WO2010061443A1

WO2010061443A1 - Network management program, network management method, and network management server

Info

Publication number: WO2010061443A1
Application number: PCT/JP2008/071505
Authority: WO
Inventors: 杉中順子
Original assignee: 緒方延泰
Priority date: 2008-11-27
Filing date: 2008-11-27
Publication date: 2010-06-03

Abstract

A selection section (201) selects one encryption program and decryption program selected by a predetermined method for information processing terminals (1), which a distribution section (202) distributes. When a communication processing section (204) receives a file encrypted and transmitted by a information processing terminal (1) of a transmission source, a transmitter/receiver information extracting section (205) identifies each information processing terminal (1) of the transmission source and transmission destination from the received file, which a decryption processing section (206) decrypts. An encryption processing section (207) then encrypts the decrypted file using the encryption program corresponding to the decryption program distributed to the information processing terminal (1) of the transmission destination, which the communication processing section (204) transmits to the information processing terminal (1) of the transmission destination.

Description

Network management program, network management method, and network management server

The present invention relates to a network management technique for managing transmission / reception of an encrypted file performed between a plurality of information processing terminal devices connected to a network.

When a document file created by an information terminal such as a personal computer is transmitted to another information terminal via a network such as the Internet, the document file is transmitted divided into packets. Since this packet can be obtained by a third party using a packet capture function on the network, there is a risk of secret leakage. Therefore, in order to ensure security when sending information over the network, the plaintext file to be sent is encrypted and sent, and the received file is decrypted by the receiving information terminal. In recent years, a security method for returning to plaintext has been generally adopted. As a security method, a method using a common key and a method using a public key are well known. The common key method has a problem in secrecy in transmission of the key itself. On the other hand, the public key method is preferable from the viewpoint of secrecy because a file encrypted with the public key can be decrypted only with the private key of the receiving information terminal. In addition, a method of setting an expiration date for the public key or authenticating the public key is also adopted, but it is effective because it can be input by a third party before the expiration date or impersonated the certificate authority. There are limits.

Furthermore, in the common key system, as shown in Patent Document 1, if the common key is changed, the secrecy can be further improved. In Patent Document 1, a computer provided with two modem circuits or ISDN interface circuits is used. The first channel is connected to a receiver via a router via the Internet or an in-house network, and the second channel is connected via an exchange. An electronic authentication system that directly connects to a recipient via a public line or an in-house communication line is described. The document file is encrypted with a secret key and transmitted on the first channel, and the public key is transmitted on the second channel. Since the public key and the private key can be changed every time the document is transmitted, the possibility of being stolen by a third party is reduced.
JP 2002-51038 A

However, in the public key system disclosed in Patent Document 1, a first channel that connects to a recipient via the router using the Internet or an in-house network, and a second channel that connects to the recipient using a public line or an in-house communication line via an exchange. Since a channel is required, the configuration becomes special and the operation burden on the sender increases. Further, in a mode in which the public key creation program is stored in the information terminal, the public key creation program itself is easily stolen through mechanical or electrical access. If a public key creation program is stolen, there is a risk that a file to be transmitted or received may be stolen by packet capture and easily decrypted.

The object of the present invention is to update the encryption program between the sender and the decryption program with the receiver at a predetermined timing by the management server on the network, thereby improving the confidentiality of the file to be transmitted / received. It is to raise it further.

A network management server according to the present invention includes a plurality of encryption programs and a corresponding decryption program in a network management server that manages transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network. And a selection means for selecting one encryption program for an information processing terminal device that can be a transmission source and a one decryption program for an information processing terminal device that can be a transmission destination, respectively. Distribution means for distributing at least the encrypted encryption / decryption program before transmission of the file, management means for managing the encryption program and the decryption program distributed to each information processing terminal device, and transmission source information Receiving means for receiving a file that has been encrypted and transmitted by the processing terminal device, and whether the received file Extraction means for specifying each of the information processing terminal devices of the transmission source and the transmission destination, and decoding for decoding the file transmitted from the information processing terminal of the transmission source with a corresponding decoding program according to management information of the management means Means, an encryption means for encrypting the decrypted file with an encryption program corresponding to a decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means, and the encryption means And a transmission unit configured to transmit the encrypted file to the information processing terminal device of the transmission destination detected by the detection unit.

The network management program of the present invention is a network management program for managing transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network by a network management server. And a storage means for storing the corresponding decryption program, one encryption program for the information processing terminal device that can be the transmission source, and one decryption program for the information processing terminal device that can be the transmission destination, respectively. Selection means, delivery means for delivering the selected encryption / decryption program at least before transmission of the file, management means for managing the encryption program and decryption program delivered to each information processing terminal device, transmission source Receive files that have been encrypted and sent by other information processing terminal devices A communication unit, an extraction unit that identifies each information processing terminal device of a transmission source and a transmission destination from the received file, and a decoding program that corresponds to a file transmitted from the information processing terminal of the transmission source by management information of the management unit Decrypting means for decrypting with, an encrypting means for encrypting the decrypted file with an encryption program corresponding to the decryption program distributed to the information processing terminal device of the transmission destination extracted by the extracting means, The network management server is caused to function as a transmission unit that transmits a file encrypted by the encryption unit to a destination information processing terminal device detected by the detection unit.

