WO2008041419A1

WO2008041419A1 - Communication system, intervening terminal and intervening program

Info

Publication number: WO2008041419A1
Application number: PCT/JP2007/065691
Authority: WO
Inventors: Shoji Onoto; Hiroaki Matsuba; Makoto Tanaka; Junko Hirano; Akiko Yamato; Yoshiaki Komatsu; Yoshibumi Kato
Original assignee: Brother Kogyo Kabushiki Kaisha
Priority date: 2006-09-29
Filing date: 2007-08-10
Publication date: 2008-04-10
Also published as: JP2008090392A

Abstract

A communication system (1) comprises a database apparatus (2), a client terminal (3), and an intervening terminal (4) that intervenes in communication between the database apparatus (2) and the client terminal (3). These apparatuses (2-4) incorporate agents. When the client terminal (3) wants to acquire some information from the database apparatus (2), it issues an information request to the intervening terminal (4). The intervening terminal (4) then asks the client terminal (3) to provide client information suitable for the contents of the requested information. If the intervening terminal (4) successfully obtains appropriate information from the client terminal (3), then it transfers the request to the database apparatus (2) to obtain the information, which is then transmitted to the client terminal (3) from the intervening terminal (4).

Description

Specification

Communication system, mediation terminal, and mediation program

Technical field

The present disclosure relates to a communication system that performs communication between agents, a mediation terminal that mediates between a database device and a client terminal, and a mediation program that causes a computer to function as the mediation terminal. Background art

[0002] Conventionally, agent technology has been used to execute requests for information retrieval / collection, etc. to computers placed on a network. An agent is autonomous software that consists of a program that runs in one of the devices and executes a predetermined process and related data. Among agents, what is called a mobile agent can move between devices connected to each other, and performs a predetermined operation at the destination. When collecting information using such an agent, it is necessary to authenticate that the communication by the agent is valid. As such an authentication means, a method of registering an ID and a password in advance is widely used. In addition, an authentication method using a public key method has been proposed to cope with password theft and leakage (for example, Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2003-173324

Disclosure of the invention

[0003] However, in the authentication using an ID and password as in the conventional method, the communication policy for determining what level of information is provided at the time of registration is uniformly determined for each user, and then flexibly changed. There is nothing. With such a method, even for the same user, a request to dynamically set the security level according to the information to be collected is obtained, and information is obtained safely without complicated registration procedures! ! /, Responding to requests! /, Na! /, And! /, There are problems.

[0004] The present disclosure provides a communication system, an intermediary terminal, and an intermediary program capable of dynamically changing a communication policy for communication between agents (hereinafter referred to as "agent communication"! /). We will make it available. [0005] The communication system of the present disclosure includes a database device, a client terminal, and an intermediary terminal that mediates communication between the database device and the client terminal, and includes the database device and the client terminal. And an agent provided in each of the broker terminals communicates. The client terminal transmits an information request for requesting the database device to provide predetermined information to the mediation terminal, and transmits client information in response to a request from the mediation terminal. Client information transmission means, and formatting request transmission means for transmitting to the mediation terminal a formatting request in which the information request is adapted to the format transmitted from the mediation terminal. The intermediary terminal analyzes the information request received by the information request receiving means for receiving the information request for the client terminal power and the information request received by the information request receiving means, and the client terminal Client information determining means for determining client information that is information to be provided; client information requesting means for requesting the client terminal to provide client information determined by the client information determining means; and the client terminal. A connection permission judging means for judging whether or not to permit the connection based on the information, and a format for determining an information request format corresponding to the client information based on the client information received from the client terminal. And a format transmission means for transmitting the format determined by the format determination means to the client terminal when the connection is permitted by the connection permission determination means, and the formatting request from the client terminal. When the formatting request received by the formatting request receiving means and the formatting request received by the formatting request receiving means conform to the format, the database device is notified of the information request from the client terminal. Notification means, and provision information transmission means for returning the provision information provided by the database device in response to the information request by the notification means to the client terminal.

