JP2014072733A - Communication system, communication terminal, and management device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system, communication terminal, and management device in which a user device can acquire user information from a slave apparatus, but the number of times of transmission of the user information by the slave apparatus is not increased.SOLUTION: In a communication system, when user information is transmitted to a master unit 1 by using multi-hop communication, a slave unit 201 as a transmission source of a first hop encrypts user information on an own user 401 by using a common key K1, and simultaneously transmits the encrypted information to a slave unit 202 that is an adjacent node and a management device 301 of the same user 401. The slave unit 202 as a transmission source of a second hop decrypts the user information received from the slave unit 201 by using the common key K1, encrypts the decrypted user information by using a public key Ka1 of the master unit 1, and transmits the encrypted user information to a slave unit 203 that is an adjacent node. The management device 301 of the same user 401 as the slave unit 201 obtains the user information by decoding the user information received from the slave unit 201 by using the common key K1.

Description

  The present invention relates to a communication system, a communication terminal, and a management apparatus that perform multi-hop communication in which each of a plurality of slave units transmits information to a master unit using another slave unit as a repeater.

  Conventionally, by incorporating a slave unit (node) that can communicate with other slave units into a power meter or gas meter of each consumer (home), each customer's consumer in the master unit (key setting device) A system for collecting information (amount of power and gas used) has been proposed (see, for example, Patent Document 1).

  In the system described in Patent Document 1, the handset is a wireless communication device that performs multi-hop communication with other handset within a predetermined communication range. Multi-hop communication is a technology in which slave units that do not exist within the communication range of each other communicate with each other via another slave unit that exists within the communication range of each slave unit.

  Further, in the system described in Patent Document 1, each slave unit is set with a key for encrypting and decrypting data transmitted / received between the slave units. Secure communication is possible by communicating with other slave units using a common key.

International Publication No. 2012/049776

  By the way, in recent years, it has been proposed that each customer is provided with a customer device that acquires customer information of the customer from a child device, and the customer also uses the customer information. The consumer device visualizes the consumer information by displaying consumer information such as power consumption on a television or the like, for example.

  However, in the system described in Patent Document 1, the customer information that the slave unit transmits to the master unit by multi-hop communication is encrypted using a key that is common between the slave units. The customer information cannot be received and used as it is. Therefore, in order for a consumer apparatus to acquire consumer information, it is necessary for a subunit | mobile_unit to transmit customer information separately with respect to each of a main | base station and a consumer apparatus, and the frequency | count of transmission of consumer information There is a problem that increases.

  The present invention has been made in view of the above-described reason, and a communication system and communication in which a consumer device can acquire consumer information from a slave unit but does not increase the number of times customer information is transmitted in the slave unit An object is to provide a terminal and a management device.

  The communication system of the present invention includes a master unit that collects customer information from a plurality of consumers, and a plurality of units that are provided in a plurality of consumers and have a function of transmitting the customer information of each consumer to the master unit. And a consumer device that is provided in a consumer and obtains the consumer information of the consumer from the slave unit, wherein one slave unit of the plurality of slave units is another child unit A communication system for transmitting the customer information to the parent device by multi-hop communication using a machine as a repeater, wherein each of the plurality of child devices receives customer information without relaying other child devices A storage unit that stores a common key that is common between the adjacent node that is a possible slave unit and the customer device of the same customer, and a public key of the master unit, and the common key in the storage unit is used A first encryption unit for encrypting data and the common in the storage unit A first decryption unit that decrypts data using the data, and a second encryption unit that encrypts data using the public key in the storage unit, and transmits the customer information to the base unit The first-hop transmission slave unit transmits the customer information encrypted by the first encryption unit to the customer device of the adjacent customer and the same customer, and the second-hop and subsequent hops The transmission child unit is configured to transmit the customer information encrypted by the second encryption unit.

  In this communication system, the slave transmits the common key encrypted with the public key of the adjacent node to the adjacent node, and the common key encrypted with the public key of the consumer device of the same consumer. It is desirable to distribute the common key by transmitting it to the consumer device.

