JP2012100188A - Authentication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an authentication system that can be used continuously without requiring users to reacquire root certificates even if the service of a first certificate authority is stopped.SOLUTION: An individual certificate authority 3 is disposed separately from a commercial certificate authority 2 so that the individual certificate authority 3 issues a root certificate Tx to an authentication entity 4. The individual certificate authority 3 issues a commercial certificate authority public key Ka acquired from the commercial certificate authority 2 to the authentication entity 4 as a commercial certificate authority public key certificate Ta. The authentication entity 4 verifies the certificate Ta via the root certificate Tx and trusts the public key Ka if the verification is successful. The commercial certificate authority 2 issues an authenticated entity public key certificate Tb2 to an authenticated entity 5. When acquiring the certificate Tb2, the authentication entity 4 verifies it via the public key Ka and trusts an authenticated entity public key Kb2 if the verification is successful.

Description

  The present invention relates to an authentication system for confirming the validity of a communication partner through a certificate authority.

  Conventionally, as an authentication system, an authentication method using PKI (Public Key Infrastructure) (see Non-Patent Document 1, etc.) has been widely used. As shown in FIG. 7, the PKI authentication system is constructed from three parties: a commercial certificate authority 81, a certificate owner 82, and a user terminal 83. The certificate owner 82 has a private key and a corresponding public key that has been issued a certificate from a certificate authority.

  The commercial certificate authority 81 issues a certificate 84 to the certificate owner 82 who has contracted. When the user terminal 83 wants to use the certificate 84, the certificate owner 82 distributes the certificate 84 to the user terminal 83. Then, the user terminal 83 confirms whether or not the certificate 84 is genuine by using the root certificate 85 acquired in advance from the commercial certificate authority 81. When the user terminal 83 confirms that the certificate 84 is correct, the user terminal 83 determines that the certificate 84 can be trusted.

http://www.ipa.go.jp/security/pki/index.html

  By the way, since the commercial certification authority 81 is a private company, it is assumed that the management situation deteriorates and the bankruptcy is assumed, but at this time, the service of the authentication system provided by the commercial certification authority 81 is stopped. become. In this case, since the root certificate 85 becomes unreliable, the user terminal 83 has to acquire the root certificate 85 again from another certificate authority, and this reacquisition operation is troublesome. Another problem is that there is no mechanism for incorporating another authentication system into the user terminal 83, and there is a possibility of a security hole when a further mechanism is created.

  An object of the present invention is to provide an authentication system that can continue to use the system without imposing re-acquisition of the root certificate on the user even if the service of the first certificate authority is stopped. .

  In order to solve the problem, in the present invention, a certificate authority distributes a root certificate to an authentication entity, an authenticated entity holds an authenticated entity private key, and the certificate authority authenticates the authenticated entity to the authenticated entity. When an entity public key certificate is issued and the authenticated entity acquires the authenticated entity public key certificate, the authenticated entity public key certificate is verified with the root certificate, and if the verification is established, The authenticated entity registers the authenticated entity public key included in the authenticated entity public key certificate, whereby the authenticated entity and the authenticated entity use the authenticated entity public key and the authenticated entity private key. In the authentication system that enables the authentication to be performed separately from the general-purpose first certificate authority The second certification authority is provided for, and summarized in that the root certificate from the second certificate authority was to distribute to the authentication entity.

  According to this configuration, when the first certificate authority issues the certificate of the first certificate authority to the authentication entity, the second certificate authority guarantees the certificate of the first certificate authority by signing the second certificate authority. . For this reason, even if the service is stopped due to the first certificate authority going bankrupt or the like, as long as the second certificate authority provides the service, the root certificate can be handled as reliable. Therefore, even when the first certificate authority stops the service, it is not necessary to impose the user on the operation of re-registering the root certificate in the authentication entity, so that convenience can be improved.