[0006] Further, the mediation terminal of the present disclosure mediates communication between agents performed by the database device and the client terminal, and includes an information request receiving unit that receives an information request from the client terminal; The information request received by the information request receiving means. Analyzing the contents of the list, the client information determining means for determining the client information that is information to be provided by the client terminal for the information request of the contents, and providing the client information determined by the client information determining means Based on the client information requesting means for requesting the client terminal, the connection permission determining means for determining whether or not to permit connection based on the received client terminal power, and the client terminal power based on the received client information. When the connection is permitted by the format determination means for determining the information request format corresponding to the client information and the connection permission determination means, the format determined by the format determination means is sent to the client terminal. And when the formatting request received by the formatting request receiving means conforms to the format, the formatting request receiving means receives the formatting request from the client terminal. Notification means for notifying the database device of an information request from the client terminal, and provided information transmission means for returning the provided information provided to the database device in response to the information request by the notification means to the client terminal .

Brief Description of Drawings

FIG. 1 is a system configuration diagram of a communication system 1.

FIG. 2 is a block diagram showing an electrical configuration of the database device 2.

FIG. 3 is a block diagram showing an electrical configuration of the client terminal 3.

FIG. 4 is a block diagram showing an electrical configuration of the mediation terminal 4.

FIG. 5 is a schematic diagram showing the configuration of the agent 10.

FIG. 6 is a flowchart showing the flow of main processing (client terminal processing) of the client terminal 3.

FIG. 7 is a flowchart showing a flow of main processing (mediation terminal processing) of the mediation terminal 4.

FIG. 8 is a flowchart showing the flow of main processing (database device processing) of the database device 2.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments for carrying out the present disclosure will be described with reference to the drawings. First, Honkai An overview of a communication system 1 that is an embodiment to which the above description is applied will be described with reference to FIG.

As shown in FIG. 1, the communication system of the present embodiment includes a database device 2 having various databases, a client terminal 3 that tries to obtain information from the database device 2, a database device 2, and a client. It consists of an intermediary terminal 4 that mediates communication with terminal 3. The client terminal 3 is connected to a wide area network (WAN) 6 and communicates with the mediation terminal 4 via the WAN 6. The mediation terminal 4 and the database device 2 are connected via a LAN 5. A gateway 7 composed of a router or the like is provided between the WAN 6 and the intermediary terminal 4. There are many client terminals 3, but only one is shown here for convenience of explanation. There may also be a plurality of database devices 2 and intermediary terminals 4.

[0010] The database device 2, the client terminal 3, and the intermediary terminal 4 are each equipped with an agent, and these agents operate autonomously without the need for sequential user input, and cooperate with each other. Achieve the goal. In this embodiment, such communication between agents is handled. Gateway 7 is a dedicated device provided for inter-agent communication. By preparing a device other than the normal communication gateway, the communication path can be divided, and the load on the LAN 5 to which the intermediary terminal 4 and the database device 2 belong can be reduced.

Next, the configuration of the database device 2, the client terminal 3, and the mediation terminal 4 will be described with reference to FIGS. 2 to 4.

[0012] The database device 2 is a so-called personal computer and is a general-purpose device.

As shown in FIG. 2, the database device 2 is provided with a CPU 210 that controls the database device 2. The CPU 210 is connected to a ROM 211 that stores a BIOS and the like, a RAM 212 that temporarily stores various types of data, and an I / O interface 214 that mediates data transfer. A hard disk device 230 is connected to the I / O interface 214, and the hard disk device 230 stores a product information database 231 and an in-company information database 232 as examples of various databases. . In addition, the hard disk device 230 includes an agent program and other various programs. Program storage area 233 that stores the seed control program and other information storage areas 2

[0013] In addition, a mouse 221, a video controller 216 for controlling the display 222, and a key controller 217 for controlling the keyboard 223 are connected to the I / O interface 214, and the display controller 222 is connected to the video controller 216. A keyboard 223 is connected to the key controller 217. Further, a communication device 215 is connected to the I / O interface 214, and communication with the mediation terminal 4 is performed from the communication device 215 via the LAN 5.