  In this communication system, the slave unit can select the master unit as a transmission destination of the customer information from a plurality of master units, and a communication route with the master unit as a transmission destination The master unit periodically exchanges a hello message, and distributes the public key of the master unit to the slave unit on the communication route in which the master unit is included by using the hello message. It is more desirable.

  The communication terminal according to the present invention includes a master unit that collects customer information from a plurality of consumers, and a plurality of functions that are provided in a plurality of consumers and transmit the customer information of each customer to the master unit. And a consumer device that is provided in a consumer and obtains the consumer information of the consumer from the slave unit, wherein one slave unit of the plurality of slave units is another child unit A communication terminal used as the slave unit in a communication system that transmits the customer information to the master unit by multi-hop communication using a machine as a repeater, and can receive customer information without relaying other slave units A storage unit that stores a common key that is common between an adjacent node that is a slave unit and the customer device of the same customer, and a public key of the parent unit, and the common key in the storage unit A first encryption unit for encrypting data, and the shared unit in the storage unit. A first decryption unit that decrypts data using a key; and a second encryption unit that encrypts data using the public key in the storage unit, and transmits the customer information to the base unit. At that time, when the transmission source is the first hop, the customer information encrypted by the first encryption unit is transmitted to the customer device of the adjacent node and the same customer, and the second and subsequent hops. Is configured to transmit the customer information encrypted by the second encryption unit.

  The management apparatus according to the present invention includes a master unit that collects customer information from a plurality of consumers, and a plurality of functions that are provided in a plurality of consumers and transmit the customer information of each customer to the master unit. And a consumer device that is provided in a consumer and obtains the consumer information of the consumer from the slave unit, wherein one slave unit of the plurality of slave units is another child unit A management device used as the customer device in a communication system for transmitting the customer information to the parent device by multi-hop communication using a machine as a repeater, the child device of the same consumer and customer information from the child device A storage unit that stores a common key that is common to adjacent nodes that are slave units that can be received without relaying other slave units, and a first unit that decrypts data using the common key in the storage unit A slave unit of the same consumer is the consumer When transmitting broadcast to the master unit, characterized in that it is configured to receive the customer information slave unit is transmitted to the adjacent node encrypted with the common key.

  In the present invention, the slave device at the transmission source of the first hop transmits the customer information encrypted by the first encryption unit to the adjacent node and the customer device of the same customer, and the transmission after the second hop is transmitted. The original slave unit is configured to transmit the customer information encrypted by the second encryption unit. Therefore, while the consumer device can acquire consumer information from the slave unit, the number of transmissions of consumer information in the slave unit does not increase, and at least the load factor required for encryption can be reduced. There are advantages.

It is explanatory drawing which shows the operation example of the communication system which concerns on this embodiment. It is a block diagram which shows the subunit | mobile_unit and management apparatus of the communication system which concern on this embodiment. It is explanatory drawing which shows the operation example of the communication system which concerns on this embodiment. It is a sequence diagram which shows the operation example of the communication system which concerns on this embodiment.

  As shown in FIG. 1, the communication system according to the present embodiment includes a master unit 1, a plurality of slave units 200, 201, 202... And a plurality of management devices 300, 301, 302. I have.

  Hereinafter, when the slave units 200, 201, 202... Are not individually distinguished, they are referred to as “slave unit 2”, and when the management devices 300, 301, 302. " The subunit | mobile_unit 2 comprises a communication terminal, and the management apparatus 3 comprises a consumer apparatus. The subunit | mobile_unit 2 and the management apparatus 3 are provided for every electric power consumer 400,401,402 ... (henceforth "the consumer 4" when not distinguishing individually). Here, the slave device 200 and the management device 300 are provided in the consumer 400, the slave device 201 and the management device 301 are provided in the consumer 401, and the slave device 202 and the management device 302 are provided in the consumer 402. Is provided. In addition, below, although illustrated about the case where the consumer 4 is a detached house, not only this example but the consumer 4 may be each dwelling unit of a housing complex, an office, a factory, etc., for example.

