JP2000305621A - Monitoring control system using internet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent illegal access such as tapping and alteration to monitored information and control information from occurring and to secure the reliability and safety of transmitted and received information by enciphering monitored information and control information transmitted and received through a network in each communication packet. SOLUTION: In this monitoring control system in which a monitoring controller 19 monitors and controls facilities 11 through the Internet 18, a pair of enciphering and decoding devices 21 and 16 encipher control information or monitored information which is included in communication packets 28 and 25 and outputted from the monitoring controller or the facilities with the communication packets and all, include the enciphered communication packets in new IP packets 30 and 26 and transmit them to the Internet, also decode the enciphered communication packets included in the IP packets received from the Internet into the original communication packets and transmit them to the facilities and the monitoring controller are inserted between the monitoring controller and the Internet and between the facilities and the Internet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supervisory control system in which a supervisory control device monitors and controls equipment via the Internet.

[0002]

2. Description of the Related Art For example, in a supervisory control system for monitoring and controlling a large number of facilities dispersed over a wide area, such as station facilities arranged at railway stations, in a central control room of a terminal, for example, the system is provided at each station. Monitoring information and control information are transmitted and received between the installed equipment and a monitoring control device located remotely via a dedicated line.

FIG. 7 is a block diagram showing a schematic configuration of a monitoring control system. For example, a facility 1 to be monitored and controlled disposed in each station is connected to a station-side network 3 that employs an Ethernet communication protocol via a monitoring and control transmission device 2. The network 3 on the station side is connected via a dedicated line 4 to a network 5 on the central control room side employing an Ethernet communication protocol.
The monitoring control device 6 is connected to the network 5 on the central control room side. It should be noted that the dedicated line 4 is often configured by a railway dedicated line laid along the track.

In the monitoring control system having such a configuration, the monitoring information transmitted from each facility 1 to the monitoring control device 6 and the control information transmitted from the monitoring control device 6 to each facility 1 include the destination address (DA) and the transmission address. It is transmitted on each of the networks 3 and 5 and the dedicated line 4 in a state of being incorporated in a communication packet to which the original address (SA) is attached.

[0005] As described above, by connecting the network 3 on the station side and the network 5 on the central control room side via the dedicated line 4, the monitoring information transmitted and received between each facility 1 and the monitoring control device 6. And control information, eavesdropping from outside,
It is possible to almost completely block unauthorized access such as falsification.

It is possible to employ the Internet instead of the dedicated line 4. However, since the Internet is open to an unspecified number of people, it is susceptible to unauthorized access such as eavesdropping and falsification from outside. .

[0007]

However, the monitoring control system shown in FIG. 7 still has the following problems to be improved.

That is, as described above, it is necessary to lay a dedicated line 4 in order to block unauthorized access such as eavesdropping and tampering from the outside. The laying of the dedicated line 4 has a problem of laying cost, a problem that requires a long time to lay, and a problem that maintenance and management after the laying is complicated.
Therefore, when constructing a monitoring and control system for remotely monitoring and controlling equipment distributed over a wide area, the dedicated line 4 becomes a major obstacle.

The present invention has been made in view of such circumstances, and encrypts monitoring information and control information transmitted and received via a network for each communication packet, so that even if the Internet is adopted, It is possible to prevent unauthorized access such as eavesdropping and tampering with monitoring information and control information beforehand, and to build a system at low cost and in a short time while ensuring the reliability and security of information transmitted and received. Another object of the present invention is to provide a monitoring and control system using the Internet, which can simplify the maintenance and management after the construction.

[0010]

According to a first aspect of the present invention, there is provided a monitoring control system in which a monitoring control device monitors and controls equipment via the Internet. The control information or the monitoring information, which is inserted into the communication packet from the monitoring control device or the facility and is output from the monitoring control device or the facility, is encrypted for each communication packet, and the encrypted communication packet is newly added. A pair of IP packets received from the Internet and transmitted to the Internet, and an encrypted communication packet embedded in the IP packet received from the Internet is decrypted into the original communication packet and transmitted to the facility or the monitoring and control device. It has an encryption / decryption device.

In the monitoring and control system using the Internet configured as described above, an encryption / decryption device is installed between the monitoring and control device and the Internet and between the facility and the Internet. And
Each encryption / decryption device incorporates control information and monitoring information output from the monitoring control device and equipment to the Internet, encrypts communication packets for each communication packet, and decrypts communication packets received from the Internet.

