JP4761348B2 - User authentication method and system - Google Patents

Description

  The present invention relates to a user authentication method and system, and more particularly to a user authentication method and system suitable for a public key authentication method.

  As a method of authenticating the user who receives the service, the server that provides the service authenticates the password authentication method that authenticates the condition that the login name and password match, and the server and the user terminal share the same encryption key for authentication. A common key authentication method for performing is known. Furthermore, as an authentication method that is more secure than these methods, Patent Document 1 discloses a public key authentication method in which a server and a user terminal authenticate using individual encryption keys (public key and private key). It is disclosed.

In such an authentication method, in order to efficiently and safely authenticate a large number of users, a system for managing information necessary for authentication, i.e., an authentication infrastructure, is required. In the public key authentication method, a public key authentication infrastructure (PKI : Public Key Infrastructure).
JP 2003-309546 A

  When a user desires to provide a wide variety of services, the user needs to individually contract with a number of service providing servers. At this time, in the public key authentication method described above, public key registration must be requested from the certificate authority in advance for each service providing server, and an encryption key pair of a public key and a private key and a public key certificate must be acquired. However, a great burden is imposed on the user because a great deal of effort is required to obtain a public key registration request and obtain a public key / private key encryption key pair and a public key certificate.

  An object of the present invention is to solve the above-described problems of the prior art and provide a user authentication method and system capable of easily performing authentication by a public key authentication method between a user terminal and a number of service providers.

To achieve the above object, the present invention provides a user terminal, a user management system that issues a public key certificate in response to a request from the user terminal, and a plurality of services that provide a service in response to a request from each user terminal. In a user authentication method in which each service providing server authenticates a user terminal on a network including the service providing server, a procedure for transmitting a registration request from the user terminal to the user management system, and the user management system responding to the registration request Generating a first user identifier and an encryption key pair of a first public key and a first secret key, a procedure for generating a public key certificate related to the first public key by the user management system, and the user management A procedure in which the system transmits the first user identifier, the first public key, the first private key, and the public key certificate to the user terminal; Serial user terminal comprises a step of generating a second user identifier and the second public key and the second private key encryption key pair, wherein the user terminal, and a procedure of issuing a proxy certificate with respect to the second public key A procedure in which the user terminal transmits a service request including the proxy certificate to the service providing server; and a procedure in which the service providing server transmits a verification request including the received proxy certificate to a user management system; A procedure in which the user management system extracts a public key certificate corresponding to the received proxy certificate; a procedure in which the user management system verifies the public key certificate and the proxy certificate; and And a step of transmitting the verification result to the service providing server.

  According to the present invention, a user terminal can generate an encryption key pair of a user identifier, a public key and a private key by itself, and a proxy certificate certified with the public key certificate for this public key can be uniquely and simply Can be issued. Therefore, if public key authentication is performed using this proxy certificate, authentication by the public key authentication method can be easily performed between the user terminal and a number of service providing destinations.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a user authentication system to which a user authentication method according to the present invention is applied. A plurality of service providing servers 1 (1a, 1b...) And each service providing server 1 are used. A user terminal 2 (2a, 2b...) And a user management system 3 having a function as a certificate authority are connected to each other via a wide area network such as the Internet. The user management system 3 is provided with a directory 4 for centrally managing attribute information of each user.

  FIG. 2 is a flowchart showing a procedure for a user requesting user registration from the user terminal 2 to the user management system 3 to acquire an encryption key pair and a public key certificate, and FIG. 3 is a sequence flow thereof. Here, a case where user A requests user registration from his / her user terminal 2a will be described as an example.

  When the user A requests user registration, the user A registers his / her name, date of birth, gender, current address and its telephone number, and personal information such as office and telephone number as attribute information in the user terminal 2a. It transmits to the user management system 3 with a user registration request message. In the user management system 3, when the user registration request transmitted from the user terminal 2a is received in step S101, the attribute information included in the user registration request is extracted and temporarily stored in step S102. In step S103, a unique user identifier IDa is assigned to the user A. In step S104, a secret key SKa and a public key PKa are generated as an encryption key pair unique to the user A. In step S105, a public key certificate PKCa is issued for the public key PKa.

  A public key certificate (PKC) is a combination of information about the owner name (subject) of the public key, public key data, the validity period of the certificate, and information on the certificate authority that issued the certificate. This is a certificate issued by the certificate authority with an electronic signature.