  Master device 1 has a function of collecting customer information for each customer 4 from a plurality of customers 4. The subunit | mobile_unit 2 is each attached to the electric power meter (not shown) of the consumer 4, and transmits the meter-reading data containing the electric energy (electric power consumption) used by the consumer 4 to the main | base station 1 as consumer information. It has a function to do. The management device 3 is provided in the customer 4 and has a function of acquiring customer information (meter reading data) of the customer 4 from the slave unit 2. Here, the power meter is connected to a power line (not shown) to which commercial power from an electric power company (electricity provider) is supplied, and measures the amount of power actually used by the customer 4.

  The base unit 1 is installed in the vicinity (for example, a utility pole) of a step-down transformer (not shown) that supplies commercial power to the customer 4. The master unit 1 acquires customer information of each customer 4 from a plurality of slave units 2 under its management, and passes the acquired customer information through a dedicated line (not shown) using an optical fiber or the like. Transmit to a host device (not shown). The host device is managed by an electric power company or a provider that performs a customer information aggregation service. As a result, the host device can acquire the customer information of the plurality of consumers 4 acquired by the parent device 1 from each of the managed child devices 2, from the plurality of parent devices 1, and as a result, many The remote meter-reading system which can collect the customer information of the customer 4 of this can be comprised.

  The subunit | mobile_unit 2 comprises what is called a smart meter with an electric power meter, transmits meter-reading data to an electric power company by communicating with the main | base station 1, and enables remote meter-reading etc. The subunit | mobile_unit 2 enables transmission / reception of data with an electric power meter by the structure connected to an expansion terminal (not shown) of an electric power meter, for example. The subunit | mobile_unit 2 may be the structure which carries out radio | wireless communication with an electric power meter not only in the structure connected with an electric power meter, and the measurement part is measured by image processing from the image imaged with the camera (not shown). It may be configured to read the result.

  In this embodiment, as an example, a case where meter reading data including the power usage amount of the customer 4 is used as customer information will be described as an example. However, the customer information is not limited to the power usage amount, for example, gas, water, etc. The amount used may be information other than meter reading data. Moreover, the subunit | mobile_unit 2 may once memorize | store the acquired meter-reading data in the memory 22 (refer FIG. 2).

  This communication system is configured such that one slave unit 2 among a plurality of slave units 2 transmits customer information to the master unit 1 by multi-hop communication using the other slave unit 2 as a repeater. . That is, for example, the slave unit 201 of the customer 401 transmits the customer information of the customer 401 to the master unit 1 via the slave units 202, 203. And indirectly transmit customer information. In short, the slave unit 2 that cannot directly communicate with the master unit 1 can communicate with the master unit 1 by relaying the packet by another slave unit 2 at a communicable distance. At this time, the subunit | mobile_unit 2 transmits the packet which contains customer information in a data part, and specifies the subunit | mobile_unit 2 used as a communication route, ie, a repeater, by the transfer destination information contained in the header part of a packet.

  Thus, when the base unit 1 communicates with the handset 2, it collects data from all the handset 2 even if it is not in an environment where it can communicate directly with all the handset 2 due to the influence of transmission distance, noise, etc. It becomes possible. Specifically, the handset 2 exchanges transmission status information for constructing a communication route according to the multi-hop protocol, and determines the communication route based on the information. In the present embodiment, each slave unit 2 periodically transmits a hello message for constructing a route for multi-hop communication to the slave unit 2 existing in a range where the signal (radio wave) can reach directly. Then, a communication route is constructed according to the reception status of the hello message (reception field strength, etc.).

  In the present embodiment, the communication between the child devices 2 and the communication between the child device 2 and the parent device 1 are realized by wireless communication using radio waves as a transmission medium. However, the communication between the slave units 2 and the communication between the slave unit 2 and the master unit 1 are not limited to wireless communication, for example, power line communication (PLC: Power Line Communications) for performing communication using a power line as a transmission path It may be realized by wired communication.

