JP2002244998A - Transmission control system, server, terminal device, transmission control method, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly preclude an occurrence such that a request message including words and/or phrases restricted for being transmitted is undeliberately transmitted using analytical information of an HTML document. SOLUTION: The system according to the invention is equipped with a restricted words database 30 in which restricted words are accommodated, a request transmission control part 13 to forward the request message transmitted from a WEB browser to an external network and examines whether the request message contains a symbol(s) depending upon the HTML file, and a restricted words checking part 14 which if it contains such symbol(s), analizes the symbol using the associated portion of the symbol described in the HTML file and decides if the transmission of the request message is to be admitted or not in accordance with whether the analytical result of the symbol meets the specification of restricted words, wherein the request transmission control part 13 controls the transmission of the request message in conformity to the decision of the admission or none of the transmission made by the restricted words checking part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing predetermined information from leaking when information is transmitted from a computer device to an external network.

[0002]

2. Description of the Related Art Today, the Internet and WAN (Wide Ar
With the spread of ea Network), the number of Internet users has also increased in schools and homes. In public facilities such as schools and general households, there are many cases where the same computer device is shared and used by a plurality of people and connected to the Internet.

[0003] By the way, various services exist on the WEB site connected by the Internet. And some of the various services include:
There is a service provided by transmitting personal data to a company or the like which holds contents, and a service provided by paying a price using a credit card or the like. In this case, in a use environment in which a plurality of users share a computer device as described above, one of the users transmits personal information of another user to an external network (Internet), or a family member in a general home. It is possible to use a credit card possessed by another person to make shopping without permission. Therefore, there may be a need for a system for preventing such personal information or specific information from being transmitted by others.

[0004] Conventionally, as one of measures to prevent others from transmitting such personal information to an external network without permission, there is a method using a filtering function of a proxy server. The proxy server
It is installed at an exit from an internal network such as a LAN to an external network such as the Internet to prevent unauthorized intrusion into the internal network and to relay and manage access from the internal network to the external network. As a result, security in the internal network is realized, and traffic required for access to the external network is reduced to realize high-speed access. Using the general filtering function of this proxy server, the proxy server may request the transmission of personal information or the like at the URL of a WEB site (Unknown).
By holding iform Resource Locators) and restricting access, it is possible to prevent such personal information from leaking to an external network.

[0005] As another measure for preventing another person from transmitting personal information or the like to an external network without permission,
There is a method of disabling information transmission by deleting a specific tag from HTML text sent from an external network. HTM, the source of web pages
The structure of an L (HyperText Markup Language) sentence is described by a combination of tags, and the function of transmitting information from the client machine is also defined by the tag. Therefore, when the browser displays the web page on the display device of the client machine, if the tags used for transmitting the information are filtered and deleted, the information cannot be transmitted from the client machine to the external network.

Further, as another measure for preventing another person from transmitting personal information or the like to an external network without permission, there is a method of filtering a request message (HTTP request) transmitted from a client machine to an external network. . That is, a phrase or URL that restricts transmission is set in advance, and when a request message that is transmission information is transmitted from the client machine, the phrase or URL that is set to restrict transmission of the request message is changed. If it does, transmission of the request message is prohibited. Checking the request message is done by proxy or OS (Operating Sy
stem), browser and other functions.

[0007]

However, the method for preventing the above-mentioned personal information from being transmitted to an external network without permission has the following problems. In the method of restricting access to a specific URL using the filtering function of the proxy server, access to the content having the URL itself is denied, so only transmission of personal information and the like is restricted, and browsing of the content is restricted. I couldn't cope when I wanted to do it. In addition, with the spread of network environments such as the Internet, it is expected that the number of contents requesting personal information such as IDs and credit card numbers will increase more and more. It is not realistic to search for all and filter the URL.

Also, in a method of deleting a specific tag from an HTML sent from an external network, it is necessary to perform filtering corresponding to a specific URL, so that access to the specific URL is restricted. In the same way as in the case of, the increase in contents requesting personal information could not be met.

In the method of filtering a request message transmitted from a client machine to an external network, transmission may not be restricted because a phrase intended to restrict transmission is replaced in the request message. To explain this, first, a mechanism for generating a request message, which is information transmitted from an HTML document, will be described.

FIG. 13 is a diagram showing a HT tag from a form (FORM) tag displayed on a browser of a client machine.
FIG. 4 is a diagram for explaining a request message that is information transmitted to a TP (HyperText Transfer Protocol). FIG. 13A shows a part of an HTML document which is a source of a WEB page displayed on a browser of a client machine. Here, “<FORM>” to “</ FORM>” are elements for the user to perform operations such as input and selection, such as “<INPUT>” and “<FORM”.
SELECT> ”and“ <OPTION> ”. On this WEB page, the user enters “type
= "Submit""at the stage of pressing the send button, the content of the information selected in the form,
The CGI (Com) of the URL specified by the "action" attribute
mon Gateway Interface). Figure 1
In the case of 3 (a), it is sent to “default.cgi”.

When a character string “Tokyo” is selected on the WEB page displayed on the browser of the client machine by the HTML document of FIG. 13A, a value “tk” is returned to the SELECT object “WTS”. And “WTS = tk”. That is, FIG.
HTTP request message "geth
http: // abc / default. cgi? WTS
= Tk ”will be issued.

[0012] Therefore, even if "Tokyo" is set as a phrase for restricting the transmission and the word "Tokyo" is actually entered in the input form of the web page, the information transmitted as the request message is transmitted. Is "WTS =
tk ”, the transmission of the request message cannot be prevented. This replacement information is, as shown in FIG.
It can be set arbitrarily using an OPTION tag in the ML document. Therefore, when the transmission of the phrase "Tokyo" is to be restricted, it is practically impossible to assume all the replacement information and set the phrase as the phrase for restricting the transmission in advance.