[0014] The client terminal 3 is a so-called personal computer, and is a general-purpose device. Figure

As shown in FIG. 3, the client terminal 3 is provided with a CPU 310 that controls the client terminal 3. The CPU 310 is connected to a ROM 311 that stores BIOS and the like, a RAM 312 that temporarily stores various data, and an I / O interface 314 that mediates data transfer. A hard disk device 330 is connected to the I / O interface 314, and at least a program storage area 331 that stores an agent program and other various control programs and another information storage area 332 are provided.

[0015] The I / O interface 314 is connected with a mouse 321, a video controller 316 that controls the display 322, and a key controller 317 that controls the keyboard 323, and the video controller 316 has a display 322. A keyboard 323 is connected to the key controller 317. Further, a communication device 315 is connected to the I / O interface 314, and the communication device 315 communicates with the mediation terminal 4 via the WAN 6.

[0016] The mediation terminal 4 is a so-called personal computer and is a general-purpose device. As shown in FIG. 4, the mediation terminal 4 is provided with a CPU 410 that controls the mediation terminal 4. The CPU 410 is connected to a ROM 411 that stores a BIOS, a RAM 412 that temporarily stores various data, and an I / O interface 414 that mediates data transfer. The hard disk device 430 is connected to the I / O interface 414, and the information requested to the client terminal 3 that has transmitted the information request is stored in the hard disk device 430 in correspondence with the content of the information request. Request information storage area 4 31, a mobile agent that stores in advance a mobile agent that stores a format in accordance with client information obtained from the client terminal 3 and transmits it to the client terminal 3 A memory area 432 is stored. In addition, the hard disk device 430 includes a program storage area 433 that stores an agent program and other various control programs, and a program storage area 433.

[0017] The I / O interface 414 is connected to a mouse 421, a video controller 416 for controlling the display 422, and a key controller 417 for controlling the keyboard 423, and the video controller 416 has a display 422 power. A keyboard 423 is connected to the key controller 417. Further, a communication device 415 is connected to the I / O interface 414, and the communication device 415 communicates with the database device 2 via the LAN 5 from the communication device 415 and the client terminal 3 via the WAN 6 via the gateway 7. Communication is performed.

[0018] Next, with reference to FIG. 5, the configuration of the agent 10 stored in the program storage area 233 of the database device 2, the program storage area 331 of the client terminal 3, and the program storage area 433 of the intermediary terminal 4 will be described. I will explain.

As shown in FIG. 5, the agent 10 manages an agent program main body 11, a communication program 12 for communicating with other agents, and a key for confirming the validity of the caller The key management program 13 is composed of an object area 14 in which objects to be handled by the agent program main body 11 are stored, and a data storage area 15 in which data is stored. In the data storage area 15, the other agent 10 can use the force S.

Note that the agent 10 stored in the database device 2, the client terminal 3, and the intermediary terminal 4 and executing the processing of the present embodiment is configured as described above. Agent 1 that also explained the configuration of the client-side mobile agent and mediation-side mobile agent called by agent 10 of mediation terminal 4.

Same as 0.

Next, regarding the operation of the communication system 1 configured as described above, processing in each of the client terminal 3, the mediation terminal 4, and the database device 2 will be described with reference to FIGS.

First, the processing executed by the agent 10 of the client terminal 3 will be described with reference to FIG. In the client terminal process, the user of client terminal 3 When information is to be obtained from device 2, it is started by specifying the content of the information and instructing agent 10. First, an information request is transmitted to the intermediary terminal 4 (Sl). The information request is a request to receive some information provision from the database device 2 specified by the user of the client terminal 3. For example, download of files from the database device 2 can be assumed, such as product update information owned by the user of the client terminal 3, company information inquiry from the client terminal 3 which is a business partner of the company, etc. . Here, the information that is desired to be provided is the power owned by the database device 2 The client terminal 3 and the database device 2 cannot communicate directly, so the client terminal 3 must be the intermediary terminal 4 Send an information request to.

