JP2007228430A - Encryption wireless security system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the safety of an encryption security system for houses, shops and offices. <P>SOLUTION: An encryption wireless security system is constituted of a master unit 10 and several slave units 30 and 50. The slave units 30 and 50 have sensors. Each of the master unit 10 and the slave units 30 and 50 has a reconfigurable logic circuit 18 and a radio communication part 22. The logic configuration of the reconfigurable logic circuit 18 provides a dynamically modifiable encryption wireless security system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a security system for a house, a store, or an office, and more specifically to an encrypted wireless security system using a reconfigurable circuit.

  In recent years, an increasing number of homes are equipped with a theft security system for ordinary houses against the increasing number of empty nests and robbery crimes. Many of such security systems are composed of a master unit that is a central control device and a slave unit equipped with a sensor, and the master unit and the slave unit are connected by a wire. Therefore, it is necessary to provide mounting holes for wire connection wiring on walls, ceilings, etc. when installing a security system, and to install sensor slave units on glass doors, entrance doors, etc., relative to the movable range of the doors and doors It is necessary to consider extra wiring length. By performing these processes, the aesthetics of the house is impaired, and the number of installed sensor slave units is limited due to wiring cost restrictions. In addition, a system failure occurs due to the cutting of the wire.

  Further, claim 6 of Patent Document 1 suggests that information is transmitted wirelessly in the home security system. However, in wireless information transmission, there is a risk of disabling the security system by sending disturbance information such as a virus from the outside to the system or by intercepting a wireless signal. Moreover, according to the system using wireless communication, it is difficult to detect when the signal of the slave unit is interrupted or when the power source of the slave unit is stopped. As described above, when wireless is used, the range of use of the security system is widened, but there are many problems in terms of safety and stability, and practical application is difficult.

JP 2004-270172 A

  The present invention provides a highly secure security system for houses, stores, and offices that solves at least some of the problems of the prior art.

  The present invention is an encrypted wireless security system composed of a master unit and a plurality of slave units. The slave unit has a sensor, and each of the master unit and the slave unit includes a reconfigurable logic circuit, An encrypted wireless security system having a wireless communication unit and capable of dynamically changing the configuration of the reconfigurable logic circuit is provided.

  Here, each of the master unit and the slave unit is always operated under the same logic configuration. The reconfigurable logic circuit is preferably one that performs encryption. Furthermore, it is preferable that the encryption key for encryption performed by the reconfigurable logic circuit is incorporated in the reconfigurable logic circuit and is changed when the configuration is rewritten. The master unit and the plurality of slave units constitute a network that performs peer-to-peer wireless communication and exchanges data between each other, that is, between the master unit, each slave unit, and each slave unit. In this case, it is more preferable to further provide a mobile slave unit for performing wireless communication only with the master unit.

  The master unit preferably has a function of predicting when the power of the slave unit is exhausted based on power supply voltage data sent from the slave unit, or a function of grasping a network configuration configured with the slave unit. . Furthermore, it is preferable that the master unit has a function of identifying the slave unit once disappeared from the network by its ID, and re-authenticating to make it a member of the network.

  The security system according to the present invention has a wireless communication as a basic configuration, but it goes without saying that wired communication may be performed between some slave units and the master unit.

By employing this reconfigurable logic circuit, the encrypted wireless security system of the present invention is highly secure against attacks by third parties. In addition, by performing peer-to-peer communication between the master unit and the slave unit, the status of the slave unit can be grasped in more detail, or the situation when the slave unit leaves the network can be grasped in more detail. In addition, the security of the encrypted wireless security network can be further enhanced.

  FIG. 1 shows a case where an overview of the entire security system according to the first embodiment of the present invention is applied to a general house. In FIG. 1, a solid square represents a controller (centralized control device) that is the base unit 10 of the security system. What is indicated by an open square is a fixed type sensor slave unit 30. In addition, a mobile sensor slave unit 40 is indicated by a black circle. A dotted line indicates a peer-to-peer network composed of a plurality of fixed-type slave units 30 and a master unit 10. That is, communication is performed not only between the base unit 10 and the fixed type slave unit 30 but also between the fixed type slave units 30. In this embodiment, the mobile slave device 50 attached to a moving vehicle such as an automobile 60, a bicycle 62, and an auto dubai 64 does not belong to the mutual network including the fixed slave device 30, and is the master device. It is possible to communicate with only 10.