[0013] Accordingly, the present invention provides a method for receiving an HT received from a server.
The ML document is analyzed, and by using this analysis information, it is confirmed whether or not the information to be transmitted includes a phrase whose transmission is restricted, thereby including the phrase whose transmission is restricted. An object is to reliably prevent a request message from being transmitted.

[0014]

In order to achieve the above object, the present invention provides a transmission control system having the following configuration. That is, the transmission control system of the present invention relays a request message transmitted from a WEB browser to an external network, and a restricted word database storing a restricted word set to restrict transmission. A request transmission control unit that checks whether a code dependent on the source file of the WEB page displayed on the WEB browser is included in the request message. If the request message includes the code, the request transmission control unit describes the code. The code is analyzed using the relevant part of the code, and whether or not the transmission of the request message is accepted is determined depending on whether or not the analysis result of the code corresponds to the restricted word stored in the restricted word database. And a restricted word check Control unit in accordance with the determination of yes or no transmission by the limiting word checking section and controlling the transmission of the request message.

Here, this code is an attribute name defined in a form, for example, and is included in the query data in the request message. The analysis of the code can be performed based on the source file of the web page displayed on the web browser at the time when the request message is issued from the web browser. Further, the source file can be analyzed in advance to obtain information about the code, and stored. In this case, the transmission control system described above uses the W
A configuration is further provided with a correspondence information database that stores information on the correspondence between the code extracted from the source file of the EB page and the attribute value of the code. Then, the restricted word check unit analyzes the code based on the information on the correspondence stored in the correspondence information database.

Further, in the transmission control system described above, a source file of a web page returned from the server in response to a request from the web browser is obtained, and a correspondence between a code in the source file and an attribute value of the code is obtained. And a response file analysis unit for extracting the response file and storing the extracted response file in the correspondence information database.

Further, the transmission control system described above has a W
The system includes a login management unit that specifies a user who is logged in to the EB browser. The restricted word database stores restricted words individually set for each user using the WEB browser.
It is possible to adopt a configuration in which information on the restricted word set for the user specified by the login management unit is acquired from the restricted word database, and is collated with the analysis result of the code. As a result, fine transmission control can be realized by setting a different restricted word for each user.

Further, in the above-described transmission control system, the restricted word database stores the restricted words individually set according to the transmission destination of the request message, and the restricted word check unit transmits the request transmitted from the WEB browser. Information about the restricted word corresponding to the transmission destination of the message may be acquired from the restricted word database and collated with the analysis result of the code. As a result, it is possible to set a different restricted word for each transmission destination of the request message, and realize fine transmission control.

Further, in the transmission control system described above, the restricted word database stores a plurality of types of restricted words specified by specifying a time zone, and the restricted word check unit transmits a request message from a WEB page. Depending on the time period, the information on the corresponding restricted word may be acquired from the restricted word database and collated with the analysis result of the code.
Thereby, fine transmission control can be realized by using different restricted words according to the time zone in which the request message is issued.

Further, according to the present invention, a server for receiving a request message transmitted from a client machine, performing a relay process and transmitting the request message to an external network receives the request message, and a predetermined content of a predetermined content is included in the request message. A request transmission control unit for checking whether a code dependent on the source file is included, and, if the code is included in the request message, using a relevant part of the code described in the source file, Analyzing the code, the analysis result of the code, depending on whether or not corresponds to a restricted word set to restrict transmission, comprising a restricted word check unit to determine whether to accept the transmission of the request message, The request transmission control unit transmits the request by the restricted word check unit. Of as determined by the yes or no and controls the transmission of the request message.
This server is a proxy server or ISP (Internet Server)
vice Provider). Further, the server includes a router for accessing the external network from the internal network to which the client machine is connected. Thereby, reliable transmission control can be performed for request messages transmitted from all client machines on the internal network connected to this server.

Here, the server acquires information on the correspondence between the code extracted from the source file of the content and the attribute value of the code from a database on a network (internal network) and performs the transmission control. It can be carried out. Further, such a database may be provided in the server. In this case, the server is returned from a predetermined server in response to a request from a client machine, and a correspondence information database storing information on a correspondence between a code extracted from a source file of the content and an attribute value of the code. W
The configuration further includes a response file analysis unit that acquires a source file of the EB page, extracts a correspondence between a code in the source file and an attribute value of the code, and stores the extracted relationship in a correspondence information database. Then, the restricted word check unit analyzes the code based on the information on the correspondence stored in the correspondence information database.

Further, the server described above includes a login management unit for specifying a user who has transmitted a request message from a client machine, a restricted word database storing restricted words individually set for each user who uses the client machine, and The restricted word check unit acquires information on the restricted word set for the user specified by the login management unit from the restricted word database, and compares the information with the analysis result of the code. be able to. As a result, fine transmission control can be realized by setting a different restricted word for each user. As a method for specifying the user, it is possible to request a password and prompt the user to directly log in, or use login information in the OS of the client machine.

According to the present invention, in a terminal device connected to an external network and provided with a display means for a web page, a request message generated according to the form of the web page includes a code dependent on a source file of the web page. And a request message analyzing means for checking whether or not this code is included. If the request message includes this code, the code is analyzed using a relevant part of the code described in the source file, and Request message transmission control means for controlling transmission of the request message according to whether or not the analysis result of the code corresponds to the restriction information set to restrict the transmission. To realize such a function in a terminal device, W
It can be incorporated as a function of an EB browser or an OS, or implemented as an independent application program.

Further, the terminal device is provided with a sender specifying unit for specifying a sender of the request message, and the request message transmission control unit is configured to specify, among the restriction information set for each user of the terminal device, The transmission of the request message can be controlled based on the restriction information set for the specified sender.