Therefore, since live control information and monitoring information do not flow on the Internet, the probability of unauthorized access such as eavesdropping and falsification is reduced. In addition, since the existing Internet is used, a system can be constructed simply and in a short time.

According to a second aspect of the present invention, the monitoring and control system of the present invention is further interposed between the monitoring and control device and the Internet and between the facility and the Internet, and the facility or the monitoring and control device is provided with control information or information. It has a pair of transmission / reception confirmation units that mutually confirm that the monitoring information has been normally received by transmitting / receiving reception confirmation information via the Internet.

In the supervisory control system using the Internet configured as described above, as a result, the equipment or the supervisory control device mutually confirms that the control information or the supervisory information has been normally received. Reliability is improved.

According to a third aspect of the present invention, in the monitoring and control system according to the above-described invention, the reception confirmation information is encrypted, incorporated into an IP packet, and transmitted to the Internet. Therefore, the confidentiality of information transmitted and received can be maintained.

According to a fourth aspect of the present invention, in the monitoring control system according to the above-mentioned invention, the pair of transmission / reception confirming units is configured to transmit the control information or the IP packet of the monitoring information to the Internet after the encryption / decryption device on its own side transmits the IP packet. If the reception confirmation information is not received within the time, a retransmission request is made to the monitoring and control device or the facility on the own side.

According to a fifth aspect of the present invention, in the supervisory control system according to the above-mentioned invention, when the supervisory control device and the equipment receive the retransmission request, they incorporate the control information or the supervisory information transmitted immediately before into the communication packet. It is re-sent to its own encryption / decryption device.

In the monitoring control system configured as described above, even if the control information or the monitoring information is lost on the Internet for some reason, it is automatically restored.

According to a sixth aspect of the present invention, in the supervisory control system according to the above invention, the pair of encryption / decryption devices encrypts and incorporates an authenticator for packet authentication into an IP packet of the control information or the supervisory information, and transmits the encrypted packet to the Internet. The unauthorized access to the monitoring information or the control information is detected from the state of the authenticator incorporated in the IP packet received from the IP.

In the monitoring control system configured as described above, since the authenticator for packet authentication is encrypted and incorporated in the IP packet of the control information or the monitoring information,
Even if an unauthorized access is attempted, the unauthorized access can be detected. Therefore, the portion where the unauthorized access exists may be discarded.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a monitoring control system using the Internet according to the embodiment. The monitoring control system according to the present embodiment, for example, monitors and controls equipment to be monitored and controlled provided at each station in a railway company by a monitoring control device installed in a central management room of a railway terminal.

The equipment 11 to be monitored and controlled installed at each station
Is connected to a station-side network 13 that employs an Ethernet communication protocol via a monitoring control transmission device 12. The station-side network 13 is connected to another network 16 employing an Ethernet communication protocol via an encryption / decryption device 14. For example, a transmission / reception check unit 15 is incorporated in an encryption / decryption device 14 having a function of a communication server for the facility 11 to be monitored and controlled. The network 16 is a router 17
Is connected to the Internet 18 via the Internet.

On the other hand, the monitoring and control device 19 installed in the central control room of the railway terminal is connected to a network 20 of the central control room which employs an Ethernet communication protocol. The network 20 of the central control room
Is connected via an encryption / decryption device 21 to another network 23 employing an Ethernet communication protocol. The transmission / reception check unit 2 is provided in the encryption / decryption device 21 having the function of the communication server for the monitoring control device 19
2 are incorporated. The network 23 is connected to the Internet 18 via a router 24.

The monitoring control transmission device 1 of the facility 11
2 has an IP address [A], and the monitoring control device 19
It has a P address [B], and each of the encryption / decryption devices 14 and 21 has an IP address [C] and [D], respectively.

The procedure for transmitting the monitoring information from the equipment 11 to the monitoring and control apparatus 19 and the procedure for transmitting the control information from the monitoring and control apparatus 19 to the equipment 11 in the monitoring and control system having such a configuration will be described with reference to FIGS. Will be explained.