  FIG. 4 is a diagram showing the format of the public key certificate PKCa issued to the user A in the present embodiment. The serial number (SNa), owner name (SUBJECTa), issuer name (ISSUERa), expiration date ... and various kinds of information including the public key PKa assigned to the user A, and an electronic signature performed by the user management system 3 for these pieces of information are registered. In the present embodiment, as the owner name (SUBJECTa), the user identifier IDa is used as a CN (Common Name), and an issuer name (ISSUERa) is added to this [CN (= IDa) + ISSUERa]. Used.

  Returning to FIG. 2, in step S106, the user identifier IDa, the encryption key pair (SKa, PKa), and the public key certificate PKCa are returned to the user terminal 2a. In step S107, the user identifier IDa, the encryption key pair (SKa, PKa), the public key certificate PKCa, and the attribute information provided from the user A are stored in the directory 4 in association with each other. In step S108, when a completion confirmation is received from the directory 4, a series of public key registration processing ends.

  Next, a procedure until the user A accesses the service providing server 1 and receives service provision through the authentication procedure will be described with reference to the flowcharts of FIGS. 5 and 6 and the sequence flow of FIG.

When the user A accesses any one of the service providing servers 1, an arbitrary user identifier IDan is generated in step S201 in FIG. 5, and an encryption key pair of an arbitrary secret key SKan and public key PKan is further generated. . In step S202, a proxy certificate PCan of the public key certificate PKCa is issued to the public key PKan based on IETF RFC (Request for Comments) 3820 . However, the issuer name item shall be the original procedure shown below.

  FIG. 8 is a diagram showing the contents of the proxy certificate PCan, which includes a serial number (SNan), an owner name (SUBJECTan), an issuer name (ISSUERan), certificate authority information, and various types including the public key PKan. And the electronic signature made by the user A for these pieces of information are registered.

  In this proxy certificate PCan, the owner of the public key certificate PKCa (SUBJECTa = [CN + ISSUERa]))) and the serial number (SNan) of the proxy certificate PCan are concatenated, and this is connected in advance to the user management system 3 What is encrypted with the public key PKc provided by, as CN (Common Name) [= EPKc (SUBJECTa + SNan)], and is given the issuer name (ISSUERa) of the public key certificate PKCa to this CN [ EPKc (SUBJECTa + SNan) + ISSUERa] is the issuer name (ISSUERan).

  In this way, in this embodiment, by including the serial number (SNan) in the issuer name, even if it is a proxy certificate issued by the same user, the issuer name is no longer relevant, so the user's anonymity Can be protected.

  In step S203, a service request including the proxy certificate PCan is transmitted to the service providing server 1. Upon receiving a service request including the proxy certificate PCan from the user terminal 2a, the service providing server 1 transmits a verification request message including the proxy certificate PCan to the user management system 3 to request verification.

  FIG. 6 is a flowchart showing a verification procedure by the user management system 3 that has received the proxy certificate PCan transferred from the service providing server 1.

  In step S301, whether or not the management domain related to the issuer of the received proxy certificate PCan is under the control of the user management system 3 (that is, the portion other than the CN of the issuer of the proxy certificate represents the user management system 3). Whether or not) is determined. If it is under management, the process proceeds to step S302, where the issuer CN (encrypted with the public key PKc) registered in the proxy certificate PCan is decrypted with the secret key SKc of the user management system 3, The owner name (SUBJECTa) of the public key certificate PKCa and the serial number (SNan) of the proxy certificate PCan are reproduced. In step S303, the reproduced serial number (SNan) is compared with the serial number registered in the proxy certificate PCan, and if they match, the process proceeds to step S304.

  In step S304, the user identifier IDa is extracted from the reproduced owner name (SUBJECTa). In step S305, the directory 4 is searched using the user identifier IDa as a parameter, and the public key certificate PKCa associated with the user identifier IDa is obtained. In step S306, verification of the signature attached to the public key certificate PKCa, verification of whether the verification time point is within the validity period, verification of whether the verification target certificate has been revoked, and issue of the public key certificate If it is verified that the certificate of the institution that has been revoked has not been revoked, and it is confirmed that there is no problem with all of these, in step S307, the public key certificate PKCa is determined to be valid (verification is OK). The

  On the other hand, if any of the verification of the signature and the verification of whether the verification time point is within the validity period becomes invalid in step S306, the public key certificate PKCa is invalid (verification NG) in step S308. ). If it is determined in step S301 that the issuer's management domain is not under management, or if it is determined in step S303 that the serial numbers do not match, the process proceeds to step S308 and the public key is entered. The certificate PKCa is determined to be invalid. In step S309, the verification result is returned to the service providing server.