According to the present invention, there is provided a transmission control method for a request message generated in accordance with the form of a web page.
Checking whether a code dependent on the source file of the EB page is included, and, if the code is included, analyzing the code using a relevant part of the code described in the source file; And a step of determining whether or not to transmit the request message according to whether or not the analysis result of the code corresponds to the restriction information set to restrict the transmission.

Further, the method for controlling transmission of a request message includes a step of specifying a sender of the request message, and a step of determining whether or not to permit the transmission of the request message includes: A configuration may be included that includes a step of checking whether the information corresponds to the set restriction information.

Further, in the request message transmission control method, the restriction information is individually set according to the transmission destination of the request message, and the step of deciding whether to permit transmission is performed based on the transmission of the request message. It may be configured to include a step of extracting information on the destination and a step of checking whether or not the analysis result of the code corresponds to the restriction information set for the extracted destination.

Furthermore, in the request message transmission control method, the restriction information is the length of a character string, and the step of determining whether to permit transmission is performed by determining the length of the character string, which is the result of analyzing the code, It may be configured to include a step of comparing the length specified in the restriction information with the request message to determine whether or not to transmit the request message.

Further, in the request message transmission control method, the restriction information is a numerical value, and the step of determining whether to permit or reject transmission includes the information on the number in the analysis result of the code and the restriction information. It may be configured to include a step of determining whether to accept the transmission of the request message by comparing the received numerical value with the received numerical value. The information regarding the number in the analysis result of the code includes a case where the numerical value of the analysis result itself and a case where the number of digits of the numerical value which is the analysis result.

Further, according to the present invention, in a transmission control method for an HTTP request generated in accordance with a form of an HTML file, the HTML file is analyzed to obtain a correspondence between a code dependent on the HTML file and its attribute value. If the code is included as query data in the HTTP request, an attribute value corresponding to the code is acquired based on the correspondence, and the acquired attribute value restricts transmission. The transmission of the request message is controlled depending on whether the information corresponds to the information set as described above. Also,
The present invention relates to a transmission control method for a message generated in accordance with a form of a page displayed on a display device of a computer device, wherein a code depending on a source file of the displayed page is included in the message. A step of determining whether or not to accept the transmission of the message according to a result of analyzing the code.

Furthermore, the present invention can be provided as a program for causing a computer to realize a predetermined function. That is, this program relays a request message transmitted from the WEB browser to the external network to a computer connected to the external network, and transmits the request message to the source file of the WEB page displayed on the WEB browser in the request message. A function to check whether a dependent code is included,
If the request message contains this code, the function to analyze this code using the relevant part of this code described in this source file and the analysis result of this code to restrict transmission The function of controlling transmission of the request message is realized according to whether or not the set restriction information is met.

Further, the program has a function of acquiring a source file of a WEB page returned from a predetermined server in response to a request from a WEB browser to the computer, The function of extracting the correspondence with the attribute value and storing it in the correspondence information database is further realized,
The function of analyzing this code can be configured to analyze this code based on information on the correspondence stored in the correspondence information database.

Further, the program causes the computer to further realize a function of specifying a user who has transmitted the request message from the client machine, and a function of controlling transmission of the request message is provided for the specified user. The transmission of the request message can be controlled based on individually set restriction information.

Further, the present invention provides a computer connected to an external network with a function of acquiring a source file of a web page returned from a predetermined server in response to a request from a web browser, and a function included in the source file. It is possible to provide a program that realizes a function of extracting a correspondence between a code dependent on the source file and an attribute value of the code and storing the extracted relationship in a correspondence information database.

Further, the present invention can be provided as a storage medium storing these programs, or a program transmission device for distributing these programs via a network. With such a configuration, it is possible to realize the transmission control according to the present invention in a computer loaded with these programs.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. FIG. 1 is a diagram showing a configuration of a keyword restriction mechanism (system) according to the present embodiment. In this embodiment, a case where information is transmitted from a client machine connected to the Internet to a predetermined server via a web page form will be described as an example. However, it goes without saying that the present embodiment can be used as it is for access to an external network in a WEB-based network environment other than the Internet.

The keyword restricting mechanism 100 of the present embodiment shown in FIG. 1 is provided between the web browser 200 and the Internet 300 in the client machine. A web server 400 is connected to the Internet 300, and provides various services. That is, W
When the EB browser 200 accesses the WEB server 400 via the Internet 300, it is always connected to the Internet 300 via the keyword restriction mechanism 100, and there is no detour. Keyword restriction mechanism 100
Is a web browser 200 on a network system.
And the Internet 300, and does not depend on hardware. That is, the ISP (Internet S
service as a service of a service provider, or as a function of a router or a proxy server for connecting a client machine to the Internet 300. Furthermore, the OS of the client machine
(Operating System) or as a function of the web browser 200, or may be realized as independent application software operating on a client machine.

Referring to FIG. 1, keyword restricting mechanism 1
00 is a relay processing unit 10 that relays communication between the WEB browser 200 of the client machine and the Internet 300 to monitor and control transmission information transmitted from the WEB browser 200, and a content file received by the WEB browser 200 ( A response file storage database 20 for storing server responses), and a restricted word database 30 in which words restricting transmission (hereinafter, these words are referred to as restricted words) are registered.

The relay processing unit 10 is provided with a normal proxy (Prox
As in the case of y), the WEB browser 200 relays all communications when the WEB browser 200 connects to the Internet 300.
That is, the Web browser 200 transmits the Web server 40
0 and the server response transmitted from the web server 400 to the web browser 200 are all transferred via the relay processing unit 10. Then, the relay processing unit 10 refers to the response file storage database 20 and the restricted word database 30 and sends the WEB browser 200 to the WEB server 40
It is checked whether or not the request message transmitted to 0 contains a restriction word, and the transmission of the request message containing the restriction word is stopped. Further, the relay processing unit 10 relays the response file sent from the web server 400 to send it to the web browser 200 and also sends it to the response file storage database 20.