  In the present invention, the first certificate authority distributes the first certificate authority public key created by itself to the second certificate authority, and the second certificate authority confirms the validity of the first certificate authority public key. 2 When the certificate authority obtains the first certificate authority public key certificate, the certificate authority publicly issues a first certificate authority public key certificate signed by the certificate authority. If the verification is established by the root certificate and the verification is established, the first certificate authority public key included in the first certificate authority public key certificate is trusted, and the first certificate authority The authenticated entity public key certificate signed by the first certificate authority with the validity of the public key is issued to the authenticated entity. When the authenticated entity obtains the authenticated entity public key certificate, the authenticated entity public key certificate is issued. Authentication entity public key certificate The certificate is verified with the first certificate authority public key whose trust has been confirmed, and if the verification is established, the authenticated entity public key is trusted, and the authenticated entity and the authenticated entity are The gist is that the authentication using the authentication entity public key and the authenticated entity private key can be executed.

  According to this configuration, the first certificate authority issues a public key or public key certificate as usual, and the second certificate authority only needs to distribute the root certificate. Therefore, since it is not necessary to impose all authentication processing on the second certificate authority, the second certificate authority can be kept small. Therefore, it is possible to reduce the initial investment when starting up the second certification authority.

The gist of the present invention is that the authenticated entity is an on-vehicle device of a vehicle electronic key or a vehicle electronic key system.
According to this configuration, it is possible to freely use the authenticated entity as an electronic key by, for example, downloading an ID code for the electronic key from the authenticating entity to the authenticated entity. It is also possible to apply the authentication system of this configuration to the electronic key system of the vehicle.

  According to the present invention, even if the service of the first certificate authority is stopped, the system can be used continuously without imposing re-acquisition of the root certificate on the user.

The block diagram of the authentication system of 1st Embodiment. The operation | movement flow explaining operation | movement of an authentication system. Explanatory drawing which shows the operation example of an authentication system. Explanatory drawing which shows the other operation example of an authentication system. Explanatory drawing which shows the other operation example of an authentication system. The block diagram of the authentication system of 2nd Embodiment. The schematic block diagram of the conventional authentication system.

(First embodiment)
Hereinafter, a first embodiment of an authentication system embodying the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the authentication system 1 is constructed from four parties: a commercial certificate authority 2, an individual certificate authority 3, an authentication entity 4, and an authenticated entity 5. The authentication system 1 performs authentication by an authentication method using PKI (Public Key Infrastructure) when the authentication entity 4 and the entity to be authenticated 5 communicate with each other. PKI is a public key infrastructure in which an organization equivalent to a certificate authority issues certificates to users for authentication. The commercial certificate authority 2 corresponds to the first certificate authority, and the individual certificate authority 3 corresponds to the second certificate authority.

  The commercial certificate authority 2 is connected to the individual certificate authority 3 and the authenticated entity 5 via the Internet network. The commercial certificate authority 2 can create a key pair (secret key and public key), and can distribute the public key for the commercial certificate authority 2 (commercial certificate authority public key Ka) to the individual certificate authority 3. Further, the commercial certificate authority 2 sends to the authenticated entity 5 a private key for the authenticated entity 5 (authenticated entity private key Kb1) and a certificate of a public key for the authenticated entity 5 (authenticated entity public key). Certificate Tb2) can be distributed. The authenticated entity public key certificate Tb2 includes the authenticated entity public key Kb2 and the signature (validity) of the commercial certificate authority 2 for the authenticated entity public key Kb2. The commercial certificate authority public key Ka corresponds to the first certificate authority public key.

