JP2002314521A - Secret key transmission device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secret key transmission device and method by which a user can simply acquire and identify a corresponding secret key even when the secret key for a certificate cannot locally be found. SOLUTION: A certificate user uses a client terminal 30 to request an authentication agency 10 to issue a certificate (x01). The authentication agency 10 issues a certificate X.509 based on the information of the certificate user (x02). The certificate user transmits a certificate/secrete key file PKCS#12 together with a secret key storage request (x03). A storage agency 20 stores the received file PKCS#12 in cross-reference with the user. When the certificate user desires extraction of the secret key from the storage agency 20, the certificate user transmits a secret key extract request with an expiration date designated thereto to the storage agency 20 (x05). Then the storage agency 20 refers to a collation table 216 to extract the certificate/secret key file PKCS#12 that is probably highly validated at that time and transmits the file to the certificate user (x06). The certificate user receives the certificate/secret key file PKCS#12 transmitted from the storage agency 20 and identifies the desired secret key.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secret key sending technique for managing a secret key paired with a certificate and sending the secret key based on a request of a certificate subscriber.

[0002]

2. Description of the Related Art ITU-TXX. Regarding the transmission of the private key paired with the certificate in the 509 certificate, the certificate is specified and the private key for the certificate is transmitted. The secret key only needs to be held by the user himself, and depending on the method, a form in which the secret key is passed only to the user himself may be considered. However, if the user loses the secret key, the user will not be able to decrypt the ciphertext, which is troublesome.

[0003] When the number of certificates is small and the user can easily specify the certificate, there is not much problem (for example, when only one certificate is obtained from the certificate authority that issues the certificate). If you have been using certificates for a long time,
There may be cases where you have more than one certificate. Accordingly, the number of private keys paired with the certificate naturally increases by the same number. Certificates have an expiration date (usually about one year), so if you use certificates for more than one year, the number of certificates will increase, and you may need to obtain certificates from multiple certificate authorities. Many. When you start using certificates, the situation with multiple certificates is a normal situation, not a special one.

[0004] When accessing a web server using SSL (secure socket layer) or the like, it is only necessary to hold a valid certificate / private key at the time of use. , Especially when storing e-mail encrypted mail (S / MIME, etc.)
Or if you are using a certificate for file encryption (such as Microsoft NTFC5,
(Microsoft is a trademark of Microsoft Corporation in the United States) requires a valid certificate / private key at the date and time of sending an e-mail and at the date and time of file encryption.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to enable a certificate user to easily obtain a corresponding private key.

[0006]

According to the present invention, a certificate or a private key is narrowed down at any time when a certificate is valid as hint information. According to a specific aspect of the present invention, when requesting the transmission of a private key, the user is required to input the date and time when the certificate was valid, and to narrow down the certificate against the issuance record of the certificate stored in the certificate authority. Then, for the narrowed-down private key, the private key and the corresponding certificate are sent as a pair.

The transmission date and time is recorded in the electronic mail, and it is easy to know the encrypted date and time of the encrypted mail. As for the electronic file, the encrypted date and time are held as attributes, so that the encrypted date and time can be known in the same manner.

[0008] Every certification authority has a record of issuance of all certificates issued since the certification authority started the service. The certificate contains information on the expiration date, so if the certificate is specified, the expiration date can be checked. However, it is difficult to identify the certificate by checking the expiration date of each certificate against the information at any time when the private key was valid. Therefore, the validity period is divided into appropriate intervals (for example, every month), and a list of valid certificates is held during that period. This table may be a simple table, a hash may be created with a validity period, or a binary tree.

This table may be created and stored by the certification organization that issued the certificate in conjunction with the issuance of the certificate. It may be stored in the host device of the certificate subscriber. In addition, a mechanism outside the certification body may store it. The table and the secret key may be stored by another mechanism or device.

The present invention will be further described. According to an aspect of the present invention, in order to achieve the above object, a secret key sending device connected to a host device of a certificate user via a communication network is issued to the certificate user. Means for storing a private key paired with the generated certificate; means for associating a certificate issued to the certificate subscriber at predetermined intervals and valid for the predetermined period;
Means for using the associating means to determine the certificate associated with the designated period; and storing the private key stored corresponding to the determined certificate in the certificate user's host device. A means for sending is provided.