  The management device 3 is a HEMS (Home Energy Management System) device, and performs bidirectional communication with a terminal (not shown) attached to or integrated with various electric devices (not shown). Examples of electrical equipment to which the terminal is attached or integrated include power equipment such as solar cells, storage batteries, and power conditioners, equipment equipment such as IH cooking heaters, water heaters, and housing information panels, home appliances such as televisions, personal computers, There are information devices such as tablet terminals. The management device 3 may be housed in a distribution board (not shown) of the customer 4 or may have a casing separately from the distribution board.

  The management device 3 acquires customer information of the customer 4 in which the management device 3 is provided from the handset 2 provided in the same customer 4. In the present embodiment, the management device 3 is configured to perform two-way wireless communication with the handset 2 using radio waves as a transmission medium, and periodically from the handset 2 of the same consumer 4. Acquire customer information. Based on the customer information acquired from the handset 2, the management device 3 obtains information such as the power consumption per unit time of the customer 4, a housing information panel of the customer 4, a television, a personal computer, a tablet terminal, etc. It has a function to display on the electrical equipment. Moreover, the management apparatus 3 receives the signal transmitted from the electric power company via the subunit | mobile_unit 2 in order to suppress the peak of energy demand (peak cut), and controls operation | movement of a terminal (electric equipment) based on this signal It has a function to do.

  Next, the structure of the subunit | mobile_unit 2 and the management apparatus 3 is demonstrated with reference to FIG.

  The slave unit 2 includes a (slave unit side) communication unit 21, a (slave unit side) memory 22, a (slave unit side) first conversion unit 23, a (slave unit side) second conversion unit 24, (Machine side) has a key generation unit 25, a control unit 26, and a (slave unit side) power supply unit 27. The control unit 26 has a CPU (Central Processing Unit) as a main component, and executes a predetermined program stored in the memory 22 to execute a communication unit 21, a first conversion unit 23, a second conversion unit 24, and a key generation unit. 25 to realize various functions. The power supply unit 27 supplies power to each unit of the child device 2.

  The communication unit 21 includes an antenna 211, and is configured to be capable of bidirectional communication with other slave units 2, the master unit 1, and the management device 3 by radio communication using radio waves as a transmission medium. ing. The memory 22 functions as a storage unit that stores a program executed by the control unit 26, an identifier (ID) assigned in advance to each slave unit 2, and a common key and a public key described later.

  The first conversion unit 23 has a function of encrypting and decrypting data using a common key stored in the memory 22. Specifically, the first conversion unit 23 encrypts data using the common key in the memory 22 and first decryption that decrypts the data using the common key in the memory 22. Part 232.

  The second conversion unit 24 has a function of encrypting data using a public key stored in the memory 22. Specifically, the second conversion unit 24 includes a second encryption unit 241 that encrypts data using a public key in the memory 22. Further, in the present embodiment, the second conversion unit 24 includes a second decryption unit 242 that decrypts data using a secret key generated in a pair with the public key.

  The key generation unit 25 has a function of generating a common key used in the first conversion unit 23 and a public key / private key pair used in the second conversion unit 24 and storing them in the memory 22.

  The management device 3 includes a (management side) communication unit 31, (management side) memory 32, (management side) first conversion unit 33, (management side) second conversion unit 34, and (management side) key generation. Unit 35, communication interface 36, first control unit 37, second control unit 38, and (management side) power supply unit 39. A terminal attached to or integrated with an electric device is connected to the communication interface unit 36 wirelessly or by wire via a network such as a LAN (Local Area Network). The first control unit 37 has a CPU as a main configuration, controls the communication interface 36 by executing a predetermined program stored in the memory 32, and communicates with a terminal attached to or integrated with an electric device. . The second control unit 38 has a CPU as a main configuration, and executes a predetermined program stored in the memory 32 to thereby make the communication unit 31, the first conversion unit 33, the second conversion unit 34, and the key generation unit 35. Control and realize various functions. The power supply unit 39 supplies power to each unit of the management device 3.

  The communication unit 31 includes an antenna 311 and is configured to be capable of bidirectional communication with the slave unit 2 by wireless communication using radio waves as a transmission medium. The memory 32 stores, in addition to programs executed by the first control unit 37 and the second control unit 38, an identifier (ID) assigned in advance to each management device 3, and a common key and a public key described later.

