JP2006154125A - Local authentication system, local authentication device and local authentication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and appropriately perform the authentication of a node that is not connected to a network in the network where respective nodes perform communication based on connection established with the adjacent nodes. <P>SOLUTION: An effectiveness confirmation request for confirming effectiveness on a public key certificate and an issue request of a new certificate on a public key are transmitted from a local node 301 which is not connected to the Internet N. A request from the local node 301 is transferred from a node 401 connected to the Internet N to a CRL confirmation server 502 and an authentication authority 501. Thus, the node which is not connected to the Internet N can confirm whether the certificate of the other node is invalidated or not or can request issue of the new certificate. Thus, the node which is connected to the Internet N and the node which is not connected to the network authenticate each other and realize encrypting communication. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a local authentication system, a local authentication device, and a local authentication method, and more particularly, to a local authentication system, a local authentication device, and a local authentication system in a network in which a plurality of nodes are configured based on connections established between adjacent nodes. It relates to the local authentication method.

A conventional authentication method will be described.
In the conventional authentication method using PKI (Public Key Infrastructure) as in Non-Patent Document 1, each node makes a public announcement issued by a certificate authority (CA) when each node performs communication. Exchange key certificate (including public key). Next, a CRL (Certificate Revocation List) confirmation server is inquired as to whether or not the certificate has been revoked. If it has not been revoked, it is authenticated as the correct partner, and encrypted communication is started using the public key.

An example will be described with reference to FIG. In the figure, a node 103 and a node 104 have issued certificates and public keys (based on X.509) that certify their public keys from the certificate authority 101. Also, the CRL confirmation server 102 obtains a certificate revocation list (CRL) from the certificate authority 101 as needed.
Here, the authentication procedure when the node 103 and the node 104 perform mutual authentication and start communication will be described. First, the node 103 and the node 104 exchange certificates with each other (1). Next, the CRL confirmation server 102 is inquired of whether or not the certificate has expired (2). If the corresponding certificate has not expired, encrypted communication is started using the public key (3).

On the other hand, in the conventional authentication method using PKI (Public Key Infrastructure) as in Non-Patent Document 2, each node issues a public key certificate with a very short expiration date (for example, about one day) from the certificate authority (CA). Is done. When the nodes communicate with each other, they exchange each other's public key certificates issued by a certificate authority (CA). Next, if the certificate is within the validity period, encrypted communication is started using the public key for authentication as the correct counterpart.
In other words, since the original expiration date of the certificate is extremely short, it is considered unlikely that the certificate has been revoked within that period, so that the certificate revocation confirmation is omitted. Therefore, mutual authentication is possible even in a state where it is not connected to the network.

An example will be described with reference to FIG. In the figure, as a premise, a certificate and a public key (based on X.509) proving its own public key are issued from the certificate authority 201 to the node 202 and the node 203. However, this certificate has a short expiration date and is updated by connecting to the network, for example, once every few days.
Here, an authentication procedure when the nodes 202 and 203 perform mutual authentication and start communication will be described. First, the node 202 and the node 203 exchange certificates with each other (1). Next, the expiration date of the certificate is confirmed, and if it is within the expiration date, encrypted communication is started using the public key (2).

“X.509 Internet PKI Certificate Status Protocol”, [online], [searched on November 12, 2004], Internet <URL: http://www.ietf.org/rfc/rfc2560.txt?number=2560> "Short-Lived Server Certificate", [online], [searched on November 12, 2004], Internet <URL: http://www.verisign.co.jp/press/2001/pr162#mot.html>

In the conventional example described above, when performing mutual authentication with a node that cannot be connected to the network at all, there is a problem in that mutual authentication cannot be performed because the validity of the certificate cannot be confirmed. For example, in Non-Patent Document 1, it is necessary to check the revocation of a certificate by connecting to a network at the time of mutual authentication. In Non-Patent Document 2, since the validity period of a certificate is short, it is necessary to connect to a network and perform update processing.
The present invention has been made in view of the above, and its purpose is to provide efficient and appropriate communication with nodes not connected to a network in a network in which each node communicates based on a connection established with an adjacent node. It is to provide a local authentication system, a local authentication device, and a local authentication method capable of performing proper authentication.