  FIG. 2 shows the relationship between the configuration example of the parent device 10 and the child devices 30 and 50 in the system of the present invention. The configuration of the parent device 10 can be composed of an adapter unit 12 that performs wireless communication with the child device 30 and a central control device 14. The adapter unit 12 and the central control device 14 can be connected by wire. The central control device 14 may be basically the same as the centralized control device of the existing home security system, and both the fixed type and the mobile type slave units 30 inputted from the adapter unit 12 are used. , 50 processes the signal from the sensor of the slave unit, generates a warning sound and warning display, and at the same time, detects an abnormality in the monitoring device of the security company outside the house or the user's mobile phone or personal computer. Sends information about the occurrence and its status. That is, the central control device 14 is a control device including a display unit, an input unit, and a memory, and can perform communication with the outside of the house security system by wire or wirelessly. Of course, the adapter unit 12 and the central control unit 14 can be integrated.

  As sensors in the stationary slave unit 30, a triaxial shock sensor, a movement sensor that detects movement, a magnetic or pressure sensor that captures the opening and closing of doors and windows, as well as confirmation of a person's home and detection of illegal intruders are performed. Infrared human detection sensor, gas leak sensor, temperature sensor to detect forgetting to fire or stove, switch sensor to detect the use of electrical equipment, smoke detection sensor to detect fire, forgetting to lock Various sensors, such as a lock sensor for detecting, can be used without particular limitation. As a sensor of the mobile slave unit 50, a GPS (Global Positioning System) sensor that can grasp the position of the moving body, a shock sensor that detects an impact on the moving body, and the like can be used.

  For mutual wireless communication between the parent device 10 and the child devices 30 and 50, for example, radio waves of 400 MHz, 900 MHz, and 2.4 GHz band are used, IEEE 802.11a, b, g standards, IEEE 802 , 15.4 (ZigBee) standard or Bluetooth standard. However, these wireless communication standards themselves are vulnerable to attacks by third parties, and are capable of intercepting wireless signals. Currently, encryption methods that can be used for such digital wireless communication include DES, Triple DES, AES (Advanced Encryption Standard) such as Rheindahl, WPA (Wi-Fi Protected Access), WEP (Wired Equivalent Privacy), etc. Several encryption standards are known, but the danger of interception and decryption remains. And there are cases where encryption cannot sufficiently cope with radio wave interference and signal destruction. Therefore, the present invention proposes the use of a reconfigurable logic circuit for a security system in addition to the encryption of a radio signal.

  FIG. 3 shows a block diagram of the circuit configuration of the adapter unit 12 and the slave units 30 and 50 of the master unit 10. As a preferred example, an example in which the same printed circuit board (indicated by a dotted line) can be used in the parent device 10 and the child devices 30 and 50 will be described. First, there is an A / D converter 16 that receives an analog input from a sensor and outputs a digital signal. In order to process the A / D converted sensor signal and encrypt the signal, as described above, an FPGA (Field Programmable Gate Array) 18 that can constitute a reconfigurable logic circuit is used. Is preferred. An FPGA is an LSI that can be programmed. It was developed for the purpose of sending a simulation drawing of a microprocessor or ASIC and simulating it, but it is used as a kind of programmable logic device. Unlike devices with fixed logic, the FPGA can change the logic executed by the hardware at any time, and can perform any number of functions. The FPGA is a reconfigurable logic circuit or a reconfigurable logic circuit. Also known as one of Such processors are commercially available from, for example, Xilinx (Xilinx Corporation in Japan) and Altera (Japan Altera Corporation), and generally include a processor core, a memory, a flash memory, a controller, and the like. By using such an FPGA, the protocol of the security system can be dynamically changed, and protection against interference from a third party can be enhanced at a stretch.

  The FPGA 18 is connected to the control circuit 20 by a bus. The control circuit 20 controls the wireless communication unit 22 to perform communication with the other parent device 10 and the child devices 30 and 50. When used as the adapter unit 12 of the parent device 10, the output of the control circuit 20 is wired to the central control device 14 of the parent device 10. The power source of the base unit 10 can be stably supplied by combining a normal AC power source and a secondary battery.