(A) Transmission of monitoring information In FIG. 2, first, the device 11 is a transmission device 1 for monitoring and control.
2 to send monitoring information. The monitoring control transmission device 12 includes:
This monitoring information is used as data, and a communication packet 25 with the IP address B of the monitoring control device 19 as the destination (DA) and the own IP address A as the transmission source (SA) is created and transmitted to the network 13. This network 13
The communication packet 25 transmitted to the network 1
3 is received by the encryption / decryption device 14 connected to the communication device 3.

The encryption / decryption device 14 adds an authenticator 27 for packet authentication using a digital famous technology or the like to the input communication packet 25, and combines the communication packet 25 and the authenticator 28 as a whole. Encrypt. Then, the encryption / decryption device 14 embeds the encrypted communication packet 25 and authenticator 28 into a new IP packet 26 and sends the new IP packet 26 to the Internet 18 via the router 17.
The destination (DA) of this IP packet 26 is the IP address D of the encryption / decryption device 21 in the central control room, and the source (SA) is its own IP address C.

The IP packet 26 sent to the Internet 18 is sent to the network 23 via the router 24, and is further input to the encryption / decryption device 21 in the central control room, which is the destination (DA). . The encryption / decryption device 21 sends the destination (D
A) and the IP header consisting of the source (SA) are removed, and then the encrypted original communication packet 25 and authenticator 27
Is decrypted.

At this time, the encryption / decryption device 21 inspects the authenticator 27 added for packet authentication, and eavesdrops on the monitoring information while the decrypted communication packet 25 is transmitted through the Internet 18. It is confirmed that unauthorized access such as falsification has not been performed, and that the communication packet 25 has been sent from the monitor control transmission device 12 which is a legitimate source (SA).

When the encryption / decryption device 21 confirms that the communication packet 25 is correct in these inspections, the encryption / decryption device 21 transmits the communication packet 25 to the network 20 in the central control room.
Output to The monitoring control device 19 specified as the destination (DA) of the communication packet 25 receives the communication packet 25 from the monitoring control transmission device 12. At this time, the monitoring control device 19 does not need to be aware that the monitoring information from the monitoring control transmission device 12 has been encrypted on the Internet 18.

(B) Transmission of control information In FIG. 3, the monitoring and control device 1 installed in the central control room
Reference numeral 9 denotes control information for the equipment 11 to be monitored and controlled as data, and a monitoring control transmission device 12 attached to the equipment 11.
IP address A as the destination (DA), and its own I
Communication packet 28 with P address B as the source (SA)
And sends it to the network 20 on the central control room side. Communication packet 2 transmitted to this network 20
8 is received by the encryption / decryption device 21 connected to the network 28.

The encryption / decryption device 21 adds an authenticator 29 for packet authentication using a digital well-known technology or the like to the input communication packet 28, and combines the communication packet 28 and the authenticator 29 as a whole. Encrypt. Then, the encryption / decryption device 21 embeds the encrypted communication packet 28 and authenticator 29 into a new IP packet 30 and sends the new IP packet 30 to the Internet 18 via the router 24.
The destination (DA) of this IP packet 30 is the IP address C of the encryption / decryption device 14 on the equipment side, and the source (SA) is its own IP address D.

The IP packet 30 transmitted to the Internet 18 is transmitted to the network 16 via the router 17 and further input to the encryption / decryption device 14 on the equipment side as the destination (DA). Encryption / decryption device 1
4 removes the IP header consisting of the destination (DA) and the source (SA) of the input IP packet 30, and subsequently decrypts the encrypted original communication packet 28 and authenticator 29. .

At this time, the encryption / decryption device 14 inspects the authenticator 29 added for packet authentication, and eavesdrops on the monitoring information while the decrypted communication packet 28 is transmitted through the Internet 18. It is confirmed that unauthorized access such as tampering has not been performed, and that the communication packet 28 has been sent from the monitoring control device 19, which is a legitimate transmission source (SA).

When the encryption / decryption device 14 confirms that the communication packet 28 is correct in these checks, it outputs the communication packet 28 to the network 13 on the equipment side. The monitoring control transmission device 12 specified as the destination (DA) of the communication packet 28 receives the communication packet 28 from the monitoring control device 19. Then, the control information included in the communication packet 28 is transmitted to the facility 11 to be monitored and controlled. At this time, the monitoring control transmission device 12 does not need to be aware that the control information from the monitoring control device 19 has been encrypted on the Internet 18.

