JP2003036023A - Network system and information transmission method using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In transmitting information on a network using a digital signature, a high security level is realized while reducing the number of keys to be managed, and fraudulent acts such as spoofing and tampering are effectively prevented. Provide technology to do. A service application device 1 uses a network system in which a plurality of information processing devices are arranged in a tree shape.
01 to the service providing server 1 via the registration server 102
04 to send a message. The source information processing device transmits a message between the information processing devices constituting the network with an electronic signature created by using a secret key unique to the source information processing device, and the destination information processing device transmits the message. The message is verified by decrypting the electronic signature using the public key of the original information processing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission technique using a digital signature.

[0002]

2. Description of the Related Art With the progress of network technology in recent years, various kinds of information communication have come to be performed via a communication network. In this context, infrastructure development for electronically applying for various documents to administrative service organizations is progressing.

Generally, when information is exchanged via a network, it is difficult to confirm the identity of the communication partner, and the transmitted data may be stolen or tampered with. Therefore, countermeasures for it are indispensable. As one of such measures, an electronic authentication method using an electronic signature is widely used. In this electronic authentication method, the sender adds a digital signature encrypted with a private key to a message and sends the message, and the receiver decrypts the digital signature using the sender's public key, and the digest value of the message is sent. To match.
According to this method, it is possible to confirm the sender and securely check the presence or absence of tampering.

When applying such a system to an electronic document application in an administrative service organization, for example, it is an important technical problem to smoothly perform electronic authentication between the administrative organizations. This point will be described below.

[0005] Since the authority for issuing documents to be applied by the users of the administrative agencies covers a plurality of institutions, it is necessary for the users to apply to various administrative institutions according to the types of documents. Therefore, if the user attempts to send the application with his / her electronic signature to the authority that has the authority to issue documents, it is necessary to register his / her public key in each of the organizations to which the application is applied. However, the labor of the registration procedure becomes great. In particular, if each government agency uses a different certificate authority and does not have a certificate of a certificate authority used by another government agency, the user must use several types of private key, public key and digital certificate. It is necessary to apply for and obtain the combination of
The application for keys and certificates requires strict identification and examination, so the effort for this is extremely large. Also, the management of the acquired keys and the like becomes complicated. For government agencies,
Since it becomes necessary to possess a large amount of public keys and certificates, and it is necessary to manage the expiration date of the certificates, etc., the burden is large.

Since many documents provided by the administrative body contain personal information, a particularly high level of security is required to prevent spoofing and falsification. Under these circumstances, there is a strong demand for a technology that facilitates electronic authentication between administrative agencies while maintaining a high level of security.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and realizes a high security level while reducing the number of keys to be managed in information transmission on a network using a digital signature. However, it is an object of the present invention to provide technology for effectively preventing fraudulent acts such as spoofing and falsification.

[0008]

According to the present invention, a plurality of information processing devices have a hierarchical structure arranged in a tree structure,
A second message in the hierarchical structure that responds to the message by passing a message received by the first information processing device in the hierarchical structure from the user through one or more paths between interconnected information processing devices. Of the information processing device, each information processing device has a secret key unique to the device, and another information processing device directly connected to the device is a public key corresponding to the secret key. Have
When a message is sent on a path between interconnected information processing devices, the sender information processing device sends the message with an electronic signature created using a private key unique to the sender information processing device, and then sends the message. The destination information processing device is
There is provided a network system characterized by verifying a message by decrypting the electronic signature using a public key of a sender information processing device.

In this network system, the message is transmitted from the first information processing device to the second information processing device via a path between the mutually connected information processing devices. For each path, the private key unique to that path −
A message is sent while electronically authenticating with a public key pair. Therefore, in the process of transmitting a message from the first information processing device to the second information processing device,
Electronic authentication will be performed one by one between the information processing devices. As a result, the message is surely verified, and spoofing and tampering with the message can be effectively prevented.

Further, since the information processing devices are arranged in a tree form, each information processing device has its own secret key,
Only the public keys of the upper and lower information processing devices that are directly connected need to be held, and the number of keys held in the entire system can be significantly reduced.

In this network system, each information processing device except the information processing device located at the top of the tree structure may have a single parent device. In this case, the number of keys held in the entire system can be reduced significantly.

