JP2002123434A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain protection from illegal access. SOLUTION: A security system 1 is constituted by providing a sub-host device 5, with which terminal equipment such as card reader 13, window sensor 14 or door controller 15 is connected for each room, for example, and mutually connecting such plural sub-host devices 5 and a host device 4 provided in the maintenance room of a building, for example, through an open LAN 6. The other service device such as air conditioner system 10 is connected to the LAN 6 as well. Besides, the host device 4 is connected with the outside through an external network 8. A communication cutting device 7 is provided for physically cutting communication when illegal access is judged in the connecting part of each of sub-host devices 5 with the LAN 6. A similar communication cutting device 9 for host device is provided in the connecting part of the host device 4 and the external network 8 as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a sub-host device to which a plurality of terminal devices are connected, and a host device.
The present invention relates to a network system connected by a network.

[0002]

In recent years, for example, in a building management system (security system), a sub-host device is provided for each room (each company), and a plurality of sub-host devices are provided in each room by the sub-host device. A terminal device, for example, a card reader for entry / exit management provided near the door, an automatic door mechanism, a human detection sensor, a window sensor, and the like are managed and controlled. Each of the sub-host devices is connected to a host device provided in, for example, a security room of the building via a network (LAN) in the building to form a system. It is also possible to control and set and release the security device.

In the above network,
It has been desired to construct an open LAN in which other services (for example, an air-conditioning system and a lighting system) are piggybacked from the conventional one dedicated to a security system. Further, the host device is further connected to an external network (LAN, Internet, etc.). However, when a security system is configured with such an open network, there is a concern that unauthorized communication access or intrusion from outside (third party) may be made, and it is important to prevent such unauthorized access.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a network system which is constructed on an open network and can protect against unauthorized access.

[0005]

In order to achieve the above object, a network system according to the present invention, by providing a communication disconnection device, judges unauthorized access to a sub-host device or a terminal device under its control through a network. The communication between the sub-host device and the network is disconnected when an unauthorized access is determined (the invention of claim 1).

According to this, when an unauthorized access is made to the sub-host device or the terminal device under its control through the network, the communication between the sub-host device and the network is cut off. The terminal device can be protected.
At this time, even if the sub-host device is disconnected from the network, the minimum operation of the system can be performed by the sub-host device and the terminal device.

Further, when the host device is connected to an external network, a communication disconnection device for the host device is provided to determine unauthorized access to the host device through the external network. The communication between the host device and the external network can be cut off (the invention of claim 2). According to this, it is possible to protect the host device and the system against unauthorized access from outside through the external network.

[0008] As means for determining unauthorized access, an authentication request is made to the other party when there is access,
It is possible to adopt a configuration in which if a correct authentication response is not made within a predetermined time, an unauthorized access is determined (the invention of claim 3). Here, in general, unauthorized access is repeated a plurality of times in a short period of time in order to break through authentication. Therefore, if a correct authentication response is not made within a predetermined time, it can be determined that the access is unauthorized. As a specific method of authentication, a method using a password, a method of encrypting a random number using a secret key and an encryption algorithm, and the like are conceivable.

As means for disconnecting the communication, logical means, that is, a configuration in which communication data cannot be passed by software, or physical means, that is, a contact portion inserted in a communication line is disconnected. Configurations are possible. Also,
Once the communication is disconnected, it is necessary to restore the communication again. Therefore, in the case where the communication is logically disconnected, the communication can be restored by receiving a dedicated authentication command from the host device thereafter (the invention of claim 4). If the communication is cut off temporarily, the communication can be restored by a subsequent switch operation (the invention of claim 5).

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a building management system (security system) will be described below with reference to the drawings. First, FIG. 1 schematically shows an entire configuration of a security system 1 as a network system according to the present embodiment, and FIG.
A specific example of an arrangement of components such as a terminal device in the security system 1 is shown on behalf of two rooms 2 and 3.

As shown in FIG. 1, the security system 1 includes a host device 4 provided in, for example, a security room (management center) of a building, and a plurality of sub-host devices provided in, for example, each room (each company). 5 (only two are shown in FIG. 1) and an open LAN 6 as a network.
And are mutually connected. At this time, a communication disconnecting device 7, which will be described later, is inserted in a connection portion between each of the sub-host devices 5 and the LAN 6. Further, as will be described later, a plurality of terminal devices relating to security in each room are connected to each of the sub-host devices 5.

Although not described in detail, the host device 4 is mainly composed of a computer, and controls the security of the entire building. In this embodiment, the host device 4 is connected to an external network (external LAN).
8 and connected to the outside (for example, a security company or the like). In this case, the host device 4 and the external network 8
The communication disconnecting device 9 for the host device is also inserted in the connection portion with the host device. Other services are so-called carpooling on the LAN 6, and other service devices such as an air conditioner system 10, a ventilation system 11, and a lighting system 12 in the building are also connected.