  A local authentication system according to claim 1 of the present invention is a local authentication system that makes a request for a public key certificate to a certificate management apparatus connected to a network, and is not connected to the network, A first node that transmits at least one request of a validity check request for checking the validity of the public key certificate and a request for issuing a new certificate for the public key, and is connected to the network And a second node that forwards a request from the first node to the certificate management apparatus. With such a configuration, a node that is not connected to the network can check whether a certificate of another node has expired or issue a new certificate. Therefore, a node connected to the network and a node not connected to the network can mutually authenticate and perform encrypted communication.

  A local authentication device according to claim 2 of the present invention is a local authentication device that transmits a request relating to a public key certificate to a certificate management device connected to a network to which the device itself is not connected. And a transmission unit configured to transmit the request to the certificate management apparatus via another connected apparatus. With this configuration, a node that is not connected to the network can make a request for a public key certificate.

  The local authentication device according to claim 3 of the present invention is characterized in that, in claim 2, the local authentication device further includes an encryption means for encrypting a request transmitted by the transmission means. With such a configuration, a node that is not connected to the network can surely check the revocation status of a certificate of another node or request reissuance of a certificate.

  The local authentication device according to claim 4 of the present invention is the certificate revocation list holding device according to claim 2 or 3, wherein the certificate management device holds a certificate revocation list for a public key, and the request is It is a validity check request for checking the validity of a public key certificate. With such a configuration, a node that is not connected to the network can check whether the certificate of another node has expired.

  The local authentication device according to claim 5 of the present invention is the certificate authentication device according to claim 2 or 3, wherein the certificate management device is a certificate issuing device for issuing a certificate for a public key, and the request is for issuing a new certificate. It is a request. With such a configuration, a node not connected to the network can make a new certificate issuance request.

  A local authentication method according to claim 6 of the present invention is a local authentication method for making a request regarding a public key certificate to a certificate management apparatus connected to a network, and confirming the validity of the public key certificate. Transmitting at least one of a validity check request to be performed and a request for issuing a new certificate for a public key from a first node not connected to the network; from the first node; Transferring the request to the certificate management device from a second node connected to the network. With such a configuration, a node that is not connected to the network can check whether the certificate of another node has expired or issue a new certificate. Therefore, a node connected to the network and a node not connected to the network can mutually authenticate and perform encrypted communication.

According to the present invention, since a node not connected to the network can communicate with the certificate authority and the CRL confirmation server via the node connected to the network, mutual authentication with the node not connected to the network is possible. .
In addition, by performing mutual authentication using a certificate having validity with guaranteed accuracy, it is possible to perform mutual authentication and secure encrypted communication with a node not connected to the network.
In this way, when a node not connected to the network communicates via a node connected to the network, a reply attack using a past response message is added by adding a different random value to the message each time. For example, it is possible to detect an illegal response by an intervening node and to ensure secure communication with a target node without fail.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings referred to in the following description, the same parts as those in the other drawings are denoted by the same reference numerals.
(System configuration)
In FIG. 1, a node 401 is a node connected to the Internet N. The node 401 is connected to several nodes 301 by local connection. A certificate authority 501 and a CRL confirmation server 502, which are certificate management devices, are connected to the Internet N. The certificate authority 501 and the CRL confirmation server 502 may exist as separate devices as shown in the figure, or a single device having both functions may exist.

The node 301 is in a state where local communication with only the node 401 is possible. That is, the node 401 is connected to the Internet N, while the node 301 is not connected to the Internet N (hereinafter referred to as a local node).
The local node 301 transmits a certificate validity confirmation request to the CRL confirmation server 502 via the node 401. In addition, the local node 301 transmits a certificate reissue request to the CRL confirmation server 502 via the node 401.

  Here, in the present invention, the local node 301 is not connected to the network (Internet N in this example), and the node 401 is connected to the network (Internet N in this example). It is assumed. Therefore, when the local node 301 originally does not have a network connection function, it also has a network connection function, but may not be connected to the network when transmitting the request. , "Not connected to the network". In the following example, a case where the node 401 has a network connection function and the local node 301 does not have the function will be described.

(Node configuration example)
FIG. 2 is a block diagram showing a configuration example of a local node 301 that does not have a function of connecting to a network in the local authentication system according to the embodiment of the present invention.
In the figure, a local node 301 does not have a function of connecting to a network, but is a node having a function of connecting locally to a nearby node. The local node 301 includes a certificate holding unit 302, a certificate verification unit 303, an encryption / decryption processing unit 304, a secret key holding unit 305, and a local communication unit 306.