In the above network system, the plurality of information processing devices include storage means for storing a secret key unique to the information processing device and a public key of a connection destination device interconnected with the information processing device, and a connection destination. Receiving means for receiving a message with an electronic signature of the connection destination device from the device, and electronic signature decoding for decrypting the electronic signature using the public key of the connection destination device when the message is received Means for verifying whether the message is authentic by comparing the data value obtained by decoding with the received message or its digest value; and the message is authentic. When it is determined that the message or its digest value is encrypted with the secret key, an electronic signature creating means for creating an electronic signature The additional message of the electronic signature, and transmitting means for transmitting to one device selected from the connection destination device can be configured to include a. By adopting such a configuration, it is possible to more reliably perform electronic authentication in the process of transmitting a message, and it is possible to surely reduce the number of held keys.

In the above network system,
Further comprising a message sender terminal connected to the first information processing device, wherein at least one of the plurality of information processing devices is a message sender registration device having a public key of the message sender, and the message the sender terminal includes a digital signature creation section that creates a digital signature S _U encrypts the message sender specific secret key messages or the digest value received from the message sender, an electronic signature to the first information processing apparatus Sending means for sending the message with S _U , wherein the message sender registration device is interconnected with the message sender registration device private key, the message sender public key and the message sender registration device. Storage unit that stores the public key of the connection destination device A receiving means for receiving additional messages of the electronic signature S _U via the processing device, and the electronic signature decoding means for decoding the digital signature S _U using the public key of the sender of the message, obtained by the decoding Verification means for verifying whether the message is authentic by comparing the data value with the received message or its digest value; and the message or its digest if it is determined that the message is authentic. The value is encrypted with a secret key unique to the message sender registration device to obtain a digital signature S unique to the message sender registration device.
An electronic signature creation unit configured to create _R, and transmitting means for transmitting the added the message of the digital signature S _R to another information processing apparatus can also be configured to include a.

According to this network system, a message sender can easily send a message from his own terminal to the network while maintaining security. Then, if any one of the information processing devices constituting the network system possesses the public key of the message sender, the message can be made to reach the intended place. Therefore, the message sender can register the public key and the like only once, and thereafter can send the message while maintaining security, which is an advantage that labor is reduced. On the other hand, for the network system, the public key of the message sender needs to be owned by only one information processing device, which has an advantage that the number of keys to be managed can be reduced. Particularly in a network system having many message senders as users, the effect of reducing the number of keys to be managed is great.

Further, in the network system, when the message is received, the second information processing apparatus is designated by the user through one or more paths between mutually connected information processing apparatuses. A network system that sends response contents to the message to an information processing device, wherein when the response contents are transmitted in a path between interconnected information processing devices, the transmission source information processing device The response content is transmitted with the electronic signature created by the device-specific secret key added, and the destination information processing device decrypts the electronic signature by using the public key of the source information processing device. A configuration for verifying the response content can also be adopted.

When such a configuration is adopted, the message sender can obtain the response content of the message sent via the network through the network, so that the message sender is kept highly secure. The advantage is that the response contents of the message can be quickly obtained in the state, while for the network system, the response contents can be sent quickly and
In some cases, the cost reduction effect can be obtained as compared with the case of sending it in the form of printed matter.

Further, according to the invention, there is provided an information transmitting method using a network system having a hierarchical structure in which a plurality of information processing devices are arranged in a tree shape, wherein the first information processing device in the hierarchical structure is from a user. And executing the step of transmitting the received message to a second information processing device in a hierarchical structure that responds to the message via one or more paths between interconnected information processing devices. At this time, the transmission source information processing apparatus transmits the message with the electronic signature created by the private key unique to the transmission source information processing apparatus added, and the transmission destination information processing apparatus uses the public key of the transmission source information processing apparatus. An information transmitting method is provided, characterized in that a message is verified by decrypting a digital signature by using the method.