The network management method of the present invention is a network management method in which a network management server manages transmission / reception of an encrypted file performed between a plurality of information processing terminal devices connected to a network. The encryption program and the corresponding decryption program are stored, and the selecting means stores one encryption program in the information processing terminal device that can be the transmission source and one decryption program in the information processing terminal device that can be the transmission destination. The management unit manages the encryption program and the decryption program distributed to each information processing terminal device, and the distribution unit selects the selected encryption and decryption program at least for the file. Deliver before transmission, and the receiving means encrypts the transmitted file and sends it to the information processing terminal device And the extracting means identifies the information processing terminal device of the transmission source and the transmission destination from the received file, and the decoding means manages the file transmitted from the information processing terminal of the transmission source by the management means An encryption program corresponding to a decryption program that is decrypted by a corresponding decryption program according to information, and wherein the encryption means distributes the decrypted file to a destination information processing terminal device extracted by the extraction means. The encryption unit and the transmission unit transmit the file encrypted by the encryption unit to the information processing terminal device of the transmission destination detected by the detection unit.

According to these inventions, the storage means stores a plurality of encryption programs and corresponding decryption programs. Then, one encryption program selected by the selection unit by the selection unit is selected by the distribution unit by the distribution unit, and the selection unit by the selection unit selects the information processing terminal unit by which the transmission unit can be the transmission destination. The one decrypted program is distributed at least before transmission of the file. The management means manages the encryption program and the decryption program distributed to each information processing terminal device. When a file encrypted and transmitted by the information processing terminal device of the transmission source is received by the reception unit, the information processing terminal device of the transmission source and the transmission destination is specified from the received file by the extraction unit. The decryption means extracts a decryption program corresponding to the file transmitted from the information processing terminal of the transmission source according to the management information of the management means, and decrypts with this decryption program. Next, the encrypted means encrypts the decrypted file with an encryption program corresponding to the decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means, and thereafter the transmission means Thus, the file encrypted by the encryption unit is transmitted to the information processing terminal device of the transmission destination specified by the extraction unit.

Accordingly, the file transmitted from the information processing terminal device of the transmission source is changed to a ciphertext that differs almost every transmission, and the encrypted file is transmitted from the information processing terminal device of the transmission source by the network management server. Since the ciphertext is substantially different from the ciphertext and is transmitted to the information processing terminal device of the transmission destination (that is, received by the information processing terminal device of the transmission destination), the confidentiality is remarkably improved. Further, since different encryption programs and decryption programs can be distributed (provided) to a large number of information processing terminal devices, this network is used, for example (having authority to access this network). Even if there are many members, efficient security management can be realized easily. In addition, since the network management server distributes a predetermined method, for example, a complicated rule or a random encryption program and decryption program, for the server administrator, which encryption program is currently in each information processing terminal device. Therefore, it is not known which decryption program is in a distributed state, and security from an artificial aspect is ensured.

The distribution means according to the present invention distributes one encryption program and decryption program selected by a predetermined method to each information processing terminal device at a predetermined timing. According to this configuration, since each information processing terminal device always has one encryption program and decryption program, it is possible to support transmission of encrypted files and reception of encrypted files. In addition, since each information processing terminal device has different encryption programs and decryption programs in the direction of time, even if the encryption program or decryption program leaks temporarily for some reason, At this point, since there is another encryption program and decryption program, confidentiality is ensured.

In the present invention, the predetermined timing is every preset period. According to this configuration, since the encryption program and the decryption program are periodically updated, the significance of illegal acquisition or theft of the encryption program and the decryption program is lost. Note that the term “periodic” refers to every predetermined time, every day, every few days, and the like, and can be set based on network traffic and the required security level.

In the present invention, when the selection means receives a transmission request signal including information on a transmission source and a transmission destination, which is transmitted prior to transmission of a file from the information processing terminal device of the transmission source, the transmission request signal 1 is selected for the information processing terminal device that has transmitted the message, and one decryption program is selected for the information processing terminal device that is the transmission destination, and the distribution means transmits the transmission request signal. The selected encryption program is distributed to the terminal device, and the selected decryption program is distributed to the information processing terminal device of the transmission destination. According to this configuration, the encryption program is distributed immediately before the transmission of the file, and the decryption program is distributed to the transmission destination of the transmission file at the same time. Even if done, the program is virtually useless.

Further, the predetermined method in the present invention is to select at random. According to this configuration, the server administrator itself cannot grasp the current distribution status of the encryption program and the decryption program, and cannot leak from the human side. As a random method, typically, a method in which a random number generator or the like is provided and the corresponding encryption program and decryption program are individually set based on the generated random value can be employed.

Also, the distribution means in the present invention distributes a plurality of encryption programs and corresponding decryption programs to all information processing terminal devices in advance, and corresponds to the encryption programs and the same at the predetermined timing. The identification information for identifying the decryption program is distributed by the predetermined method. According to this configuration, since the encryption program and the decryption program are not distributed directly from the network management server, it is possible to extremely limit the chance of unauthorized acquisition.

In addition, the present invention includes a member management unit, wherein the network is a dedicated network provided together with the Internet, and the member management unit sets authority to permit connection to the dedicated network in the information processing terminal device It is characterized by being. According to this configuration, since the use of the dedicated network is restricted to file transmission / reception between members, it is difficult to enter from other networks, and high security management is possible.