  A certificate holding unit 302 in the local node 301 holds public key certificates of the own node and other nodes. The certificate verification unit 303 in the local node 301 confirms the expiration date and the revocation status of the certificate of another node. The encryption / decryption processing unit 304 processes encrypted communication based on the public key infrastructure. The secret key holding unit 305 holds the secret key of the own node. The local communication unit 306 communicates with a node having a nearby local communication unit.

On the other hand, FIG. 3 is a block diagram showing a configuration example of a node having a function of connecting to a network in the local authentication system according to the embodiment of the present invention.
In the figure, a node 401 is connected to the network and is a node having a function of connecting to a nearby node locally. The node 401 includes a certificate holding unit 402, a certificate verification unit 403, an encryption / decryption processing unit 404, a secret key holding unit 405, a local communication unit 406, and a network communication unit 407. It is configured.

  The certificate holding unit 402 in the node 401 holds the public key certificates of the own node and other nodes. A certificate verification unit 403 in the local node 401 confirms the expiration date and the revocation status of a certificate of another node. The encryption / decryption processing unit 404 processes encrypted communication based on the public key infrastructure. The secret key holding unit 405 holds the secret key of the own node. The local communication unit 406 communicates with a nearby node having a local communication unit. The network communication unit 407 communicates with other nodes having the network communication unit via the network.

(Certificate validity check request)
Hereinafter, the procedure of certificate validity confirmation by the certificate verification unit 403 in the node 401 and the certificate verification unit 303 in the local node 301 in the case of FIG. 1 will be described with reference to FIGS. 4 and 5. .
FIG. 4 is a flowchart showing processing contents of the node 401, the local node 301, and the CRL confirmation server 502. In the figure, when the node 401 and the local node 301 communicate, the certificates held in the certificate holding units 302 and 402 are exchanged with each other through the local communication units 306 and 406 (step 601).

  Upon receipt of the certificate from the local communication unit 406, the certificate verification unit 403 in the node 401 inquires of the CRL confirmation server 502 via the network communication unit whether the corresponding certificate has expired (step 602). ). At this time, the local node 301 encrypts the inquiry message with its own private key held in the private key holding unit 405 by the encryption / decryption processing unit 404 by encrypted communication based on the public key infrastructure. The CRL confirmation server that has received the inquiry message decrypts the message with the public key of the node 401, encrypts the message including the revocation information of the corresponding certificate with its own private key, and transmits the encrypted message to the local node 401 (step). 603).

  On the other hand, the certificate verification unit 303 in the local node 301 that has received the certificate from the local communication unit 306 inquires of the CRL confirmation server 502 via the node 401 whether or not the corresponding certificate has expired ( Step 604). At that time, the local node 301 performs encrypted communication based on the public key infrastructure by the encryption / decryption processing unit 304, but the inquiry message includes a different random value each time, and the message is held by the secret key holding unit 305. It encrypts with its own private key. The CRL confirmation server 502 that has received an inquiry message including a different random value each time decrypts the message with the public key of the node 301, and sends a response message including the revocation information of the corresponding certificate and the random value to its own private key. And is transmitted to the local node 301 via the node 401 (step 605).

  Thereafter, the validity of both certificates is determined (step 606). If the validity of the certificate is confirmed by the local node 301 and the certificate verification units 303 and 403 in the node 401 as a result of this determination, mutual authentication is performed and encrypted communication using the public key infrastructure is started (step 606 → Step 607). On the other hand, if the validity of the certificate cannot be confirmed, authentication fails and communication is not started (step 606 → step 608).

  FIG. 5 is a sequence diagram showing processing procedures of the node 401, the local node 301, and the CRL confirmation server 502. In the figure, when the node 401 and the local node 301 communicate, the certificates held in the certificate holding units 302 and 402 are exchanged with each other through the local communication units 306 and 406 (step 701).

  Upon receiving the certificate from the local communication unit 406, the certificate verification unit 403 in the node 401 inquires of the CRL confirmation server 502 via the network communication unit whether the corresponding certificate has expired (step 702). ). At that time, the node 401 uses the encryption / decryption processing unit 404 to encrypt the inquiry message with its own private key held in the private key holding unit 405 by encrypted communication based on the public key infrastructure. Upon receiving this inquiry message, the CRL confirmation server 502 decrypts the message with the public key of the node 401, encrypts the message including the revocation information of the corresponding certificate with its own private key, and transmits it to the local node 401. (Step 703).