  The individual certificate authority 3 is an in-house certificate authority established independently from the commercial certificate authority 2 and is connected to the commercial certificate authority 2 and the authentication entity 4 via the Internet network. The individual certificate authority 3 can create a key pair (secret key and public key), and can distribute the public key for the individual certificate authority 3 (individual authentication public key Kc) to the authentication entity 4 as the root certificate Tx. is there. The individual certificate authority 3 can distribute the certificate of the commercial certificate authority public key Ka acquired from the commercial certificate authority 2 (commercial certificate authority public key certificate Ta) to the authentication entity 4. The commercial certificate authority public key certificate Ta includes the commercial certificate authority public key Ka and the signature (validity) of the individual certificate authority 3 for the commercial certificate authority public key Ka. The commercial certificate authority public key certificate Ta corresponds to the first certificate authority public key certificate.

  The root certificate Tx is a digital certificate that is issued and signed by the individual certificate authority 3 in order to prove the validity of the communication partner. In other words, the root certificate Tx is one element constituting the public key infrastructure, the issuer and the subject are the same, and the public key corresponding to it is signed with its own private key. It is a public key certificate.

  The authenticated entity 5 is a mobile phone possessed by the user, and accesses the authentication entity 4 to communicate with the authentication entity 4. The authenticated entity 5 sends the authenticated entity public key certificate Tb2 to the authenticated entity 4 when communicating with the authenticated entity 4, and causes the authenticated entity 5 to verify the authenticated entity public key certificate Tb2.

  The authentication entity 4 is, for example, a server disposed at each point, and executes communication with the authenticated entity 5 in response to an inquiry from the authenticated entity 5. When obtaining the commercial certificate authority public key certificate Ta from the individual certificate authority 3, the authentication entity 4 verifies the commercial certificate authority public key certificate Ta with the root certificate Tx (individual certificate authority public key Kc). When this verification is established, the authentication entity 4 trusts the commercial certificate authority public key Ka included in the commercial certificate authority public key certificate Ta.

  Further, when the authenticating entity 4 acquires the authenticated entity public key certificate Tb2 from the authenticated entity 5, the authenticating entity public key certificate Tb2 is verified with the commercial certificate authority public key Ka whose trust has been confirmed. When this verification is established, the authentication entity 4 trusts the authenticated entity public key Kb2 included in the authenticated entity public key certificate Tb2. Therefore, during actual communication, the authenticated entity 4 and the authenticated entity 5 challenge the authenticated entity public key Kb2 registered in the authenticated entity 4 and the authenticated entity private key Kb1 registered in the authenticated entity 5. Response authentication is possible.

  Next, operation | movement of the authentication system 1 of this example is demonstrated according to FIG.1 and FIG.2. Steps 100 to 106 in the figure are registration operations that are performed in advance before the authentication entity 4 and the authenticated entity 5 perform actual communication.

In step 100, the individual certificate authority 3 creates a key pair (secret key and public key).
In step 101, the individual certificate authority 3 distributes the created individual certificate authority public key Kc to each authentication entity 4 as a root certificate Tx. The root certificate Tx is distributed to the authentication entity 4 registered in the authentication system 1.

In step 102, the commercial certificate authority 2 creates a key pair (private key and public key).
In step 103, the commercial certificate authority 2 distributes the created commercial certificate authority public key Ka to the individual certificate authority 3. Note that the order of the operations of Steps 100 and 101 and the operations of Steps 102 and 103 may be interchanged.

  In step 104, the individual certificate authority 3 issues a commercial certificate authority public key certificate Ta to the authentication entity 4. The commercial certificate authority public key certificate Ta is issued when the individual certificate authority 3 receives a certificate issuance request from the authentication entity 4.

  In step 105, the authentication entity 4 verifies the commercial certificate authority public key certificate Ta acquired from the individual certificate authority 3 with the root certificate Tx. When the authentication entity 4 confirms that this verification is established, the authentication entity 4 trusts the commercial certificate authority public key Ka included in the commercial certificate authority public key certificate Ta. That is, the authentication entity 4 registers the commercial certificate authority public key Ka to itself as a usable public key.