  The first conversion unit 33 has a function of encrypting and decrypting data using a common key stored in the memory 32. Specifically, the first conversion unit 33 encrypts the data using the common key in the memory 32 and the first decryption that decrypts the data using the common key in the memory 32. Part 332.

  The second conversion unit 34 has a function of encrypting data using a public key stored in the memory 32. Specifically, the second conversion unit 34 includes a second encryption unit 341 that encrypts data using a public key in the memory 32. Furthermore, in this embodiment, the 2nd conversion part 34 has the 2nd decoding part 342 which decodes data using the private key produced | generated with a public key and a pair.

  The key generation unit 35 has a function of generating a public key / private key pair used by the second conversion unit 34 and storing the pair in the memory 32.

  A common key and a public key as described below are stored in advance in the memory 22 of the slave unit 2.

  That is, the memory 22 of the child device 2 stores the common key generated by the key generation unit 25 in advance. This common key is used when communicating between the child device 2 which is an adjacent node and the management device 3 of the same customer 4. The adjacent node referred to here is the slave unit 2 that can receive the customer information transmitted by itself during multi-hop communication without relaying another slave unit 2. In other words, when transmitting a consumer information to the master unit 1 by multi-hop communication using a slave unit 2 as a transmission source, the slave unit 2 that forms a communication path between the transmission source and the master unit 1 Among them, the slave unit 2 that first (directly) receives customer information from the transmission source is an adjacent node of the slave unit 2 that is the transmission source.

  For example, the slave unit 201 of the customer 401 first transmits the customer information to the slave unit 202 of the customer 402 when transmitting the customer information of the customer 401 to the master unit 1. Becomes a handset 202. Therefore, the slave unit 201 has a common key K1 common to the slave unit 202 that is an adjacent node and the management device 301 provided in the same customer 401. That is, a common common key K1 is stored in advance in the slave unit 201, the memory 22 of the slave unit 202, and the memory 32 of the management apparatus 301. Similarly, the slave unit 202 of the consumer 402 has a common key K2 that is common between the slave unit 203 that is an adjacent node and the management device 302 of the same consumer 402.

  Further, the slave unit 2 stores the public key of the master unit 1 in the memory 22 in advance. That is, the parent device 1 generates a public key Ka1 and a secret key Kb1 as a pair, and distributes only the public key Ka1 to the child device 2 while holding the secret key Kb1. Data encrypted using the public key Ka1 can be decrypted only by the secret key Kb1 paired with the public key Ka1.

  By the way, in the communication system of this embodiment, when the subunit | mobile_unit 2 transmits the customer information of the self-customer 4 to the main | base station 1 by multihop communication, this consumer information is not only the hop destination subunit | mobile_unit 2 but. The data is also transmitted to the management device 3 provided in the same customer 4 as the child device 2 that is the transmission source. That is, when the handset 2 transmits the customer information to the adjacent node, the signal from the handset 2 reaches the management device 3 of the same consumer 4, so that the management device 3 receives the signal from the handset 2. By providing the (communication part 31), it becomes possible to transmit consumer information from the subunit | mobile_unit 2 to the management apparatus 3. FIG. For example, when transmitting the customer information to the parent device 1, the child device 201 of the customer 401 transmits the customer information all at once to the child device 202 that is an adjacent node and the management device 301 of the same customer 401. To do.

  As described above, the management device 3 is configured to be able to acquire the customer information from the child device 2 when the child device 2 of the same customer 4 transmits the customer information to the parent device 1. In other words, the subunit | mobile_unit 2 will transmit customer information also to the management apparatus 3 simultaneously only by transmitting customer information toward the main | base station 1. FIG. Therefore, the subunit | mobile_unit 2 can transmit customer information with the frequency | count of transmission small compared with the case where customer information is separately transmitted with respect to each of the main | base station 1 and the management apparatus 3. FIG.

  However, the signal from the handset 2 may be received not only by the management device 3 of the same customer 4 as that of the handset 2 but also by the management device 3 of the neighboring customer 4 existing within the reach of the radio wave. . For example, when the slave unit 201 of the customer 401 transmits the customer information to the master unit 1, this consumer information is not only the neighboring node slave unit 202 and the management device 301 of the same consumer 401, but also the neighborhood demand. It may be received also by the management apparatus 300 of the house 400.