[0011] With this configuration, the certificate user can narrow down the certificate and obtain a corresponding private key using the information of the date and time or the period when the certificate is recognized as valid. The narrowed-down secret key may be sent to the certificate subscriber, or a list showing the narrowed-down result may be presented, and a desired secret key may be selected from the list. That is, all the narrowed-down secret keys may be sent, or a desired part of them may be sent.

The private key is stored by binding to the certificate by using a private key exchange file in the private secret information exchange format of PKCS # 12 (Public Key Encryption Standard 12), for example. The secret key may be sent from the storage location to the certificate user's host device via the communication network, or may be output to a predetermined recording medium, and the recording medium may be sent to the certificate user.

The present invention can be realized not only as an apparatus or a system, but also as a method, and a part thereof can be implemented as a computer program.

[0014] The above aspects of the invention and other aspects of the invention are set forth in the appended claims and will be described in detail hereinafter with reference to embodiments.

[0015]

Embodiments of the present invention will be described below.

FIG. 1 shows an outline of a secret key sending system according to an embodiment of the present invention.
0, a storage institution 20, a client terminal 30, and the like are connected via a communication network 40. Certification body 1
0 is for issuing and managing a certificate in response to a request from the client terminal 30. For example, when the client terminal 30 sends a public key and a certificate issuance request to the certification authority 10, the certification authority sends the public key and the certificate validity request to ITU-T Recommendation X.264. 509-compliant certificate is issued. The certification organization 10 manages the issued certificate in a database. The certificate authority 10 may publish the certificate issued to the user by an LDAP (Lightweight Directory Access Protocol) server or the like. The storage institution 20 has the client terminal 3
The secret key and the like are stored based on the secret key storage request from 0. Specifically, a pair of a certificate and a private key is stored in PKCS # 12.
The file formatted by (Public Key Encryption Standard 12) is received from the client terminal 30 and stored and managed. The client terminal 30 is an information device such as a personal computer and a workstation used by the certificate subscriber. The client terminal 30 may be anything that can provide a resource that can use the certificate.
As long as the computing ability and the storage ability are sufficient, a mobile phone or a form information terminal may be used, or a fixed telephone or an intelligent home electric appliance may be used. The communication network 40 is a wide area communication network (WAN) or a local area communication network (LAN), and is typically the Internet.

The storage institution 20 is, for example, a web server 2
1, an application server 202, a database management system 203, and the like are connected to a LAN 204. The LAN 204 is connected to the communication network 40 via a router 205.

The web server 201 provides a user interface with the client terminal 30. The user of the client terminal 30 selects and sends the PKCS # 12 file (pair of certificate and private key) to the storage organization 20 using this user interface, inquires about the private key, and Make a send request.

The application server 202 stores the file sent from the client terminal 30 in the certificate / private key file database 215 (storage processing unit 211), and stores the file in the certificate / private key file database 215. The certificate / private key file is sent to the client terminal 30 via the web server 201 (sending processing unit 212). Application server 20
2 outputs a list of applicable certificates (private keys) in response to a certificate (private key) inquiry from the client terminal 30 (private key inquiry unit 214). This will be described later in detail.

The database management system 203 stores the certificate / private key file sent from the client terminal 30 in the certificate / private key file database 215.
to manage. Certificate / private key files are, for example, phone numbers,
Searching can be performed using an identification number, a certificate, and a code (such as a password or a family name). The database management system 203 manages an inquiry table 216. As shown in FIG. 2, the inquiry table 216 stores, for each period (one month), the I of the certificate valid at that time.
Holds a query table that associates D. Only a certificate valid for the entire period of one period may be associated, or a certificate valid at any one point in the period may be associated. In this example, the latter is adopted. The inquiry table 216 is generated based on the ID of the certificate, the start date, and the end date. Certificate / private key file database 21
5 is a certificate of ITU-T Recommendation X. 509, and an inquiry table 216 is generated using the certificate ID, start date, and end date of the information. In the case of the example of FIG. 2, the ID, start date, and end date of the certificate are as shown in FIG.

