JP5393556B2 - Internal / external document protection system - Google Patents

Description

  The present invention relates to a document protection system for protecting an electronic document used in an organization such as a company with two protection / authentication servers in accordance with an in-house use or an external use and preventing leakage of confidential information. It is.

In an organization such as a company, various documents are digitized and operated in a PDF (Portable Document Format) format. Since PDF is internationally standardized and does not depend on the OS or language environment, it also has excellent long-term storage, so it is widely used as an electronic document format in a wide range of fields, such as internal notifications, electronic manuals for products, contracts, and contracts. doing.
There are two types of PDFs handled by companies, roughly divided according to usage. One is an internal secret document such as an internal notice or company rule that is used only within the company and is not disclosed to the outside, and the other is an externally disclosed document that is intended to be sent and disclosed outside the company.
In general, documents used by companies often contain confidential information that should not be leaked outside the parties other than for public use. A password is set in PDF as a protection method for this confidential information. And a technique for performing browsing control such that authentication processing is performed when a PDF is opened and information is disclosed only to authorized users.
For example, in the system disclosed in Patent Document 1, browsing control is performed by the latter method. In this method, control is performed such that when an operation for opening a document is performed, network access to an authentication server is performed, and browsing is accepted and internal content is displayed only after the authentication to the server is completed.

Japanese translation of PCT publication No. 2007-511821

  Conventionally, there are two methods for protecting PDFs used inside and outside organizations such as corporations: password protection as described above, and protection by connecting to an authentication server for browsing and authenticating. However, in the former case, since password information is embedded in the PDF, anyone can view the contents once the password is found, and the browsing cannot be stopped. On the other hand, in the latter case, browsing is not possible unless a network connection with the authentication server is established. However, from the viewpoint of exchanging PDF with the inside and outside, DMZ (DeMilitized Zone) that can be accessed not only inside but also outside. It is necessary to install an authentication server on top. For this reason, even if the protection by the user authentication is performed, if the ID and password of the user permitted to browse are leaked, there is a problem that anyone can browse the information that should be protected.

  An object of the present invention is to arrange servers for document protection / authentication on two locations on an intranet that cannot be accessed from outside (outside the organization such as a company) and on a DMZ that can be accessed from outside the company. By providing a protection / authentication server for internal and external documents, it provides protection means with the same operation for both internal and external uses, and does not impair user convenience. Even if authentication information is leaked outside the company, it is impossible to connect to an in-house protection / authentication server.

In order to achieve the above object, the internal / external document protection system of the present invention includes :
Is installed on the intranet, the tissue in a user terminal PDF conversion and protection application is installed, it is installed on the intranet, and PDF conversion server that receives the protected document from the tissue in a user terminal, on the intranet are installed in, it can be accessed from the tissue in a user terminal installed on the intranet, and protection and authentication server for the inaccessible tissue from the installed external user terminal over the Internet, is installed on the DMZ, intranet A document protection system comprising an external organization protection / authentication server accessible from both an internal user terminal installed on the Internet and an external user terminal installed on the Internet ,
The in-house user terminal is
And conversion protection request transmitting means for transmitting the files and information security policy that is specified in the PDF conversion and protection applications in the PDF conversion server,
Means for receiving and storing a protected file from the PDF conversion server;
Have
The PDF conversion server
A destination server selection transmitting means for transmitting the file received from the tissue in a user terminal to said security the in-tissue protective and authentication server or the tissue external protection and authentication server according to the policy after converting into the PDF format,
Means for transmitting the protected file received from the internal protection / authentication server or the external protection / authentication server to the internal user terminal;
Have
The internal protection / authentication server and the external protection / authentication server are respectively
Means for encrypting a PDF file received from the PDF conversion server, and generating the protected file by adding its own URL to the encrypted PDF file;
Means for sending the protected file to the PDF conversion server;
Have
It is characterized by the appropriate protection of documents inside and outside the organization.