  Therefore, in the communication system of the present embodiment, the slave unit 2 that is the transmission source (source of consumer information) of the first hop transmits demand information by transmitting customer information encrypted using a common key. House information is prevented from leaking to the neighboring customer 4 (the management device 3). That is, as described above, the slave device 2 that is the transmission source of the first hop stores in the memory 22 a common key that is common between the slave device 2 that is an adjacent node and the management device 3 of the same customer 4 in advance. Therefore, the customer information is encrypted by the first encryption unit 231 using this common key. The slave device 2 that is the transmission source of the first hop transmits the encrypted customer information to the slave device 2 that is an adjacent node and the management device 3 of the same customer 4 at the same time.

  As a result, the customer information transmitted from the slave unit 2 that is the transmission source can be shared only by the slave unit 2 that is a neighboring node and the management device 3 of the same consumer that has a common key common to the slave unit 2 that is the transmission source. Decoding is possible. Therefore, even if the customer information transmitted from the child device 2 that is the transmission source of the first hop may be received by the management device 3 of the neighboring customer 4, the management device 3 of the neighboring customer 4 Since the customer information cannot be decrypted, the customer information does not leak to the neighboring customer 4.

  Further, in the communication system of the present embodiment, the slave unit 2 that is the transmission source after the second hop (relays the customer information) is the consumer encrypted using the public key Ka1 of the master unit 1. By transferring information, leakage of customer information is prevented. That is, since the handset 2 that is the transmission source of the second hop (the transmission destination of the first hop) stores the public key Ka1 of the base unit 1 in the memory 22 in advance as described above, this public key Ka1 is stored. The second encryption unit 241 is used to encrypt customer information. At this time, the handset 2 that is the transmission source of the second hop uses the common key to store the customer information encrypted with the common key in the handset 2 that is the transmission source of the first hop. After being decrypted by H.232, the second encryption unit 241 performs encryption. In addition, the subunit | mobile_unit 2 used as the transmission source of 2nd hop encrypts only the data part containing customer information, without encrypting the header part etc. which contain transfer information among the packets used as a relay object.

  The slave device 2 that is the transmission source after the third hop transfers the customer information encrypted with the public key Ka1 of the master device 1 to the slave device 2 or master device 1 that is the hop destination. The customer information encrypted with the public key Ka1 of the parent device 1 can be decrypted only by the parent device 1 having the public key Ka1 and the paired secret key Kb1. Therefore, even if the customer information transmitted from the slave unit 2 which is the transmission source after the second hop is received by the management device 3 of the same customer 4 as that of the slave unit 2 or the neighboring customer 4, the management is performed. Since the device 3 cannot decrypt the customer information, the customer information does not leak.

  In short, in the communication system of the present embodiment, when transmitting customer information to the parent device, the child device 2 of the transmission source at the first hop sends the first encryption to the adjacent node and the management device 3 of the same customer 4. The customer information encrypted by the conversion unit 231 is transmitted all at once. In addition, the second slave device 2 as a transmission source after the second hop is configured to transmit the customer information encrypted by the second encryption unit 241. As a result, when the slave unit 2 transmits the customer information of the customer 4 to the master unit 1 by multi-hop communication, not only the slave unit 2 at the hop destination but also the management device 3 of the same consumer 4 While transmitting customer information, it is possible to avoid leakage of customer information to other management devices 3.

  In the present embodiment, the slave unit 2 transmits the common key encrypted with the public key of the adjacent node to the adjacent node, and the common key encrypted with the public key of the management device 3 of the same customer 4 is the same. By transmitting to the management device 3, the common key is distributed. That is, since the handset 2 needs to distribute a common key in advance to the handset 2 that is an adjacent node and the management device 3 of the same consumer 4 when transmitting customer information, the common key is distributed. The common key is distributed using the public key of the adjacent adjacent node and management device 3.

