KR20020086030A - User Authentication Method and System on Public Key Certificate including Personal Identification Information - Google Patents

Abstract

The present invention securely injects personal identification information, such as social security number or biometric information, into a public key certificate of a public key infrastructure (PKI), which is used as a user authentication and digital signature solution on the Internet. The present invention relates to a method and system for authenticating a user using a public key certificate including identification information.

To this end, the present invention provides a method for injecting personal identification information into a public key certificate by a certificate authority that issues a public key certificate, and a means for a certificate server to authenticate a client user using a public key certificate including personal identification information. .

The present invention provides a more accurate user authentication method by including personal identification information, such as a social security number, which is more identifiable in a public key certificate, and in the case of including biometric information such as fingerprint information in a public key certificate, public key certificate. By performing user authentication and user authentication using biometric information at the same time, stronger user authentication can be achieved.

Description

User authentication method and system using public key certificate including personal identification information {User Authentication Method and System on Public Key Certificate including Personal Identification Information}

The public key certificate standard currently used as a standard in P-K-I is X.509 V3, which was amended by ITU-T in March 2000 after several revisions. In X509 V3, the area related to the issuer is Subject Name, which is a basic area, and Subject Alternative Name (203) among extended areas of X.509 area.

The Subject Name should contain a Distinguished Name (DN) that uniquely identifies the issuer. There are nine types of Subject Alternative Names (203), and eight of these fields are defined to be entered. For example, rfc822Name is determined by an Internet mail address, and iPAddress is determined by an IP address. The other, OtherName, allows the user to define and use eight different types of expressions. Therefore, the place where the information related to the personal identification information raised in the present invention can be injected becomes the Subject Alternative Name area 203 in the public key certificate.

Conventional techniques merely suggest a method of utilizing public key certificates defined in existing standard documents, and how to safely include user identification information in a public key certificate and can be used safely without exposing such personal identification information. There is no known technique for the method. In general, a method of authenticating a user by using a public key certificate is to check whether the user has a secret key corresponding to the public key certificate. However, as shown in the case of the certification authority certificate currently used in Korea, if the user is the same name, the user related information should be inquired by another method to determine exactly which user is authenticating. When using a certificate, if a system that requires not only the private key corresponding to the certificate but also commonly used personal identification information such as a social security number is included in the public key certificate, it is necessary to process it at once without this additional procedure. It is possible.

The following is a list of standard documents dealing with authenticating users with common public key certificates.

(1) ISO / IEC 9798-1, "Information technology-Security techniques-Entity authentication mechanisms-Part 1: General Model", International Organization for Standardization, Geneva, Switzerland, 1991 (first edition)

(2) ISO / IEC 9798-3, "Information technology-Security techniques-Entity authentication mechanisms-Part 3: Entity Authentication", International Organization for Standardization, Geneva, Switzerland, 1993 (first edition)

(3) ISO / IEC 9594-8, "Information technology-Open Systems Interconnection-The Directory: Authentication framework", International Organization for Standardization, Geneva, Switzerland, 1995 (equivalent to ITU-T Rec. X.509, 1993)

(4) ITU-T Rec. X.509 (Revised), "The Directory-Authentication framework", International Telecommunication Union, Geneva, Switzerland, 1993

(5) ITU-T Rec. X.509 (Revised), "The Directory-Authentication framework", International Telecommunication Union, Geneva, Switzerland, 2000

More accurate user identification and more secure user authentication can be realized by including biometric information such as social security numbers or fingerprint information in public key certificates that are widely used for user authentication in electronic commerce on the Internet. However, since anyone can obtain the public key certificate information, including the social security number or biometric information without any protection measures in the public key certificate causes a big problem in terms of personal information protection.

Therefore, in the present invention, when including personal identification information about a user, such as a social security number or biometric information, in a public key certificate, personal information (such as a resident identification number or biometric information) is prevented from being exposed to any person. Personal identification information is used to authenticate users more accurately and safely.

In the present invention, no one who can access the public key certificate can safely inject personal identification information such as social security number or biometric information (fingerprint recognition information, iris recognition information, voice recognition information, etc.) injected into the public key certificate and securely inject such personal information. We propose a method and system for providing more secure and accurate user authentication in open network environments such as the Internet using identification information.

1 is a system configuration diagram of the present invention,

2 is a block diagram of a public key certificate,

3 is an ASN.1 representation of a Subject Alternative Name field 203 of a public key certificate;

4 is a flowchart illustrating a process of injecting personally identifiable information into a certificate by a certification authority.

5 is a view showing a user authentication process using a public key certificate including personal identification information according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a decryption process of the personal identification information confirmer using the authentication information decoding module.

[Description of Symbols for Main Parts of Drawing]

101: certification authority

102: public key directory

103: server system for authenticating clients

104: Hardware module that is connected to server as authentication information decryption module and supports client user personal identification information verification.

