JP2011138209A - Document management system, document management method, and program for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that is caused when having a personal computer and moving to another place in the middle of browsing a document downloaded from a document management server on the personal computer, or when a session (communication) with the server is temporarily shut off caused by temporary coming off or the like of a network cable, wherein it is difficult to determine whether to end or continue the browsing having been performed up to now, in view of an aspect of security or operability. <P>SOLUTION: When displaying a page that is not a page presently displayed on the personal computer, it is decided by a session shutoff effective time whether the page display can be continued even if the session is shut off. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a document management system, a document management method, and a program therefor, in particular, a document to be viewed is encrypted by a server via a network, downloaded to a terminal, and then the terminal decrypts and browses the document. The present invention relates to a document management system, a document management method, and a program thereof.

  In the document management system, document security is ensured by access restrictions. However, once a document is downloaded by the client, no security can be applied to the document. For this reason, if the document is downloaded and illegally distributed, the security on the document management system is not ensured. As one example, in Patent Document 1, authentication is performed to determine whether or not the user is a valid user by comparing authentication information with the one-time password generated by the one-time password generation means. Means and the authentication means

When a user is authenticated as a valid user, a decryption key for decrypting the encrypted file is transmitted to the other terminal device, and the encrypted file is decrypted to the other terminal device. There is disclosed an electronic file management system characterized in that it further comprises a decryption key transmitting means for enabling the above-described decryption key transmission means.

JP2007-286935

  However, the electronic file management system and the electronic file management program described in Patent Document 1 can store the decrypted file in the USB memory and the portable storage device after authentication.

  In addition, if the session (communication) with the server is temporarily interrupted, such as when you move to another place with a computer after browsing starts, or when the network cable is temporarily disconnected, etc. Considering from the viewpoint of security and operability whether to end or continue the browsing process that has been performed, there arises a problem that the determination is difficult.

  The present invention has been made in order to solve the above-mentioned problems. Decoding is performed in units of pages at the time of browsing, and only a necessary minimum page is not decoded, thereby ensuring a display response at the time of browsing, and advanced. Even if it is possible to ensure security and the session is temporarily disconnected even after the document is started to be viewed on the client terminal, if the session can be reestablished within the set effective time, the browsing operation performed so far The purpose is to provide a mechanism that allows browsing of pages other than the displayed page.

  The present invention is a document management system configured such that a document management server and a browsing terminal can communicate with each other, and the document management server transmits an encrypted document including address information for each page. Means, answering means for answering the system time to the viewing terminal, the viewing terminal receiving the encrypted document, the encrypted document receiving means, and the document received by the encrypted document receiving means for each page Based on the address information, decoding means for decoding for each page, page display means for displaying the document decoded for each page for each page, inquiry means for inquiring the system time to the document management server, A determination unit that determines a predetermined time at which the decoding unit permits decoding for each page from the system time of the document management server; and the page display unit. After displaying the page of the decrypted document, a first determination unit that determines whether communication is established between the document management server and the viewing terminal, and the first determination unit includes If it is determined that there is no page, a second determination unit that determines whether to allow display of a page that is not displayed by the page display unit from the predetermined time and the system time of the browsing terminal is provided. .

  The browsing terminal further includes an operation stop instruction means for instructing stop of operations such as copying, editing, and printing of a page displayed by the page display means, and the first determination means is not in communication establishment. When the determination is made, the operation stop means gives an operation stop instruction.

  Further, when the second determination unit determines that the predetermined time is earlier than the system time of the browsing terminal, the page display unit does not display a page.

  The browsing terminal further includes a first storage unit that stores the predetermined time and a second storage unit that stores the predetermined time determined by the determination unit. The determination unit includes the predetermined unit. And the system time of the document management server inquired by the inquiry means, the predetermined time is determined.

  When the second determination unit determines that the predetermined time is later than the system time of the browsing terminal, the inquiry unit inquires of the document management server about the system time, and the second storage unit It further has an update means for updating the predetermined time stored in the memory.

  According to the present invention, it is possible to ensure a high level of security while ensuring a display response at the time of browsing by not decrypting other than the necessary minimum pages, and even after the start of document browsing on the client terminal, If the session is temporarily expired and the session can be re-established within the set effective time, the browsing operation performed so far can be continued and browsing other than the displayed page can be permitted. .

It is a figure which shows the system configuration | structure of the document management system of this invention. It is a figure which shows the hardware constitutions of the document management server and client of this invention. It is a flowchart which shows the document download process of the client terminal of embodiment of this invention. It is a flowchart which shows the document upload process of the client terminal of embodiment of this invention. It is a figure which shows the detailed processing flow of the encryption process of the document of the document management server of embodiment of this invention. It is a figure which shows the detailed processing flow of the decoding process of the document of the document management server of embodiment of this invention. It is a figure which shows the detailed processing flow of the browsing (decryption) process of the encrypted document of the client terminal of embodiment of this invention. It is a figure which shows the screen at the time of document download operation of a client terminal. It is a figure which shows the screen at the time of document upload operation of a client terminal. It is a figure which shows the screen at the time of document upload operation of a client terminal. It is a figure which shows the screen of the client terminal during document browsing. It is a figure which shows the example of an item of document management DB. It is a figure which shows the example of an item of a user master. It is a figure which shows the example of an item of an organization master. It is a figure which shows the example of an item of a document management master. It is a figure which shows the example of an item of a temporary file, a document header file, and an initialization file.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a system configuration of a document system according to an embodiment of the present invention. The document management server 100 is configured to be able to communicate with the client terminal 200 via the communication line 300. Various tables and print forms are stored in the hard disk of the external memory 211 of the document management server 100. A document browsing request is transmitted from the client 200 to the document management server 100 via the communication line 300, and the document management server 100. Transmits the document to the client 200 after encrypting the document.
Next, FIG. 2 is a schematic diagram illustrating a schematic configuration of hardware of the document management server 100 and the client 200.