Further, according to the invention, a plurality of information processing devices have a hierarchical structure arranged in a tree shape, and a message sender terminal connected to at least one information processing device in the hierarchical structure is provided. A method for transmitting information using a network system including a message sender registration device having a message sender's public key in a hierarchical structure, wherein a message sender terminal sends a request received from a service recipient or its digest value. encrypts to create the digital signature S _U by the message sender specific secret key, then the first information processing apparatus to be connected to the message sender terminal transmits a message marked with electronic signature S _U created If the first information processing device and the message sender registration device are different from the first step, the first information processing device To followers registration device, a second step of transferring the message marked with the electronic signature S _U, from the message sender registration device, by way of the path between interconnected information processing apparatus one or more, the message And a third step of transmitting to the second information processing device in the hierarchical structure that responds, and when performing the third step, the transmission source information processing device uses the secret key unique to the transmission source information processing device. Information characterized by transmitting a message with the created digital signature added, and the destination information processing device verifies the message by decrypting the digital signature using the public key of the transmission source information processing device. A transmission method is provided.

According to the above information transmitting method, the message passes through the path between the mutually connected information processing devices,
It is transmitted from the first information processing device to the second information processing device. In each path, a message is transmitted while performing electronic authentication using a private key-public key pair unique to the path. Therefore, in the process of transmitting a message from the first information processing device to the second information processing device, electronic authentication is performed for each information processing device. As a result, the message is surely verified, and spoofing and tampering with the message can be effectively prevented.

Further, since the information processing devices are arranged in a tree shape, each information processing device has its own secret key,
Only the public keys of the upper and lower information processing devices that are directly connected need to be held, and the number of keys held in the entire system can be significantly reduced.

In the above information transmission method, when the message is received, the second information processing apparatus makes the information processing apparatus designated by the user pass through one or more paths between the mutually connected information processing apparatuses. The method further includes the step of sending the response content to the message, and when executing the step, the transmission source information processing apparatus adds the response content with the electronic signature created by the private key unique to the transmission source information processing apparatus added. The transmission destination information processing apparatus may be configured to verify the response content by decrypting the electronic signature using the public key of the transmission source information processing apparatus.

When such a configuration is adopted, the message sender can obtain the response content of the message sent via the network through the network, so that the message sender maintains high security. In the state, there is an advantage that the response contents of the message can be promptly obtained. On the other hand, for the network system, the response contents can be promptly delivered, and the cost reduction effect can be obtained as compared with the case where it is delivered in the form of a printed matter or the like. In some cases.

In the present invention, if transmission / reception of information between each information processing apparatus and the nearest connection destination apparatus is ensured, information can be transmitted between arbitrary apparatuses in the network system. Therefore, various communication methods may be mixed in the network system.

The message sender terminal according to the present invention is
It is also possible to adopt a system in which a medium reading means for reading information stored in a storage medium such as an IC card is provided and the secret key of the message sender is read from this storage medium.

It is to be noted that any combination of the above-mentioned constituent elements, or the expression of the present invention converted between a method, an apparatus, a system, a recording medium, a computer program, etc. is also effective as an aspect of the present invention.

[0026]

1 is a diagram showing an example of a preferred embodiment of the present invention. The service application device 101 is a device for transmitting a service application form of the service beneficiary 130. The service application apparatus 101 calculates the message digest value of the service application using the one-way function, and the I connected to the service application apparatus 101.
The private key is read from the C card 110, the message digest value is encrypted by using the private key, and the electronic signature S _U
To create. Specifically, for example, a hash function operation is performed on the service application form to obtain a hash value, and this is encrypted with a secret key to create the electronic signature S _U.

FIG. 7 shows the internal structure of the service application apparatus 101.
Shown in. The main body unit 40 of the service application apparatus 101 connects to the network 41 via the interface 45b to exchange data. Also, the interface 45
It is connected to the reader / writer 42 and the external storage device 43 via a to exchange data. The reader / writer 42 is an IC
It plays the role of obtaining information such as a private key from the card. A CPU 46 that controls the entire movement of the main body 40 and a memory 48 that stores various programs and data are connected to the inside of the main body 40 via a bus. The memory has a part having the following functions. (A) A storage unit that stores the private key unique to the main body unit 40 and the public key of the connected destination device (b) The message or its digest value is encrypted with the private key to create an electronic signature S _U When the electronic signature creation unit (c) receives a message with an electronic signature, the electronic signature decryption unit (d) that decrypts the electronic signature and the data value obtained by the decryption, and the received message or its digest value A verifier that verifies whether the message is authentic by comparing.

The interface 45, from the connected device, with accepts input message from the user, serves to transmit to the target device bear the digital signature S _U of the service application unit 101.