The sub-host device 5 is also constituted mainly by a computer, and manages a plurality of connected terminal devices. As a specific example, as shown in FIG. 2, in the room 2 (for example, a computer center), as a terminal device, only a person who is located near the entrance door 2a and has a predetermined ID card is allowed to enter the room. The card reader 13 is provided, and a window sensor 14 for detecting an abnormality of the window 2b is provided in the window. Control of locking and unlocking of the door lock (or automatic opening and closing of the door) is provided in the room 2. Is provided with a door controller 15 for controlling the vehicle.

In the room 3, a card reader 16 is provided as a terminal device, which is located near the entrance door 3a and allows only a person having a predetermined ID card to enter the room.
A person detection sensor 17 for detecting that a person has entered the room 3 is provided on the ceiling, and a door lock is locked in the room 3.
A door controller 18 that controls unlocking (or automatic opening and closing of the door) is provided.

At this time, the sub-host device 5 and the communication disconnecting device 7 (and their connection lines) are
It is designed to be placed inside. Also in this case, room 2
In the sub-host device 5 and the plurality of terminal devices 13 to
15 enables minimum operation, that is, the host device 4
The minimum security management for each of the rooms 2 and 3 is possible even when the connection with the server is disconnected. Similarly, the room 3 can be operated at a minimum by the sub-host device 5 and the plurality of terminal devices 16 to 18.

FIG. 3 schematically shows the structure of the communication disconnecting device 7. As shown in FIG. The communication disconnecting device 7 is mainly connected to a communication unit (communication transceiver) 19 for transmitting and receiving communication data and a microcomputer (CPU), which is connected to the upper side (LAN 6), and a control circuit connected to the communication unit 19 20, a communication unit (communication transceiver) 21 connected to the control circuit 20 for transmitting and receiving communication data on the lower side (sub-host device 5);
A relay 22, which is a contact for physically disconnecting communication, is inserted into a communication line connecting the communication unit 21 and the sub-host device 5.

As will be described in detail later in the description of the operation, the control circuit 20 has a software configuration so that the sub-host device 5 through the LAN 6 or the terminal devices 13 to 15 (or 16 to 15) under its control. 18)
Is determined, and when the unauthorized access is determined, the relay 22 is operated to physically disconnect the communication between the sub-host device 5 and the LAN 6. Therefore, the control circuit 20 functions as an unauthorized access determination unit and constitutes a communication disconnecting unit together with the relay 22.

Specifically, an unauthorized access is determined when an authentication request is made to the other party when the access is made and a correct authentication response is not made within a predetermined time (when a predetermined number of authentication failures is recognized). ) Is determined to be an unauthorized access. For the authentication at this time, a method of confirming the transmission source using a password or a method of confirming the transmission source by encrypting a random number using a secret key and an encryption algorithm is adopted. Although not shown, the communication disconnecting device 7 is provided with a switch for returning the contact of the relay 22, and the switch is operated by a human hand so that the communication is restored. Has become.

Although a detailed description is omitted, the communication disconnecting device 9 for the host device is also
Therefore, an unauthorized access judging means for judging an unauthorized access to the host device 4 from the outside through the external network 8, and the host device when the unauthorized access judging means judges the unauthorized access. 4 and a communication disconnecting means for disconnecting the communication between the external network 8.

Next, the operation of the above configuration will be described with reference to FIG. As described above, when the host device 4 causes the sub-host device 5 (or the terminal device under the control of the sub-host device 5) to execute any request, the host device 4 transmits the authentication request from the communication disconnecting device 7. Must return the correct authentication response to In addition, when the sub-host device 5 (or the terminal device under the control of the sub-host device 5) executes another request to another sub-host device 5 (or the terminal device under the control of the sub-host device 5), the transmission is performed. The original sub-host device 5 is a communication disconnecting device 7
It is necessary to return the correct authentication response to the authentication request from.

FIG. 4 is a flowchart showing a processing procedure for judging an unauthorized access executed by the communication disconnecting device 7 (control circuit 20) at that time. That is, for example, when a terminal operation request message is received from the upper side (step S
First, an authentication request is transmitted to the transmission source (Step S2). Then, an authentication response from the transmission source is received (step S3). At this time, if there is no reception (timeout occurs) within one reception wait time (Yes in step S4), it will be described later. Step S
The process proceeds to step No. 6 and is counted as the number of authentication failures.

When an authentication response is received (Yes in step S3), it is determined whether a correct authentication response has been made (step S5). When a correct authentication response is not made (No in step S5), the number of authentication failures is added to the number of times (step S6), and then a predetermined number of times (for example, 5 times) within a predetermined time (for example, 1 minute). It is determined whether authentication failures (or 10 times) have been counted (step S7).

Here, in the unauthorized access, since the access is repeated a plurality of times in a short time to break the authentication, if a correct authentication response is not made within a predetermined time (Yes in step S7), the unauthorized access is made. The access is determined, and the communication is disconnected by turning off the contact of the relay 22 (step S8). If the number of authentication failures has not reached the predetermined number (No in step S7), the process returns to step S2 and the authentication operation is performed again.

On the other hand, if a correct authentication response is made within the predetermined time (Yes in step S5), the number of authentication failures is cleared (step S9), and the lower side (sub-host device 5) becomes higher. Is transmitted (step S10). Thereby, based on recognizing the authentication failure of a certain number of times or more within the predetermined time, it is possible to reliably determine whether the access is an unauthorized access and disconnect the communication. Further, when a correct authentication response is not received by chance due to a factor such as noise, it is prevented from being determined as an unauthorized access.