  In addition, the certificate verification unit 303 in the local node 301 that has received the certificate from the local communication unit 306 transmits a certificate validity check request to determine whether the certificate has expired (step 704). . The node 401 that has received the validity confirmation request transmitted by the local node 301 transfers the validity confirmation request to the CRL confirmation server 502 (step 705).

In this way, the local node 301 makes an inquiry to the CRL confirmation server 502 via the node 401. At that time, the encryption / decryption processing unit 304 performs encrypted communication based on the public key infrastructure with the CRL confirmation server 502. The inquiry message includes a different random value every time, and the message is stored in the secret key holding unit 305. It encrypts with its own private key held in. The CRL confirmation server 502 that has received an inquiry message including a different random value each time decrypts the message with the public key of the node 301, and sends a response message including the revocation information of the corresponding certificate and the random value to its own private key. And is transmitted to the local node 301 via the node 401 (steps 706 and 707).
When the validity of the certificate is confirmed by the local node 301 and the certificate verification units 303 and 403 in the node 401 by the above message exchange, the mutual authentication is completed (step 708), and encryption using the public key infrastructure is performed. Start communication (step 709).

(Certificate reissue request)
In the following, the certificate reissue request procedure by the certificate verification unit 403 in the node 401 and the certificate verification unit 303 in the local node 301 in the case of FIG. 1 will be described with reference to FIGS. 6 and 7. .
FIG. 6 is a flowchart showing processing contents of the node 401, the local node 301, and the certificate authority 501.
In this case, a public key certificate with an extremely short expiration date is issued to the node 401 and the local node 301 and held in the certificate holding units 302 and 403, respectively. The node 401 updates certificates as needed.
In the figure, when the node 401 and the local node 301 start communication, the certificate verification unit in the local node 301 confirms whether or not its certificate has expired (step 801).

  If it is determined that the expiration date has expired, the local node 301 transmits a reissue request message for issuing a new certificate to the certificate authority 501 via the node 401 (step 802 → step 803). . At that time, the local node 301 performs encrypted communication based on the public key based on the encryption / decryption processing unit 304, but includes a different random value each time in the reissue request message, Encrypt with your own private key. Upon receiving the reissue request message including a different random value each time, the certificate authority 501 decrypts the message with the public key of the node 301, and uses the public key of the response message including the corresponding new certificate and the random value. The data is encrypted and transmitted to the local node 301 via the node 401 (step 804).

Thereafter, the local node 301 and the node 401 exchange certificates with each other through the local communication units 306 and 406 (step 805). The same applies when it is determined in step 802 that the expiration date has not expired (step 802 → step 805).
Thereafter, the validity of both certificates is determined (step 806). If the validity of the certificate is confirmed by the local node 301 and the certificate verification units 303 and 403 in the node 401 as a result of this determination, mutual authentication is performed and encrypted communication using the public key infrastructure is started (step 806 → Step 807). On the other hand, if the validity of the certificate cannot be confirmed, authentication fails and communication is not started (step 806 → step 808).

FIG. 7 is a sequence diagram showing processing procedures of the node 401, the local node 301, and the certificate authority 501. In the figure, when the node 401 and the local node 301 start communication, the certificate verification unit in the local node 301 confirms whether or not its certificate has expired (step 901).
When the expiration date has expired, the local node 301 transmits a reissue request message for requesting the certificate authority 501 to issue a new certificate via the node 401 (step 902). The node 401 that has received the reissue request message transmitted by the local node 301 transfers the message to the certificate authority 501 (step 903).

  In this way, a reissue request message is transmitted from the local node 301 to the certificate authority 501 via the node 401. At this time, the encryption / decryption processing unit 304 performs encrypted communication based on the public key based on the certificate authority 501, but the reissue request message includes a different random value each time, and the message is stored in the secret key holding unit 305. It encrypts with its own private key held in.

Upon receiving the reissue request message including a different random value each time, the certificate authority 501 decrypts the message with the public key of the node 301, and uses the public key of the response message including the corresponding new certificate and the random value. The data is encrypted and transmitted to the local node 301 via the node 401 (steps 904 and 905).
The local node 301 and the node 401 exchange certificates with each other through the local communication units 306 and 406 (step 906).
As described above, when the validity of the certificate is confirmed by the local node 301 and the certificate verification units 303 and 403 in the node 401, mutual authentication is completed (step 907), and encrypted communication using the public key infrastructure is performed. Start (step 908).