[0023] As will be described later, the intermediary terminal 4 that has received the information request analyzes the content of the information request and requests the provision of client information suitable for that level. Therefore, it is determined whether or not such a client information request has been received (S5). If no client information request has been received (S5: NO), it waits until it is received. When a client information request is received (S5: YES), it is determined whether or not to respond to this client information request (S10). If it is difficult to satisfy the client information request, the client terminal 3 cannot provide it, it is the type of information, or it does not respond for some reason! / (S10: NO), do nothing. The process is terminated as it is.

When responding (S10: YES), the requested client information is transmitted (S15). Here, as client information, for example, when requesting product update information, when requesting serial number or user ID of the product, appointment with a person in charge within the company, or reservation of a conference room, This corresponds to the company information of the company that has the client terminal 3.

[0025] The intermediary terminal 4 that has received the client information determines whether or not the client information is sufficient to respond to the information request, and notifies whether the client terminal 3 can be connected or not based on the determination result. Next, it is determined whether or not a connection rejection notification is received from the mediation terminal 4 (S20). If the connection is refused (S20: YES), the answer to the requested information request cannot be obtained, so the process is terminated.

[0026] If the connection is not rejected (S20: NO), the agent 10 is received from the intermediary terminal 4 (S25). ). In the following, the agent that moves among the agents 10 of the broker terminal 4 is referred to as “broker side mobile agent”. Next, it is determined whether the received mediation-side mobile agent has been correctly transmitted from the mediation terminal 4 (S30). This validity judgment is performed using an electronic signature by a public key cryptosystem known in the art. That is, since the mediation terminal 4 encrypts and transmits the mediation side mobile agent with the secret key, the client terminal 3 decrypts the received mediation side mobile agent using the public key of the mediation terminal 4, Make sure that it has not been tampered with.

If the intermediary mobile agent is not valid (S30: NO), the connection is stopped (S45) and the process is terminated. If the intermediary mobile agent can be validated (S30: YES), the agent 10 of the client terminal 3 (hereinafter referred to as the agent 10 of the client terminal 3) moves to the data storage area 15 of the intermediary mobile agent. (The client side mobile agent is stored), and the mediation side mobile agent is returned to the mediation terminal 4 (S35).

[0028] The intermediary terminal 4 receives the intermediary mobile agent that stores the client side mobile agent, confirms its validity, notifies the database device 2, receives the requested information, and moves the client side mobile agent. Stores the provided information in the agent and returns it. Therefore, the client side mobile agent in which the provided information is stored is received (S40). As described above, since the obtained information is provided from the database device 2 to the client terminal 3 via the mediation terminal 4, the agent 10 of the client terminal 3 ends the processing.

Next, processing performed by the agent 10 of the mediation terminal 4 will be described with reference to FIG.

When an information request is received from the agent 10 of the client terminal 3, the processing in FIG. 7 is started. Then, the content of the received information request is analyzed, and the client information requested to the client terminal 3 in the case of the content is read from the request information storage area 431 (S105). Analysis of the contents of the information request is performed by preparing a dictionary for analysis and checking whether a predetermined keyword is included in the information request. In the request information storage area 431, client information to be requested is stored in association with the contents of the information request.

[0030] Next, based on the requirements read in S105, information is sent to the client terminal 3. Request (S110). As already mentioned, client terminal 3 sends client information of the requested content (Fig. 6, S20), so satisfying what is requested by such client information power SI 10! / Whether or not is determined (S115).

[0031] If the received client information is not appropriate for the information request (S115:

NO), since the requested information cannot be provided to the client terminal 3, the connection rejection is notified to the client terminal 3 (S120). Then, the intermediary terminal process ends.