  The CPU 201 comprehensively controls each device and controller connected to the system bus 204. In addition, the ROM 202 or the external memory 211 is provided with a function for executing a basic input / output system (BIOS), an operating system program (hereinafter referred to as an OS), which is a control program of the CPU 201, and a program for executing each program of the document management server 100. Various programs and the like which will be described later are stored.

  The RAM 203 functions as a main memory, work area, and the like for the CPU 201. The CPU 201 implements various operations by loading a program necessary for execution of processing into the RAM 203 and executing the program. The input controller 205 controls input from a pointing device such as a keyboard (KB) 209 or a mouse (not shown). The video controller 206 controls display on a display device such as a CRT display (CRT) 210. The display device may be a liquid crystal display as well as a CRT.

  The memory controller 207 is stored in a hard disk (HD), floppy (registered trademark) disk (FD), or PCMCIA card slot for storing a boot program, browser software, various applications, font data, user files, editing files, various data, and the like. Controls access to an external memory 211 such as a compact flash (registered trademark) memory connected via an adapter. The communication I / F controller 208 is connected to and communicates with an external device via a network, and executes communication control processing on the network. For example, network communication using TCP / IP is possible.

  The hard disk of the external memory 211 has screen information as a part of the operating system, the application program shown in the flowcharts of FIGS. 3 to 7 and the application program for displaying each screen shown in FIGS. 12 stores each database, table, and master file such as the document management DB shown in FIG. 12, the user master shown in FIG. 13, the organization master shown in FIG. 14, and the document management master shown in FIG. The client 200 may use a nonvolatile memory that is also used as the RAM 203 instead of the hard disk of the external memory 211.

Note that the CPU 201 enables display on the CRT 210 by executing outline font rasterization processing on a display information area in the RAM 203, for example. In addition, the CPU 201 enables a user instruction with a mouse cursor (not shown) on the CRT 210.
Here, the table and the master file will be described.

  The document management DB shown in FIG. 12 includes a unique document number (key), a document name, a document type (a document type such as a plan, a proposal, a specification, a minutes, etc.), a confidential rank (described later), a creator ID (document creator's user ID), storage location (full document path + document file name), creation date (document creation date), revision date, revision ID (user revision last user ID) Each item of storage expiration date (document storage expiration date, 99999999 is stored for many years) is stored. The confidential rank of the document management DB indicates that access is possible when the confidential rank of the user master described later is equal to or higher than the confidential rank of the document management DB. For example, the confidential rank S of the document management DB can be accessed only by a person whose confidential rank of the user master is S rank, and the confidential rank C of the document management DB is accessed by a person whose confidential rank of the user master is S rank to C rank. It shows that it is possible. The actual data of the secret rank is stored as S rank 7, A rank 6, B rank 5, C rank 4, D rank 3, E rank 2, F rank 1. If the confidential rank of the document management DB is F rank (1), it means that the person of F rank of the user master can access, and this means that this document is a general document that is not confidential.

  The user master shown in FIG. 13 stores items such as a unique user ID (key item), name, belonging organization code, confidential rank, position, e-mail address, extension telephone number, and belonging domain. For example, S is an officer or higher, A is the head of the business department, B is the head of the department or equivalent, C is the department manager or equivalent, D is the section manager or equivalent, E is the manager or equivalent, and F is a general position Indicates. The actual data of the secret rank stores 7 to 1 for the S rank to F rank as in the document management DB. The secret rank indicates which rank of the confidential document can be accessed. For example, S (7) can access the confidential document of the entire company, A can access the confidential document of the business department to which the company belongs, B is the headquarters to which the company belongs. Can access confidential documents, C can access confidential documents in the department to which he belongs, D can access confidential documents in the department to which he belongs, E can access confidential documents created by himself, F can access confidential documents It means you can't. The belonging domain indicates the domain of the network to which the user's PC is connected.

  The organization master shown in FIG. 14 includes a unique organization code (key), organization name, organization rank (5 to 1, the higher organization is a larger number), organization manager user ID (line length user ID), and organization code 1 (Organization code one level above the organization), Higher organization code 2 (Organization code two levels above the organization), Upper organization code 3 (Organization code three levels above the organization) , Upper organization code 4 (organization code four levels above the organization), organization reorganization date (date when the organization started), organization abolition date (date when the organization was abolished) Each item of the old organization code (the organization code of the old organization in the case of an organization change) is stored. For example, the organizational rank means 5 for the business division, 4 for the head office, 3 for the division, 2 for the section, and 1 for the section. For example, when the upper organization code is a section, the upper organization code 1 is the organization code of the department including the section, the upper organization code 2 is the organization code of the headquarters including the section, and the upper organization code 3 is the organization of the business department including the section Indicates the code.