  As described above, when the validity of the proxy certificate PCan is confirmed, the service providing server authenticates the user A, and then the requested service is provided.

  As described above, according to the present invention, the user terminal can generate the encryption key pair of the user identifier, the public key and the private key by itself, and the proxy certificate proved by the public key certificate with respect to this public key. Can be issued independently and easily. Further, since only the user management system 3 can detect the association between a plurality of proxy certificates issued by the same user terminal, the anonymity of the user is maintained. Therefore, if public key authentication is performed using this proxy certificate, authentication by the public key authentication method can be easily performed between the user terminal and a number of service providing destinations.

1 is a block diagram showing a configuration of a user authentication system to which a user authentication method according to the present invention is applied. It is the flowchart which showed the procedure in which a user requests | requires user registration to a user management system, and acquires an encryption key pair and a public key certificate. It is the sequence flow which showed the procedure in which a user requests | requires user registration to a user management system and acquires an encryption key pair and a public key certificate. It is the figure which showed an example of the format of a public key certificate. It is the flowchart which showed the procedure until a user accesses a service provision server and receives provision of a service through an authentication procedure. It is the flowchart which showed the procedure until a user accesses a service provision server and receives provision of a service through an authentication procedure. It is a Siemens flow showing a procedure from a user accessing a service providing server until receiving a service through an authentication procedure. It is the figure which showed an example of the format of a proxy certificate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Service provision server, 2 ... User terminal, 3 ... User management system, 4 ... Directory

Claims (5)

Providing each service on a network including a user terminal, a user management system for issuing a public key certificate in response to a request from the user terminal, and a plurality of service providing servers for providing a service in response to a request from each user terminal In a user authentication method in which a server authenticates a user terminal,
A procedure for sending a registration request from a user terminal to a user management system;
A procedure in which a user management system generates an encryption key pair of a first user identifier and a first public key and a first secret key in response to the registration request;
The user management system generating a public key certificate for the first public key;
A procedure in which the user management system transmits the first user identifier, a first public key, a first secret key, and a public key certificate to a user terminal;
The user terminal generating a second user identifier and an encryption key pair of a second public key and a second secret key;
The user terminal issuing a proxy certificate for the second public key ,
A procedure in which the user terminal transmits a service request including the proxy certificate to the service providing server;
The service providing server sends a verification request including the received proxy certificate to the user management system;
The user management system extracting a public key certificate corresponding to the received proxy certificate;
The user management system verifying the extracted public key certificate and the received proxy certificate;
The user management system further includes a procedure for transmitting the verification result to the service providing server. The public key certificate of the user management system is provided in advance to the user terminal,
The user terminal includes a procedure of encrypting a part of the information of the proxy certificate with the public key of the service providing server,
The user management system includes a procedure for decrypting the partial information of the received proxy certificate with its own private key,
The user authentication method according to claim 1, wherein the user management system verifies the proxy certificate based on the decrypted partial information.   The partial information of the proxy certificate includes another partial information of the proxy certificate and a part of information included in the public key certificate of the user terminal. The user authentication method according to 2. The user management system uses the public key of the user management system based on a part of the information included in the public key certificate among the information obtained by decrypting a part of the information of the proxy certificate with a secret key. The user authentication method according to claim 3, wherein a certificate is specified. Providing each service on a network including a user terminal, a user management system for issuing a public key certificate in response to a request from the user terminal, and a plurality of service providing servers for providing a service in response to a request from each user terminal In a user authentication system in which a server authenticates a user terminal,
User management system
Means for generating an encryption key pair of the first user identifier and the first public key and the first secret key in response to the public key registration request received from the user terminal;
Means for generating a public key certificate for the first public key;
Means for transmitting the first user identifier, the first public key, the first private key and the public key certificate to a user terminal,
User terminal
Means for transmitting a public key registration request to the user management system;
Means for receiving the first user identifier, first public key, first private key and public key certificate from the user management system;
Means for generating a second user identifier and an encryption key pair of a second public key and a second secret key;
Means for issuing a proxy certificate for the second public key ;
Means for transmitting a service request including the proxy certificate to the service providing server,
The service providing server includes means for transmitting a verification request including the received proxy certificate to the user management system;
The user management system further comprises:
Means for extracting a public key certificate corresponding to the received proxy certificate;
Means for verifying the extracted public key certificate and the received proxy certificate;
And a means for transmitting the verification result to the service providing server.

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