105: client system used by the user

106: Internet where Certificate Authorities, Clients and Servers Connect to Send and Receive Information

Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a system configuration to which the present invention is applied. The certification authority 101 generates a key for issuing a certificate for generating a public key certificate, an encryption key (EK) for protecting personal identification information (RID), and a decryption key (DK) to generate an encryption key (EK). 101 is used, and the decryption key (DK) is injected into the authentication information decryption module 104 to securely transmit the authentication information decryption module 104 to the server 103. The authentication information decryption module 104 is a hardware module, the processing of the core information is performed in a PCMCIA card or a smart card, and is generally configured as a card interface equipment for communication with the server 103. The client 105 requests the public authority certificate from the Internet 106 or directly in a face-to-face manner to the certification authority 101, and registers the personal identification information (RID) such as a social security number and fingerprint information with the certification authority 101. The certification authority (101) combines the RID and the random number (rnd) information and injects the result value encrypted with the encryption key (EK) into the public key certificate. The public key certificate is issued and provided to the client 105. The server 103 is also issued a public key certificate from the certification authority 101, the server 103 may not have personal identification information, in this case the process of injecting personal identification information in the public key certificate of the server is omitted. The certificate authority 101 stores and manages the public key certificate issued to the client 105 and the server 103 in the public key directory 102. The public key directory 102 is accessed by the client 105 and the server 103. Public key certificates can be retrieved. After the client 105 and the server 103 have issued the public key certificate, the server 103 checks the validity of the client 105 personal identification information securely by using the authentication information decryption module 104 at the time of authenticating the client 105. Protocol is performed via the Internet 106.

2 is a block diagram of a public key certificate defined in X.500 V3. The basic area 201 is divided into eleven parts, and the extended area of the basic area is further divided into fourteen extended areas 202. Since the basic areas 201 have already been used, additional information such as personal identification information cannot be entered. Although the 14 extended areas 202 are mostly used, the new information may be added to the Subject Alternative Name area 203 of the extended area 202 in the form of OtherName.

3 shows the Subject Alternative Name 203 in ASN.1 representation. As shown in the figure, there are nine types of Subject Alternative Names (203), all of which have eight formats.

For example, rfc822Name is determined by an Internet mail address, and iPAddress is determined by an IP address. The other, OtherName, allows the user to define and use eight different types of expressions. Therefore, the present invention intends to insert a personal identification information identifier (VID) in the form of OtherName.

4 is a process of generating a public key certificate including personal identification information (RID). The certification authority 101 uses an encryption key (EK) and a decryption key (DK) to protect the personal identification information (RID). Generate (401). The client user provides his / her personal identification information (RID) to the certification authority 101 and requests the certificate authority 101 to issue a certificate (402). The certification authority 101 generates a personal information identifier (VID) with an encryption key (EK) (403). For example, when the personal identification information is a social security number, the certification authority 101 generates a 64-bit or higher random number (rnd) and generates a social security number (RID) and a random number (rnd) such as MD5, SHA-1, HAS160, and the like. It hashes with a hash algorithm, concatenates the hash result value with a random number (rnd), encrypts the result with an encryption key (EK) (403), and injects it in the form of OtherName into the Subject Alternative Name field 203 in the public key certificate (404). . In this case, the personal identification information identifier (VID) is as follows.

[Formula 1] VID = E _EK {h (RID rnd) rnd}

( : Means concatenation, h (): hash algorithm, E _EK (): means encryption by EK)

As another embodiment when the personal identification information (RID) is the fingerprint information of the user, the certification authority 103 generates a random number (rnd) of 64-bit or more and the random number (rnd) such as MD5, SHA-1, HAS160, etc. Hash using a hash algorithm to perform the exclusive logical bit-by-bit of the result value and the fingerprint identification information (RID), and encrypt the result with an encryption key (EK) to generate a personal identification information identifier (VID) (403). Inject in the form of OtherName to the Subject Alternative Name field 203 in the key certificate (404). In this case, the VID is as follows.

[Formula 2] VID = E _EK [{RID xor h (rnd)} rnd]

( : Means concatenation, h (): hash algorithm, E _EK (): means encryption by EK, xor: means bitwise exclusive OR)

The certification authority 101 issues a certificate with a certificate issuing key that the certification authority has in the same manner as in the conventional method (405).