  The document management master shown in FIG. 15 stores the presence / absence of encryption for each extension, and the extension (key item) attached to the end (after.) Of the document file name and the encryption classification (encryption required). 1 is stored, and encryption is not required: 0).

  Next, a basic processing flow of the encryption / decryption system of the document management system will be described with reference to FIG. FIG. 3 shows a document management system according to an embodiment of the present invention, wherein a download request for a document to be browsed is transmitted from the client terminal to the document management server, and the document management server encrypts the document requested to be browsed by the received client. FIG. 4 is a diagram illustrating a basic processing flow when an encrypted document is transmitted to the client terminal and the client terminal receives (downloads) the encrypted document.

  Steps 101 to 107 in FIG. 3 are processes executed under the control of the CPU 201 of the client 200, and steps 121 to 126 are processes executed under the control of the CPU 201 of the document management server 100.

  First, in step 101, the client 200 transmits, to the document management server 100, login information including information specifying a user ID, a password, and a domain name to which the user belongs, via an operation screen provided from the document management server 100. To do.

In step 121, the document management server 100 stores the received login information in the work area of the RAM 203, refers to the user master using the user ID of the login information as a key, and authenticates the user as to whether the user ID and password match. I do. If the user ID and password do not match, the document management server 100 sends an error message to the client 200. The client 200 receives the login permission message, displays the error message, and then inputs the user ID and password again to manage the document. Send to server 100. When the user ID and the password match, the document management server 100 transmits a login permission message and operation screen information for causing the client 200 to display an operation screen.
In step 102, the client 200 receives the login permission message and advances the process to step 103.

  In step 103, the client 200 receives document search request information (including user ID and search condition information via the operation screen displayed using the operation screen information received from the document management server 100. Or the part of the document, the document creator name, the document creation date, etc.).

In step 122, the document management server 100 searches the document management DB using the document search condition information included in the search request information received from the client 200, and bibliographic information (document number and document number) of the document that matches the search condition. The document name, creator, revision date, etc.) are stored in the work area of the RAM 203, and the process proceeds to step 123. Specifically, referring to the user master using the user ID as a key, the confidential rank and organization code of the user are obtained, and in the search of the document management DB, the search condition information and the confidential rank are used. A document that matches the information and has a confidential rank corresponding to the user ID is searched.

That is, for example, if the confidential rank of the user is C rank, a document whose document confidential rank is C rank to F rank is searched. When the name of the document creator is included in the search condition, the document management DB is searched with the search condition including the user ID by referring to the user master by name and acquiring the user ID. It should be noted that the user ID of the user who is going to download and view the document is referred to the user master, the confidential rank and the organization code of the user who is going to browse are acquired, and the organization master shown in FIG. Whether or not viewing is possible can be determined by determining the relationship between the organization of the user who created the document with reference to the organization of the user who is downloading and viewing the document.

In step 123, the document management server 100 uses the bibliographic information of the documents stored in the work area of the RAM 203 to display screen information for displaying a list screen (search result list) of documents matching the search condition on the client 200. Is stored in the work area of the RAM 203.
In step 124, the document management server 100 transmits the created search result list screen information to the client 200.

  In step 104, the client 200 that has received the screen information for the search result list from the document management server 100 displays the search result list on the screen G100 in FIG.

  In step 105, the client 200 selects a document to be downloaded from the search result list screen, and transmits selection information for identifying the selected document to the document management server 100 together with the user ID.

  In step 125, the CPU 201 of the document management server 100 converts the user ID at the time of user login and a unique ID (such as a Mac address) that can identify the client machine into a function-operated one, creates an encryption key, and creates the RAM 203. And the process proceeds to step 126.

In step 126, the CPU 201 of the document management server 100 transmits screen information for causing the client 200 to display an encryption process in progress screen (screen G 101 in FIG. 8), and the document specified by the selection information is stored in the RAM 203. Store in the work area and perform encryption.
Here, the CPU 201 of the document management server 100 transmits the encrypted document to the client terminal.
Delete documents before encryption. A detailed flowchart of the encryption process is shown in FIG. 5 and will be described later.
In step 106, the CPU 201 of the client 200 receives the encrypted document from the document management server.

  The CPU 201 of the client 200 stores the received document in the work area of the RAM 203, and in step 107, the received document can be browsed by decrypting the received document in units of pages. A detailed flowchart of browsing in step 107 is described in FIG. 7, and details will be described later.

  Next, FIG. 4 is a diagram showing a basic processing flow of the decryption system of the document management system according to the embodiment of the present invention. The decryption system is a process for uploading a document from the client 200 to the document management server 100.

  Steps 201 to 203 in FIG. 4 are processes executed under the control of the CPU 201 of the client 200, and steps 221 to 224 are processes executed under the control of the CPU 201 of the document management server 100.

  First, in step 201, the client 200 transmits login information including a user ID, a password, and the like to the document management server 100 via an operation screen (login) displayed using the screen information received from the document management server 100. To do.

In step 221, the document management server 100 authenticates the user based on the user information by the same process as in step 121 of FIG. When the user ID and the corresponding password match, message information for permitting login is transmitted to the client 200.
In step 202, the client 200 displays message information and advances the process to step 203.

  In step 203, a desired already encrypted document is selected on the operation screen, and the selected encrypted document and the bibliographic information of the encrypted document (secret rank, document type, creator ID or revision ID, storage expiration year) (Month / day) is transmitted to the document management server 100 together with the user ID.