  In step 106, the commercial certificate authority 2 issues an authenticated entity private key Kb 1 and an authenticated entity public key certificate Tb 2 to the authenticated entity 5. The issuance of the authenticated entity private key Kb1 and the authenticated entity public key certificate Tb2 is executed when a request for sending such information is received from the authenticated entity 5. At this time, the authenticated entity private key Kb1 is registered in the authenticated entity 5 as a private key that can be used when authenticating with the authenticating entity 4 (step 109).

  Through the operations in steps 100 to 106 described above, the commercial certificate authority public key Ka is registered in the authentication entity 4 and the authenticated entity public key certificate Tb2 is registered in the authenticated entity 5. That is, preparations necessary for the actual communication after Step 107 between the authenticating entity 4 and the authenticated entity 5 are completed.

  In step 107, the authenticated entity 5 sends the authenticated entity public key certificate Tb2 to the authenticated entity 4 during actual communication. That is, when an access execution operation is performed in the authenticated entity 5 and communication with the authenticated entity 4 is started, first, the authenticated entity public key certificate Tb2 is transmitted from the authenticated entity 5 to the authenticated entity 4.

  In step 108, the authentication entity 4 verifies the authenticated entity public key certificate Tb2 with the commercial certificate authority public key Ka. When the authentication entity 4 confirms that this verification is established, the authentication entity 4 trusts the authenticated entity public key Kb2 included in the authenticated entity public key certificate Tb2. That is, the authenticated entity public key Kb2 is registered in the authenticated entity 4 as a public key that can be used when authenticating with the authenticated entity 5 (step 109).

  In step 109, the authenticating entity 4 executes challenge response authentication using the authenticated entity public key Kb 2 and the authenticated entity private key Kb 1 with the authenticated entity 5. That is, challenge-response authentication is executed using the authenticated entity public key Kb2 registered in the authenticated entity 4 and the authenticated entity private key Kb1 registered in the authenticated entity 5. And if challenge response authentication is materialized, communication with the authentication entity 4 and the to-be-authenticated entity 5 will be permitted.

  When the authentication entity 4 confirms that challenge-response authentication is established with the authenticated entity 5, the authenticating entity 4 transmits various information requested by the authenticated entity 5 to the authenticated entity 5. For example, when the authenticated entity 5 is used as an electronic key for a vehicle, there are an ID code for an electronic key, an encryption key (common key) for challenge response authentication executed with the vehicle, and the like. When the authenticated entity 5 receives various information from the authenticated entity 4, it registers it in itself.

  By the way, as shown in FIG. 3, for example, a case where the service by the commercial certificate authority 2 is stopped due to the bankruptcy of the commercial certificate authority 2 or the like is assumed. However, in this example, since the root certificate Tx used in the authentication system 1 is guaranteed by the individual certificate authority 3, even if the service by the commercial certificate authority 2 is stopped, the root certificate Tx is not changed. It can be used without problems. Therefore, it is possible to continue using the authentication system 1 without imposing rewriting or the like on the user.

  As described above, in this example, the individual certification authority 3 is provided in the authentication system 1 separately from the commercial certification authority 2, and the root certificate Tx is distributed from the individual certification authority 3 to the authentication entity 4. Therefore, even if the commercial certificate authority 2 goes bankrupt and the service is stopped, the root certificate Tx registered in the authentication entity 4 maintains a state guaranteed by the individual certificate authority 3, so this route The certificate Tx can be used continuously. Therefore, even if the commercial certificate authority 2 stops the service, it is not necessary to impose a re-acquisition of the root certificate Tx on the user, so that convenience can be improved.

  As shown in FIG. 4, when the authentication system 1 of this example accepts the service of the separate certificate authority 15 and expands the system, the separate certificate authority public key certificate Th is distributed from the separate certificate authority 15 to the authentication entity 4. It is possible to cope with. The separate certificate authority public key certificate Th includes the separate certificate authority public key that is a public key created by the separate certificate authority 15 and the signature (validity) of the individual certificate authority 3 for the separate certificate public key. It is. Therefore, in this case, the system can be freely expanded on the assumption that the root certificate Tx is commonly used.