[0029] Returning to FIG. 1, it transmits a service application marked with the electronic signature _{S U} to the registration server 102. The registration server 102 includes a database (not shown) in which the public key of the service beneficiary 130 and its electronic certificate are registered in advance. In the registration server 102, the electronic signature S _U received from the service application apparatus 101 is decrypted using the public key of the service beneficiary 130, and by comparing this with the message digest value of the service application, the message sender Confirmation and message tampering check are performed. After that, registration server 1
The service application form with the electronic signature S _R created in 02 is transmitted from the registration server 102 to the service providing server 104 via the network 120 including a plurality of contact servers.

The service providing server 104 receives the service application form of the service beneficiary 130 and provides the service to the service beneficiary 130 in response thereto. Various forms can be adopted for providing the service. For example, a network may be used, and the object of the service may be electronically transmitted by following the above flow in reverse.
A method in which a person who receives the service application form from the service providing server 104 directly sends the object of the service to the service beneficiary 130 or dispatches the service provider may be adopted. In addition, when transmitting the object of the service using the network, it is desirable to perform the authentication with the electronic signature between the servers one by one as in the case of the service application form. Alternatively, the target object itself may be encrypted and transmitted.

In the above embodiment, the service application device 10
1 adopts a method of reading the private key from the IC card 110 connected to the service application apparatus 101. Therefore, the service beneficiary 130 needs to create an IC card in which a secret key or the like is stored in advance. here,
The procedure for making an IC card is shown in FIG. First, an application for an IC card is made from the service beneficiary 130 to the certification body 140 (S51). Upon receiving this application, the certification body 140
Confirms that the applicant is the service beneficiary person 130 by some method, after examination, issues an IC card and sends it to the service beneficiary person 130 (S52). This IC
The card stores an electronic certificate with the public key of the service beneficiary 130. The service beneficiary 130
After receiving the C card, a secret key is created and stored in the IC card (S53). Next, the service beneficiary 130 applies to the service application apparatus 101 for registration of the public key and electronic certificate (S54). In response to this, the service application apparatus 101 registers the public key and the electronic certificate of the service beneficiary 130 in a database (not shown) connected to the IC card 110 (S55), and then the service beneficiary 13
A completion notice is sent to 0 (S56). By the above, the registration work of the information of the service beneficiary 130 with respect to the service application apparatus 101 is completed. In addition, here, the service beneficiary 130 himself creates the private key.
40 or an alternative organization creates a private key and
A method of storing in the card 110 can also be adopted.

The steps S51 and S52 in FIG. 2 will be described in more detail with reference to FIG. In the figure, the dotted line indicates offline and the solid line indicates online. Regarding the relationship between the certification body 140 and the IC card 110, for example, the IC card 110 is connected to the personal computer terminal of the certification body 140, and the IC card 110 is operated by this personal computer terminal.

In FIG. 3, first, the service beneficiary 13
0 requests the certification body 140 to issue an IC card (S
61 (corresponding to S51 in FIG. 2)). Next certification body 140
Examines for card issuance (S62). At this time, the personal information for confirming the identity and creating the electronic certificate or the like is provided to the certification body 140. It is preferable that the personal identification is a face-to-face examination or a strict confirmation method as an alternative thereto.

If the certification is passed, the certification body 140
A key creation command is sent to the C card 110 (S63). In response to this, the program contained in the IC card 110 is activated and a public key is created (S64). This public key is IC
The public key is stored in the card 110 and is transmitted to the certification authority 140 (S65). The certification authority 140 creates a certificate of this public key (S66), and then transmits it to the IC card 110 (S67). The certificate is stored in the IC card 110 (S68), and the completion notice is sent to the certification body 14
0 (S69). The IC card 110 is created as described above. The internal structure of this IC card 110 is shown in FIG. The CPU 11 controls the functions of the entire card, and the CPU 11 is connected to the interface unit 12, the key generation unit 13, the electronic signature generation unit 14 and the memory 15 via the bus. The interface unit 12 is I
This is a part for exchanging data with a device in which the C card 110 is incorporated. The key creation unit 13 is a part that creates a public key. The electronic signature creating unit 14 is a unit that creates an electronic signature using a public key. The memory 15 is a part for storing personal information of the card holder, other data, and various programs. Returning to FIG. 3, the IC card having such a structure is sent from the certification authority 140 to the service beneficiary 130 (S70).

