JP2004248184A - Partner authentication method / program / recording medium / system using certificate authority having a plurality of signature algorithms, certificate authority, user terminal - Google Patents

Abstract

A method is provided in which a user terminal switches a CA signature algorithm for each application, and a certificate path can be constructed between user terminals having public key certificates signed by different signature algorithms.
A user terminal sets a CA signature algorithm by a desired signature algorithm setting unit when applying. The CA extracts the signature algorithm set by the user terminal by the desired signature algorithm extraction unit 3, extracts the signature key corresponding to the signature algorithm by the corresponding CA signature key extraction unit 4, and signs the signature by the signature unit 5. Do. In addition, the CA uses the cross-signature mutual certificate issuing unit 1 to authenticate the public key corresponding to the installed signature algorithm with the signature key corresponding to another mounted signature algorithm. The user terminal uses the certificate path construction unit 6 to construct a path between certificates having different signature algorithms.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to authentication using a certification authority (hereinafter abbreviated as CA).
[0002]
[Prior art]
In the case of authentication using CA, a different signature algorithm is used so that a transition to a signature key having another signature algorithm can be performed promptly in case the signature key is leaked or the signature algorithm itself is compromised. It has been proposed to implement a plurality of signing keys in CA.
[0003]
The following methods exist as methods for implementing a plurality of signature keys having different signature algorithms.
[0004]
The signature key used to sign the certificate returned to the user terminal from the CA or the service result is uniquely specified by the CA from among multiple signature keys implemented by the CA and having different signature algorithms. Then, a signature is performed using the signature key.
[0005]
However, this method has the following problems.
[0006]
In an environment (application or the like) where a verifiable signature algorithm is limited, such as a Web browser, there is a case where a user terminal cannot verify a signature algorithm of a key used as a signature key by a CA. For example, when the CA uses a DSA key as a signature key, a user who has applied for registration of an RSA public key and who can verify only the RSA will sign the certificate with the DSA signature key. In this case, the user terminal that has received the certificate cannot perform the verification.
[0007]
Then, in order to solve the above problems, the following methods have been proposed.
[0008]
A CA implementing a plurality of signature keys having different signature algorithms switches the CA's signature algorithm for each user terminal by managing the correspondence between the user terminal and the CA's signature algorithm (for example, see Patent Document 1). ).
[0009]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-207426
[Problems to be solved by the invention]
However, the method of implementing a plurality of signature keys having different signature algorithms disclosed in Patent Document 1 has the following problems.
[0011]
Since the CA signature algorithm is switched for each user terminal, the CA needs to manage the correspondence between the user terminal and the CA signature algorithm. Therefore, if the user terminal wants the CA to change the signature algorithm of the CA, the user terminal instructs the CA to use any method for the communication between the user terminal and the signature algorithm of the CA managed by the CA. You have to change the response. Therefore, it is impossible for the user terminal to switch the CA signature algorithm for each application.
[0012]
Further, since the CA switches the signature algorithm of the CA for each user terminal, a certificate path cannot be constructed between user terminals having public key certificates issued by different signature algorithms. Therefore, authentication using CA fails between such user terminals. For example, in an environment in which a CA implements RSA and DSA, a public key certificate is issued using an RSA signature key and a DSA signature key. Does not exist, a certification path can be constructed between a user terminal having a public key certificate issued with an RSA signature key and a user terminal having a public key certificate issued with a DSA key. Authentication fails.
[0013]
An object of the present invention is to allow a user terminal to switch a CA signature algorithm for each application, and to construct a certification path between user terminals having public key certificates issued by different signature algorithms. It is to provide a method.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, when a CA receives an application from a user terminal, the CA extracts a signature algorithm set in the application form from the application form, and extracts a CA corresponding to the signature algorithm. Signing a certificate or service result returned from the CA to the user terminal with the signature key of Further, a mutual certificate between signature algorithms is created by authenticating a public key corresponding to a signature algorithm implemented by the CA with a signature key corresponding to another signature algorithm implemented by the CA.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to FIG.