Response file storage database 20
Is the same as a response file storage database provided in a normal proxy, and stores a response file received from the relay processing unit 10. Further, in the present embodiment, as will be described later, a correspondence information database that stores a correspondence relationship between a code (attribute name of an element in a form) in the HTML document as a response file and the attribute value thereof is described. Function.

The restricted word database 30 registers restricted words that should be restricted from being transmitted to the Internet 300. Accordingly, when the request message transmitted from the web browser 200 includes a word registered in the restricted word database 30 or information corresponding to the word, the transmission of the request message is stopped. .

The above-described relay processing unit 10 is realized by a program that controls a proxy server, a CPU of a client machine, a processor of a router, and the like according to the hardware on which the keyword restriction mechanism 100 of the present embodiment is constructed. Is done. The program can be provided by being stored in a magnetic disk, an optical disk, a semiconductor memory, or another storage medium, or can be transmitted via a network. The response file storage database 20 and the restricted word database 30 are realized by a storage device such as a cache memory or a magnetic disk device.

FIG. 2 is a diagram showing the configuration of the relay processing unit 10. Referring to FIG. 2, the relay processing unit 10 analyzes a response file sent from the web server 400 and stores the response file in the response file storage database 20. Response file analysis unit 12
And a request transmission control unit 13, a restricted word check unit 14, and a login management unit 15 that receive a request message transmitted from the web browser 200, check whether a restricted word is included, and perform necessary processing.
These components can be provided as modules of a program that implements the relay processing unit 10. Less than,
The operation of the present embodiment will be described in detail according to the function of each component.

FIG. 3 is a diagram for explaining the function of the restricted word registration unit 11. It is assumed that the restricted word is registered by a special user who has administrative authority. Therefore, as shown in FIG. 3, the restricted word registration unit 11 includes a password matching unit 11 for confirming that the user has the management authority.
a and registration means 11b for registering a restricted word. When registering a restricted word, a user having administrative authority first enters a password and logs in. The restricted word registration unit 11 performs password collation by the password collation unit 11a. If the password is accepted and the login is successful, then the user enters a list of restricted words. The restricted word registration unit 11 stores the input restricted word list in the restricted word database 30 by the registration unit 11b.

FIG. 4 shows an example of a list of restricted words.
The restriction word can be set individually for each user, or a default restriction word common to all users can be set. Also, a plurality of restricted words can be set for each user. For example, in the illustrated example, the user whose user ID is “aaa” has the phrase “Yamato City Central Rinkan Shimotsuruma” and “123456890”.
Is a restricted word, and for the user with the user ID “bbb”, the restricted words “Kanagawa Chuo-Rinma” and the phrase “0123456” are restricted words. In the request message transmission control,
If at least one of the restricted words presented in the list appears in the request message, transmission of the request message may be stopped, or transmitted if a certain number or more of the restricted words appear. May be set to be canceled.

Further, since the destination (URL) of the request message can be known by referring to the request message, the restriction words are individually set in the restriction word database 30 for each transmission destination, and the restriction word is set in accordance with the transmission destination. Control such as switching words is also possible. Furthermore, it is also possible to specify a time zone in the restricted word database 30 and set different restricted words, and to use a corresponding restricted word according to the time zone in which the request message is issued.

Further, instead of using a specific word as a restriction word (restriction information) as described above, the length of a character string can be set as restriction information. With such a setting, when a character string requiring a certain length, such as an address, is included in the request message, control can be performed to prohibit transmission of the information.
In addition, a fixed numerical value can be set as the restriction information. In this case, the numerical value to be set may refer to the input numerical value itself, or may indicate the number of digits of the input numerical value. In this case, when the transmission information of the request message includes a numerical value that is equal to or greater than (or less than) the set numerical value, or a numerical value that is larger (or smaller) than the set numerical value, the request message is not transmitted. It is also possible to set to cancel. With such a setting, restrictions based on numerical values, such as prohibiting shopping above a certain amount, can be performed.

FIG. 5 is a diagram for explaining the function of the response file analysis unit 12. Response file analysis unit 1
2 receives a response file transmitted from the Web server 400 via the Internet 300 in response to a request transmitted from the Web browser 200 of the client machine. Then, the received response file is sent to the web browser 200, the contents of the HTML document as the response file are analyzed, and the file and the analysis result are stored in the response file storage database 20.
To be stored.

Here, the analysis of the HTML document is performed as follows. First, a FORM tag is detected from an HTML document that is a response file. Then, using the information obtained by adding the URL of the HTML document to the ACTION attribute of the detected FORM tag as a key, a correspondence table indicating the correspondence between the attribute names defined in the form and the attribute values is created. This correspondence table is stored in the response file storage database 20 as an analysis result of the HTML document.

The analysis of the HTML document will be described in more detail with a specific example. FIG. 6 shows “<FORM></FORM>” detected from the HTML document.
FIG. 6 is a diagram showing an example of a form part surrounded by. The form shown in FIG. 6 is assumed to be included in an HTML document whose URL is http: //abc/index.html. The response file analysis unit 12 uses the HTM of http: //abc/index.html
When the form shown in FIG. 6 is detected from the L document, a correspondence table of attributes in this form is created.

The correspondence table includes a detailed table in which attribute names and attribute values in a form are associated with each other, and a form reference table in which the detailed table is associated with an HTML document including the form. The response file analysis unit 12 executes the FORM
UR in “address.cgi” which is the ACTION attribute of the tag
A form ID “abc / address.cgi” for specifying this form is generated by adding “abc” which is the site name of L. Then, the name of the detail table relating to this form is determined and associated with the form ID. Here, the form ID may be any information as long as it can specify which HTML document the form belongs to, and is not limited to the above example. FIG. 7A shows a form reference table created based on the form shown in FIG. FIG.
In the form reference table 21 shown in (a), the detailed table name corresponding to the form ID “abc / address.cgi” is “addresscgi”.