  As shown in FIG. 5, when the commercial certificate authority 2 stops the service or the private key of the commercial certificate authority 2 leaks, a security problem arises. The certificate authority 18 may be started up. The separate certificate authority 18 may be started up by the company that manages the individual certificate authority 3 itself.

  At this time, the separate certificate authority 18 executes the processing of steps 102, 103, and 106 similar to those of the commercial certificate authority 2. In other words. The separate certificate authority 18 creates a secret key and a public key, and distributes the self-created separate authentication public key Kl to the individual certificate authority 3. Further, the separate certificate authority 18 reissues the authenticated entity private key Km1 and the authenticated entity public key certificate Tm2 to the authenticated entity 5 by itself. The authenticated entity public key certificate Tm2 includes the authenticated entity public key created by the separate certificate authority 18 and the signature (validity) of the separate certificate authority 18 for the authenticated entity public key.

  Further, the individual certificate authority 3 invalidates the commercial certificate authority public key certificate Ta and reissues another certificate authority public key certificate Tn to the authentication entity 4. The separate certificate authority public key certificate Tn includes another certificate authority public key that is a public key created by the separate certificate authority 18 and the signature (validity) of the individual certificate authority 3 for the separate certificate public key. . Then, when the authentication entity 4 obtains another certificate authority public key certificate Tn from the commercial certificate authority 2, it verifies this with the root certificate Tx. Trust another authentication public key included.

  Therefore, in this case, even if a problem occurs in the service of the commercial certificate authority 2, the system can be used continuously without imposing re-registration of the root certificate Tx on the user. For this reason, the user can continue to use the system only by receiving a certificate reissue, which is very convenient.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) Since the individual certificate authority 3 is provided separately from the commercial certificate authority 2 and the root certificate Tx is distributed from the individual certificate authority 3, even if the service of the commercial certificate authority 2 stops, the individual certificate authority As long as 3 provides the service, the root certificate Tx can be used continuously. Therefore, even if the commercial certificate authority 2 stops the service, it is not necessary to impose the work of reacquiring the root certificate Tx on the user, so that convenience can be improved.

  (2) When the service of the commercial certificate authority 2 is stopped (see FIG. 5), if another certificate authority 18 is started as an alternative to the commercial certificate authority 2, the authentication system is not imposed on the user to rewrite the root certificate Tx. 1 can be used continuously.

  (3) The commercial certificate authority 2 is in charge of conventional services, and the individual certificate authority 3 is made to distribute the root certificate Tx. For this reason, since the processing imposed on the individual certificate authority 3 can be reduced as much as possible, the scale of the individual certificate authority 3 can be reduced. Therefore, initial investment when starting up the individual certificate authority 3 can be reduced.

  (4) When the authenticated entity 5 is an electronic key, the authenticated entity 5 can be freely used as a key by downloading the electronic key ID code from the authenticated entity 5 to the authenticated entity 5. .

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In this example, the idea of the first embodiment is applied to an electronic key system of a vehicle. Therefore, in this example, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different portions are described in detail.

  As shown in FIG. 6, the vehicle 20 is added as a component to the authentication system 1 of this example. The vehicle 20 is equipped with an electronic key system 21 capable of various vehicle operations (door lock locking / unlocking, engine starting, etc.) using the authentication entity 4 as a vehicle key. In this example, the authenticated entity 5 will be described by replacing it with the electronic key 22. The electronic key system 21 includes a key operation free system that performs ID collation using communication from the vehicle 20 as a trigger, and a wireless key system that performs ID collation using communication from the electronic key 22 as a trigger.