Further, the application server 202 can authenticate a certificate user by using the authentication unit 213.

FIG. 4 shows the operation of the embodiment. In this figure, the certificate subscriber requests the certificate authority 10 to issue a certificate using the client terminal 30 (x0).
1). At this time, the certificate subscriber generates a pair of a secret key and a public key, and sends the public key to the certification authority 10. Certification body 1
0 is based on the information of the relying party. 509 certificate is issued (x02). The relying party combines the certificate with the private key by PKCS # 12 and sends the file together with the private key storage request (x03). For example, a file of the PKCS # 12 to be transmitted is specified and transmitted using the HTML document of the input form for selecting a file (x04). The storage agency 20 receives the PKCS #
Twelve files are stored in association with the user. The storage organization 20 reproduces the secret key from the received PKCS # 12 file and sends it to the relying party (x05).

The above procedures x01 to x05 are performed every time a certificate subscriber requests a certificate issuance, and each time the certificate / private key is stored in the storage organization 20.

Next, when the certificate user wants to retrieve the private key from the storage organization 20 (for example, when the private key is not found locally), the private key is first used to identify the private key to be retrieved. A secret key removal request is transmitted to the storage organization 20 by designating the date and time (x0
6). At this time, a telephone number, a personal identification number, and the like can be used to identify the certificate subscriber. Storage Agency 2
0 specifies the certificate subscriber by telephone number, personal identification number, etc., and further uses the certificate subscriber's inquiry table 216 to specify the ID of the certificate valid during the period corresponding to the designated date and time. Identify and corresponding certificate / private key file based on the ID of this certificate (may be multiple files)
Is extracted from the certificate / private key file database 215 and sent to the certificate subscriber (x07). It is preferable to authenticate the identity of the certificate user at the time of requesting storage and retrieval of the private key (certificate / private key file) (authentication unit 213, FIG. 1).

The relying party receives the transmitted PKCS #
Twelve files are received, and a desired private key is specified by relying on certificate information and the like.

As described above, according to the secret key sending system of this embodiment, even if the locally stored secret key is lost, the intended secret key can be easily obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made. For example, the private key to be stored can be handled by a file other than a file that complies with the PKCS # 12 secret key exchange standard. Further, any information that can identify a secret key may be used instead of a certificate. Further, the secret key or the like may be encrypted and sent to a storage organization, or may be distributed and stored in a plurality of storage organizations. Also, the secret key may not be taken out via the communication network but may be recorded on a recording medium and sent to the user. In addition, the exchange of the secret key may be performed using not only the HTTP protocol but also other transmission means such as mail (SMTP protocol). In addition, information for associating a period with a certificate, such as an inquiry table, may be stored in a certificate authority, or may be stored in a certificate user such as a client terminal. In addition, the inquiry table finally stores the period and certificate ID for each certificate subscriber.
And an intermediate relationship may be held as a relationship table. For example, the relationship between the term and the certificate ID and the relationship between the certificate user and the certificate ID are defined, and the relationship between the term and the certificate ID is defined for each certificate user using this. A query table may be generated. Further, the period and the private key corresponding to the certificate valid in the period (may be a part of the period or the whole period) may be directly related. is there. As for the specification of the period, the period itself may be specified directly, or the date and time (date) included in the period may be specified to specify the period. The period does not have to be in units of months, but may be in units of days, weeks, or years.

[0028]

As described above, according to the present invention, a secret key can be easily obtained and used even when the certificate user cannot specify the secret key locally.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an entire system of a secret key sending system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an inquiry table used in the embodiment.

FIG. 3 is a diagram illustrating an example of a certificate ID, a start date, and an end date corresponding to the contents of the inquiry table.

FIG. 4 is a diagram illustrating the operation of the above embodiment.

