business server 6: server system, authentication client 8 ...
Client system, user 11: user, challenge data 101: data generated by server 6 and using different values each time authentication is performed from the client, password 1
00: password input by the user 11 from the keyboard, hash value 102: value obtained by connecting and irreversibly converting the password 100 and challenge data 101, password DB 30: user ID and password for each user registered in the server in advance Table, hash value 103 ...
A value obtained by connecting and irreversibly converting the password 31 and the challenge data 101 obtained from the password DB 30, input data 200... Data before any conversion, the reversible conversion device 3
00: device capable of restoring original data after converting input data; output data 201: data obtained by converting input data 200 by reversible conversion device 300; output data 202
... Data obtained by converting the output data 201 by the reversible conversion device 300, input data 210: data before any conversion, irreversible conversion device 310: a device whose original data cannot be restored again after the input data is converted, output data 211: data obtained by converting the input data 210 by the irreversible conversion device 310;
Output data 212: data obtained by converting the output data 211 by the irreversible conversion device 310; 2001 to 2013: processing in client authentication based on the present invention; 3001 to 3010: processing in conventional authentication.

Claims (2)

[Claims] In a network system in which a client and a business server can communicate with each other, means for converting authentication information of a client by an irreversible function so that confidential information possessed by the client cannot be taken out, generated by the server. A client authentication method using an irreversible function, characterized in that authentication information is changed safely each time by using a different value each time and a means for preventing impersonation due to eavesdropping is used to securely exchange authentication information. 2. The irreversible function according to claim 1, wherein a different value is generated each time by a client or a third device, and the authentication information is securely exchanged by generating authentication information based on the value. Client authentication method using.