JP2002108209A - Method of confirming for effectiveness of certificate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable even a system which does not have a real time clock to confirm the effectiveness of a certificate safely. SOLUTION: A system 102 being ready to performing the confirming of the effectiveness of a certificate generates unique data (random number) for every confirmation request. A certifying station 101 generates a response including the data and adds a signature to the request. Thus, it is assured that the response of the certifying station is generated after the confirmation request of the effectiveness is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a certificate validity confirmation method for transmitting a validity confirmation request to a certification authority and confirming the validity of the certificate by a validity confirmation response returned from the certification authority.

[0002]

2. Description of the Related Art Unlike conventional face-to-face transactions, in network transactions, it is not possible to directly confirm a trading partner. Therefore, there has been proposed a method of confirming a partner using an authentication technique using a certificate by a certificate authority. See “RF
C2459 Internet X.509 PublicKey Infrastructure: Cer
tificate and CRL Profile ". The certificate has an expiration date. If it is determined that the certificate has been compromised, the certificate will be revoked even within the expiration date. When using a certificate, check the validity of the certificate with a certificate authority before using it. This prevents trust of the other party with an invalid certificate. See RFC2560 Internet X.509 Public Key Infrastructur for more information.
e: Online Certificate Status Protocol-OCSP.

A response time is written in a response from the certificate authority. The user compares the response time written in the response with the time on his / her own clock. If it is determined that the response time is sufficiently new for the purpose, the response is accepted; otherwise, it is determined that the validity could not be confirmed. This allows an unauthorized third party to interrupt the communication between the user and the certificate authority and send the user an old acknowledgment of the certificate authority, as if the already revoked certificate were valid. It prevents fraudulent acts such as masquerading.

[0004]

In order for the validity checking means to function, the system for performing the validity check must have an accurate clock. Unless you know the current exact time, there is nothing to compare with the response time of the certificate, and it cannot determine whether the certificate is new or old. An object of the present invention is to provide a method for securely validating a certificate even in a system without a real-time clock.

[0005]

According to the present invention, a system for performing a validity check generates unique data for each check request and adds it to the request. The certificate authority generates a response including the data and signs the response. Accordingly, it is possible to guarantee that the response of the certificate authority is generated after the validity check request is made. That is, the certificate validity confirmation method according to the present invention sends a certificate validity confirmation request to a certificate authority, and the certificate validity response is returned from the certificate authority in response to the validity confirmation request. In the certificate validity confirmation method for confirming the validity, a step of adding arbitrary data to the validity confirmation request and transmitting it to the certificate authority, and incorporating the data into the electronic signature of the validity confirmation response returned from the certificate authority Comparing the obtained arbitrary data with the arbitrary data transmitted by itself.

Further, in the certificate validity confirmation method according to the present invention, a validity confirmation response sent from the certification authority is sent from the IC card to the certificate authority by sending a certificate validity confirmation request to the certificate authority. In a certificate validity confirmation method for confirming the validity of a certificate, a step of adding arbitrary data to a validity confirmation request and transmitting the data to a certificate authority, and an electronic confirmation of the validity confirmation response returned from the certificate authority. Comparing any data embedded in the signature with any data transmitted by itself.

Focusing on the processing in the certificate authority, the certificate validity confirmation method according to the present invention generates a validity confirmation response on the basis of the result of the examination by the certificate authority upon receiving the certificate validity confirmation request. Receiving a request for validating a certificate to which arbitrary data is added, in a certificate validity confirming method including a step of attaching a digital signature to the response using a certificate authority private key and returning the certificate; A step of incorporating the arbitrary data into a response to the request for validity confirmation of the document, performing an electronic signature, and returning the result as a response. Arbitrary data added to the certificate validity check request can be a random number. According to the method of the present invention, the validity of a certificate can be securely confirmed even in a system having no real-time clock such as an IC card.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the overall configuration of a system according to the present invention. Here, the IC card 102 is used as an example of a device having no real-time clock. One or a plurality of applications 120 are executed inside the IC card 102. The application 120 performs a predetermined task such as electronic commerce and electronic authentication. The application 120 may need to confirm the validity of the certificate in the course of executing the business. In this case, the application 120 executes a certificate validity confirmation process using a function of the present invention described below.

Generally, an IC card cannot directly communicate with a certificate authority. The IC card 102 communicates with the certificate authority 101 via the card terminal device 103. The IC card 102 includes a validity confirmation request generation unit 110, a validity confirmation response processing unit 112, and a communication device 115, and internally holds the public key 111 of the certificate authority 101. The request generator 109 includes a random number generator 109 therein.
The certificate authority 101 includes a validity confirmation response generation unit 104, a signature generation unit 105, a communication device 108, a certificate database 10
7 and holds a certificate authority private key 106 therein.

[0010] The validity check request generator 110 of the IC card 102 receives a random number from the random number generator 109 and generates a validity check request based on the random number. The details of the validation request are described in the next section. Upon receiving the validity check request from the IC card 102, the terminal device 103 searches for an appropriate certificate authority and transfers the request. Upon receiving the validity confirmation request, the certificate authority 101 refers to the certificate database 107 and checks the validity state of the requested certificate. Next, a random number is extracted from the validity check request. The response generation unit 104
Generates a validity confirmation response based on the search result and the extracted random numbers. Further, an electronic signature is attached to the response using the certificate authority private key 106, and the response is returned.