  In the case of this example, in addition to the authenticated entity public key Kb2, a vehicle public key Kd2 is registered in the authentication entity 4 in advance. Since the authentication entity 4 is installed in a vehicle factory or the like, the vehicle public key Kd2 is registered in the authentication entity 4 during the vehicle manufacturing process. On the other hand, a vehicle secret key Kd1 paired with the vehicle public key Kd2 of the authentication entity 4 is registered in the vehicle 20 in advance. The vehicle secret key Kd1 is also registered in the vehicle 20 during the vehicle manufacturing process.

Next, operation | movement of the authentication system 1 of this example is demonstrated according to FIG.
In step 200, the authentication entity 4 is used for challenge response authentication at the time of key ID verification in encrypted communication using the authenticated entity private key Kb1 and the authenticated entity public key Kb2 when authenticating with the authenticated entity 5. The common key Ke is issued to the authenticated entity 5. Therefore, a common key Ke for challenge response authentication with the vehicle 20 is registered in the electronic key 22.

  In step 201, the authentication entity 4 gives the vehicle 20 the common key Ke used for challenge response authentication at the time of key ID verification in encrypted communication using the vehicle secret key Kd1 and the vehicle public key Kd2 at the time of vehicle shipment, for example. Issue. The common key Ke is issued using, for example, a network communication device (G-Book) mounted on the vehicle 20. For this reason, a common key Ke for challenge response authentication with the electronic key 22 is registered in the vehicle 20.

  In step 202, when the electronic key 22 performs wireless ID verification with the vehicle 20, the vehicle 20 and the electronic key 22 check the ID code registered in the electronic key 22, and the common key Ke, Perform challenge response authentication with Ke. And if both ID code collation and challenge response authentication are materialized, door lock locking / unlocking of the vehicle 20, engine starting, etc. will be permitted or performed.

According to the configuration of this embodiment, in addition to (1) to (4) described in the first embodiment, the following effects can be obtained.
(5) Since the authentication system 1 of this example is applied to the electronic key system 21, the registration of the common key to the vehicle 20 or the electronic key 22 can be executed by a process that ensures security.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
In each embodiment, the authenticated entity 5 is not limited to acquiring the authenticated entity private key Kb1 from the authenticated entity 5. For example, the authenticated entity 5 may hold the authenticated entity private key Kb1 in advance, or may acquire it separately from a registration authority.

  In each embodiment, the authentication entity 4 is not limited to acquiring the authenticated entity public key certificate Tb2 from the authenticated entity 5. That is, the individual certificate authority 3 issues the authenticated entity public key certificate Tb2, but the place from which it is obtained is not particularly limited.

  In each embodiment, the authentication entity 4 is not limited to acquiring the commercial certificate authority public key certificate Ta from the individual certificate authority 3. For example, the authentication entity 4 may hold the commercial certificate authority public key certificate Ta in advance, or may separately acquire it from another registration authority.

In each embodiment, the authenticated entity 5 is not limited to a mobile phone or an electronic key, but may be another communication terminal.
-In each embodiment, the authentication entity 4 is not restricted to the key of the vehicle 20, For example, the vehicle equipment of the electronic key system 21 mounted in the vehicle 20 may be sufficient. The vehicle-mounted device is a device that manages the operation of the electronic key system 21 on the vehicle 20 side, and executes processing such as communication management for ID verification and confirmation of the ID code of the key.

  In each embodiment, authentication (entity authentication) performed by the authentication entity 4 and the authenticated entity 5 is not limited to challenge response authentication, and other authentication may be used.

In each embodiment, the individual certificate authority 3 may play a role of guaranteeing at least the root certificate Tx.
Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.

  (A) In any one of claims 1 to 3, a plurality of sets of the authentication entity and the authenticated entity are provided, and the second certificate authority issues different root certificates to these sets. According to this configuration, it is possible to issue root certificates to a plurality of groups, so that the system can be expanded.