[0032] If the received client information is appropriate for the information request (S115: YE S), then, based on the provided client information, an intermediary for receiving the mobile agent from the client terminal 3 The mobile agent storage area 432 is also read from the side mobile agent (S125). The mediation-side mobile agent is prepared in advance according to the type of client information and stored in the mobile agent storage area 432.

[0033] Then, the read-out mediation-side mobile agent is encrypted with the secret key, and then transmitted to the client terminal 3 (S130). As described above, when the client terminal 3 receives the mediation-side mobile agent and confirms its validity, the client-side mobile agent stores its own mobile agent in the data storage area of the mediation-side mobile agent. Then, the intermediary mobile agent is returned (Fig. 6, S35). Therefore, the mediating side mobile agent returned in this way is received (S135).

Subsequently, it is determined whether or not the client-side mobile agent stored in the mediation-side mobile agent is that of the client terminal 3 (validity) (S140). Similar to the mediation-side mobile agent, the client-side mobile agent is encrypted using the private key of the client terminal 3 at the client terminal 3 by the public key cryptosystem. Therefore, in this step, the client-side mobile agent is decrypted with the public key of the client terminal 3 to confirm that it has not been tampered with.

[0035] If the client-side mobile agent is not valid (S140: NO), the client-side mobile agent is discarded (S145), the connection rejection is notified to the client terminal 3 (S150), and the intermediary terminal The process ends.

If the validity of the client-side mobile agent can be confirmed (S 140: YES), then the client-side mobile agent is evacuated (S 155). And data The contents of the information request from the client terminal 3 are notified to the base device 2 (S1 60).

[0037] As will be described later, when the database device 2 receives the notification of the information request from the intermediary terminal 4, the database device 2 determines whether to reply and then searches the database to transmit the requested information. . Therefore, next, it is determined whether or not an answer is received from the database device 2 (S165).

[0038] If there is no response from database device 2 (S165: NO), the information requested by the information request is not provided! /, So save it! /, And discard the client side mobile agent (S 145), the client terminal 3 is notified of connection refusal (S 150), and the mediation terminal processing is terminated.

[0039] When the response is obtained from the database device 2 (S165: YES), the provided information that the database device 2 is also sent to the data storage area 15 of the client-side mobile agent saved in S155 (S 170), and the client side mobile agent is returned to the client terminal 3 (S175). As described above, when appropriate client information is obtained, the information request of the client terminal 3 can be mediated to the database device 2 to provide the information, so the agent 10 of the mediation terminal 4 ends the process.

Next, processing performed by the agent 10 of the database apparatus 2 will be described with reference to FIG. When the information request notification is received from the intermediary terminal 4, the processing of FIG. 8 is started. As described above, when receiving an information request from the client terminal 3, the intermediary terminal 4 requests to provide client information suitable for the content of the information, and when appropriate information is obtained, the client terminal 3 Accepts the mobile agent to bring back the information, and notifies the database device 2 of the information request.

Therefore, the database apparatus 2 that has received the notification determines whether or not to reply to the information request (S205). Appropriate for an information request! /, Whether it is a client terminal 3 has already been judged by the intermediary terminal 4! /, It has been requested! /, Information that cannot be provided! /, Is of a nature, etc. If it is determined that the answer is not made for some reason (S205: NO), the relay terminal 4 is notified of connection refusal (S210), and the database device processing is terminated.

[0042] If it is determined that the information request is answered (S205: YES), the requested information A database having data corresponding to is searched and searched (S215). For example, if specific product information or update information is requested, the product information database 231 is searched. Then, the information obtained as a result of the search is transmitted to the mediation terminal 4 (S220), and the database device process is terminated.