FIG. 7B shows a detailed table created based on the form shown in FIG. In the detail table 22 shown in FIG.
D “Aa”, attribute value “Tokyo”, element ID “Ab”
And the attribute value “Kanagawa”, the element ID “Ba” and the attribute value “Yamato”, the element ID “Ca” and the attribute value “Chuo Rinkan”
Are associated with each other.

FIG. 8 is a diagram for explaining the functions of the request transmission control unit 13, the restricted word check unit 14, and the login management unit 15. The request transmission control unit 13
The request message transmitted from the B browser 200 is received and analyzed to check whether or not query data (query data) which is a code depending on the HTML file is included. If query data is included, the query data is sent to the restricted word check unit 1.
4 and waits for an answer. If no query data is included, the request message is transmitted as it is.

FIG. 9 is a flowchart for explaining the processing by the request transmission control unit 13. Referring to FIG. 9, first, the request transmission control unit 13 checks whether or not the received request message includes query data (step 901). Here, it is assumed that the request transmission control unit 13 has received the request message “http: //abc/address.cgi? A = b & B = a & C = a” transmitted from the web browser 200.

Next, the request transmission control unit 13 transmits the request message if the query data is not included (steps 902 and 905), and if the query data is included, the URL which is the destination of the request message is transmitted. And the query data are extracted (steps 902 and 903). Here, "http: // abc / addre
Since the request message "ss.cgi? A = b & B = a & C = a" is input, "abc / address.cgi" is extracted as the URL, and three query data A = b, B = a, and C = a are obtained. Is extracted. When the query data is extracted, the request transmission control unit 13 passes the extracted information to the restricted word check unit 14 and executes a restricted word check process (step 904).

The restricted word check unit 14 checks whether or not the query data includes a restricted word in the request message received from the request transmission control unit 13. Then, when the restriction word is included, the request transmission control unit 13 is notified to stop the transmission of the request message. When the restriction word is not included, the request transmission control unit 13 is requested to transmit the request message. Notify the transmission control unit 13.

FIG. 10 is a flowchart for explaining the processing by the restricted word check unit 14. Referring to FIG. 10, first, based on the URL received from the request transmission control unit 13, the restricted word check unit 14 extracts a detailed table corresponding to the URL from the form reference table 21 stored in the response file storage database 20. First name is acquired (steps 1001, 100
2). Here, since the URL received from the request transmission control unit 13 is “abc / address.cgi”, FIG.
Referring to the form reference table 21 shown in FIG.
A detailed table name "addresscgi" is obtained.

Next, the restricted word check unit 14 specifies the detailed table 22 to be referred to by the obtained detailed table name, makes an inquiry about the query data received from the request transmission control unit 13, and acquires the attribute value. (Steps 1003 and 1004). Here, A = b, B =
The attribute table of three query data, a and C = a, is inquired to the detail table “addresscgi”. FIG. 7B
Referring to the detailed table 22 shown in FIG. 7, "Kanagawa" is an attribute value corresponding to A = b, "Yamato-shi" is an attribute value corresponding to B = a, and "Chuo-Rinkan" is an attribute value corresponding to C = a. Can be obtained respectively.

Next, the restricted word check section 14 refers to the restricted word database 30 to check whether or not these obtained attribute values are set as restricted words (step 1005). Then, if these attribute values are set as restriction words, the request transmission control unit 13 is notified to stop the transmission of the request message. The request transmission control unit 13 is notified to perform transmission.

As described above, in the present embodiment, the HT
Based on the contents of the ML document, the correspondence between the information (attribute name) used in the query data of the request message and the restriction word is recognized, and it is determined whether or not the request message includes information corresponding to the restriction word.
Therefore, if the user enters a restricted word,
Even if the information described in the request message is replaced, it can be reliably determined that the information corresponds to the restricted word. Note that various methods can be adopted as to whether or not the transmission of the request message is approved, as described above. In other words, when a plurality of restricted words are set, transmission of the request message can be stopped if at least one of the restricted words is present in the query data. Transmission can also be stopped. Also,
It is also possible to set a numerical value instead of a word as a restricted word, and control to stop transmission of a request message containing a numerical value higher than the numerical value (or a numerical value lower than the numerical value).

By the way, when an individual restricted word is set for each user, the request message is requested only when the query data of the request message corresponds to the restricted word set for the user who has input the information of the request message. It is necessary to perform control such as stopping transmission of the message. That is, if a predetermined word is a restricted word for a predetermined user and not a restricted word for another user, even if the other user inputs the phrase, transmission of a request message based on the input should be stopped. is not. In other words, the other user has the authority to transmit the phrase. Therefore, means for specifying the user who has input the information of the request message is required. In the present embodiment, this control is performed by the login management unit 15.

Referring to FIG. 8, the login management unit 15
Requests the user via the web browser 200 for a password when the restricted word check unit 14 determines that the query data in the request message includes the restricted word. When the user returns the password in response to the request, the login management unit 15 specifies the user based on the password, and the restricted word determined to be included in the query data is the restricted word set for the user. That is, it is checked whether or not the user has the right to transmit the restricted word.
When it is determined that the request word is not a restricted word set for the user (has transmission authority), the request transmission control unit 13 is notified to transmit the request message. On the other hand, if it is determined that the restriction word is set for the user (there is no transmission authority), the request transmission control unit 13 is notified to stop transmitting the request message. Also, the user is notified that transmission of the request message is refused.