  (B) In any one of claims 1 to 3 and the technical idea (a), the authenticated entity is an electronic key of a vehicle, and the authenticated entity is for the vehicle in addition to the authenticated entity public key. A vehicle public key that is a public key of the vehicle, the vehicle holds a vehicle secret key corresponding to the vehicle public key, and the authenticating entity and the electronic entity On the condition that authentication by the authentication entity public key is established, an encryption key used for authentication of the electronic key system is registered in the electronic key, and authentication with the vehicle secret key and the vehicle public key is performed with the vehicle. On the condition that it is established, an encryption key used for authentication of the electronic key system is registered in the vehicle. According to this configuration, the authentication system of this example can be applied to an electronic key system.

(C) distributing the first CA public key created by the first CA to the second CA;
The second certificate authority issuing a first certificate authority public key certificate signed by the second certificate authority to the authenticating entity, the legitimacy of the first certificate authority public key;
When the authentication entity acquires the first CA public key certificate, the first CA public key certificate is verified with the root certificate. If the verification is established, the first CA public key is verified. Trusting the first CA public key included in the certificate;
The first certificate authority issuing the authenticated entity public key certificate signed by the first certificate authority to the authenticated entity, the legitimacy of the authenticated entity public key;
When the authenticating entity obtains the authenticated entity public key certificate, the authenticated entity public key certificate is verified with the first CA public key whose trust has been confirmed, and if the verification is established, the authenticated entity public key certificate is verified. Trusting the entity public key,
As described above, the authentication method allows the authentication entity and the authenticated entity to execute authentication using the authenticated entity public key and the authenticated entity private key.

  DESCRIPTION OF SYMBOLS 1 ... Authentication system, 2 ... Commercial certification authority as 1st certification authority (certification authority), 3 ... Individual certification authority as 2nd certification authority (certification authority), 4 ... Authentication entity, 5 ... Authenticated entity, 20 ... Vehicle, 21 ... Electronic key system, 22 ... Electronic key, Kb1, Km1 ... Authenticated entity private key, Tb2, Tm2 ... Authenticated entity public key certificate, Kb2 ... Authenticated entity public key, Ka ... First certificate authority release Commercial certificate authority public key as a key, Ta ... Commercial certificate authority public key certificate as a first certificate authority public key certificate, Tx ... Root certificate.

Claims (3)

The certificate authority distributes the root certificate to the authenticating entity, the authenticated entity holds the authenticated entity private key, the certificate authority issues the authenticated entity public key certificate to the authenticated entity, and the authenticating entity When the authenticated entity public key certificate is obtained, the authenticated entity public key certificate is verified with the root certificate. If the verification is established, the authenticated entity public key certificate includes the authenticated entity public key certificate. In the authentication system in which the authentication entity registers an entity public key, whereby the authentication entity and the authenticated entity can execute authentication using the authenticated entity public key and the authenticated entity private key.
An authentication system, wherein a separate second certificate authority is provided separately from a general-purpose first certificate authority, and the root certificate is distributed from the second certificate authority to the authentication entity. The first certificate authority distributes the first certificate authority public key created by itself to the second certificate authority;
The second certificate authority issues a first certificate authority public key certificate signed by the second certificate authority to the authenticating entity, and the validity of the first certificate authority public key is issued;
When acquiring the first CA public key certificate, the authentication entity verifies the first CA public key certificate with the root certificate, and if the verification is successful, the first CA public key certificate. Trusting the first CA public key included in the key certificate;
The first certificate authority issues the authenticated entity public key certificate signed by the first certificate authority to the authenticated entity, the legitimacy of the authenticated entity public key,
When the authenticating entity obtains the authenticated entity public key certificate, the authenticating entity public key certificate is verified with the first CA public key whose trust has been confirmed, and if the verification is established, the authenticated entity public key certificate is verified. Trust the authenticating entity public key,
The authentication entity and the authenticated entity can perform authentication using the authenticated entity public key and the authenticated entity private key as described above. Authentication system. The authentication system according to claim 1, wherein the authenticated entity is an electronic key of a vehicle or an on-vehicle device of an electronic key system of the vehicle.

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