[Explanation of symbols]

 Reference Signs List 10 certification institution 20 storage institution 30 client terminal 40 communication network 201 web server 202 application server 203 database management system 204 LAN 205 router 10 certification institution 20 storage institution 30 client terminal 40 communication network 201 web server 202 application server 202 application server 203 database management System 205 Router 211 Storage processing unit 212 Sending processing unit 213 Authentication unit 214 Private key inquiry unit 215 Certificate / private key file database 216 Inquiry table

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B085 AA08 AE00 5J104 AA16 EA01 EA04 EA11 EA16 JA03 NA02 PA07

Claims (11)

[Claims] 1. A secret key sending device connected to a host device of a certificate user via a communication network for storing a secret key paired with a certificate issued to the certificate user. Means and is issued to the relying party at predetermined intervals,
Means for associating the certificate valid for the predetermined period, means for determining the certificate associated with the specified period by using the associating means, and stored corresponding to the determined certificate Means for sending the secret key to the certificate user's host device. 2. A private key sending device connected to a host device of a relying party via a communication network, wherein a private key paired with a certificate issued to the relying party is stored. Means and is issued to the relying party at predetermined intervals,
Means for associating the certificate valid for the predetermined period, means for determining the certificate associated with the specified period by using the associating means, and stored corresponding to the determined certificate Means for outputting a secret key. 3. A private key sending apparatus connected to a host apparatus of the relying party via a communication network, wherein the private key sending apparatus is connected to the relying party based on a private key storage request from the relying party. Means for storing a private key paired with the issued certificate, and for a predetermined period, issued to the relying party,
Means for associating the certificate valid for the predetermined period, means for determining the certificate associated with the specified period by using the associating means, and stored corresponding to the determined certificate Means for sending the secret key to the certificate user's host device. 4. A private key sending device connected to a host device of a relying party via a communication network, the private key sending device being connected to the relying party based on a private key storage request from the relying party. Means for storing a private key paired with the issued certificate, and for a predetermined period, issued to the relying party,
Means for associating the certificate valid for the predetermined period, means for determining the certificate associated with the specified period by using the associating means, and stored corresponding to the determined certificate Means for outputting a secret key. 5. The secret key together with a corresponding certificate
5. The secret key sending device according to claim 1, wherein the secret key sending device constitutes one file. 6. The secret key sending device according to claim 5, wherein the file is stored in a PKCS # 12 format. 7. A secret key sending device for sending a secret key to a host device of a certificate user via a communication network, the secret key pairing with a certificate issued to the certificate user. Storing the key, and is issued to the relying party at predetermined intervals,
A step of holding association information for associating the certificate valid for the predetermined period; a means for identifying the certificate associated with the specified period by using the association information; Sending the private key stored in advance to the host device of the relying party. 8. A private key delivery method for receiving a private key output request from a host device of a relying party via a communication network and outputting a private key, the certificate issued to the relying party. And storing a private key paired with each other, and is issued to the relying party at predetermined intervals,
A step of holding association information for associating a certificate valid for the predetermined period; means for determining a certificate associated with the specified period by using the association information; Outputting a secret key stored as a secret key. 9. A means for storing a private key paired with a certificate issued to a relying party, and issued to the relying party at predetermined time intervals;
Means for associating the certificate valid for the predetermined period, means for determining the certificate associated with the specified period by using the associating means, and stored corresponding to the determined certificate Means for outputting a secret key. 10. A secret key sending device connected to a host device of a certificate user via a communication network, wherein a secret key paired with a certificate issued to the certificate user is stored. Means and is issued to the relying party at predetermined intervals,
Means for associating a secret key corresponding to the certificate valid for the predetermined period, means for determining the secret key associated with the designated period using the associating means, and Means for sending the certificate to the host of the certificate user. 11. A secret key sending device connected to a host device of a certificate subscriber via a communication network,
Means for storing a private key paired with a certificate issued to the relying party, and issued to the relying party at predetermined intervals,
Means for associating a secret key corresponding to a certificate valid during the predetermined period, means for determining the secret key associated with the specified period using the associating means, and outputting the determined secret key And a secret key sending device.