As described above, the internal / external document protection system of the present invention has the following effects.
Because the same protection is provided for both internal and external documents, the convenience of the user is not impaired, and even for confidential documents, even if authentication information is leaked outside the organization Control that does not allow PDF to be viewed can be realized.

It is the schematic which shows the whole structure about the internal / external document protection system which concerns on embodiment of this invention. FIG. 3 is a flowchart between the PDF conversion server 102, the in-house protection / authentication server 103, and the external protection / authentication server 110 in the process of protecting a document from the in-house user terminal 104 using the PDF conversion / protection application 105 shown in FIG. is there. FIG. 3 is a schematic diagram of an internal data structure of a protected PDF generated by the process of FIG. 2. It is a flowchart of the process at the time of the user in a company browsing the PDF file protected by the process of FIG. It is a flowchart of the process at the time of a user outside the company browsing the PDF file protected by the process of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram according to an embodiment of the present invention. In this specification, the system means a computer system. Both the server and the terminal are computers, and the functions are realized by reading and executing necessary computer programs. “Means” to be described later is also expressed by capturing that a computer such as a server or a terminal reads and implements a specific program. In this embodiment, a company (company) is described as an example of an intranet usage environment, but the present invention is also applicable to general organizations such as offices and organizations.

  In FIG. 1, an in-house user terminal 104, a PDF conversion server 102, and an in-house protection / authentication server 103 are connected to an intranet 101. An external protection / authentication server 110 is installed on the DMZ 107.

Access from the intranet 101 is permitted to the in-house protection / authentication server 103, and access from the Internet 111 side is blocked by the firewall 108. On the other hand, the external protection / authentication server 110 on the DMZ 107 is set in the firewalls 108 and 109 so that it can be accessed from either the intranet 101 or the Internet 111.
Document protection by an in-house user is performed by the PDF conversion / protection application 105 installed in the in-house user terminal 104.

FIG. 2 is a flowchart of document protection processing by the PDF conversion / protection application 105, the PDF conversion server 102, the in-house protection / authentication server 103, and the external protection / authentication server 104.
In the PDF conversion / protection application 105 started in step 201, a file to be protected is accepted by drag and drop (step 202), and the user is allowed to specify a security policy for protecting the file under what rule (step 202). 203). There are two types of this policy, a confidential policy and an externally disclosed policy, depending on the purpose of the document. The protection target file selected by the user and the security policy to be applied are transmitted to the PDF conversion server 102 as a PDF conversion / protection request by the processing of the application (step 204). The PDF conversion server 102 converts the transmitted file into the PDF format (step 205), and then transmits the confidential policy to the in-house protection / authentication server 103 according to the designated security policy (step 207). The public policy is transmitted via the firewall 108 to the external protection / authentication server 110 installed on the DMZ 107 (step 210). Each protection / authentication server generates an encrypted PDF file by embedding special information in the PDF file (steps 208 and 211).

A schematic diagram of the internal data structure of the protected PDF file is shown in FIG. Each protection / authentication server assigns a document ID for management to the PDF and sets it in the document ID section 302. Furthermore, in order to perform authentication at the time of browsing the file, the URL of its own server is set in the connection destination authentication server URL section. Based on these two pieces of information, authentication is performed when viewing the file.
The PDF file 301 protected in this way is transmitted to the PDF conversion server 102 (steps 209 and 212), and returned to the requesting PDF conversion / protection application 105 (step 213).
The protected PDF file 301 is automatically saved in the local disk of the requesting in-house user terminal 104 by the PDF conversion / protection application 105 (step 214). This PDF file is sent to an internal user on the intranet 101 or an external user terminal 112 via the Internet 111 by means such as mail.