  In step 222, the document management server 100 receives the encrypted document, bibliographic information, and user ID transmitted from the client 200, stores them in the work area of the RAM 203, and advances the process to step 223.

  In step 223, the encrypted document stored in the work area of the RAM 203 is decrypted. A detailed flowchart of the decoding process is described in FIG. 6 and will be described later.

  In step 224, the document management server 100 registers the decrypted document. Specifically, the decrypted document is moved to a predetermined folder, and bibliographic information is registered in the document management DB. If the decrypted document already exists, it is replaced with a predetermined folder, and the bibliographic item including the full path and file name stored in the document management DB is overwritten. This is the end of the description of the flowchart of FIG.

FIG. 5 is a detailed flowchart of the encryption process (step 126 in FIG. 3) performed by the document management server 100 in the encryption system in FIG. 3 of the document management system according to the embodiment of the present invention.
In the flowchart of FIG. 5, steps 301 to 331 are processes executed under the control of the CPU 201 of the document management server 100.

  First, in step 301, the encryption key created in step S125 is moved from the work area of the RAM 203 to a predetermined register of the CPU 201, and the process proceeds to step 302.

  In step 302, the work area of the RAM 203 is referred to, the user master is referred to using the user ID of the user who requested the document as a key, the domain to which the user belongs is obtained, and it is determined whether to execute the encryption process. If the document is not encrypted, the document management server 100 and the client 200 used by the user are in the same domain. If the domain is not encrypted, the process proceeds to step 320.

  In step 320, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display an original file download dialog. Using the received screen information, the client 200 displays an original file download dialog and ends the process. If the domain is to be encrypted (when the document management server 100 and the client 200 used by the user are in the same domain), the process proceeds to step 303.

  In step 303, the document management server 100 refers to the document management master shown in FIG. 15 using the extension of the selected document as a key, stores the encryption classification in the work area of the RAM 203, and advances the process to step 304.

  In step 304, it is determined whether the extension is an encryption target extension using the encryption classification stored in the work area of the RAM 203. If the extension is not the encryption target extension, the process proceeds to step 320.

In step 320, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display an original file download dialog. Using the received screen information, the client 200 displays an original file download dialog and ends the process.
If it is determined in step 304 that the extension is encrypted, the process proceeds to step S305.

  In step 305, the CPU 201 of the document management server 100 transmits to the client 200 screen information for causing the client 200 to display a subwindow indicating that encryption processing is in progress. The client 200 displays a sub-window (G101 in FIG. 8) indicating that encryption processing is in progress using the received screen information, and advances the processing to step S306.

  In step 306, the document to be encrypted is encrypted in units of pages using the encryption key stored in the register of the CPU 201, and the encrypted data in units of pages together with the number of bytes of the encrypted data is stored in the RAM 203. Store in the work area.

  Furthermore, after all pages are encrypted, the address when combined using the start address and end address of each page is calculated, and the header information (encrypted document (document) of the encrypted document (document)) is displayed before the encrypted document body. This is a kind of jump table that uses the number of bytes per page to record the number of each page, the first address of the encrypted file where the encrypted data of this page starts, and the last address where the encrypted data of this page ends. An encrypted document (document) is created by adding a table of contents information).

  Further, the encrypted document (document) is stored in the encryption folder, the encryption key created in 125 of FIG. 3 is stored in an encryption key table (not shown), and the process proceeds to step 307.

  In step 307, the existence of the encrypted file is confirmed. If there is no encrypted file and the encryption fails (encryption error) or a timeout (an error that the encryption is not completed within a predetermined time) occurs, the process is performed. The process proceeds to step S330.

  In step 330, an error log file including the details of the error that has occurred (error type, date of occurrence, user ID, document name) is output, and the process proceeds to step 331.

In step 331, when the generated error is an encryption error, the document management server 100 transmits to the client 200 screen information for displaying the encryption error screen on the client 200, and the client 200 receives the received screen information. Is used to display an encryption error screen (G105 in FIG. 8). In the case of a timeout error, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display a timeout error screen, and the client 200 uses the received screen information to display a timeout error screen (FIG. 8). G103) is displayed and the process is terminated.
If there is an encrypted file in step 307, the process proceeds to step 308.

  In step 308, the document copied to the encrypted folder (unnecessary file whose capacity after encryption is zero) is deleted, and the process proceeds to step 309.

  In step 309, the document management server 100 transmits screen information for displaying the download screen of the encrypted file on the client 200 to the client 200, and the process proceeds to step 310. The client 200 displays an encrypted file download screen (G102 in FIG. 8) using the received screen information.

  In step 310, when the document management server 100 receives from the client 200 information indicating that the download button has been pressed (clicked) on the client 200, the process proceeds to step 311.

  In step 311, the document management server 100 transmits screen information for causing the client 200 to display a download dialog, and waits for a response from the client 200. The client 200 displays a download dialog (G104 in FIG. 8) on the screen using the received screen information.

  When the document management server 100 receives information indicating that the “open” button or the “save” button has been pressed from the return client 200, the document management server 100 starts downloading the encrypted document to the client 200. Proceed to 312.