[0016]
A partner authentication system using a CA in which a plurality of signature keys having different signature algorithms are mounted according to an embodiment of the present invention includes: (1) a desired signature algorithm setting unit 2 provided in a user terminal; The CA extracts the signature algorithm set in the application form by the user terminal from the application form by the desired signature algorithm extraction section 3, the corresponding CA signature key extraction section 4, and the signature section 5, and executes the CA corresponding to the signature algorithm. Signing a certificate or service result returned from the CA to the user terminal with the signature key of (2) The CA is implemented by the inter-signature algorithm mutual certificate issuing unit 1 provided in the CA, the certification path construction unit 6 provided in the user terminal, and the inter-signature algorithm mutual certificate acquisition unit 7. Create a mutual certificate between signature algorithms that authenticates the public key corresponding to one signature algorithm with the signature key corresponding to another signature algorithm implemented by the CA, and certifies public key certificates issued by different signature algorithms. Build a certification path between owned user terminals.
[0017]
Next, processing in the system of the present embodiment will be described separately for each unit.
[0018]
(1) The processing CA in the inter-signature algorithm mutual certificate issuance unit 1 uses the inter-signature algorithm mutual certificate issuance unit 1, and converts the public key corresponding to the signature algorithm implemented by the CA into another A mutual certificate between signature algorithms authenticated with a signature key corresponding to the signature algorithm is created, and this processing is repeated for all the signature algorithms held.
[0019]
(2) The processing user terminal in the desired signature algorithm setting unit 2 sets the signature algorithm in the application using the desired signature algorithm setting unit 2 in response to creation of various service applications for CA.
[0020]
(3) Processing in Desired Signature Algorithm Extraction Unit 3 The CA receiving this application extracts the signature algorithm set by the user terminal from the application using the desired signature algorithm extraction unit 3.
[0021]
(4) The processing CA in the corresponding CA signature key extraction unit 4 uses the corresponding CA signature key extraction unit 4 to determine whether a CA signature key corresponding to the signature algorithm extracted by the desired signature algorithm extraction unit 3 exists. The determination is made based on the signature key management file (or database) 8, and if it is present, the CA signature key is extracted.
[0022]
(5) The processing CA in the signature unit 5 uses the signature key of the CA extracted by the corresponding CA signature key unit 4 to sign the certificate or service result returned to the user terminal using the signature unit 5.
[0023]
(6) The processing user terminal in the certification path construction unit 6 and the inter-signature algorithm mutual certificate acquisition unit 7 performs certification path verification using the certification path construction unit 6 when authenticating a communication partner. . If the certification path verification fails, the inter-signature algorithm mutual certificate obtaining unit 7 is used to transfer the inter-signature algorithm mutual certificate created by the inter-signature algorithm mutual certificate issuing unit 1 to a CA or a directory (such as an external database). To get from. The certification path verification is performed again using the mutual certification between the signature algorithms and the certification path construction unit 6.
[0024]
【Example】
Next, an example of the present embodiment will be described in detail with reference to FIGS.
[0025]
In one example of the present embodiment, the CA already uses the DSA and newly uses the ESIGN signature key. As a signature algorithm specified by the user terminal included in the application, a signature algorithm stored in the Algorithm Identifier element of the Signature element of the application is used, and the user terminal specifies DSA as the signature algorithm. An example will be described. In the present embodiment, the Algorithm Identifier element of the Signature element of the application is used. However, as a signature algorithm specified by the user terminal included in the application, an item for the signature is separately provided in the application. There are various ways.
[0026]
(1) The process CA in the inter-signature algorithm mutual certificate issuing unit 1 uses the inter-signature algorithm mutual certificate issuing unit 1 to newly create an ESIGN public key certificate when creating a new ESIGN public key certificate. Is created using a DSA signature key, which is another signature algorithm already implemented by this CA. Conversely, a cross-signature-algorithm inter-certificate certificate that authenticates a DSA public key, which is another signature algorithm already implemented by the CA, is created using the ESIGN signature key to be newly registered.
[0027]
(2) The processing user terminal in the desired signature algorithm setting unit 2 uses the desired signature algorithm setting unit 2 to generate an application using the desired signature algorithm setting unit upon creation of various service applications for the CA, such as a public key registration application and a public key certificate invalidation application. The DSA signature algorithm is set as the signature algorithm of the Algorithm Identifier element of the Signature element of the document.