According to the present invention, a file transmitted from the information processing terminal device of the transmission source is changed to a ciphertext that differs almost every transmission, and the encrypted file is transmitted from the information processing terminal device of the transmission source by the network management server. Since the ciphertext that is substantially different from the transmitted ciphertext is transmitted to the information processing terminal device of the transmission destination, the confidentiality can be significantly improved.

In addition, since different encryption programs and decryption programs can be distributed (provided) to a large number of information processing terminal devices, efficient security management using this network, for example, even if there are a large number of members Can be realized easily.

Further, since the network management server distributes the encryption program and the decryption program in a predetermined method, for example, a complicated rule or at random, for the server administrator, which information processing terminal device currently has Without knowing which encryption program and which decryption program are distributed, it is possible to ensure security from an artificial viewpoint.

1 is an overall schematic configuration diagram of the Internet and a dedicated network system. 1 is a configuration diagram illustrating an embodiment of an information processing terminal device 1. FIG. 4 is a block configuration diagram of the information processing terminal device 1. FIG. It is a block diagram of the functional part relevant to this invention among the functional blocks of the management server 2. FIG. 5 is a flowchart of a program distribution process executed by the control unit 200 using a management program of the management server 2. 6 is a flowchart of a file relay process executed by the control unit 200 using a management program of the management server 2. It is a flowchart of other program delivery processing (II) performed by the control part 200 using the management program of the management server 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information processing terminal device 10 Personal computer terminal 11 Information processor 2 Management server (network management server)
200 Control Unit 201 Selection Unit 202 Distribution Unit (Distribution Means)
203 management section (management means)
204 Communication processing unit 205 Sender information extraction unit (extraction means)
206 Decryption Processing Unit 207 Encryption Processing Unit 208 Timer 211 Management Program Storage Unit 212 Encryption / Decryption Program Storage Unit (Storage Unit)
221 Distribution data storage unit 5 Dedicated network

FIG. 1 is an overall schematic configuration diagram of the Internet and a dedicated network system. This system includes the Internet 4 and a dedicated network 5 different from the Internet 4. The dedicated network 5 is configured such that only members who have become members are authorized to connect, so that information can be exchanged between the members via the dedicated network 5. Specifically, the dedicated network 5 supports electronic payment between members registered in the established organization. For example, payment in general commercial transactions, for example, issuance of invoices from dealer stores, Various electronic documents (referred to as files) regardless of whether they are received, issued from the purchaser to the account of the contract financial institution that issued the invoice (ie, payment), issued, or other electronic payments This makes it possible to perform transmission / reception processing.

The system shown in FIG. 1 includes an information processing terminal device 1 owned by each member and a management server 2 arranged in a management organization that manages information exchanged between the information processing terminal devices 1. In the present embodiment, both the Internet 4 and the dedicated network 5 are communicably connected via a contracted provider (ISP) 3. Each information processing terminal device 1 only needs to be connected to the dedicated network 5 and does not necessarily have to be connected to the Internet 4 (see, for example, the information processing terminal device 1 at the right end of FIG. 1).

Management server 2 is connected to a dedicated network 5. The management server 2 may be installed in one ISP 3.

FIG. 2 is a configuration diagram showing an embodiment of the information processing terminal device 1. The information processing terminal device 1 includes a known personal computer terminal (hereinafter referred to as a personal computer terminal) 10 and an information processing device 11 interposed between the personal computer terminal 10 and the ISP 3. The personal computer terminal 10 is a general personal computer connected to the Internet 4 via a corresponding ISP 3, and uses a browser in the computer to store public information on a website and the like. Information (not shown) can be searched and viewed. The information processor 11 has a built-in router function, is positioned as a modem, for example, and has a predetermined information processing function (for example, related to the electronic payment described above).

FIG. 3 is a block diagram of the information processing terminal device 1. The personal computer terminal 10 includes an input unit 10a for inputting information and an instruction for information processing, and a monitor 10b for displaying information. Further, the personal computer terminal 10 is roughly divided into a hard disk (HDD) 101, a control board unit including an information processing unit 102 and a storage unit 103 configured by a CPU (Central processing unit), a monitor 10b for displaying various images, An input unit 10a composed of a keyboard, a mouse and other operation members for inputting the operation instructions and information, and a disc loading unit 10c for detachably loading a disc such as a CDROM.

The information processing unit 11 has a predetermined shape, for example, a rectangular parallelepiped housing, and is provided with a modulator and a demodulator (not shown) for executing an original modem function, and for input / output at an appropriate place on the surface. Wiring terminals are provided. The modulator modulates information created by the personal computer terminal 10 over the Internet 4 and information created by the personal computer terminal 10 or the information processor 11 into a signal form that can be transmitted through the dedicated network 5. In this case, the signal received via the Internet 4 is demodulated into a signal form that can be processed by the personal computer terminal 10 and the signal received via the dedicated network 5 by the information processor 11.

The information processor 11 includes a liquid crystal panel or a plasma display panel at an appropriate surface, and includes a display unit 11a that displays an image and an operation unit 11b such as a touch panel that is stacked on the display unit 11a. The information processor 11 includes a control unit 110, a router function unit 120, and a data storage unit 130. The control unit 110 includes a CPU, and executes a creation support process for information (file) such as a required document or image, a data storage process, and a file transmission / reception process.