  In step 312, the document management server 100 deletes the encrypted document remaining in the encrypted folder, transmits to the client 200 screen information indicating that the encrypted document download screen (G 102 in FIG. 8) is closed, and the client 200. Closes the download screen. This is the end of the description of FIG.

FIG. 6 is a flowchart showing details of the decryption process (step 223 in FIG. 4) of the document management server 100 in the decryption system in FIG. 4 of the document management system according to the present invention.
Steps 401 to 441 in the flowchart of FIG. 6 are processes executed under the control of the CPU 201 of the document management server 100.

  First, in step 401, the document management server 100 refers to the document management DB using the file name as a key, determines whether the uploaded document is a new addition or an update (version addition), and The determination result is stored in the work area of the RAM 203, and the process proceeds to step 402.

  In step 402, the document management server 100 refers to the document management master using the file extension as a key, acquires the encryption classification, stores it in the work area of the RAM 203, and proceeds to step 403.

  In step 403, the document management server 100 determines whether the document is to be decrypted using the encryption classification stored in the work area of the RAM 203. If it is determined that the document is to be decrypted, the process proceeds to step 404. On the other hand, if the extension is not subject to decryption, the process proceeds to step 420.

  In step 420, the document management server 100 performs document registration processing (processing for storing the document in a predetermined folder and registering bibliographic information in the document management DB) in the document management server 100, and advances the processing to step S414.

  In step 404, the document management server 100 transmits screen information for causing the client 200 to display the list screen (G200 in FIG. 9) to the client 200, and the client 200 uses the received screen information to display the list screen (FIG. 9 G200) is displayed and the process is terminated.

  On the other hand, when it is determined in step 403 that the extension is to be decrypted, in step 404, the document management server 100 displays screen information for causing the client 200 to display a screen (G204 in FIG. 10) indicating that decryption processing is in progress. The client 200 displays a screen (G204 in FIG. 10) indicating that the decryption process is being performed using the received screen information.

  During this time, the document management server 100 uses the encryption key created by functionally operating the user ID at the time of login of the client 200 and a unique ID (Mac address etc.) that can identify the client machine in the same manner as in step 125. The server encryption key table is referenced, and if the same encryption key is stored, the document is decrypted using this encryption key, and the process proceeds to step 405.

If the decryption process is successful, an empty “.success” file is created. On the other hand, if the decryption processing fails, a “.error” file including error contents (for example, error contents such as extension and document contents do not match) is created.
In step 405, the document management server 100 copies the decrypted predetermined document to the decryption folder, and advances the processing to step 406.

In step 406, the document management server 100 determines whether a file with the extension “.success” or a file with the extension “.error” exists, and the file with the extension “.success” also has the extension “ If neither of the “.error” file exists, the process proceeds to step 440.
In step 440, an error log file indicating that the process has ended abnormally is output, and the process proceeds to step 441.

  In step 441, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display a timeout error screen (G206 in FIG. 10), and the client 200 uses the received screen information to output a timeout error screen. (G206 in FIG. 10) is displayed, and the process proceeds to step 433.

  In step 433, the client 200 transmits a message indicating that the “return” button is pressed on the timeout error screen to the document management server 100, and the document management server 100 detects that the “return” button is pressed. Is received, the process proceeds to step 410.

In step 410, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display a list screen (G200 in FIG. 9), and the client 200 uses the received screen information to display a list screen ( This process is terminated by displaying G200) in FIG.
On the other hand, if there is either a file with the extension “.success” or a file with the extension “.error”, the process proceeds to step 407.

In step 407, the document management server 100 proceeds to step 408 if there is a file with the extension “.success”, and proceeds to step 430 if there is a file with the extension “.error”. Proceed.
In step 408, the document management server 100 deletes the file with the extension “.success” and advances the process to step 409.

  In step 409, the document management server 100 stores the decrypted document file in a predetermined folder, and registers bibliographic information in the document management DB. If the extension is “.error” in step 407,

In step 430, the contents of the file with the extension “.error” are stored in the work area of the RAM 203, the file with the extension “.error” is deleted, and the process proceeds to step 431.
In step 431, an error log file is output using the error contents stored in the work area of the RAM 203, and the process proceeds to step 432.

  In step 432, the document management server 100 transmits to the client 200 screen information for causing the client 200 to display an error screen (G207 in FIG. 10), and the client 200 uses the received screen information to display an error screen (FIG. 10G207) is displayed, and the process proceeds to step 433.

  In step 433, the client 200 sends a message to the document management server 100 indicating that the “return” button on this error screen has been pressed or the “return” button on the timeout screen has been detected, and the document management server 100 “returns”. When a message indicating that the button has been pressed is received, the process proceeds to step 410.

  In step 410, the document management server 100 transmits screen information for causing the client 200 to display a list screen (G200 in FIG. 9) to the client 200, and the client 200 uses the received screen information to display the list screen (FIG. 9 G200) is displayed and the process is terminated.

Next, FIG. 7 shows details of the document management system according to the embodiment of the present invention, in which the client (viewing terminal) 200 receives the document (document) encrypted by the document management server described with reference to FIG. It is a figure which shows a flow.
Steps 701 to 724 in the flowchart of FIG. 7 are processes executed under the control of the CPU 201 of the client terminal 200.
First, in step 701, the CPU 201 of the client 200 confirms the establishment of a session with the document management server 100.
Here, the CPU 201 of the client 200 determines whether communication with the document management server is being established.