The transmission / reception confirmation units 15 and 22 provided in the encryption / decryption devices 14 and 21 execute the transmission / reception confirmation processing of the monitoring information and the control information in accordance with the flowcharts of FIGS. I do.

(C) Processing for confirming transmission of monitoring information and control information As shown in FIG. 4, monitoring information encrypted by the encryption / decryption devices 14 and 21 incorporated therein via the respective networks 16 and 23. Or an IP packet 26 containing control information,
30 is transmitted to the Internet 18 (S
1), counting the elapsed time from the transmission time of the IP packets 26 and 30 is started.

Within a certain period of time from the transmission time of the IP packets 26 and 30, the encrypted reception confirmation information from the transmission / reception confirmation units 22 and 15 incorporated in the encryption / decryption devices 21 and 14 of the transmission destination is incorporated. If the transmitted IP packet is not transmitted (S3), it is determined that the previously transmitted IP packets 26 and 30 including the monitoring information or the control information have been lost on the Internet 18. Then, a request for retransmission of monitoring information or control information is made to the monitoring control transmission device 12 or the monitoring control device 19 of the own facility 11 (S4).

(D) Processing for confirming reception of monitoring information and control information As shown in FIG. 5, monitoring information or control information encrypted by the encrypting / decrypting devices 14 and 21 incorporated therein via the Internet 18 as shown in FIG. Are received, and the encrypted communication packets 28 and 25 included in the IP packets 30 and 26 are converted into the original communication packets 2 and 25.
When it is determined that the IP packets 30 and 26 have been decrypted and transmitted to the supervisory control transmission device 12 or the supervisory control device 19 (Q1), the encryption / decryption devices 21 and 14 as the transmission sources of the IP packets 30 and 26 are transmitted. To send the acknowledgment information. Specifically, the reception confirmation information is encrypted, incorporated into an IP packet, and transmitted to the Internet 18 (Q2).

It should be noted that the decrypted original communication packet 2
If the transmission data 8 and 25 cannot be normally transmitted to the monitoring control transmission apparatus 12 or the monitoring control apparatus 19, the IP packet of the reception confirmation information is not transmitted.

Further, each of the encryption / decryption devices 14, 21
Performs an unauthorized access monitoring process according to the flowchart of FIG.

(E) Monitoring process of unauthorized access Each of the encryption / decryption devices 14 and 21
(DA) of the IP packets 30 and 26 received from No. 8
Then, the IP header including the source (SA) is removed, and the encrypted communication packets 28 and 25 and the authenticators 29 and 27 are decrypted. Then, the authenticators 29 and 27 added for the packet authentication are inspected, and the decrypted communication packets 28 and 25 are eavesdropped on the monitoring information or the control information while being transmitted through the Internet 18.
It is checked whether unauthorized access such as falsification has been performed (R1).

When unauthorized access has been performed (R
2) Discard the IP packets 30, 26 received from the Internet 18 (R3). Since the reception confirmation information is not transmitted to the discarded IP packets 30 and 26, the discarded IP packets 3 and 26 are not transmitted.
Correct IP packets 30, 26 for 0, 26 are retransmitted.

In the monitoring and control system using the Internet configured as described above, the Internet 18
Encryption / encoding devices 14 and 21 are provided on the equipment 11 side and the monitoring control device 19 side, respectively. Then, the communication packets 25 and 28 in which the monitoring information or the control information output onto the Internet 18 are incorporated by the encryption / encoding devices 14 and 21 are encrypted.

Therefore, on the Internet 18,
Since live monitoring information and control information do not flow, the probability of unauthorized access such as eavesdropping and falsification is reduced. Furthermore, since the monitoring information or the control information is encrypted for each of the embedded communication packets 25 and 28, the monitoring control device 19 and the equipment 11 at the destination and the transmission source cannot be decrypted by a third party. Information security can be further improved.

Since the existing Internet 18 is used, the system can be constructed simply and in a short time as compared with the conventional monitoring and control system using the dedicated line 4 shown in FIG. Further, the maintenance cost of the system can be reduced.

Further, transmission / reception confirmation units 15 and 22 are provided to mutually confirm that the equipment 11 or the monitoring control device 19 has normally received control information or monitoring information by transmitting / receiving reception confirmation information. In addition, the reliability of information communication is further improved.

The reception confirmation information is encrypted and I
Since the packet is incorporated into the P packet and transmitted to the Internet, the confidentiality of information transmitted and received can be maintained.