The data storage unit 130 includes a ROM and a RAM. The ROM stores a processing program (OS program, application program) for performing various operations (including a mode installed from the outside), and various documents. On the other hand, the RAM stores electronic files and the like related to its own electronic payment.

The router function unit 120 distributes (routes) information transmission paths among the personal computer terminal 10, the control unit 110 of the information processing device 11, the Internet 4, and the dedicated network 5. When only the information processing unit 11 is activated, the router function unit 120 is set by the information processing unit 11 so that the dedicated network 5 and the control unit 110 can transmit and receive information, and is disconnected from the Internet 4.

On the other hand, when the personal computer terminal 10 is activated, a routing setting process is performed at the time of activation as follows. That is, when the personal computer terminal 10 is used in a normal mode, the router function unit 120 of the information processing device 11 is connected to the personal computer terminal 10 and another computer on the Internet 4 via the ISP 3 and the Internet 4. Routing is set as follows. In this state, the information processor 11 is simply made part of the transmission path by the router function unit 120.

On the other hand, when the personal computer terminal 10 is used as an auxiliary to the information processing device 11, the personal computer terminal 10 is activated in a state where a predetermined disk, for example, a CDROM is loaded in the disk loading unit 10c. In this case, as will be described later, the personal computer terminal 10 is connected only to the control unit 110 (and the data storage unit 130) of the information processing device 11, and through the information processing device 11, the ISP 3, and the dedicated network 5, The router function unit 120 is routed so as to be connected to the other information processing terminal device 1 and the management server 2. In the routing setting, for example, the address information indicating the transmission destination added to a predetermined position of each packet as a transmission or reception signal is a global IP address based on the Internet 4 protocol, or this global IP address is attached. Address for identifying a specific local IP address (MAC address) according to, for example, Ethernet (registered trademark) for the dedicated network 5 that is different from the private network (in a form that is identifiable from the global IP address) Information (routing table and arp (Address Resolution Protocol) table) is set. The packet is checked against the table and transmitted only to the route with the matching address, thereby limiting (switching) the transmission path. The control unit 200 of the management server 2 to be described later sets the address according to the above for a new member who wishes to become a member, thereby permitting access to the dedicated network as a member (authorization is granted). It will be.

For example, a dual boot personal computer is preferably employed as the personal computer terminal 10 as an aspect for realizing such processing. An example of the dual boot process will be briefly described below.

The HDD 101 includes an MBR1 (Master Boot Recorder) area in which a master boot program is written, an OS1 area in which an operation system program (OS1) such as Windows (registered trademark) is written, a document creation browser, a mailer, and the like. It includes an AP1 area in which various application programs are written. The storage unit 103 includes a BIOSROM, which checks the memory and peripheral devices, and stores a BIOS program that activates the MBR1 program of the HDD 101 when the disk loading unit 10c is not loaded with a CDROM. The RAM in the storage unit 103 is a program that is sequentially expanded (read) from the HDD 101 when the personal computer terminal 10 is activated. The application program activated by the OS1 program includes a communication control program for routing setting that permits connection between the personal computer terminal 10 and the Internet 4 to the router function unit 120 of the information processor 11. It is. Specifically, the address information is set for setting a transmission path that connects only the personal computer terminal 10 and the Internet 4.

On the other hand, the CDROM loaded in the disk loading unit 10c has an MBR2 (Master Boot Recorder) area in which a master boot program is written, an OS2 area in which an operation system program (OS2) of a type different from OS1 is written, It includes an AP2 area in which a communication application program such as transmission / reception of information with the document or the information processor 11 is written.

The BIOS program stored in the BIOS ROM in the storage unit 103 checks the memory and peripheral devices, and if the CD ROM is loaded in the disk loading unit 10c, the CD ROM MBR2 program takes precedence over the HDD 101. Is to start. When the personal computer terminal 10 is started up, the programs in the storage unit 103 are sequentially loaded from the CDROM. Of the various application programs activated by the OS2 program, only the personal computer terminal 10 and the control unit 110 of the information processor 11 and the data storage unit 130 are connected to the router function unit 120 of the information processor 11. A communication control program for routing setting to allow is included. Specifically, the address information is set for setting a transmission path that connects only the personal computer terminal 10 and the information processor 11 (and the data storage unit 130).

By adopting such a method, the personal computer terminal 10 is connected to the Internet 4 side, or is connected only to the dedicated network 5 via the information processor 11.

Returning to FIG. 3, the control unit 110 of the information processing device 11 uses the dedicated network 5 via the document creation unit 111, the personal computer terminal 10, and the ISP 3 to create various documents necessary for electronic payment based on the operation of the operation unit 11 b. Communication control unit 112 that performs data communication with the communication side, an address setting unit 113 that assigns a transmission source and transmission destination address (transmission source information, transmission destination information) in a transmission document file (predetermined position of each packet), and a display unit 11a Is provided with a display control unit 114 for performing a confirmation display of the input contents. The data storage unit 130 is a document form storage unit 131 that stores forms of various documents, a self and member address information storage unit 132, and a distribution program storage that stores an encryption program and a decryption program distributed from the management server 2. Section 133 and a display image storage section 134.