[0043] As described above, in the communication system 1 of the present embodiment, when the mediation terminal 4 receives an information request from the client terminal 3, it provides client information suitable for the content of the requested information. If appropriate information is obtained, the request is mediated by the database device 2 and the information is obtained and transmitted to the client terminal 3. Therefore, since the database device ₂ does not connect directly to the client terminal 3, the data in the database it holds can be kept safe. Further, the client terminal 3 can receive the necessary information each time by providing its own information according to the information desired to be obtained without using a fixed ID or password. In addition, because it is possible to flexibly set whether to connect according to the information provided, the registration process using ID and password can be omitted, and the complexity is reduced compared to uniform registration while maintaining high security. The power to do S. In addition, since a mobile agent is used as an information providing medium, it is possible to store desired information in a data storage area and take it home by taking advantage of its characteristics, and it is easy to prevent troubles associated with information exchange.

[0044] It should be noted that conventional user registration using an ID and a password coexists, requesting an ID or password for an existing user, and client information corresponding to the request contents described in the above embodiment for a user without registration. It may be possible to determine whether or not connection is possible each time. In addition, users who do not register may be able to register or select the information provision level and the ability to shift by providing client information! /.

[0045] In the communication system according to the present disclosure, when the client terminal wants to obtain some information from the database device, it first transmits an information request to the mediation terminal. The mediation terminal requests client information from the client terminal to determine whether the information request is appropriate. If the client information is appropriate for the content of the information request, the connection from the client terminal is permitted, and the format to adapt the information request is sent to the client terminal. The client terminal sends an information request to this format. Is converted into a form adapted to the network and sent as a formatting request. When the request for formatting is appropriate, the intermediary terminal notifies the database device, is provided with information corresponding to the information request, and transmits the provided information to the client terminal. Therefore, compared to the case of permitting connection from a client terminal with a predetermined ID and password, the client permission is requested according to the content of the information request, so the connection permission criteria can be set flexibly according to the information request level it can. In addition, since the information is always routed through an intermediary terminal, the database device that holds the information and the client terminal are not directly connected, so security can be kept high. Furthermore, even if the connection is permitted, it is necessary to keep the security high in order to make the information request according to the format.

[0046] Further, in the communication system of the present disclosure, the format is stored in the mobile agent, and information is exchanged between the mediation terminal and the client terminal using the mobile agent. That is, first, the mediation-side mobile agent that stores the format moves to the client terminal. Next, the client-side mobile agent is stored in the mediation-side mobile agent, and moves from the mediation-side mobile agent that stores the client-side mobile agent to the mediation terminal. Next, the provision information obtained from the database device by the mediation terminal is stored in the client side mobile agent, and the client side mobile agent storing the provision information returns from the mediation terminal to the client terminal. As described above, information is exchanged using a mobile agent, that is, necessary information is “taken back” to the main body, so there is an advantage in checking the safety of information!

[0047] In addition, the communication system according to the present disclosure confirms the validity of the transmission source of the mobile agent by a method such as an electronic signature, so that the security of information provision can be further improved.

[0048] Also, when the mediation terminal of the present disclosure receives an information request, the mediation terminal requests client information from the client terminal in order to determine whether the information request is appropriate. If the client information is appropriate for the content of the information request, the connection from the client terminal is permitted, and a format to which the information request should be adapted is sent to the client terminal. The client terminal sends a request adapted to the format Then, the information corresponding to the information request is received by notifying the database device, and the provided information is transmitted to the client terminal. Therefore, compared to the case where the connection from the client terminal is permitted using a predetermined ID password, the client permission is determined according to the content of the information request. Can be set. In addition, since it always passes through an intermediary terminal, there is no direct connection between the database device that holds the information and the client terminal, so it is possible to maintain high security. Furthermore, even when connection is permitted, information requests are made according to the format, so security can be kept high.

[0049] Also, the mediation terminal of the present disclosure stores the format in the mobile agent, and exchanges information between the mediation terminal and the client terminal using the mobile agent. That is, first, the mediation side mobile agent storing the format moves from the mediation terminal to the client terminal. Next, the client side mobile agent is stored in the mediation side mobile agent, and the mediation side mobile agent storing the client side mobile agent moves from the client terminal to the mediation terminal. Next, the provision information obtained from the database device by the mediation terminal is stored in the client side mobile agent, and the client side mobile agent storing the provision information returns from the mediation terminal to the client terminal. As described above, information is exchanged using a mobile agent, that is, necessary information is “taken back” to the main body, so there is an advantage in checking the safety of information!