Next, another example of the present invention will be described.
FIG. 10 is a diagram showing a schematic structure of the network system according to the present embodiment. This network system has a hierarchical structure in which a plurality of servers and devices interconnected by bidirectional links are arranged in a tree. Each information processing device except the information processing device located at the top of the tree structure has a single parent device.

Service application device 101, registration server 10
2 and relay server 103 both have an internal structure as shown in FIG. That is, the server body 70
Connects to the network 71 via the interface 75 and exchanges data. A CPU 76 that controls the entire movement of the main body 70 and a memory 78 that stores various programs and data are connected to the inside of the main body 70 via a bus.

The memory 78 has a portion having the following functions. (A) A storage unit that stores the private key unique to the information processing apparatus and the public key of the connected destination apparatus (b) Decrypt the electronic signature using the public key of the apparatus that is the data transmission source (C) Verification for verifying whether or not the received information is authentic by comparing the data value obtained by the electronic signature decoding with the received information or its digest value. Part (d) An electronic signature creation unit that creates an electronic signature by encrypting the above information or its digest value with a secret key when it is determined that the above information is authentic.

The interface 75 plays a role of receiving information to which the electronic signature of the connection destination device is added from the connection destination device, and transmitting the information to the connection destination device with the electronic signature of the main body section 70. .

Next, the method according to the present invention will be described using a network system having the structure shown in FIGS. 5 and 8, the service application form of the service beneficiary 130 received by the IC card 110 is transmitted to the service providing server 104 via the registration server 102 and the relay servers 103a to 103e (FIG. 5, S12a).
~ S12f), the service providing server 1 that has received this application
04 is the registration server 102 and the relay server 103a-
The flow up to electronically sending a service object to the service application apparatus 101 via e (FIG. 8, S13a to S13f) is shown. In this embodiment, service application and service enjoyment are performed by the same service application apparatus 101.

In FIG. 5, first, the service application device 1
A service application form is transmitted from 01 to the registration server 102 (S11). At this time, the private key possessed by the service beneficiary 130 is read out from the IC card 110, and the electronic signature is given to the service application form using this. Based on this electronic signature, the service application device 101 and the registration server 1
Authentication between 02 is performed. The registration key of the service beneficiary 130 and its electronic certificate are registered in advance in the registration server 102. The registration server 102 confirms whether the message received from the service application apparatus 101 is authentic and confirms the electronic certificate to determine whether the registration key (public key) of the service beneficiary 130 is valid. To do.

Here, the authentication method based on the electronic signature will be described with reference to FIG. 6 by taking the confirmation procedure of the above message as an example. In the device A that is the transmission source, a hash value 32a is created from the plaintext 31 of the message, and this is encrypted with the secret key unique to the device A. As a result, the electronic signature 33 is created. The electronic signature 33 is transmitted from the devices A to B together with the plain text 31. Device B that received this
Decrypts the electronic signature 33 using the public key distributed in advance from the device A to obtain the hash value 32b. This is collated with the hash value 32c created based on the plaintext 31. If the two match, it can be confirmed that the sender is A, and that the sent plaintext 31 is a genuine document without falsification. When confirming the validity of the public key of the service beneficiary 130, the same method as above is adopted. That is, the reliability of the digital certificate is confirmed by comparing the digest of the encrypted digital certificate with the digest of the digital certificate created by the registration server 102 based on the plaintext of the digital certificate. The validity of the public key can be confirmed. Electronic authentication between the service application apparatus 101 and the registration server 102 in FIG. 5 is performed by the method described above.

Subsequently, the service application form is transmitted from the registration server 102 to the service providing server 104 via the relay server 103. In the process of transmission, an electronic signature created by a unique asymmetric key is added to the service application form between the servers, and electronic authentication is performed step by step according to the method described in FIG. In this way, the service providing server 104 receives the service application form.

Upon receiving the service application form, the service providing server 104 transmits the response content to the service application to the service beneficiary 130. At this time, the response content is
It is transmitted to the service application apparatus 101 by tracing the route of FIG. 5 in reverse (FIG. 8). In the process of transmission, an electronic signature created by a unique asymmetric key is added to the service application form between the servers, and electronic authentication is performed step by step according to the method described in FIG.