Similarly, the information processing unit 102 of the personal computer terminal 10 includes a document creation unit 1021 that creates various documents, a communication control unit 1022 that performs communication processing of information with the Internet 4 or with the information processing device 11, And a display control unit 1023. The storage unit 103 includes a document creation data storage unit 1031 and a display image storage unit 1032 for storing application programs for document creation and forms of various documents, in addition to the program data necessary for the dual boot described above.

FIG. 4 is a block diagram of functional parts related to the present invention in the functional blocks of the management server 2. The management server 2 includes a control unit 200 configured by a microcomputer, a ROM 210, and a RAM 220. The ROM 210 includes a member information storage unit 211 that stores member information such as a member's name, name, and address, a management program storage unit 212 that stores a management program for executing the entire management process, and a plurality of types of encryption programs. And an encryption / decryption program storage unit 213 in which a composite program corresponding to each encryption program is stored. The RAM 220 temporarily stores data being processed. For example, a file information storage unit 221 that stores a file transmission / reception history, files, and the like of each member for management as necessary, and a distribution data storage described later. Part 222 is provided.

In the above description, it is assumed that the encryption program stored in the encryption / decryption program storage unit 213 and the types of decryption programs corresponding to the respective encryption programs are about tens to hundreds.

As the type of encryption, various methods can be adopted as long as it can be processed by a computer. For example, as a substitution expression that replaces a character or phrase in a general format with another character or symbol (group), a character substitution expression that replaces a single character with another character / symbol (group), two characters, or three A spelling substitution formula that changes a character group such as a character to another character or symbol (group), a dictionary formula that changes to another character or symbol group in units of characters, words, phrases, short sentences, etc., or two or more substitution tables A multi-table expression that encrypts while changing the table according to the rules, and a random number (character) expression that encrypts by adding a random number (letter) to a single-format ciphertext converted to a number (character) Encrypted text that is frequently updated using lexicographic or spelling ciphers is often updated with character substitutions, secondary expressions that are encrypted with spelling substitutions, and the first part is used as the key, and then the original text or cipher is used as the key. As a result, it is not suitable for a chaining system that encrypts sequentially or a strip called strip. There are strips formula to encrypt those alphabet law is are repeated twice using several tens of times. There is also a transposition formula that replaces an array different from a sentence based on characters or words. Even with the same type of encryption, a number of encryption programs can be prepared if the encryption obtained by slightly changing the specific method is handled as another encryption.

Returning to FIG. 4, the control unit 200 includes a selection unit 201, a distribution unit 202, a management unit 203, a communication processing unit 204, a sender / receiver information extraction unit 205, a decryption processing unit 206, an encryption processing unit 207, and a timer 208.

The selection unit 201 selects an encryption program and a decryption program that are provided regularly or irregularly for each information processing terminal device 1 of each member. For example, when it is assumed that the encryption program E10 and the decryption program D30 are currently distributed to the information processing terminal device 1 of a certain member (in this example, the encryption programs are E01 to E100, the decryption program 100 types are prepared as shown in D01 to D100.) As an encryption program and a decryption program distributed this time, for example, an encryption program E25 and a decryption program D08 are selected. Is. The correspondence between the encryption program and the decryption program distributed to the information processing terminal device 1 of a certain member is not necessary. Therefore, the selection unit 201 randomly selects an encryption program and a decryption program, for example, by using a random value obtained from a random number generator.

Alternatively, it may be individually selected by including variation information such as time axis information in a complicated selection rule, for example, a general rule expression, or in advance, an encryption program and a decryption Many or all combinations with the program are prepared, and any one of them may be selected preferably at random. More specifically, the following method, that is, a method of incorporating variation information can be employed. These can be similarly applied to selection of a decryption program.

That is, the encryption program is set as a serial number of E01 to E100. Each time a file from the transmission source is received, the number of packets is acquired as variation information, and the number is accumulated in a predetermined internal memory unit for each transmission source. For each reception, logical processing of the cumulative number so far and the serial number of the program (binary format), in this case, the value 100 (binary format), for example, logical product calculation processing is performed. If the logical product is “0”, E01 is selected as the encryption program, and for the other, “1” is added to the calculated value to select the encryption program. If variation information is included in this way, a logical value between 0 and 100 is obtained, and irregularity is substantially ensured.

As another method, similarly, the encryption program is a serial number of E01 to E100, and identification information (for example, the MAC address described above) is previously set in the binary format in the information processing device 11. And Each time a file is transmitted from the transmission source, a time stamp which is transmission time information (binary format) is added to the identification information as variation information. The management server 2 extracts the addition value (binary format) of the identification information and the time stamp from the received file, and adds this addition value and the serial number of the program (binary format), here the value 100 (binary format). Logical processing, for example, logical product calculation processing is performed. If the logical product is “0”, E01 is selected as the encryption program, and for the other, “1” is added to the calculated value to select the encryption program. If variation information is included in this way, a logical value between 0 and 100 is obtained, and irregularity is substantially ensured.

The selection unit 201 uses time information from the timer 208 in a mode in which distribution (that is, update) of a new encryption program and decryption program is executed by reaching a predetermined time. As the update time, it is generally considered at night, especially around midnight, when there are few opportunities for data transmission and reception. Further, the update cycle may be in units of one day, but may be shorter or in units of several days.