[0011] The IC card 102 receives the response via the terminal device 103 and takes it into the validity confirmation processing unit 112.
The validity confirmation processing unit 112 extracts a random number from the validity response data and compares it with the random number transmitted by the random number comparison unit 113. If they match, the signature confirmation unit 114 is activated. The signature confirmation unit 114 authenticates the response using the public key 111 of the certificate authority inside the card. If the electronic signature is correct, it can be determined that the response is a correct response to the validation request.

FIG. 2 is a diagram showing a format example of a validity confirmation request. The validity check request 201 includes the certificate identification information 20
2, three items of random number 203 and requester information 204. The certificate identification information 202 is information for identifying a certificate whose validity is to be confirmed. Certificate serial number 205
Is the number assigned by the certificate authority that issued the certificate,
It uniquely identifies a certificate. Certificate Authority Distinguished Name 20
Reference numeral 6 denotes an identification name for uniquely identifying the certificate authority that issued the certificate. The certificate authority connection means 207 is information used when the IC card reader connects to the certificate authority. This stores information such as the URL of the certificate authority, the IP address of the certificate authority, and the telephone number of the certificate authority. The random number 203 is a random number generated by the IC card 102 that issues the validity check request.
The requester information 204 includes validity check requester identification information 208
Contains. The validity check requester identification information 208 stores the certificate authority registration number of the requester, the serial number of the IC card, the name and identification code of the IC card owner, and the like. This item may be empty. However, in that case, the certificate authority may reject the validity check. How to handle it depends on the operation rules of the certificate authority.

FIG. 3 is a diagram showing a format example of a validity confirmation response. The validity confirmation response 301 includes the certificate validity information 3
02, the received random number 303, and the digital signature 304 of the certificate authority. The certificate validity information 302
Certificate serial number 305, inquiry result 306, expiration date 30
7, the response date and time 308 are included. Certificate serial number 30
5 is the serial number of the requested certificate itself. Query result 306 indicates whether the queried certificate is valid. Valid, invalid, or unknown. Unknown means that there is no record in the CA's database. The reasons may be that the certificate is a forgery, that the serial number of the certificate is incorrectly transmitted, or that the certificate authority to be queried is incorrect. In either case, the validity cannot be confirmed and is often treated as invalid. The expiration date 307 is set by the responding certificate authority according to its own security standard. The response date and time 308 is the date and time when the validity confirmation response 301 was created. Random number 303
Is the random number itself stored in the request. The digital signature 304 of the certificate authority prevents the above two items from being tampered with. By authenticating the signature, it is possible to confirm that the validity confirmation response has been issued by the correct certificate authority and that no unauthorized tampering has been performed.

FIG. 4 is a diagram showing a procedure of validity confirmation. The process starts from the IC card side. First, step 40
In step 1, the random number generation device 109 is activated to obtain a random number. Next, in step 402, the validity check request generation unit 110 creates the validity check request 201 according to the format shown in FIG.
From the certificate to be confirmed, data such as a certificate serial number, a certificate authority identification name, and a certificate authority connection means are extracted. Further, validity confirmation requester identification information is generated from the user information in the card, the serial number of the IC card and the like. The validity check request is generated by incorporating these data into a predetermined format. When the request data is completed, control is transferred to step 403, the communication device 115 is activated, and a validity confirmation request is transmitted.

Steps 404 to 409 are processing on the certificate authority side. In step 404, the certificate authority 10
1 receives a validity confirmation request from the communication device 108. In step 405, the certificate authority 101 extracts a random number and a certificate serial number from the validity check request. Step 406
Thus, the certificate authority 101 establishes an internal certificate database 107
And retrieve the corresponding certificate data. In step 407, the random number and the retrieved certificate data are sent to the response generation unit 104, and the validity confirmation response 301 is generated. Next, in step 408, the validity confirmation response 301 is sent to the signature generation unit 105. The signature generation unit 105 stores the certificate authority private key 10
6, the digital signature 304 of the certificate authority is generated. This is incorporated into the validity confirmation response 103, and a complete validity confirmation response is completed. In step 409, the validity confirmation response 103 is sent back to the inquiry source via the communication device 108.

Steps 410 to 412 are processing on the IC card side. In step 410, the validity confirmation response 301 is received from the communication device 115 and sent to the validity confirmation processing unit 112. Validity confirmation processing unit 12
2 extracts the random number 303 from the response. Step 4
At 11, the random number 303 is sent to the random number comparison unit 113 and compared with the transmitted random number 203. If the random numbers match, it is a correct response. If they do not match, it is considered that an incorrect response was received. The means to be taken depends on the application, but in general, the processing is often the same as when the certificate is invalid. In step 412, the validity confirmation processing unit 112 checks the signature 304 of the certificate authority from the response.
And sends it to the signature confirmation unit 114. Signature confirmation unit 11
4 authenticates the electronic signature using the certificate authority public key 111. If the authentication is successful, it can be determined that a response has been obtained from the correct certificate authority. The certificate validity information 302 is extracted from the response, and is returned as a response to the application that has requested confirmation of the certificate. If the signature verification fails, it is considered that an invalid response was sent. The countermeasure depends on the application, but in general, it is often handled in the same way as when the certificate is invalid.