Next, another example of the present invention will be described with reference to FIG. In this example, the service application form is transmitted by a method similar to that of FIG. 5, but the server that accepts the service application with the electronic signature from the service application apparatus 201, which is the user terminal, and the user's public key and electronic certificate are registered. 5 is different from the case of FIG. 5 in that the server is different. Service reception server 202 and relay server 203
Cannot decrypt the user's digital signature because the user does not own the user's public key or digital certificate, and can confirm whether the user's public key is valid by checking the digital certificate. Can not. Therefore, in this example, the service application form with the electronic signature of the user is temporarily transferred to the registration server 205 (S22a to f). In the transfer process from the service reception server 202 to the registration server 205, it is desirable to perform electronic authentication one by one using a signature with an asymmetric key unique to the path when passing through the path between the information processing apparatuses.

When the service application form is transferred to the registration server 205, the electronic signature of the user is decrypted and authentication is performed here. After that, transmission is sequentially performed on the path between the relay servers 203 by the same procedure as in FIG. 5, and the service application form arrives at the service providing server 206 (S22).
g-1).

Although the embodiments of the present invention have been described above, more specific application examples will be described below.

(Application Example 1)

In this application example, a network system having the same structure as in FIGS. 5 and 8 is used. Ranks 1, 2, 3, and 4 in FIG. 5 and FIG. 8 are made to correspond to the levels of country, prefecture, city, and town, respectively.

An example will be described below in which an individual A who has a domicile in Chuo-ku, Sapporo-shi, Hokkaido requests an issuance of a family register abstract in Wakaba-ku, Chiba-shi, Chiba prefecture, which has registered an electronic signature. Prior to applying for the service, A is to create a private key and public key for digital signature, register the created public key in a registration server, and create an electronic certificate of the public key created by myself (with the public key of the certificate authority). An application for issuance is made, and the created private key and issued electronic certificate are stored in a storage medium such as an IC card, and the electronic certificate is registered in a registration server.

At the stage where the above preparations have been completed, A is shown in FIG.
Registration server 1 through service application device 101 in
A request for issuing a computerized family register abstract is sent to 02. The confirmation of the electronic certificate accompanying the request form (confirmation of the applicant's public key) can be confirmed in the registration server 102.

In this example, the authority to issue a family register abstract is on the server in Chuo-ku, Sapporo city. Therefore, the application form needs to be finally sent to the server in Chuo Ward. However, when the server in Wakaba Ward sends the Wakaba Ward signed application directly to the server in Chuo Ward, Sapporo, the server in Chuo Ward does not have the public key or digital certificate of the server in Wakaba Ward. Therefore, the authenticity of the application form and public key cannot be verified. Therefore, in this example, the request form is transmitted by the following procedure. First, the server in Wakaba Ward sends a request form with an electronic signature,
It sends it to a higher-ranking server in Chiba City, and after checking the electronic signature of Wakaba Ward, the server in Chiba City attaches its own electronic signature and transfers it to the server in Chiba Prefecture. By the same procedure, the application form is transferred from Chiba Prefecture to Japan, Japan to Hokkaido, Hokkaido to Sapporo City, and Sapporo City to Chuo Ward while confirming the authenticity of the request form. Then, after the server in Chuo-ku, Sapporo receives the request form, the family register abstract is issued. This family register extract is transmitted while proceeding in the opposite direction along the route from which the application form was transmitted. Finally, a family register abstract will be issued with the electronic signature of Wakaba Ward, the place of application.

(Application example 2)

In this application example, a network system having the same structure as in FIG. 9 is used. Ranks 1, 2 in FIG.
Make 3 and 4 correspond to the levels of country, prefecture, city and town, respectively.

An example will be described below in which an individual A who has a permanent residence in Chuo-ku, Sapporo-shi, Hokkaido requests a family register abstract in Takaishi-shi, Osaka, which is a business trip destination. The service reception server 202 in FIG. 9 is a server in Takaishi City, Osaka Prefecture, and a registration server 205.
Corresponds to the server in Wakaba Ward, Chiba City, and the service providing server 206 corresponds to the server in Chuo Ward, Sapporo City.