  Regarding the status monitoring of the slave units 30 and 50, the following detection is possible. That is, power management, signal interruption management, detection of destruction of the slave unit, detection of movement of the slave unit, and the like.

  First, as a power source for the slave units 30 and 50, it is possible to use various types of batteries or power sources including primary batteries, secondary batteries, solar cells, and household AC power sources. Then, the power management becomes necessary. In general, it is possible to detect the remaining battery level as a change in voltage and predict the time when the slave units 30 and 50 disappear from the network based on the remaining battery level. The signal interruption can be detected by detecting a change in the network configuration between the parent device 10 and the fixed child device 30. When signal interruption is detected, the signal transmission bus can be changed. And destruction of the subunit | mobile_unit 30 and 50 can be detected by extinguishing from a network unexpectedly. The shock or movement of the slave units 30 and 50 can be detected by a shock sensor or a movement sensor, and an earthquake (all shock sensors react simultaneously) by analyzing the shock or movement signal obtained from each slave unit. Case) and a case where one or a limited number of handset sensors show a reaction (possible intrusion by a third party, etc.). As for the mobile slave unit 50, it is possible to confirm the movement or the current position in the vicinity of the house or near the house by using the GPS as a sensor.

  FIG. 4 shows a state in which the base unit 10, three fixed type slave units 30 and one mobile type slave unit 50 are operating normally. Peer-to-peer communication is performed between the fixed child device 30 and the parent device 10, and communication is also performed between the fixed child devices 30, and the parent device 10 also grasps the situation as a network topology. is doing. The mobile slave unit 50 (slave unit No. 4) that is attached to a moving vehicle such as an automobile, a bicycle, or a motorcycle, or that is held by an elderly person who has a tendency to be jealous, performs peer-to-peer communication only with the master unit 10. Can be. The master unit 10 collects and manages data from all the slave units 30 and 50 and power supply information of all the slave units together with the network topology described above.

  FIG. 5 shows a state in which the cordless handset 3 has a voltage drop due to battery consumption. It is conceivable that communication with the slave units 1 and 2 will be weakened or stopped in order to slow down the voltage drop. In addition, for the slave units 30 and 50, in order to reduce power consumption, the logic circuit is normally set in the sleep mode, and the activation signal from the master unit 10 is received and the signal is input from the sensor. Only at times can you switch to normal operation mode. FIG. 6 shows a situation where some kind of failure has occurred in transmission of communication radio waves. For example, since a person enters between the first and third handsets, radio waves do not reach between the first and third handsets. However, since the communication state is maintained between No. 3 and No. 2 and the master unit, the entire system operates without any abnormality. FIG. 7 shows a state in which handset 3 is destroyed by an intruder or the like. The data from the slave unit 3 does not enter the master unit 10 not only directly from the slave unit 3 but also suddenly does not enter via the slave unit 1 or 2. FIG. 8 shows a situation when the mobile handset 4 leaves the network. If it is not expected to leave the network, it may be stolen and an alarm can be issued. In addition, since this child device No. 4 is registered in the parent device 10, when returning from outside and entering the vicinity of the house or inside the house, it automatically becomes a member of the network again, and the monitoring of the parent device 10 is performed. It becomes the object of.

  FIG. 9 to FIG. 11 show examples of modes of protection against interference from a third party using a reconfigurable logic circuit. FIG. 9 shows an example of a protocol for dynamically changing the logical configuration of the master unit 10 and the slave units 30 and 50. That is, the logic configuration of the FPGA processor is rewritten and the encryption algorithm is changed. First, while the security system is operating using the encryption A in the logical configuration A, the next logical configuration B is downloaded from the parent device 10 to each of the slave units 30 and 50. The new logical configuration B is stored in the shadow area of the slave units 30 and 50. When the download is confirmed, the slave units 30 and 50 check whether the downloaded data is sound by the check function. Then, at a predetermined timing, the logical configuration of the master unit 10 and the slave units 30 and 50 is changed, and the new encryption unit B is used in the new logical configuration B, so that the master unit 10 and the slave units 30 and 50 Communication between them continues. The change from the cipher A to the cipher B can change not only the encryption algorithm itself but also the encryption key only. When the encryption key is changed by reconfiguring the logic circuit, the key such as the memory of the slave unit is not stored, so that the safety is further improved. Then, preparation for a change to the next logical configuration C is performed.