[0050] In addition, since the intermediary terminal of the present disclosure confirms the validity of the transmission source of the mobile agent by a method such as an electronic signature, it is possible to further improve the security of providing information.

Claims

The scope of the claims

A database device, a client terminal, and an intermediary terminal that mediates communication between the database device and the client terminal, and an agent provided in each of the database device, the client terminal, and the mediation terminal communicates A communication system that performs

The client terminal is

Information request transmitting means for transmitting to the intermediate terminal an information request for requesting the database device to provide predetermined information;

Client information transmitting means for transmitting client information in response to the request for the intermediary terminal power;

Formatting request transmission means for transmitting a formatting request in which the information request is adapted to the format transmitted from the mediation terminal to the mediation terminal;

The intermediary terminal is

An information request receiving means for receiving an information request for the client terminal power; a client which is information to be provided by the client terminal with respect to the information request of the content by analyzing the content of the information request received by the information request receiving means Client information determining means for determining information;

Client information requesting means for requesting the client terminal to provide client information determined by the client information determining means;

Connection permission judging means for judging whether or not to permit connection based on client information received from the client terminal;

Based on the received client information, the client terminal capability is also determined by the format determination means when the connection is permitted by the format determination means for determining the information request format corresponding to the client information and the connection permission determination means. Format transmission means for transmitting the formatted format to the client terminal;

A formatting request for receiving the formatting request from the client terminal; A reception means;

A notification means for notifying the database device of the information request of the client terminal when the formatting request received by the formatting request receiving means conforms to the format;

A communication system comprising: provision information transmitting means for returning provision information provided from the database device to the client terminal in response to an information request by the notification means.

[2] In the broker terminal,

The format transmission means stores the format in an intermediary mobile agent that is a mobile agent of the intermediary terminal and transmits the format to the client terminal.

The formatting request transmission means stores, as the formatting request, a client side mobile agent that is a mobile agent of the client terminal in the mediation side mobile agent and transmits it to the mediation terminal,

The intermediary terminal further includes:

The formatting request receiving means receives the intermediary mobile agent storing the client mobile agent;

Information storage means for storing provided information provided from the database device in response to the information request by the notification means in the client side mobile agent received by the formatting request receiving means;

The communication system according to claim 1, wherein the provided information transmitting means transmits the client side mobile agent in which provided information is stored by the information storing means to the client terminal.

[3] The intermediary terminal is

A legitimacy judging means for judging whether or not the client side agent stored and transmitted in the mediation side mobile agent is legitimately transmitted from the client terminal;

The notifying means, when the validity determining means determines that the validity is present, 3. The communication system according to claim 2, wherein an information request from the client terminal is notified to a database device.

[4] An intermediary technique that mediates communication between agents performed by a database device and a client terminal,

Formatting request receiving means for receiving the formatting request from the client terminal;

An intermediary terminal comprising: provision information transmission means for returning provision information provided from the database device to the client terminal in response to an information request by the notification means.

[5] The format transmitting means stores the format in an intermediary mobile agent that is a mobile agent that the intermediary terminal has, and transmits the format to the client terminal. The formatting request receiving means, as the formatting request, Said The intermediary side mobile agent storing the client side mobile agent that is the mobile agent possessed by the client terminal is received by the client terminal force,

5. The intermediary terminal according to claim 4, wherein the provision information transmitting unit returns the client side mobile agent in which provision information is stored by the information storage unit to the client terminal.

[6] It comprises legitimacy judging means for judging whether or not the client side agent stored and transmitted in the mediation side mobile agent is legitimately transmitted from the client terminal,

6. The intermediary terminal according to claim 5, wherein the notifying unit notifies the information request from the client terminal to the database device when the validity is confirmed by the validity checking unit.

7. A computer as various processing means of the intermediary terminal according to any of claims 4 to 6!