The distribution unit 202 distributes the encryption program and the decryption program selected by the selection unit 201 to the corresponding information processing terminal device 1. In this embodiment, the distribution unit 202 performs distribution processing on the information processing terminal devices 1 of all members.

The management unit 203 stores the combination of the selected encryption program and decryption program and the information processing terminal device 1 that is the distribution destination as distribution management information for collation in the distribution data storage unit 222 for each update. is there.

The communication processing unit 204 receives the document file transmitted from the information processing terminal device 1 as the transmission source to the information processing terminal device 1 as the transmission destination, so that the management server 2 manages it, and transmits it to the transmission destination after predetermined processing. This is to perform so-called relay processing.

The sender / receiver information extraction unit 205 performs processing for acquiring (extracting) transmission source information and transmission destination information from the received document file.

The decryption processing unit 206 refers to the distribution data storage unit 222 with respect to the received document file, identifies the transmission source encryption program, and performs decryption processing using the corresponding decryption program.

The encryption processing unit 207 refers to the distribution data storage unit 222 for the plain text document file decrypted by the decryption processing unit 206, identifies the decryption program of the transmission destination, and encrypts it with the corresponding encryption program. Processing is performed.

FIG. 5 is a flowchart of the program distribution process executed by the control unit 200 using the management program of the management server 2. First, it is determined whether or not the timer 208 has reached a predetermined time (step S1), and if not, the process exits this flow. On the other hand, if the predetermined time has been reached, a selection process is executed (step S3). The combination information of the encryption program and the decryption program for each information processing terminal device 1 obtained by the selection process is stored in the distribution data storage unit 222 (step S5).

Next, it is determined whether or not the combination of the encryption program and the decryption program is set for all the information processing terminal devices 1 (step S7). If the selection process is completed for the device 1, the encryption program and the decryption program stored in the distribution data storage unit 222 are distributed to the corresponding information processing terminal device 1. Each information processing terminal device 1 receives the distributed encryption program and decryption program and stores them in the distribution program storage unit 133. When the document file is transmitted from the information processing terminal device 1 via the dedicated network 5, the plain text document is converted into cipher text by the encryption program currently stored in the distribution program storage unit 133 and transmitted. Will be.

FIG. 6 is a flowchart of the file relay process executed by the control unit 200 using the management program of the management server 2. First, it is determined whether or not a document file has been received from the information processing terminal device 1 (step S21). If not received, this flow is exited. On the other hand, if it has been received, extraction processing of information relating to the information processing terminal device 1 of the transmission source and the transmission destination included in a predetermined position in the received document file is performed (step S23). Next, based on the extracted transmission source information, the corresponding encryption program is identified with reference to the distribution data storage unit 222, and the ciphertext is decompressed using the decryption program corresponding to the identified encryption program. A common culture is performed (step S25). Next, based on the extracted transmission destination information, the corresponding decryption program is identified with reference to the distribution data storage unit 222, and the received document file that has been plainly written using the encryption program corresponding to the identified decryption program is stored. Encryption is performed (step S27). Next, the encrypted document file is transmitted to the information processing terminal device 1 that is the transmission destination (step ST29). In the information processing terminal device 1 as the transmission destination, the management server 2 converts the transmitted document file into a ciphertext using a decryption program stored in the distribution program storage unit 133.

FIG. 7 is a flowchart of another program distribution process (II) executed by the control unit 200 using the management program of the management server 2. In the embodiment shown in FIG. 7, the encryption program and the decryption program distributed from the management server 2 are selected corresponding to the transmission of the document file, and are distributed immediately before the transmission. According to this aspect, when a document file is transmitted, the encryption program is selected for the transmission source, and the decryption program is selected and distributed to the transmission destination. The processing of selecting and distributing the encryption program and the decryption program at a predetermined timing to all of the information processing terminal devices 1 as shown in the figure becomes unnecessary.

More specifically, when a document file is transmitted from a certain information processing terminal device 1 to the dedicated network 5, first, a transmission request is issued to the management server 2. Next, upon receipt of response information corresponding to the transmission request from the management server 2, the original document file is transmitted. That is, the transmission request information is transmitted to the management server 2 immediately before a predetermined document is created by the information processing terminal device 1 of the transmission source, and the generated document is filed and encrypted and transmitted to the predetermined transmission destination. Is done. The information processing terminal device 1 includes transmission source information and transmission destination information in transmission request information.

First, the management server 2 determines whether or not transmission request information has been received (step S41). If the transmission request information has not been received, this flow is exited. On the other hand, if transmission request information has been received, transmission source information and transmission destination information are extracted from the received transmission request information (step ST43). Next, a process of selecting a combination of the encryption program for the extracted transmission source and the decryption program for the transmission destination is executed (step S45). When the selection process is completed, the encryption program for the transmission source information processing terminal device 1 and the decryption program for the transmission destination information processing terminal device 1 obtained in the selection process are stored in the distribution data storage unit 222. It is stored in an updated manner (step S47).