5 is a diagram of personal identification information (ID) provided by the client 501 in a step in which the server 502, 103 authenticates the client 501, 105 after receiving the public key certificate from the certification authority 101. An embodiment of authenticating accuracy is shown. (RID: personal identification information created when the certification authority issues the client's public key certificate, ID: personal identification information provided by the client when the server authenticates the client). First, the client 501 has a public key (pk _c ) and a secret key (sk _c ) corresponding to its public key certificate {cert (pk _c )}, and the server 502 has its own public key certificate {cert (pk _s )} has a public key (pk _s ) and a secret key (sk _s ). The server 502 transmits its public key certificate {cert (pk _s )} to the client 501 (503). Client 501 verifies the public key certificate {cert (pk _s )} (504). The client user inputs his personal identification information (ID) (505). The user personal identification information (ID) is encrypted with the public key (pk _s ) of the server 502 (506). Personal identification information (ID) encrypted with the public key (pk _s ) of the server 502 and the client user's public key certificate {cert (pk _c )} are transmitted to the server 502 (507). The server 502 verifies the certificate {cert (pk _c )} (508), decrypts the encrypted personal identification information (ID) with its secret key (sk _s ) (509), and sends the client 501. By extracting the personal identification information identifier (VID) from the Subject Alternative Name field 203 of the public key certificate {cert (pk _c )} with the help of the authentication information decryption module 104, the validity of the user identification information (ID) Check (510).

FIG. 6 shows a process in which the servers 601 and 103 check the accuracy of the personal identification information (ID) provided by the clients 501 and 105 in the authentication step by using the authentication information decoding module 602 and 104. One embodiment. The server 601, 103 extracts the personal identification information verifier (VID) from the Subject Alternative Name field 203 of the public key certificate {cert (pk _c )} received from the clients 501, 105, and the authentication information decryption module 602. Decode request to the personal identification information confirmer (VID) (104) and transmits the personal identification information confirmer (VID) to the authentication information decryption module 602 (604).

The authentication information decryption module 602 decrypts the personal identification information identifier (VID) with a decryption key (DK) stored in the module (605) and sends the decrypted information to the server (601) (606). The server 601 checks the validity of the personal identification information (ID) transmitted by the clients 501 and 105 by the decryption text sent by the authentication information decoding module 602. For example, if the personal identification information identifier (VID) for the social security number is equal to [Equation 1], the decryption text 606 is E _DK (VID) = h (RID rnd) rnd (E _DK (): Decoding process by decryption key DK). At this time, the server 601 hashes the personal identification information (resident registration number, user name) received from the clients 501 and 105 in the authentication step and the random number rnd in the decryption text {h (ID rnd)} and the hash value {h (RID) in the decryption statement. rnd)} to verify the validity of the ID received from the client. As another example, when biometric information such as a fingerprint is used as personal identification information, a personal identification information identifier (VID) may be created as shown in [Equation 2]. In this case, the decryption statement 606 is E _DK (VID) = [{RID xor h (rnd)} rnd]. The server 601 obtains a random number rnd from the decrypted statement 606 and hashes the random number rnd to the result value {h (rnd)} and the left value {RID xor h (rnd)} of the decrypted statement 606. [RID = {RID xor h (rnd)} xor h (rnd)] Gets the user's fingerprint identification information (RID) previously injected into the public key certificate by performing the bitwise exclusive OR of the hash value {h (rnd)}. . In operation 607, the client 501 checks the validity of the fingerprint identification information ID transmitted from the client 501 to the server 502 in the authentication step based on the fingerprint identification information RID injected into the public key certificate.

In FIG. 6, the authentication information decoding module 602 simply performs a function of decrypting the personal identification information identifier (VID), but FIG. 7 shows that the authentication information decoding module 602 is the personal authentication information (ID). To perform the function of confirming the validity of The server 701 extracts a personal identification verifier (VID) from the public key certificate, requests the authentication information decryption module 702 to verify the validity of the personal identification information (ID) of the client user (703), and a personal identification verifier (VID). And personal identification information (ID) is transmitted to the authentication information decoding module 702 (704). The authentication information decryption module 702 checks the validity of the personal identification information ID using the personal identification information identifier VID and the decryption key DK (705), and transmits the verification result to the server (706).

In general, the method of confirming personal identification information as shown in FIG. 6 may be converted in the same manner as in FIG. 7, but the method of confirming personal identification information of the method shown in FIG. 7 is converted in the same manner as in FIG. 6. It may be impossible. In case of using the encryption algorithm that can be decrypted when generating the personal identification information identifier (VID), it is possible to check the personal identification information in the same way as [Fig. 6], but one-way reverse conversion is impossible when generating the personal identification information identifier. In the case of using a function, it is impossible to identify personal identification information in the same manner as in [6], and personal identification information must be confirmed in the same manner as in [7]. For example, a one-way function (F) where the encryption key (EK) and the decryption key (DK) are the same and the certificate authority 101 does not use a cryptographic algorithm when generating the VID. You can create it in the following way.