A has registered her own public key and electronic certificate in Wakaba Ward, Chiba City, Chiba Prefecture. In this example, a server in Takaishi city that does not have A's public key or electronic certificate will accept the request form with an electronic signature of A, but the server in Takaishi cannot decrypt the signature of A, Nor can the validity of the public key be verified. Therefore, this request form is transferred from Takaishi City to the server in Wakaba Ward via Osaka Prefecture, Japan, Chiba Prefecture, and Chiba City. The server in Wakaba Ward uses the public key of A registered in advance in this server to decrypt the signature of A and perform authentication. Also, the validity of the public key is determined by checking the electronic certificate. After that, the request form is transmitted to the server in Chuo-ku, Sapporo City, which has the authority to issue family register abstracts, by the same procedure as in Application Example 1. After the server in Chuo-ku, Sapporo receives the request form, a family register abstract is issued. This family register extract is transmitted while proceeding in the opposite direction along the route from which the application form was transmitted. Finally, a family register abstract will be issued with the electronic signature of Wakaba Ward, the place of application.

In addition to the above-mentioned application examples, the following application examples are applicable as the application of the present invention.

(Application Example 1)

An individual B living in Wakaba Ward, Chiba City, uses his or her personal computer to make an electronic vote for an election. When you log in to the site of the Election Management Center, you can check whether you are the voter by using the storage medium in which you registered your electronic signature, and then add your electronic signature to vote.

(Application example 2)

An individual C who lived in Wakaba Ward, Chiba City, changes his address in Niihama City, Tokushima Prefecture, where he is transferred to. C has registered its own public key, electronic certificate, etc. in Wakaba Ward, Chiba City, Chiba Prefecture. In order to exercise civil rights in the future such as elections, it is necessary to change the registration destination of the electronic signature.

In addition, the present invention can be used to browse a real estate registry,
It can be applied to company registration, viewing registration information, etc.

The present invention has been described above based on the embodiments. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications can be made to the combinations of their respective constituent elements and processing processes, and that such modifications are also within the scope of the present invention. is there.

[0063]

As described above, according to the present invention, in transmitting information on a network using a digital signature, a high security level is realized while reducing the number of keys to be managed, and fraud such as spoofing or falsification is achieved. The action is effectively prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a network system according to the present invention.

FIG. 2 is a diagram for explaining a procedure for registering an electronic key and an electronic certificate in a registration server.

FIG. 3 is a diagram for explaining a procedure for issuing an IC card.

FIG. 4 is a diagram showing an internal structure of an IC card.

FIG. 5 is a diagram for explaining information transmission according to the present invention.

FIG. 6 is a diagram for explaining an authentication method using a digital signature.

FIG. 7 is a diagram showing an internal structure of a message sender terminal.

FIG. 8 is a diagram for explaining an information transmission method according to the present invention.

FIG. 9 is a diagram for explaining an information transmission method according to the present invention.

FIG. 10 is a diagram showing an outline of a network system according to the present invention.

FIG. 11 is a diagram showing an outline of a network system according to the present invention.

[Explanation of symbols]

11 CPU 12 Interface part 13 Key creation section 14 Digital Signature Creation Department 15 memory 31 plaintext 32a-c hash value 33 Electronic signature 40 body 41 network 42 Reader / Writer 43 external storage device 45a-b interface 46 CPU 48 memory 70 Main body 71 network 75 Interface 76 CPU 78 memory 101 Service application device 102 registration server 103a-e relay server 104 service providing server 110 IC card 120 networks 130 Service beneficiaries 140 Certification Body 201 Service application device 202 Service reception server 203a-j relay server 205 registration server 206 Service providing server

Claims (7)