Next, the encryption program and the decryption program stored in the distribution data storage unit 222 are distributed to the corresponding information processing terminal devices 1 of the transmission source and the transmission destination (step S49). The information processing terminal device 1 that is the transmission source receives the encrypted program that has been distributed and stores it in the distribution program storage unit 133. Further, the information processing terminal device 1 as the transmission destination receives the decrypted program distributed and stores it in the distributed program storage unit 133. When the document file is transmitted from the information processing terminal device 1 as the transmission source via the dedicated network 5, the plain text document is distributed by the encryption program that has been distributed and newly stored in the distribution program storage unit 133. It is sent as ciphertext. On the other hand, the management server 2 executes the file relay process shown in FIG. Therefore, when receiving the document file from the management server 2, the information processing terminal device 1 as the transmission destination performs plain culture of the ciphertext using the decryption program newly distributed recently.

In the embodiment shown in FIG. 5, there is no problem when the destination information processing terminal device 1 executes the decryption process in response to the reception of the document file, but the information processing terminal device 1 is activated. Alternatively, it can be assumed that a different encryption program is distributed when the document file is read out. In this case, according to the above embodiment, the decryption program stored in the distribution program storage unit 133 cannot decompress past received files. As a countermeasure in this case, in each information processing terminal device 1, the decryption program distributed at the time of reception of the document file is stored until the document file is decrypted, and after decryption, the corresponding decryption program is stored. This should be deleted. On the other hand, if there is no received file within a certain period, the decryption program during that period may be updated by a newly delivered decryption program as usual.

In the embodiment shown in FIG. 7, there is no problem when the destination information processing terminal device 1 executes the decryption process in response to the reception of the document file, but the information processing terminal device 1 is activated. Alternatively, it can be assumed that a plurality of document files are received by different encryption programs when the document file is read. In this case, according to the above embodiment, since only one decryption program is stored in the distribution program storage unit 133, it is not possible to decompress received files other than the most recent one received file. As a countermeasure in this case, in each information processing terminal device 1, the decryption program distributed corresponding to the reception of the document file is stored until the document file is decrypted, and after decryption, the corresponding decryption program is stored. You can delete the program.

The present invention can employ the following modes.

(1) The distribution unit 202 distributes a plurality of encryption programs and corresponding decryption programs to all the information processing terminal devices 1 in advance, instead of distributing the encryption program and the decryption program at a predetermined timing. The identification information for identifying (identifying) the encryption program and the decryption program at a predetermined timing may be selected and distributed at random, for example. According to this, since the encryption program and the decryption program are not repeatedly distributed over the dedicated network, leakage at the time of program distribution can be prevented.

(2) The management server 2 is not necessarily limited to one, and a plurality of management servers 2 may be provided. Each management server can change the assignment for each information processing terminal device 1 or in the direction of time. For example, in the temporal direction, the present embodiment may be executed periodically with different management servers when viewed from a certain information processing terminal device 1.

As described above, the present invention provides a plurality of encryption programs and corresponding decryption programs in a network management server that manages transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network. And a selection means for selecting one encryption program for an information processing terminal device that can be a transmission source and a one decryption program for an information processing terminal device that can be a transmission destination, respectively. Distribution means for distributing at least the encrypted encryption / decryption program before transmission of the file, management means for managing the encryption program and the decryption program distributed to each information processing terminal device, and transmission source information A receiving means for receiving a file encrypted and transmitted by the processing terminal device; a sender and a receiver from the received file; Extracting means for identifying each information processing terminal device of the transmission destination, decoding means for decoding the file transmitted from the information processing terminal of the transmission source by a corresponding decoding program according to management information of the management means, An encryption means for encrypting the decrypted file with an encryption program corresponding to a decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means; and encrypted by the encryption means Transmission means for transmitting the received file to the destination information processing terminal device detected by the detection means. In the present invention, it is preferable that the distribution unit distributes one encryption program and decryption program selected by a predetermined method to each information processing terminal device at a predetermined timing. According to this, since each information processing terminal device always has one encryption program and decryption program, it is possible to cope with transmission of encrypted files and reception of encrypted files. In addition, since each information processing terminal device has an encryption program and a decryption program that differ with time, even if the encryption program or the decryption program leaks temporarily for some reason, At this point, since there is another encryption program and decryption program, confidentiality is ensured.

The predetermined timing may be set for each preset period. According to this configuration, since the encryption program and the decryption program are regularly updated, the significance of illegal acquisition or theft of the encryption program and the decryption program is lost. Note that “regular” means every predetermined time, every day, every few days, or the like.

Further, when the selection means receives a transmission request signal including information on a transmission source and a transmission destination that is transmitted prior to transmission of a file from the information processing terminal device of the transmission source, the information that transmitted the transmission request signal The processing terminal device selects one encryption program, the transmission destination information processing terminal device selects one decryption program, and the distribution means selects the information processing terminal device that has transmitted the transmission request signal. It is preferable that the encrypted program is distributed and the selected decryption program is distributed to the information processing terminal device of the transmission destination. According to this, since the encryption program is distributed immediately before the transmission of the file and the decryption program is distributed to the transmission destination of the transmission file at the same time, even if unauthorized acquisition is possible in advance, the encryption is performed. It becomes possible to make the program and the decryption program useless.

The predetermined method is preferably a method of selecting at random. According to this configuration, the server administrator itself cannot grasp the current distribution status of the encryption program and the decryption program, and cannot leak from the human side.