[0028]
(3) The processing CA in the desired signature algorithm extraction unit 3 uses the desired signature algorithm extraction unit 3 in response to the reception of the application form from the user terminal, and uses the desired signature algorithm extraction unit 3 to execute the signature algorithm of the Algorithm Identifier element of the received Signature element in the application form , A DSA signature algorithm which is a signature algorithm designated by the user terminal is extracted.
[0029]
(4) The processing CA in the corresponding CA signature key extraction unit 4 receives the signature algorithm (DSA signature algorithm) designated by the user terminal extracted by the desired signature algorithm extraction unit 3 and inputs the corresponding CA signature key extraction unit 4 Is determined based on the CA signature key management file (or database) 8 to determine whether a CA signature key corresponding to the signature algorithm (DSA signature algorithm) specified by the user terminal exists. If so, the corresponding CA signature key is extracted. In this embodiment, the presence of the DSA signature key allows the DSA signature key to be extracted.
[0030]
If not, one of the following two is applied depending on the system setting value.
(A) Extract the CA signature key specified as the default.
(B) Return an error that the corresponding CA signature key does not exist.
[0031]
(5) The processing CA in the signature unit 5 uses the signature unit 5 in response to the input of the CA signature key (DSA signature key) extracted by the corresponding CA signature key extraction unit 4, and uses the signature key to generate a user terminal. Sign the certificate or service result to be returned to.
[0032]
(6) Processing in the certification path construction unit 6 and the mutual authentication between signature algorithms acquisition unit 7 The user terminal that has been issued a certificate signed with this DSA signature key is issued with the ESIGN signature key of the same CA. When authenticating the user terminal having the public key certificate obtained, the certification path construction unit 6 is called, and the ESIGN public key certificate of the communication partner → the ESIGN public key certificate of the CA and the certification path are constructed. However, a cross-signature algorithm cross-certificate linking the certification path between the CA's ESIGN public key certificate and the CA's DSA public key certificate was issued a certificate signed with this DSA signature key. Since it does not exist under the user terminal, certification path construction results in an error. With the failure in the certification path construction, the inter-signature algorithm mutual certificate acquisition unit 7 was used to authenticate the ESIGN public key created by the inter-signature algorithm mutual certificate issuing unit 1 with the DSA signature key. A mutual certificate between signature algorithms is obtained from a CA or a directory. Thereafter, the certification path verification is performed again using the mutual certification between the signature algorithms and the certification path construction unit 6 again.
[0033]
In addition, the certificate authority and the user terminal can record the program for realizing the function in a computer-readable recording medium in addition to the realization by the dedicated hardware, and store the program in the recording medium. May be read into a computer system and executed. The computer-readable recording medium refers to a recording medium such as a floppy disk, a magneto-optical disk, a CD-ROM, or a storage device such as a hard disk device built in a computer system. Further, a computer-readable recording medium is a medium (transmission medium or transmission wave) that dynamically holds a program for a short time, such as a case where a program is transmitted via the Internet, It also includes a memory that holds a program for a certain period of time, such as a volatile memory in a computer system serving as a server or a terminal.
[0034]
【The invention's effect】
As described above, according to the present invention, the user terminal can switch the CA signature algorithm for each application. Further, it is possible to construct a certification path between user terminals having public key certificates issued by different algorithms.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a partner authentication system using a certificate authority equipped with a plurality of signature keys having different signature algorithms according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a process in which a CA creates a mutual certificate between signature algorithms, and a user terminal uses the certificate to reconstruct a certification path.