Personal Identification Information Confirmator: VID = F (EK, RID)

In this case, since the function F cannot be inversely transformed, the authentication information decryption module 602 cannot decrypt the personal identification information verifier VID with the decryption key DK. Instead, the decryption key (DK) of the authentication information decryption module is the same as the encryption key (EK) of the certification authority, and as shown in FIG. 7, the server 701 converts the personal identification information (ID) into the personal identification information identifier (VID). The authentication information decryption module 702 unidirectionally decrypts the decryption key (DK or encryption key EK) and the personal identification information (ID) instead of decrypting the personal identification information identifier (VID). The function value can be calculated using the input of the function, and the result value can be verified to be the same as the personal identification information identifier (VID) to confirm the validity of the ID.

Public key certificates issued by publicly available certification authorities currently used in the country contain only the user's name information, so if there is a person with the same name, accurate user authentication is impossible. If you want to put your social security number in the public key certificate, it is important to know what area you should put this information in. Also, you need a safe and effective way to prevent anyone from using your social security number information.

The present invention can provide more secure and strong user authentication using a public key certificate by injecting personal identification information such as a social security number or fingerprint information securely into a public key certificate so that no one can access it.

Claims (9)

In step 1, the certification authority 101 generates the personal identification information encryption key (EK) and the decryption key (DK), and uses the generated decryption key (DK) and the decryption key (DK). Step 2 of inserting a program to be verified into the authentication information decryption module 104 and providing it to the server 103 performing the client 105 authentication, the client 105 with the personal identification information of the client user, the certification authority 101 In step 3 402 of requesting the public key certificate to be issued to the certificate authority, the certification authority 101 converts information related to personal identification information (RID) into an encryption key (EK) to generate a personal identification information identifier (VID) (403). 4) a method and system for generating a public key certificate comprising a fourth step (404) of inserting a personal identification information identifier (VID) into the public key certificate. Clients 501 and 105 having the public key certificate issued in Clause 1 encrypt the user personal identification information (ID) with the public key (pk _s ) of the server 502, so that the user's public key certificate {cert (pk _c). }} And the server 502 extracts the user identification information verifier (VID) from the public key certificate {cert (pk _c )} and sends the authentication information decryption module 104 to the server 502. User authentication method and system using a public key certificate, characterized in that to confirm the accuracy of the user identification information (ID) received from the client (501) by using (507). The method according to claim 1 or 2, wherein the authentication information decryption module 104 is not a separate hardware module but is made into a software module and included in the server 103 module, and only the decryption key (DK) is used in the authentication information decryption module 104. The method of storing the token (smart card or USB token, etc.) and decrypting the personal identification information identifier (VID) using the decryption key (DK) is made into a software module and included in the server 103 module. According to claim 2, the server 502, 601 gives the personal information identification verifier (VID) extracted from the client user public key certificate {cert (pk _c )} to the authentication information decryption module 602, the authentication information decryption module 602 Decodes the personal identification information identifier (VID) using the decryption key (DK) that is stored by the user (605) and returns the decrypted result back to the server 502 (607), and the server 601 decrypts the decrypted information. User authentication method and system using a public key certificate, characterized in that for verifying the user identification information (ID) received from the client (501). The server 701 determines the client 501 user personal identification information (ID) instead of the server 502 and 601 verifying the client 501 user personal identification information (ID). The authentication information decryption module 702 and 104 together with the VID are provided to the authentication information decryption module 702. The authentication information decryption modules 702 and 104 use a decryption key (DK) and a personal identification information identifier (VID). A method and system for authenticating a user using a public key certificate for confirming the validity of the request (705) and informing the server (701) of the result of the confirmation (706). The method according to claim 1, wherein the certification authority 101 uses the personal identification information (RID) and randomly generated random number (rnd) as inputs to the hash algorithm, and the result value {h (RID). rnd)} and the random number (rnd) are concatenated and encrypted with a cryptographic key (EK) of a certification authority to identify a personally identifiable identifier (VID) [VID = E _EK {h (RID rnd) rnd}]. In the modified form of paragraph 6, the random number randomly generated by the certification authority 101 is used as the input of the hash algorithm, and the result value {h (rnd)} and the personal identification information (RID) are subjected to an exclusive logical sum of bits. The result value {RID xor h (rnd)} and the random number (rnd) are concatenated and encrypted with the Cryptographic Key (EK) of the certification authority to confirm the personal identification information (VID) [VID = E _EK {RID xor h (rnd)}. rnd]. In another variation of paragraphs 6 and 7, the personal identification information (RID) is encrypted using the certification authority's encryption key (EK) without using a random number (rnd) {VID = E _Ek (RID)}. How to create it. The method according to claim 1, wherein a personal identification identifier (VID) is generated as follows using a one-way function (F) which is not capable of inverse transformation. (1) VID = F (EK, RID) (2) VID = F (EK, RID, rnd) rnd