The login management unit 15 logs out the user when a certain condition is satisfied (for example, when no input is made for a certain period of time, or when no request message is transmitted). It is necessary to cancel the login state by requesting the user or automatically logging out. This is to avoid using the restriction word correspondence table corresponding to the previous user by requesting a new login when the user of the client machine changes.

When the restricted word is not set for each user and the default restricted word is applied to all users, it goes without saying that the above-described login management unit 15 and the process of authenticating the user are unnecessary. . Further, the method of authenticating the user is not limited to the above-described method based on the request for the password, but may employ various methods such as depending on the user who has logged in to the OS. Furthermore, in the method of requesting a password and the method of requesting logout, various methods such as displaying the dialog box on the display device of the client machine or notifying by voice are used in addition to the method of performing the above-mentioned request through the web browser 200. Can take.

As described above, the request transmission control unit 13 determines that the received request message includes the query data, and waits for a response from the restricted word check unit 14. When a notification that the request message is to be transmitted is received from the unit 15, the request message is transmitted. On the other hand, when a notification that transmission of the request message is to be stopped is received from the restricted word check unit 14 or the login management unit 15,
Stop sending the request message. When the transmission of the request message is stopped, the user can be notified of the refusal of transmission by, for example, displaying an error message on a display device of the client machine.

The keyword restricting mechanism 100 described above
May be installed between the WEB browser 200 and the Internet 300 (ideally, between the user and an external network) as described above, and various hardware such as an ISP, a proxy server, a router, and a client machine may be used. Can be implemented in hardware. When implemented in a client machine, it can be incorporated as a function of a web browser or an OS, or can be implemented as an independent application program. When the keyword restricting mechanism 100 is incorporated in the client machine as a function of the OS, it is possible not only to restrict the transmission of the request message but also to prevent use of an inappropriate word in any application. As described above, it is also possible to use the OS login information to specify the sender of the request message.

Next, an example in which the keyword restriction mechanism of the present embodiment is mounted on a proxy server will be described. Figure 1
FIG. 1 is a diagram illustrating a configuration example when a keyword restriction mechanism is implemented in a proxy server. Although FIG. 11 shows only one client machine 1100, actually, a plurality of client machines 1100 are connected to the Internet 300 via the proxy server 1110. FIG. 11 illustrates only the configuration related to the request message transmission control process, and does not illustrate the restricted word registration unit 11 illustrated in FIG. further,
11, an Internet access unit 1121 has a function corresponding to the response file analysis unit 12 shown in FIG. 2, an HTML cache 1124 corresponds to the response file storage database 20 shown in FIG.
The restricted word list management unit 1112 and the restricted word storage unit 1113 correspond to the restricted word database 30 shown in FIG. Also, a login management unit 1111, a request transmission control unit 1122, a restricted word check unit 1123
Are the same as the login management unit 15, the request transmission control unit 13, and the restricted word check unit 14 shown in FIG.

FIG. 12 shows the proxy server 1 shown in FIG.
5 is a flowchart illustrating an operation of a keyword restriction mechanism implemented in 110. With reference to FIG. 11 and FIG. 12, a process when the client machine 1100 transmits a request message will be described. As an initial state, it is assumed that a predetermined HTML document is received via the Internet 300 and is displayed on the Web browser 1101 of the client machine 1100. Therefore, the HTML document is stored in the Internet access unit 1
The information is analyzed by a function corresponding to the response file analysis unit 12 in 121, and is stored in the HTML cache 1124 along with the analysis result.

When a request message is transmitted from the web browser 1101 of the client machine 1100, the request transmission control unit 1122 receives the request message and checks whether the request message includes query data (steps 1201 and 1202). If the query data is included, the query data is extracted,
The request message is sent to the restricted word check unit 1123 together with information (such as the URL of the destination) corresponding to the form ID that specifies which content file the request message was transmitted on.

The restricted word check unit 1123 first
In order to perform a check using the restricted word list corresponding to the user who transmitted the request message, an inquiry is made to the restricted word list management unit 1112. The restricted word list management unit 1112 identifies the user who transmitted the request message,
It is checked whether or not the user has logged in by inquiring of Step 1 (Step 1203). If the login has not been performed, the login management unit 1111 transmits a login dialog to the client machine 1100 (step 1204). If the login is performed with a valid password in response to the login dialog, the restricted word list management unit 1112 loads the restricted word list corresponding to the user specified by the login from the restricted word storage unit 1113, Restricted word check section 11
23 (steps 1205, 1206). On the other hand, if the login is not performed normally, the default restricted word list is loaded from the restricted word storage unit 1113 and passed to the restricted word check unit 1123 (step 1).
205, 1207).

Next, the restricted word check unit 1123
With reference to the restricted word list received from the restricted word list management unit 1112, it is checked whether or not there is a restricted word itself in the query data of the request message to be processed (step 1208). If the restriction word is included, the request transmission control unit 1122 is notified so as to immediately stop transmitting the request message. Upon receiving this notification, the request transmission control unit 1122 stops transmitting the request message (step 1212).

If it is determined in step 1208 that the restricted data is not included in the query data of the request message, then the restricted
23 loads the correspondence table corresponding to the request message from the HTML cache 1124 (step 1209). Here, if loading fails,
The restricted word check unit 1123 notifies the request transmission control unit 1122 to immediately stop transmitting the request message. Request transmission control unit 11
22 receives this notification, and stops transmitting the request message (step 1212).

In step 1209, if the loading of the desired correspondence table is successful, the restricted word check unit 1123 uses the correspondence table to determine the attribute value of the code in the query data of the request message to be processed. (The character string displayed on the web browser 1101) (step 121)
0). Here, if the acquisition of the character string has failed, the restricted word check unit 1123 notifies the request transmission control unit 1122 to immediately stop transmitting the request message. Request transmission control unit 1122
Receives this notification, stops transmitting the request message (step 1212).