FIG. 5 is a diagram showing a configuration example of the card terminal device 103. The terminal device 103 exchanges data between the IC card 102 and the certificate authority 101. Since the IC card itself cannot directly communicate with the certificate authority, it is necessary for the terminal device to take charge of the operation. Card terminal device 10
3 is a network communication device 501, a data transfer device 5
02, communication control device 503, communication request reception processing unit 50
4. It has an IC card communication device 505. Generally, the certificate authority 101 is connected via a network 507. The network communication device 501 is connected to the network 50
7, and communicates with the certificate authority 101. Communication control device 5
03 controls the network communication device 501. The IC card communication device 505 is the IC card 1
03 is communicated. The data transfer device 502 includes a network communication device 501, a communication request reception processing unit 504,
Data is relayed between the three members of the C card communication device 505. The communication request receiving process 504 is performed by the data transfer device 502
The communication controller 503 analyzes the data received from the communication controller 503 and instructs the communication controller 503 to connect to an appropriate certificate authority.

FIG. 6 is a diagram showing a processing procedure of the card terminal device 103. First, in step 601, the IC card communication device 505 receives the validity check request 201 and sends it to the data transfer device 502. In subsequent step 602, the data transfer device 502 transmits the data to the communication request reception processing unit 5
04. In step 603, the communication request reception processing unit 504 extracts the certificate authority connection unit 207 from the validity check request 201. In step 604, based on the contents of the certificate authority connection means 207, the communication control device 50
3 is instructed to connect to the certificate authority. In step 605, the communication control device 503 activates the network communication device 501 and connects to the network 507. Further, it connects to the certificate authority 101 at the further end and establishes communication. In step 606, the network communication device 501 receives the validity check request 201 from the data transfer device 502 and sends it to the certificate authority 101.

In step 607, the certificate authority 101 sends a validity confirmation response 301 to the network communication device 501. The network communication device 501 sends a response to the IC card communication device 505 via the data transfer device 502.
In step 608, the IC card communication device 608
A validity confirmation response 301 is transmitted to the card.

[0020]

According to the present invention, the validity of a certificate can be securely confirmed even in a system without a real-time clock.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of the overall configuration of a system according to the present invention.

FIG. 2 is a diagram showing a format example of a validity confirmation request.

FIG. 3 is a diagram showing a format example of a validity confirmation response.

FIG. 4 is a diagram showing a procedure of validity confirmation.

FIG. 5 is a diagram showing a configuration example of a card terminal device.

FIG. 6 is a diagram showing a processing procedure of the card terminal device.

[Explanation of symbols]

101: Certificate Authority, 102: IC Card, 104: Validity Confirmation Response Generating Unit, 105: Signature Generating Unit, 106: Certificate Authority Private Key, 107: Certificate Database, 108: Communication Device, 109: Random Number Generating Device, 110 ... Validity check request generator 111, Certificate authority public key 112, Validity check response processor 113, Random number comparator 114, Signature checker 1,
15 ... communication device, 120 ... application, 201 ...
Validity confirmation request, 202: certificate identification information, 203: random number, 204: requester information, 301: validity confirmation response, 3
02: certificate validity information, 303: received random number, 30
4 ... Electronic signature of certificate authority 501 ... Network communication device 502 ... Data transfer device 503 ... Communication control device
504: Communication request reception processing unit, 505: IC card communication device

Claims (4)

[Claims] A certificate validity confirmation request is sent to a certification authority, and the validity of the certificate is confirmed by a validity confirmation response returned from the certification authority in response to the validity confirmation request. In the validity confirmation method, a step of adding arbitrary data to the validity confirmation request and transmitting the data to a certificate authority, and transmitting any data incorporated in the electronic signature of the validity confirmation response returned from the certificate authority. Comparing with the transmitted arbitrary data. 2. An IC card sends a certificate validity confirmation request to a certificate authority, and confirms the validity of the certificate by a validity confirmation response returned from the certificate authority in response to the validity confirmation request. In the certificate validity confirmation method, a step of adding arbitrary data to the validity confirmation request and transmitting the data to a certificate authority, and an optional method incorporated in a digital signature of a validity confirmation response returned from the certificate authority. Comparing the transmitted data with the transmitted arbitrary data. 3. The certificate authority generates a validity confirmation response based on the result of the examination upon receiving the certificate validity confirmation request, and attaches an electronic signature to the response using the certificate authority private key and returns the response. Receiving a request for validity confirmation of a certificate to which arbitrary data has been added, and incorporating the arbitrary data in a response to the request for validity confirmation of the certificate. Digital signature and replying as a reply. 4. The certificate validity checking method according to claim 1, wherein said arbitrary data is a random number.