FIG. 4 is a flowchart of processing when a user in the company browses a protected PDF file.
When an in-house user browses a protected PDF file, the PDF browsing software 106 installed on the in-house user terminal 104 is used. The user activates the PDF browsing software 106 (step 401), and opens the target file (step 402). The PDF browsing software 106 acquires information of the document ID part 302 and the connection destination authentication server URL part 303 embedded in the file, and tries to connect to the connection destination server based on the URL information. If the confidential policy is applied, connection to the in-house protection / authentication server 103 is performed (step 404), and if successful, the file is decrypted and the content stored in the content data section 304 is displayed (step 404). 409). If the in-house user terminal 104 is not on the intranet 101, a connection to the server cannot be established, so a message indicating that browsing is not possible on the PDF browsing software 106 is displayed, and the file itself is not opened. Thereby, only when a terminal is connected on the intranet 101, control is performed to permit browsing.
On the other hand, if the external disclosure policy is applied, connection to the external protection / authentication server 110 is performed (step 407), and if successful, the file is decrypted and the content is displayed (step 409). If the connection to the external protection / authentication server 110 cannot be established, a message indicating that browsing cannot be performed is displayed, and the file itself is not opened (step 406).

FIG. 5 is a flowchart of processing when a user outside the company browses a protected PDF file.
When the outside user browses the protected PDF file, the PDF viewing software 113 installed on the outside user terminal 112 is used. The user activates the PDF browsing software 113 (step 501) and opens the target file (step 502). The PDF browsing software 113 acquires information of the document ID part 302 and the connection destination authentication server URL part 303 embedded in the file, and tries to connect to the connection destination server based on the URL information. When the confidential policy is applied, the connection to the internal protection / authentication server is made. However, as described above, since the access from the Internet 111 side is blocked by the firewall 108, the connection to the server cannot be made. A message indicating that browsing cannot be performed on the PDF browsing software 106 is displayed, and the file itself is not opened (step 504).
On the other hand, when the external disclosure policy is applied, connection to the external protection / authentication server 110 is performed (step 505). Since connection from the Internet 111 side is permitted for this server, browsing is permitted even if an external user is connected to the network, the file is decrypted, and the content stored in the content data unit 304 is It is displayed (step 507). In an offline environment where the network is not connected, the server cannot be connected, so a message indicating that browsing is not possible on the PDF browsing software 106 is displayed and the file itself is not opened (step 504).

  It can also be applied to protection of files other than PDF.

101 Intranet 102 PDF conversion server 103 In-house protection / authentication server 104 In-house user terminal 105 PDF conversion / protection application 106 PDF viewing software 107 DMZ
108, 109 Firewall 110 External protection / authentication server 111 Internet 112 External user terminal 113 PDF browsing software 301 Protected PDF file 302 Document ID part 303 Connection destination authentication server URL part 304 Content data part

Claims (1)

Is installed on the intranet, the tissue in a user terminal PDF conversion and protection application is installed, is installed on the intranet, and PDF conversion server that receives the protected document from those the tissue in a user terminal, an intranet It is installed on the DMZ, and an in-house protection / authentication server that can be accessed from an in-house user terminal installed on the intranet and cannot be accessed from an external user terminal installed on the Internet , A document protection system comprising an external organization protection / authentication server that can be accessed from both an internal user terminal installed on an intranet and an external user terminal installed on the Internet ,
The in-house user terminal is
And conversion protection request transmitting means for transmitting the information of the specified files and security policy in the previous Symbol PDF conversion and protection applications in the PDF conversion server,
Means for receiving and storing a protected file from the PDF conversion server;
Have
The PDF conversion server
A destination server selection transmitting means for transmitting the file received from the tissue in a user terminal to said security the in-tissue protective and authentication server or the tissue external protection and authentication server according to the policy after converting into the PDF format,
Means for transmitting the protected file received from the internal protection / authentication server or the external protection / authentication server to the internal user terminal;
Have
The internal protection / authentication server and the external protection / authentication server are respectively
Means for encrypting a PDF file received from the PDF conversion server, and generating the protected file by adding its own URL to the encrypted PDF file;
Means for sending the protected file to the PDF conversion server;
Have
An internal / external document protection system characterized by appropriately protecting internal and external documents.

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