If the desired character string has been obtained in step 1210, the restricted word check unit 112
3 refers to the restricted word list received from the restricted word list management unit 1112, and checks whether or not there is a restricted word in the acquired character string (step 1211). If the character string contains a restricted word,
The restricted word check unit 1123 notifies the request transmission control unit 1122 to stop transmitting the request message. If the character string does not include a restricted word, the restricted word checking unit 112
3 notifies the request transmission control unit 1122 to execute transmission of the request message. The request transmission control unit 1122 includes the restricted word check unit 11
23, the transmission of the request message is stopped (step 121).
2) When the transmission execution notification is received, the request message is transmitted (step 1213).

In the above implementation example, an example is shown in which the entire configuration of the keyword restriction mechanism is mounted on the proxy server 1110. For example, the login management unit 1111, the restricted word list management unit 1112, the restricted word storage unit 1113, and the Internet access Section 1121, request transmission control section 1122, restricted word check section 1123, and HTML
Implement the cache 1124 on different hardware,
It may be configured to be connected via a network.

In the above-described embodiment, the case where the content file (Web page) is an HTML document has been described as an example. However, the content file can be written in another language such as XML that is used for describing Web-based content. It goes without saying that the same can be used even if it is described.

[0077]

As described above, according to the present invention, an HTML document received from a server is analyzed, and words and phrases whose transmission is restricted are included in information to be transmitted using the analysis information. By confirming whether or not is included, it is possible to reliably prevent a request message containing a phrase whose transmission is restricted from being transmitted.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a keyword restriction mechanism according to the present embodiment.

FIG. 2 is a diagram illustrating a configuration of a relay processing unit according to the present embodiment.

FIG. 3 is a diagram illustrating a function of a restricted word registration unit according to the present embodiment.

FIG. 4 is a diagram showing an example of a restricted word list used in the present embodiment.

FIG. 5 is a diagram illustrating a function of a response file analysis unit according to the present embodiment.

FIG. 6 is a diagram illustrating an example of a form part detected from an HTML document in the present embodiment.

FIG. 7 is a diagram showing an example of a correspondence table used in the present embodiment. FIG. 7A shows a form reference table, and FIG. 7B shows a detailed table.

FIG. 8 is a diagram illustrating functions of a request transmission control unit, a restricted word check unit, and a login management unit according to the present embodiment.

FIG. 9 is a flowchart illustrating a process performed by a request transmission control unit according to the present embodiment.

FIG. 10 is a flowchart illustrating processing by a restricted word check unit according to the present embodiment.

FIG. 11 is a diagram illustrating a configuration example when the keyword restriction mechanism according to the present embodiment is implemented in a proxy server.

FIG. 12 is a flowchart illustrating the operation of a keyword restriction mechanism implemented in the proxy server shown in FIG. 11;

FIG. 13 is a diagram illustrating a request message transmitted from a form part displayed on a browser of a client machine.

[Explanation of symbols]

Reference Signs List 10 relay processing unit 11 restricted word registration unit 12 response file analysis unit 13 request transmission control unit 14 restricted word check unit 15 login management unit 20 response file storage database 30
... Restricted word database, 100 ... Keyword restricting mechanism, 200 ... Web browser, 300 ... Internet, 400 ... Web server

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tetsuya Noguchi 1623-14 Shimotsuruma, Yamato-shi, Kanagawa Prefecture Within the Tokyo Research Laboratory, IBM Japan, Ltd. 1623 Tsuruma 14 IBM Japan, Ltd. Tokyo Basic Research Laboratory F-term (reference) 5B075 KK07 ND20 5B082 HA05 5B085 BE07 BG07 CA04

Claims (23)