When the reception confirmation information is not input from the transmission destination, the control information or the monitoring information is retransmitted.
Then, even if the IP packets 26, 30 of the control information or the monitoring information on the Internet 18 are lost for some reason, it is automatically restored.

Furthermore, since the authenticators 27 and 29 for packet authentication are encrypted and incorporated in the IP packets 26 and 30 of the control information or the monitoring information, even if an unauthorized access is attempted, Can be detected. Then, the IP packets 26 and 30 having the unauthorized access are discarded, and the correct IP packets 26 and
30 has been transmitted. Therefore, the security of the transmitted / received information can be further secured.

[0051]

As described above, in the monitoring and control system using the Internet according to the present invention, the monitoring information and the control information transmitted and received via the network are encrypted for each communication packet.

Therefore, even if the Internet is adopted, unauthorized access such as eavesdropping and falsification of the monitoring information and control information can be prevented beforehand, and the reliability and security of the transmitted / received information is sufficiently ensured. The system can be constructed in a short time at a low cost, and furthermore, the maintenance and management after the construction can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a monitoring control system using the Internet according to an embodiment of the present invention.

FIG. 2 is a diagram showing a transmission operation of monitoring information in the monitoring control system.

FIG. 3 is a diagram showing a transmission operation of control information in the monitoring control system.

FIG. 4 is a flow chart showing a transmission confirmation processing operation of monitoring information and control information in a transmission / reception confirmation unit incorporated in the monitoring control system.

FIG. 5 is a flowchart showing a reception confirmation processing operation of monitoring information and control information in a transmission / reception confirmation unit incorporated in the monitoring control system;

FIG. 6 is a flowchart showing an unauthorized access monitoring processing operation in the encryption / decryption device incorporated in the monitoring control system.

FIG. 7 is a block diagram showing a schematic configuration of a conventional supervisory control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Equipment 12 ... Supervisory control transmission apparatus 13, 16, 20, 23 ... Network 14, 21 ... Encryption / decryption apparatus 15, 22 ... Transmission / reception confirmation part 17, 24 ... Router 18 ... Internet 19 ... Supervisory control apparatus 25 , 28 ... Communication packet 26, 30 ... IP packet 27, 29 ... Authenticator

Claims (6)

[Claims] 1. A monitoring control system in which a monitoring control device monitors and controls equipment via the Internet, wherein the monitoring control device is interposed between the monitoring control device and the Internet and between the equipment and the Internet. The control information or the monitoring information embedded in the communication packet from the device or the facility and output is encrypted for each communication packet, and the encrypted communication packet is rewritten with a new I / O.
The packet is embedded in a P packet and sent to the Internet, and the encrypted communication packet embedded in the IP packet received from the Internet is decrypted into the original communication packet and sent to the facility or the monitoring and control device. A monitoring control system using the Internet, comprising a pair of encryption / decryption devices. 2. The apparatus is interposed between the monitoring and control apparatus and the Internet and between the facility and the Internet, and notifies that the facility or the monitoring and control apparatus has normally received control information or monitoring information. 2. The monitoring control system using the Internet according to claim 1, further comprising a pair of transmission / reception confirmation units that mutually confirm each other by transmitting / receiving reception confirmation information via the Internet. 3. The monitoring and control system using the Internet according to claim 1, wherein the reception confirmation information is encrypted, embedded in an IP packet, and transmitted to the Internet. 4. The pair of transmission / reception confirmation units does not receive the reception confirmation information within a predetermined time after the encryption / decryption device on its own side transmits an IP packet of control information or monitoring information to the Internet. The monitoring and control system using the Internet according to claim 2 or 3, wherein a retransmission request is made to the monitoring and control device or facility on its own side. 5. The monitoring control device and the equipment, upon receiving the retransmission request, embed control information or monitoring information transmitted immediately before in a communication packet and retransmit it to its own encryption / decryption device. The monitoring and control system using the Internet according to claim 4, wherein 6. The pair of encryption / decryption devices encrypts and embeds an authenticator for packet authentication in an IP packet of control information or monitoring information, and performs authentication embedded in an IP packet received from the Internet. 6. The method according to claim 1, wherein an unauthorized access to the monitoring information or the control information is detected from a status of the child.
A monitoring control system using the Internet described in the item.