  When the session cannot be established, the browsing process is terminated. That is, when there is no session here, no decryption processing is executed. By assuming the establishment of a session as a premise for browsing, it is possible to prevent a decryption process of an already-downloaded encrypted document in an environment where a session cannot be established, and to improve security. If the session can be established, the process proceeds to step 702, and the browsing process (page display) proceeds. As a method for confirming session establishment, a known technique is used which is the same as the method recognized by the client terminal when the LAN cable is disconnected.

In step 702, the CPU 201 of the client 200 refers to the encryption key table of the document management server 100 based on the encryption key of the client, and ends the browsing process if the same encryption key does not exist. That is, if there is no encryption key here, no decryption processing is executed. If it exists, the process proceeds to step 703.
In step 703, the CPU 201 of the client 200 automatically creates a temporary file. Further, the CPU 201 of the client 200 stores a temporary file.
Here, the CPU 201 of the client 200 inquires about the current system time of the document management server.
Here, the CPU 201 of the document management server 100 answers the current system time of the document management server.

The contents of the temporary file (1601 in FIG. 16) are obtained from the document number, the document is obtained from the header information of the document, the user ID is obtained from the user master of the document management server 100, and the client 200 manages the document for the access date and access time. The date of access to the server 100 and the time of access (inquiry) are acquired from the system time (system time) of the document management server 100, and the valid time is set from the initial setting file (1603 in FIG. 16) of the document management server 100. The temporary file is stored in the work area of the RAM 203 of the client 200 in addition to the current system time of the document management server 100, and the process proceeds to 704.
The CPU 201 of the client 200 stores an initial setting file in advance.
The access time is read when the system time (system time) of the document management server 100 is accessed (inquired) from the terminal.

  The expiration date (predetermined time) is the time previously written in the initial setting file, and even if the session has expired (no step 705), the session (communication) is resumed by the effective time (predetermined time). If established, it is an allowable time for permitting subsequent document browsing (decoding process), and a value such as 10 minutes (600 seconds) is used.

In other words, the valid time (predetermined time) is the time obtained by adding the valid period (predetermined time) to the access time (system time of the document management server), and the access time is 15:10 on December 25, 2009. The valid time (predetermined time) is 15:20 on December 25, 2009, which is 10 minutes after the expiration date (predetermined time).
Here, the CPU 201 of the client 200 determines an effective time (predetermined time).

Since the valid time (predetermined time) of the temporary file is referred to when the session with the server is disconnected (step 721), it is necessary to create the temporary file here.
Since the contents of the temporary file are updated after the document is once displayed on the client (step 707), it is necessary to create the temporary file here.

In step 704, the CPU 201 of the client 200 stores the address information for each page (start address and end address for each page) acquired from the document header information and the set number of pages in the work area of the RAM 203.
Here, the CPU 201 of the client 200 decrypts the encrypted data of the first page for each page based on the address information for each page.

  Further, it is stored in the work area of the RAM 203. Next, the CPU 201 of the client 200 displays the first page (G300 in FIG. 11) of the document (document) decrypted page by page on the display screen of the client terminal, and advances the processing to step 705.

In step 705, the CPU 201 of the client 200 performs a decryption process (prefetch decryption process) for the next page currently displayed using the address information and encryption key for each page acquired from the header information of the encrypted document. Do. The CPU 201 of the client 200 stores the decrypted document data (decrypted next page data) in the work area of the RAM 203, and the process proceeds to step 706.
In step 706, the CPU 201 of the client 200 confirms the session (communication) with the document management server 100 again.
Here, the CPU 201 of the client 200 determines whether communication with the document management server is being established.

  The confirmation of the session in step 706 is for confirming the session with the server continuously after the decrypted document is once displayed. If no session is established, the process proceeds to step 720. If a session has been established, the process proceeds to step 707.

  The session confirmation here is different from the confirmation in step 701. In this session confirmation, after the reference of the encryption key is completed in step 702, the valid time of the temporary file created in step 703 is updated when there is a session (step 707). As in step 701, the session establishment confirmation method uses a known technique that is the same as the method recognized by the client terminal when the LAN cable is disconnected.

  In step 720, a known technique is used for the document displayed on the client 200 in order to ensure security for the document displayed on the client 200 while the session with the document management server 100 is disconnected. And control to limit the following.

The CPU 201 of the client 200 prohibits a screen capture function (such as a print screen key or a screen hard copy using screen capture software).
The CPU 201 of the client 200 controls a document editing function (save and copy cannot be selected from the menu list).
The CPU 201 of the client 200 prohibits copying of a character string by dragging on a document, addition or deletion of characters, symbols, diagrams, and the like.
The CPU 201 of the client 200 prohibits a document printing function (such as deleting a print button or disabling printing from a menu list).
The CPU 201 of the client 200 prohibits page transitions (screen scrolling, page turning, etc.).
In addition, functions that realize copying, editing, and printing in accordance with the above functions are prohibited.
That is, here, the CPU 201 of the client 200 issues an operation stop instruction such as capturing, copying, editing, printing, and page transition of the currently displayed document.

  In step 721, the CPU 201 of the client 200 uses the valid time (predetermined time) of the temporary file recorded in the work area of the RAM 203 of the client 200 and the current system time (system time) of the client 200 by the CPU 201 of the client 200. Get and compare.