Also, identification information for distributing a plurality of encryption programs and corresponding decryption programs to all information processing terminal devices in advance and identifying the encryption program and the corresponding decryption program at the predetermined timing Is preferably distributed by the predetermined method. According to this configuration, since the encryption program and the decryption program are not distributed directly from the network management server, the opportunity for unauthorized acquisition is suppressed.

In addition, a member management unit is provided, and the network is a dedicated network that is provided alongside the Internet, and the member management unit sets an authority to permit connection to the dedicated network to the information processing terminal device. Is preferred. According to this, since the use of the dedicated network is limited to file transmission / reception between members, it becomes difficult to enter from other networks, and high security management becomes possible.

In the present invention, the network management server selects and distributes the encryption program in advance to the information processing terminal device that is the transmission source and the decryption program in advance to the information processing terminal device that is the transmission destination, The network management server decrypts the file from the transmission source, encrypts it by another method, and transmits it to the transmission destination. As a result, it is possible to further improve the confidentiality of the transmitted / received file.

Claims

In a network management server that manages transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network,
Storage means for storing a plurality of encryption programs and corresponding decryption programs;
Selection means for selecting one encryption program for an information processing terminal device that can be a transmission source and one decryption program for an information processing terminal device that can be a transmission destination by a predetermined method;
A delivery means for delivering the selected encryption / decryption program at least before transmission of the file;
Management means for managing the encryption program and the decryption program distributed to each information processing terminal device;
Receiving means for receiving a file encrypted and transmitted by the information processing terminal device of the transmission source;
Extraction means for identifying each information processing terminal device of the transmission source and the transmission destination from the received file;
Decryption means for decrypting a file transmitted from the information processing terminal of the transmission source by a corresponding decryption program according to management information of the management means;
Encryption means for encrypting the decrypted file with an encryption program corresponding to the decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means;
A network management server comprising: a transmission unit configured to transmit a file encrypted by the encryption unit to a destination information processing terminal device detected by the detection unit.
The network management server according to claim 1, wherein the distribution unit distributes one encryption program and decryption program selected by a predetermined method to each information processing terminal device at a predetermined timing.
3. The network management server according to claim 1, wherein the predetermined timing is every preset period.
When the selection unit receives a transmission request signal including information on a transmission source and a transmission destination that is transmitted prior to transmission of a file from the information processing terminal device of the transmission source, the information processing terminal that has transmitted the transmission request signal Selecting one encryption program for the device, selecting one decryption program for the information processing terminal device of the transmission destination,
The distribution means distributes the selected encryption program to the information processing terminal device that has transmitted the transmission request signal, and distributes the selected decryption program to the information processing terminal device of the transmission destination. The network management server according to claim 1.
5. The network management server according to claim 1, wherein the predetermined method is to select at random.
The distribution means distributes a plurality of encryption programs and corresponding decryption programs to all information processing terminal devices in advance, and identifies the encryption program and the corresponding decryption program at the predetermined timing. 6. The network management server according to claim 1, wherein identification information to be distributed is distributed by the predetermined method.
With membership management means,
The network is a dedicated network attached to the Internet,
The network management server according to any one of claims 1 to 6, wherein the member management means sets an authority to permit connection to the dedicated network to an information processing terminal device.
In a network management program for managing transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network with a network management server,
Storage means for storing a plurality of encryption programs and corresponding decryption programs;
Selection means for selecting one encryption program for an information processing terminal device that can be a transmission source, and one decryption program for an information processing terminal device that can be a transmission destination, respectively.
A delivery means for delivering the selected encryption and decryption program at least before transmission of the file;
Management means for managing the encryption program and the decryption program distributed to each information processing terminal device;
A receiving means for receiving a file encrypted and transmitted by the information processing terminal device of the transmission source;
Extraction means for identifying each information processing terminal device of the transmission source and the transmission destination from the received file;
Decoding means for decoding a file transmitted from the information processing terminal of the transmission source by a corresponding decoding program according to management information of the management means;
An encryption means for encrypting the decrypted file with an encryption program corresponding to the decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means;
A network management program for causing the network management server to function as a transmission unit that transmits a file encrypted by the encryption unit to a destination information processing terminal device detected by the detection unit.
In a network management method for managing transmission / reception of encrypted files performed between a plurality of information processing terminal devices connected to a network with a network management server,
The storage means stores a plurality of encryption programs and corresponding decryption programs,
The selecting means selects one encryption program for an information processing terminal device that can be a transmission source, and one decryption program for an information processing terminal device that can be a transmission destination, respectively.
The management means manages the encryption program and the decryption program distributed to each information processing terminal device,
The distribution means distributes the selected encryption / decryption program at least before sending the file,
The receiving means receives the file that has been encrypted and transmitted by the information processing terminal device of the transmission source,
The extraction means identifies each information processing terminal device of the transmission source and the transmission destination from the received file,
The decryption means decrypts the file transmitted from the information processing terminal of the transmission source with a decryption program corresponding to the management information of the management means,
The encryption means encrypts the decrypted file with an encryption program corresponding to the decryption program distributed to the information processing terminal device of the transmission destination extracted by the extraction means,
A network management method, wherein the transmission means transmits the file encrypted by the encryption means to a destination information processing terminal device detected by the detection means.