[Claims] 1. A limited word database storing a limited word set to limit transmission, a request message transmitted from a web browser to an external network, and a request message transmitted to the web browser in the request message. WEB being displayed
A request transmission control unit that checks whether a code dependent on the source file of the page is included, and, if the code is included in the request message, using a relevant part of the code described in the source file. A restricted word check unit that determines whether or not to transmit the request message according to whether or not the analysis result of the code corresponds to the restricted word stored in the restricted word database. The transmission control system, wherein the request transmission control unit controls transmission of the request message in accordance with a determination of permission or rejection of transmission by the restricted word check unit. 2. W displayed on the WEB browser
A correspondence information database storing information on a correspondence relationship between the code extracted from the source file of the EB page and the attribute value of the code, wherein the restricted word check unit stores the correspondence stored in the correspondence information database. Based on information about the relationship,
The transmission control system according to claim 1, wherein the code is analyzed. 3. Obtaining a source file of a WEB page returned from a predetermined server in response to a request from the WEB browser, and extracting a correspondence between the code in the source file and an attribute value of the code. The transmission control system according to claim 2, further comprising a response file analysis unit that stores the response file in the correspondence information database. 4. A log-in management unit for specifying a user who has logged in to the WEB browser, wherein the restricted word database stores the restricted words individually set for each user using the WEB browser. The restricted word check unit acquires information on the restricted word set for the user specified by the login management unit from the restricted word database, and compares the information with the analysis result of the code. The transmission control system according to claim 1, wherein: 5. The restricted word database stores the restricted words individually set according to a destination of the request message, and the restricted word check unit transmits a request message transmitted from the web browser. 2. The transmission control system according to claim 1, wherein information on a corresponding restricted word is acquired from the restricted word database and compared with the analysis result of the code. 3. 6. The restricted word database stores a plurality of types of restricted words specified by designating a time period, and the restricted word check unit determines a time period during which the request message is transmitted from the WEB page. In response to the,
The transmission control system according to claim 1, wherein information on the corresponding restricted word is acquired from the restricted word database and compared with the analysis result of the code. 7. A server for receiving a request message transmitted from a client machine, performing a relay process and transmitting the request message to an external network, wherein the server receives the request message and depends on a source file of predetermined content in the request message. A request transmission control unit that checks whether or not the received code is included; and, when the request message includes the code, analyzes the code using a relevant portion of the code described in the source file. A restriction word check unit that determines whether or not to transmit the request message according to whether or not an analysis result of the code corresponds to a restriction word set to restrict transmission. The unit determines whether or not to permit transmission by the restricted word check unit. Controlling the transmission of the request message according to the following. 8. A correspondence information database storing information relating to a correspondence between the code extracted from a source file of the content and an attribute value of the code, and returned from a predetermined server in response to a request from the client machine. A response file analyzing unit that acquires a source file of the WEB page that has been set, extracts a correspondence between the code and the attribute value of the code in the source file, and stores the correspondence in the correspondence information database; The unit is based on the information about the correspondence stored in the correspondence information database,
The server according to claim 7, wherein the server analyzes the code. 9. A login management unit for specifying a user who has transmitted the request message from the client machine, and a restricted word database storing the restricted words individually set for each user using the client machine. The restricted word check unit acquires information on the restricted word set for the user specified by the login management unit from the restricted word database, and compares the information with the analysis result of the code. The server according to claim 7, wherein 10. A web server connected to an external network,
A terminal device including a page display unit, a request message analysis unit configured to determine whether a request message generated according to a form of the web page includes a code depending on a source file of the web page, When the code is included in the message, the code is analyzed using the relevant part of the code described in the source file, and the analysis result of the code is set to a limit set to limit transmission. A terminal device, comprising: request message transmission control means for controlling transmission of the request message depending on whether the information corresponds to information. 11. The apparatus according to claim 11, further comprising: a sender specifying unit that specifies a sender of the request message, wherein the request message transmission control unit includes the specified restriction information set among the restriction information set for each user of the terminal device. The terminal device according to claim 10, wherein transmission of the request message is controlled based on the restriction information set for a sender. 12. A transmission control method for a request message generated in accordance with a form of a web page, wherein a step of checking whether or not the request message includes a code depending on a source file of the web page; Is included, analyzing the code using the relevant part of the code described in the source file; andthe analysis result of the code is included in the restriction information set to restrict transmission. Deciding whether or not to transmit the request message according to whether the request is applicable. 13. The method according to claim 13, further comprising the step of specifying a sender of the request message, wherein the step of determining whether or not to permit the transmission is performed, wherein the analysis result of the code is the restriction set for the specified sender. 13. The transmission control method according to claim 12, further comprising a step of checking whether the information corresponds to the information. 14. The restriction information is individually set according to a transmission destination of the request message. The step of deciding whether to permit the transmission is a step of extracting information on a transmission destination from the request message, 13. The transmission control method according to claim 12, further comprising: checking whether the analysis result of the code corresponds to the restriction information set for the extracted destination. 15. The restriction information is a length of a character string, and the step of determining whether or not to permit the transmission includes: a length of a character string that is an analysis result of the code; and a length specified by the restriction information. 13. The transmission control method according to claim 12, further comprising the step of: determining whether the transmission of the request message is permitted or not by comparing. 16. The restriction information is a numerical value, and the step of deciding whether or not to permit transmission is performed by comparing information on a number in the analysis result of the code with a numerical value specified by the restriction information. 13. The transmission control method according to claim 12, further comprising a step of determining whether or not to accept the transmission of the message. 17. A method for controlling transmission of an HTTP request generated according to a form of an HTML file, comprising: analyzing the HTML file to obtain a correspondence between a code dependent on the HTML file and its attribute value; When the code is included as query data in the HTTP request, an attribute value corresponding to the code is acquired based on the correspondence, and the acquired attribute value is set so as to restrict transmission. Transmission control method, wherein the transmission of the request message is controlled depending on whether the received information corresponds to the received information. 18. A method for controlling transmission of a message generated in accordance with a form of a displayed page, comprising: checking whether the message includes a code dependent on a source file of the displayed page; Determining whether to accept or not to transmit the message according to a result of analyzing the code. 19. A computer connected to an external network relays a request message transmitted from a WEB browser to the external network, and displays a W message displayed on the WEB browser in the request message.
A function for checking whether a code dependent on the source file of the EB page is included, and, if the code is included in the request message, the relevant part of the code described in the source file is used for the request message. A function of analyzing a code, and a function of controlling transmission of the request message according to whether or not the analysis result of the code corresponds to restriction information set to restrict transmission, is realized. And the program. 20. A function of acquiring a source file of a WEB page returned from a predetermined server in response to a request from the WEB browser to the computer, wherein the code in the source file and an attribute value of the code are A function of extracting a correspondence and storing the same in a correspondence information database, wherein the function of analyzing the code analyzes the code based on the information on the correspondence stored in the correspondence information database. The program according to claim 19, wherein: 21. The computer further realizes a function of specifying a user who transmitted the request message from the web browser, and a function of controlling transmission of the request message is individually set for the specified user. 20. The program according to claim 19, wherein transmission of the request message is controlled based on the restricted information. 22. A function of acquiring a source file of a web page returned from a predetermined server in response to a request from a web browser to a computer connected to an external network, and a source included in the source file. A program for realizing a function of extracting a correspondence between a code dependent on a file and an attribute value of the code and storing the extracted relationship in a correspondence information database. 23. A storage medium storing a program to be executed by a computer in a manner readable by input means of the computer, wherein the program relays a request message transmitted from a web browser to an external network, Web displayed on the WEB browser inside
A function for checking whether a code depending on the source file of the page is included, and, when the code is included in the request message, the code using the relevant part of the code described in the source file. And the function of controlling the transmission of the request message depending on whether or not the analysis result of the code corresponds to the restriction information set to restrict the transmission. A storage medium characterized by the above-mentioned.