  Here, if a failure is detected due to a protocol abnormality or the like until the check of the logical configuration change, a command for returning to the previous logical configuration is sent from the master unit 10 to the slave units 30 and 50. Then, a forced initialization command is issued from the parent device 10 to the child devices 30 and 50. Each logical configuration and each encryption algorithm do not have to have a one-to-one correspondence, and a protocol in which some or all of the different encryption algorithms operate on one logical configuration is possible. In addition, a protocol in which one encryption algorithm operates on a plurality of logical configurations is also conceivable.

  In FIG. 10, the communication timing is changed as the logical configuration is changed from A to B, C, D instead of performing communication within the network at regular intervals. The vertical bar | burr shown in FIG. 10 has shown the time of performing data communication of the subunit | mobile_unit 1. As shown in FIG. At this time, the encryption algorithm may be the same or may change as in the case of FIG. FIG. 11 shows a state in which the IDs of the slave units 1 to 3 are randomly changed by changing the reconfigurable logic to prevent interference from a third party. When the IDs of the slave units 30 and 50 are dynamically changed, it is impossible to bring a duplicated slave unit and break the security system.

  By using such a dynamically changed logic circuit configuration, part or most of the hardware and software can be lost when the power is turned off, as well as the encryption key. Can be. Accordingly, it is possible to make it impossible to extract data from a security system that is not operating or to analyze the system configuration. Even if data is extracted, the data extracted at a certain point due to a dynamic system configuration change is immediately meaningless. In addition, there is a known technique for deriving encryption key information by analyzing the power consumption or operation timing of the device, but this also dynamically changes the encryption algorithm or encryption key, thus breaking protection. It is never done. The logic circuit configuration that is sequentially changed can be stored in advance in the base unit 10 of the security system, or can be transmitted from the outside to the base unit 10 of the security system and stored in the base unit 10.

It is a top view which shows the outline | summary of the whole security system which applied the 1st Embodiment of this invention to the general house. It is a schematic diagram which shows the example of a structure of the main | base station of the system of this invention, and the relationship of a subunit | mobile_unit. It is a block diagram which shows the structure of the printed circuit board which can be utilized for the main | base station of this invention and a subunit | mobile_unit. It is a block diagram which shows the normal operation state of the security system of this invention. It is a block diagram which shows the state which the power supply residual quantity of the subunit | mobile_unit 3 decreased and the operation | movement was stopped among the security systems of this invention. It is a block diagram which shows the state with a communication failure between the subunit | mobile_unit 1 and the subunit | mobile_unit 3 among the security systems of this invention. It is a block diagram which shows the state where the subunit | mobile_unit 3 of the security system of this invention was destroyed. It is a block diagram which shows the state which the subunit | mobile_unit 4 of the security system of this invention moved. It is a block diagram which shows a mode that the structure and encryption of a logic circuit are changed sequentially. It is a block diagram which shows a mode that the structure and communication timing of a logic circuit are changed sequentially. It is a block diagram which shows a mode that the structure of a logic circuit and ID of a subunit | mobile_unit are changed sequentially.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main | base station 12 Adapter part 14 Central control apparatus 16 A / D conversion part 18 Control circuit 20 Wireless communication part 30 Fixed type | mold subunit | mobile_unit 50 Movement subunit | mobile_unit

Claims (6)

  This is an encrypted wireless security system composed of a master unit and a plurality of slave units. The slave unit has a sensor, and each of the master unit and the slave unit includes a reconfigurable logic circuit, a radio communication unit, And an encrypted wireless security system in which the logic configuration of the reconfigurable logic circuit is dynamically changeable.   The encrypted wireless security system according to claim 1, wherein each of the master unit and the plurality of slave units operates under the same logical configuration.   The encrypted wireless security system according to claim 1 or 2, wherein the reconfigurable logic circuit performs encryption, and a change is made to an encryption method together with a change of a logical configuration.   The encryption wireless security system according to claim 3, wherein an encryption key for encryption performed by the reconfigurable logic circuit is incorporated in the reconfigurable logic circuit and is changed along with rewriting of the logical configuration.   The encrypted wireless security system according to any one of claims 1 to 4, wherein the master unit and the plurality of slave units can perform peer-to-peer wireless communication with each other to form a network.   The encrypted wireless security system according to claim 5, further comprising a child device that performs wireless communication only with the parent device.

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