FIG. 3 is a flowchart showing a process in which a user terminal sets a signature algorithm, a CA extracts the signature algorithm, extracts a corresponding signature key, and performs a signature using the key.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mutual certificate issuing part between signature algorithms 2 Desired signature algorithm setting part 3 Desired signature algorithm extraction part 4 Corresponding CA signature key extraction part 5 Signature part 6 Certificate path construction part 7 Inter-signature mutual certificate acquisition part 8 CA signature key Management file or database

Claims (17)

In a partner authentication method using a certificate authority having a plurality of signature algorithms,
The user terminal designating a signature algorithm in the application to the certificate authority;
The certificate authority, extracting the signature algorithm specified in the application from the user terminal,
The certificate authority extracting a signature key corresponding to the extracted signature algorithm;
The method comprising the step of the certificate authority signing a certificate or service result to the user terminal using the signature key. In a partner authentication method using a certificate authority having a plurality of signature algorithms,
A certificate authority creates a mutual certificate between signature algorithms authenticated by a public key corresponding to a signature algorithm of the certificate authority with a signature key of the certificate authority corresponding to a signature algorithm different from the signature algorithm. Steps and
The user terminal acquiring the mutual certificate between signature algorithms,
The method as claimed in claim 1, further comprising the step of the user terminal constructing a certification path between different signature algorithms using the mutual certificate between signature algorithms. To a certificate authority with multiple signature algorithms,
Extracting the signature algorithm specified in the application from the user terminal;
Extracting a signature key corresponding to the extracted signature algorithm;
A program for executing a step of signing a certificate or a service result for the user terminal using the signature key. To a certificate authority with multiple signature algorithms,
Executing a step of creating a mutual certificate between signature algorithms in which a public key corresponding to a signature algorithm of the certificate authority is authenticated with a signature key of the certificate authority corresponding to a signature algorithm different from the signature algorithm. program. To a user terminal receiving a service from a certificate authority having a plurality of signature algorithms,
A program that executes the step of specifying a signature algorithm when applying to a certificate authority. To a user terminal receiving a service from a certificate authority having a plurality of signature algorithms,
Obtaining a public key corresponding to a signature algorithm of the certificate authority, the certificate authority has a cross-certificate between signature algorithms authenticated with a signature key corresponding to a signature algorithm different from the signature algorithm,
A program for executing a step of constructing a certification path between different signature algorithms using the mutual certificate between signature algorithms. A computer-readable recording medium on which the program according to claim 3 is recorded. A computer-readable recording medium on which the program according to claim 4 is recorded. A computer-readable recording medium on which the program according to claim 5 is recorded. A computer-readable recording medium on which the program according to claim 6 is recorded. In a certificate authority having a plurality of signature algorithms,
Means for extracting the signature algorithm specified in the application from the user terminal;
Means for extracting a signature key corresponding to the extracted signature algorithm;
A certificate authority comprising means for signing a certificate or service result for the user terminal using the signature key. In a certificate authority having a plurality of signature algorithms,
A means for creating a mutual certificate between signature algorithms, in which a public key corresponding to a signature algorithm of the certification authority is authenticated by a signature key of the certification authority corresponding to a signature algorithm different from the signature algorithm. Certificate authority. In a certificate authority having a plurality of signature algorithms,
Means for extracting the signature algorithm specified in the application from the user terminal;
Means for extracting a signature key corresponding to the extracted signature algorithm;
Means for signing a certificate or service result to the user terminal using the signature key;
A means for creating a mutual certificate between signature algorithms, in which a public key corresponding to a signature algorithm of the certification authority is authenticated by a signature key of the certification authority corresponding to a signature algorithm different from the signature algorithm. Certificate authority. In a user terminal receiving a service from a certificate authority having a plurality of signature algorithms,
A user terminal having means for designating a signature algorithm when applying to the certificate authority. In a user terminal receiving a service from a certificate authority having a plurality of signature algorithms,
Means for obtaining a cross-certificate between signature algorithms authenticated by a signature key corresponding to a signature algorithm corresponding to a signature algorithm different from the public key corresponding to a signature algorithm possessed by the certification authority, and having the certification authority.
A user terminal having means for constructing a certification path between different signature algorithms using the mutual certificate between signature algorithms. In a user terminal receiving a service from a certificate authority having a plurality of signature algorithms,
Means for specifying a signature algorithm in the application to the certificate authority,
Means for obtaining a cross-certificate between signature algorithms authenticated by a signature key corresponding to a signature algorithm corresponding to a signature algorithm different from the public key corresponding to a signature algorithm possessed by the certification authority, and having the certification authority.
A user terminal having means for constructing a certification path between different signature algorithms using the mutual certificate between signature algorithms. In a partner authentication system using a certificate authority having a plurality of signature algorithms,
A certificate authority according to any one of claims 11 to 13,
A system comprising the user terminal according to any one of claims 14 to 16.

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