(Local authentication method)
In the above local authentication system, the following local authentication method is realized. That is, a local authentication method for making a request for a public key certificate to a certificate management apparatus connected to the network. About a validity check request and a public key for checking the validity of a public key certificate Transmitting a request for issuing at least one of the new certificate issuance request from the first node not connected to the network (corresponding to step 704 in FIG. 5 and step 902 in FIG. 7); Transferring the request from the first node from the second node connected to the network to the certificate management apparatus (corresponding to step 705 in FIG. 5 and step 903 in FIG. 7); Including local authentication methods. With such a configuration, a node that is not connected to the network can check whether a certificate of another node has expired or issue a new certificate. For this reason, a node connected to the network and a node not connected to the network can mutually authenticate and perform encrypted communication.

(Summary)
As described above, according to the present system, nodes that are not connected to the network can communicate with the certificate authority and the CRL confirmation server via the nodes that are connected to the network. Authentication is possible.
In addition, when a node that is not connected to the network communicates via a node that is connected to the network, a different random value is added to the message each time, such as a reply attack using a past response message, etc. It is possible to detect an illegal response by the intervening node and to ensure secure communication with the target node without fail.
In addition, as described above, mutual authentication is performed using a certificate with validity that guarantees accuracy, enabling mutual authentication and secure encrypted communication with nodes not connected to the network. Become.

It is a figure which shows the structural example of the local authentication system by embodiment of this invention. It is a block diagram which shows the structural example of the local node in the local authentication system by embodiment of this invention. It is a block diagram which shows the structural example of the node in the local authentication system by embodiment of this invention. FIG. 2 is a flowchart showing a procedure for performing validity check on a public key certificate in the local authentication system of FIG. FIG. 2 is a sequence diagram showing a procedure for checking validity of a public key certificate in the local authentication system of FIG. 1. 2 is a flowchart showing a procedure for requesting issuance of a new certificate for a public key in the local authentication system of FIG. 1. FIG. 2 is a sequence diagram showing a procedure for requesting issuance of a new certificate for a public key in the local authentication system of FIG. 1. It is a figure explaining the prior art example of the authentication system with respect to the network comprised by a some node. It is a figure explaining the other conventional example of the authentication system with respect to the network comprised with a some node.

Explanation of symbols

101 Certificate Authority 102 CRL Confirmation Server 103, 104, 203, 203, 301, 401 Node 201 Certificate Authority 302 Certificate Holding Unit 303 Certificate Verification Unit 304 Encryption / Decryption Processing Unit 305 Private Key Holding Unit 306 Local Communication Unit 402 Certificate holding unit 403 Certificate verification unit 404 Encryption / decryption processing unit 405 Private key holding unit 406 Local communication unit 407 Network communication unit 501 Certificate authority 502 Confirmation server N Internet

Claims (6)

  A local authentication system that makes a request for a public key certificate to a certificate management apparatus connected to a network, and is not connected to the network and is used to check the validity of the public key certificate. A first node that transmits at least one request of a validity check request and a request to issue a new certificate for a public key; and is connected to the network, and the request from the first node is verified by the certificate And a second node for transferring to the document management apparatus.   A local authentication device that transmits a request for a public key certificate to a certificate management device connected to a network to which the device itself is not connected, and through the other device connected to the network, A local authentication apparatus, comprising: a certificate management apparatus including transmission means for transmitting the request.   3. The local authentication apparatus according to claim 2, further comprising an encryption unit for encrypting a request transmitted by the transmission unit.   The certificate management apparatus is a certificate revocation list holding apparatus that holds a certificate revocation list for a public key, and the request is a validity check request for checking validity of a public key certificate. The local authentication device according to claim 2 or 3, wherein   4. The local authentication device according to claim 2, wherein the certificate management device is a certificate issuing device that issues a certificate for a public key, and the request is a request for issuing a new certificate.   A local authentication method for making a request for a public key certificate to a certificate management device connected to a network, and for a validity check request and a public key for validating a public key certificate. Transmitting at least one of a request for issuing a new certificate from a first node that is not connected to the network; and a request for transmitting a request from the first node to the network. And a step of transferring the certificate from the second node to the certificate management apparatus.

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