[Claims] 1. A plurality of information processing devices have a hierarchical structure in which they are arranged in a tree structure, and a message received by a first information processing device in the hierarchical structure from a user is transmitted between mutually connected information processing devices. Via one or more paths of
A network system for transmitting to the second information processing device in the hierarchical structure, which responds to the message, wherein each information processing device has a secret key unique to the device and other information directly connected to the device. The processing device has a public key corresponding to the secret key, and when the message is transmitted on the path between the mutually connected information processing devices, the transmission source information processing device determines the secret key unique to the transmission source information processing device. The message is transmitted in a state where the electronic signature created by the above is added, and the destination information processing device verifies the message by decrypting the electronic signature using the public key of the transmission source information processing device. Network system. 2. The plurality of information processing devices include a storage unit for storing a private key unique to the information processing device and a public key of a connection destination device interconnected with the information processing device, and a connection destination device, Receiving means for receiving the message to which the electronic signature of the connection destination device is added, and electronic signature decoding means for decrypting the electronic signature using the public key of the connection destination device when the message is received, By comparing the data value obtained by decryption with the received message or its digest value, verification means for verifying whether the message is authentic, and determining that the message is authentic At this time, an electronic signature creating means for creating an electronic signature by encrypting the message or its digest value with the private key, and a message to which the electronic signature is added. 2. The network system according to claim 1, further comprising: a transmitting unit that transmits the message to a device selected from the connection destination device. 3. A message sender registration device further comprising a message sender terminal connected to the first information processing device, wherein at least one of the plurality of information processing devices has a public key of the message sender. The message sender terminal includes a digital signature creating unit that creates a digital signature S _U by encrypting a message received from the message sender or a digest value thereof with a secret key unique to the message sender, and first information. Transmitting means for transmitting the message with the electronic signature S _U to the processing device;
The message sender registration device stores a secret key unique to the message sender registration device, a public key of the message sender, and a public key of a connection destination device interconnected with the message sender registration device. Section, a receiving unit that receives a message to which a digital signature _SU is added from a message sender terminal directly or via another information processing device, and a digital signature S using a public key of the message sender.
Electronic signature decryption means for decrypting _U , and verification means for verifying whether the message is authentic by comparing the data value obtained by the decryption with the received message or its digest value , If the message is determined to be authentic, the message or its digest value is encrypted with a secret key unique to the message sender registration device to create an electronic signature S _R unique to the message sender registration device. Means and
3. The network system according to claim 1, further comprising: a transmitting unit that transmits the message to which the electronic signature S _R is added to another information processing device. 4. When the message is received, the second information processing apparatus causes the information processing apparatus designated by the user to pass through one or more paths between mutually connected information processing apparatuses. A network system for sending the response content to a message, wherein when the response content is transmitted in a path between interconnected information processing apparatuses, the transmission source information processing apparatus uses a private key unique to the transmission source information processing apparatus. The response content is transmitted in a state where the electronic signature created by the above is added, and the destination information processing apparatus verifies the response content by decrypting the electronic signature using the public key of the transmission source information processing apparatus. The network system according to any one of claims 1 to 3, wherein: 5. A message transmission method using a network system having a hierarchical structure in which a plurality of information processing devices are arranged in a tree structure, wherein a message received from a user by a first information processing device in the hierarchical structure. Is transmitted to one or two or more paths between interconnected information processing devices to a second information processing device in the hierarchical structure that responds to the message. , The transmission source information processing apparatus transmits the message with the digital signature created by the private key unique to the transmission source information processing apparatus added, and the transmission destination information processing apparatus uses the public key of the transmission source information processing apparatus. An information transmitting method characterized by verifying a message by decrypting the electronic signature. 6. A hierarchical structure in which a plurality of information processing devices are arranged in a tree structure, a message sender terminal connected to a first information processing device in the hierarchical structure, and the hierarchical structure in the hierarchical structure. A method for transmitting information using a network system including a message sender registration device having a public key of the message sender, wherein the message sender terminal sends a message received from a service beneficiary or a digest value thereof. 's specific encrypted by a secret key to create a digital signature S _U, then the first step of transmitting the message attached with the electronic signature S _U to the first information processing apparatus, the first information processing apparatus And the message sender registration device is different, the first information processing device
To the message sender registration device, a second step of forwarding the message marked with the electronic signature S _U, from the message sender registration device, by way of the path between interconnected information processing apparatus one or more And a third step of transmitting to the second information processing device in the hierarchical structure that responds to the message, when performing the third step, the transmission source information processing device The message is sent with the electronic signature created using the device-specific secret key, and the destination information processing device verifies the message by decrypting the electronic signature using the public key of the source information processing device. An information transmission method characterized by: 7. When the second information processing device receives the message, the second information processing device sends the information processing device specified by the user to one or more paths between interconnected information processing devices. The method further includes the step of sending the response content to the message, and when executing the step, the transmission source information processing apparatus adds the electronic signature created by the secret key unique to the transmission source information processing apparatus to the response content. 7. The transmission destination information processing device verifies the response content by decrypting the electronic signature using the public key of the transmission source information processing device. Information transmission method.