  Here, the CPU 201 of the client terminal 200 determines which of the effective time (predetermined time) and the system time of the client terminal (viewing terminal) is greater (late).

  For example, if the effective time of the temporary file is 15:20 on December 25, 2009 and the current system time (system time) is 15:10 on December 25, 2009, the effective time is large (slow). judge. If the valid time is long, the process proceeds to step 722. If the valid time is small (early), the process proceeds to Step 1915.

  The system time in step 721 is the time built in the client terminal, and the CPU 201 of the client 200 confirms the built-in time by a known technique.

In step 722, the CPU 201 of the client 200 confirms the session with the document management server 100 again. When the session is not established, the process returns to step 721. If it is within the valid time, the processing of step 721 and step 722 is repeated, and the session confirmation is continued.
Here, the CPU 201 of the client 200 determines whether communication with the document management server is being established.
If a session has been established, the process proceeds to step 723.

  In step 723, the CPU 201 of the client 200 uses the document number and document name of the document header file (1602 in FIG. 16) of the currently viewed document as the document number and document name of the temporary file stored in the work area of the RAM 203. Compare and confirm.

  When the temporary file and the document header file are compared, and either the document number or the document name recorded in both is different, the process proceeds to step 714 to delete the temporary file. If both the document number and the document name are the same, the process proceeds to step 724.

In step 724, the CPU 201 of the client 200 cancels the operation stop instruction for the document displayed on the client 200 performed in step 720 using a known technique.
In step 707, the CPU 201 of the client 200 updates the valid time of the temporary file.
Here, the CPU 201 of the client 200 inquires about the current system time of the document management server.
Here, the CPU 201 of the document management server 100 answers the current system time of the document management server.

  The update contents are set by setting the system time of the document management server 100 to the access time of the temporary file stored in the work area of the RAM 203 of the client 200, and the expiration date read from the initial setting file of the document management server 100 (eg, 10 minutes) ) Is added to the system time of the document management server 100, the valid time of the temporary file is updated, and the process proceeds to Step 1908.

For example, if the effective time of the temporary file before update is 15:20 on December 25, 2009 and the current system time of the document management server 100 is 15:30 on December 25, 2009, the updated file is updated. The effective time of the temporary file is 15:40 on December 25, 2009.
Here, the CPU 201 of the client 200 determines an effective time (predetermined time).
Here, the CPU 201 of the client 200 updates the valid time (predetermined time).

In step 708, the CPU 201 of the client 200 determines whether or not there is a page designation input on the document browsing screen. If there is a page designation input (the GO button of G300 in FIG. 11 is pressed), the process proceeds to step 709. On the other hand, if it is determined in step 708 that there is no page designation input, the process proceeds to step 711.
In step 709, the CPU 201 of the client 200 performs a decoding process for the designated page. The process proceeds to step 710.
In step 710, the CPU 201 of the client 200 instructs display of the designated page and displays the designated page.

In step 711, the CPU 201 of the client 200 determines whether or not there is a next page designation input. If there is a next page designation input (the next page button of G300 in FIG. 11 has been pressed), the process proceeds to step 712. If no next page designation input is made at 711, the process proceeds to the browsing end determination at step 713.
In step 712, the CPU 201 of the client 200 instructs display of the next page and displays the next page.

  In step 713, it is determined whether there is an input to end browsing. If there is no input to end browsing, the process returns to the next page decoding process in step 705. If it is determined that there is an input to end browsing, the process proceeds to step 714.

In step 714, the CPU 201 of the client 200 deletes the temporary file created in the work area of the RAM 203 of the client 200 created in step 1903, and the process ends in step 715 (the display of the currently displayed document is erased). ).
This is the end of the description of FIG.
The temporary file 1601 in FIG. 16 is automatically created in step 703 during the browsing process described in FIG. 7, and the contents recorded in the temporary file are stored in the RAM 203.

The document header file 1602 in FIG. 16 is received by the client terminal in step 106 during document storage described with reference to FIG. 3, and the contents recorded in the document header file are stored in the RAM 203.
The initial setting file 1603 in FIG. 16 is saved by the client terminal, and the contents recorded in the initial setting file are stored in the RAM 203 or the external memory.
[Other Examples]

  The functions shown in the flowcharts of FIGS. 3 to 7 and the screens of FIGS. 8 to 11 in the present embodiment may be performed by the host computer by a program installed from the outside. In this case, the present invention is applied even when an information group including a program is supplied to the output device from a recording medium such as a CD-ROM, a flash memory, or an FD, or from an external recording medium via a network. Is.

  As described above, a recording medium in which a program code of software for realizing the functions of the above-described embodiments is recorded is supplied to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus is stored in the recording medium. It goes without saying that the object of the present invention can also be achieved by reading and executing the program code.

  In this case, the program code itself read from the recording medium realizes the novel function of the present invention, and the recording medium storing the program code constitutes the present invention.

  As a recording medium for supplying the program code, for example, a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, DVD-ROM, magnetic tape, nonvolatile memory card, ROM, EEPROM, A silicon disk or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) or the like running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Furthermore, after the program code read from the recording medium is written in a memory provided in a function expansion board inserted in the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or apparatus. In this case, by reading a recording medium storing a program represented by software for achieving the present invention into the system or apparatus, the system or apparatus can enjoy the effects of the present invention.
Furthermore, by downloading and reading out a program represented by software for achieving the present invention from a server, database, etc. on a network using a communication program, the system or apparatus can enjoy the effects of the present invention. It becomes.