At this time, even when the relay 22 is turned off and the communication with the host device 4 through the LAN 6 is cut off as described above, the minimum security management is performed by the sub-host device 5 and the terminal device under its control. Is allowed. As described above, when the communication is restored, the switch of the communication disconnecting device 7 is manually operated to return the contact point of the relay 22. Since the disconnecting device 7 (and the sub-host device 5) is provided in each of the rooms 2 and 3, there is no possibility that a third party illegally manipulates the return switch from outside, and security is ensured. It has become.

Although not shown or described in detail, the communication disconnecting device 9 for the host device can also be illegally operated based on the authentication operation when it is accessed from outside through the external network 8. It is determined whether the access is an access, and when it is determined that the access is unauthorized, the communication with the external network 8 is disconnected.

As described above, according to this embodiment, the communication disconnecting device 7 is provided between each host device 5 and the LAN 6,
6, the unauthorized access to the sub-host device 5 or the terminal device under its control is determined, and when the unauthorized access is determined, the communication to the sub-host device 5 is cut off. The system 1 also has an excellent effect that reliable protection against unauthorized access can be achieved.

In the present embodiment, the host device 4 is connected to the external network 8, and a communication disconnecting device 9 for the host device is provided. Since the access is determined and the communication between the host device 4 and the outside is cut off when the unauthorized access is determined, the host device 4 and thus the system 1 are protected against external unauthorized access through the external network 8. Is what you can do.

In the above embodiment, the communication disconnecting device 7
Although the communication is physically cut off by providing the relay 22 in the configuration, communication data may not be allowed to pass through by logical means, that is, by software. In this case, after the communication is disconnected, the communication disconnecting device 7 may be configured to resume the communication by receiving, for example, a dedicated authentication command from the host device 4. Further, the communication disconnecting device 9 for the host device may be provided as needed.
A similar communication disconnecting device may be provided at the connection between the AN 6 and the host device 4.

In addition, the present invention is not limited to the configuration in which the communication disconnecting device 7 and the communication disconnecting device 9 for the host device are separately provided. Apparently, the sub-host device 5 and the host device 4 determine unauthorized access and disconnect communication. Further, the present invention is not limited to the security system 1 but can be applied to a general network system in which a sub-host device to which a terminal device is connected is connected by a network. The present invention can be implemented with appropriate changes.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a security system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific example of an arrangement of terminal devices and sub-host devices.

FIG. 3 is a diagram schematically showing a configuration of a communication disconnection device.

FIG. 4 is a flowchart showing a procedure for determining unauthorized access.

[Explanation of symbols]

In the drawing, 1 is a security system (network system), 4 is a host device, 5 is a sub-host device, and 6 is L
AN (network), 7 is a communication disconnection device, 8 is an external network, 9 is a communication disconnection device for a host device, and 13-1.
Reference numeral 8 denotes a terminal device, 20 denotes a control circuit (an unauthorized access determination unit, a communication disconnection unit), and 22 denotes a relay (contact unit).

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04L 12/22 H04L 11/00 310D 5K030 // G08B 25/04 11/26 5K033 F term (reference) 2E250 AA04 BB09 BB30 BB47 DD03 FF44 5B085 AC03 BG06 5B089 GA01 GA11 GA21 HA06 KA17 KB13 KC54 KC58 5C087 AA02 AA03 BB03 BB11 BB74 DD05 DD06 DD23 EE18 EE20 FF01 FF02 FF04 FF19 FF20 GG08 GG12 AGA11 GG19 GG19 GG19 GG19 GG19 A CB01 DA01 DA05 DB01 DB19

Claims (5)

[Claims] 1. A network system in which a sub-host device to which a terminal device is connected and a host device are connected by a network, wherein unauthorized access to the sub-host device or a terminal device under its control through the network is provided. A network provided with a communication disconnection device comprising: an unauthorized access determination unit for determining; and a communication disconnection unit for disconnecting communication between the subhost device and the network when the unauthorized access determination unit determines an unauthorized access. system. 2. The host device is connected to an external network, wherein the unauthorized access determining means determines unauthorized access to the host device through the external network, and the unauthorized access determining means determines unauthorized access. 2. The network system according to claim 1, further comprising a communication disconnecting device for the host device, comprising a communication disconnecting unit for disconnecting communication between the host device and the external network when the communication is performed. 3. The unauthorized access determination means is configured to make an authentication request to the other party when there is access, and to determine an unauthorized access when a correct authentication response is not made within a predetermined time. 3. The network system according to claim 1, wherein: 4. The communication disconnecting means logically disconnects communication by disabling communication data by software, and thereafter receives a dedicated authentication command from the host device. 2. The communication according to claim 1, wherein the communication is restored.
4. The network system according to any one of claims 3 to 3. 5. The communication disconnecting means is configured to physically disconnect communication by disconnecting a contact portion inserted in a communication line, and is configured to restore communication by a subsequent switch operation. The network system according to any one of claims 1 to 3, wherein