100 document management server 200 client terminal 201 CPU
202 ROM
203 RAM
204 System Bus 205 Input Controller 206 Video Controller 207 Memory Controller 208 Communication I / F Controller 209 Keyboard 201 CRT
211 External memory (hard disk, etc.)
300 Communication line

Claims (11)

A document management system configured to allow communication between a document management server and a browsing terminal,
The document management server
Encrypted document transmission means for transmitting an encrypted document including address information for each page;
An answering means for answering the system time to the viewing terminal;
The browsing terminal is
Encrypted document receiving means for receiving the encrypted document;
Decrypting means for decrypting the document received by the encrypted document receiving means for each page based on address information for each page;
Page display means for displaying the document decrypted for each page for each page;
Inquiry means for inquiring of the system time to the document management server;
Determining means for determining a predetermined time from the system time of the document management server;
First determination means for determining whether communication between the document management server and the viewing terminal is established after the page display means displays a page of the decrypted document;
When the first determination unit determines that communication is not established, the first determination unit determines whether to allow display of a page not displayed by the page display unit from the predetermined time and the system time of the viewing terminal. A document management system comprising a second determination unit. The browsing terminal is
An operation stop instruction means for instructing stop of operations such as copying, editing, and printing of a page displayed by the page display means;
2. The document management system according to claim 1, wherein when the first determination unit determines that communication is not established, the operation stop unit issues an operation stop instruction. 3.   2. The document management system according to claim 1, wherein when the second determination unit determines that the predetermined time is earlier than the system time of the browsing terminal, the page display unit does not display a page. . The browsing terminal is
A first storage means for storing the predetermined time; and a second storage means for storing the predetermined time determined by the determination means;
2. The document management system according to claim 1, wherein the determination unit determines the predetermined time based on the predetermined time and a system time of the document management server inquired by the inquiry unit.   When the second determination unit determines that the predetermined time is later than the system time of the browsing terminal, the inquiry unit inquires of the document management server about the system time, and the second storage unit stores the time. 5. The document management system according to claim 4, further comprising update means for updating the predetermined time. A document management system control method configured to allow communication between a document management server and a browsing terminal,
An encrypted document transmitting unit of the document management server, wherein the encrypted document transmitting unit transmits an encrypted document including address information for each page;
A reply process in which the reply means of the document management server answers the system time to the viewing terminal;
An encrypted document receiving step in which the encrypted document receiving means of the browsing terminal receives the encrypted document; and
A decryption step of decrypting the document received by the encrypted document reception step for each page based on the address information for each page;
A page display step in which the page display means of the browsing terminal displays the document decrypted for each page for each page;
An inquiry step in which the inquiry means of the browsing terminal inquires about the system time to the document management server;
A determining step in which the browsing terminal determining means determines a predetermined time from the system time of the document management server;
First determining means of the viewing terminal determines whether communication between the document management server and the viewing terminal is established after displaying the page of the document decrypted in the page display step. A determination process;
When the second determination means of the viewing terminal determines that the first determination step is not establishing communication, the page display step displays the predetermined time and the system time of the viewing terminal. A control method for a document management system, comprising a second determination step of determining whether to allow display of a non-existent page. The operation stop instruction means of the browsing terminal further includes an operation stop instruction step for instructing stop of an operation such as copying, editing, and printing of a page displayed by the page display step,
The document management system according to claim 6, further comprising a step of instructing operation stop when the operation stop unit of the browsing terminal determines that the first determination step is not establishing communication. Control method.   The page display means of the browsing terminal includes a step of not displaying a page when the second determination step determines that the predetermined time is earlier than the system time of the browsing terminal. Item 7. A method for controlling a document management system according to Item 6. A first storage step in which the first storage means of the browsing terminal stores the predetermined time; and a second storage unit in which the second storage means of the browsing terminal stores the predetermined time determined by the determination step. A memory step,
The document according to claim 6, wherein the determining means of the browsing terminal includes a step of determining the predetermined time based on the predetermined time and a system time of the document management server inquired by the inquiry step. Management system control method.   When the update means of the browsing terminal determines that the second determination step is later than the system time of the browsing terminal, the inquiry step makes an inquiry about the system time to the document management server, and The document management system control method according to claim 9, further comprising an update step of updating the predetermined time stored in the second storage step. A program executed in a document management system configured to allow communication between a document management server and a browsing terminal,
The document management server
Encrypted document transmission means for transmitting an encrypted document including address information for each page;
An answering means for answering the system time to the viewing terminal;
The browsing terminal is
Encrypted document receiving means for receiving the encrypted document;
Decrypting means for decrypting the document received by the encrypted document receiving means for each page based on address information for each page;
Page display means for displaying the document decrypted for each page for each page;
Inquiry means for inquiring of the system time to the document management server;
Determining means for determining a predetermined time from the system time of the document management server;
First determination means for determining whether communication between the document management server and the viewing terminal is established after the page display means displays a page of the decrypted document;
When the first determination unit determines that communication is not established, the first determination unit determines whether to allow display of a page not displayed by the page display unit from the predetermined time and the system time of the viewing terminal. A program for a document management system, characterized by functioning as a second determination means.

Images