  Specifically, the child device 2 encrypts the common key by the second encryption unit 241 using the public key issued by the child device 2 that is the adjacent node, and the encrypted common key is the child that is the adjacent node. Transmit to machine 2. The subunit | mobile_unit 2 which is an adjacent node acquires a common key by using the 2nd decoding part 242 to decrypt the encrypted common key using the private key and the private key which it issued. Further, the slave unit 2 encrypts the common key by the second encryption unit 241 using the public key issued by the management device 3 of the same customer 4, and uses the encrypted common key as the management device of the same customer 4. 3 to send. The management device 3 of the same customer 4 acquires the common key by decrypting the encrypted common key with the second decryption unit 342 using the private key paired with the public key issued by itself.

  Here, in the memory 22 of the handset 2, a pair of a public key and a private key issued by itself is stored in advance. In this embodiment, the subunit | mobile_unit 2 transmits / receives a public key and the encrypted common key between the subunit | mobile_unit 2 used as an adjacent node using a hello message. Similarly, the memory 32 of the management device 3 stores in advance a pair of a public key and a private key issued by itself. The subunit | mobile_unit 2 and the management apparatus 3 each have the operation part (not shown) which receives the operation input from a user, and exchange of a public key and an encrypted common key is performed by operating an operation part. I do.

  In this way, the handset 2 can distribute the common key only to the intended partner by distributing the common key using the public key of the management node 3 and the adjacent node to which the common key is distributed. As a result, the subunit | mobile_unit 2 can have a common key common between the subunit | mobile_unit 2 which is an adjacent node, and the management apparatus 3 of the same consumer 4. FIG.

  By the way, as for the subunit | mobile_unit 2, the main | base station 1 used as the transmission destination of customer information is not always fixed, and may be changed, for example, when a communication route is changed by a radio wave environment. . In other words, a plurality of parent devices 1 are provided instead of one, and the child device 2 can select the parent device 1 as a transmission destination of customer information from the plurality of parent devices 1. Therefore, each slave unit 2 has a plurality of public keys of the master unit 1 used for encryption of customer information when it becomes a transmission source after the second hop (relays customer information). The public key of the base unit 1 for each unit is required.

  However, if the handset 2 stores in advance the public keys of a plurality of base units 1 in the memory 22, the capacity occupied by the public key in the memory 22 increases. In this embodiment, the following will be described. According to the configuration, the public keys of the plurality of master devices 1 can be used with a small memory 22 capacity.

  That is, the slave unit 2 periodically exchanges hello messages in order to determine a communication route with the master unit 1 that is a transmission destination of customer information, and the master unit 1 includes a communication route including itself. It distributes its own public key to the upper handset 2 using a hello message. In other words, the handset 2 is a nearby handset 2 (within a range where the hello message can be acquired) by adding the public key of the base unit 1 on the communication route including itself to the hello message. It is possible to acquire the public key of the parent device 1 that is the transmission destination of

  A specific example is shown in FIG. FIG. 3 illustrates a case where the slave device 201 is a transmission source and customer information is transmitted to either the master device 101 or the master device 102.

  When the parent device 101 is a transmission destination of customer information, the child device 201 transmits customer information to the parent device 101 via the child devices 202, 203. In this case, the parent device 101 distributes its own public key in a hello message to the child devices 201, 202, and 203 on the communication route with the child device 201. As a result, the slave unit 202 can acquire the public key of the master unit 101, and encrypts the customer information with the public key of the master unit 101 when relaying the customer information transmitted from the slave unit 201. It becomes possible.

  On the other hand, for example, when the radio wave environment between the child device 202 and the child device 203 deteriorates and a communication route is established between the child device 202 and the child device 205 instead, the child device 201 replaces the parent device 101 with the parent device 101. The machine 102 becomes a transmission destination of customer information. In this case, the slave unit 201 transmits customer information to the master unit 102 via the slave units 202, 205, and 204. In this case, the base unit 102 distributes the public key included in the hello message to the slave units 201, 202, 205, and 204 on the communication route with the slave unit 201. As a result, the slave unit 202 can acquire the public key of the master unit 102 and encrypts the customer information with the public key of the master unit 102 when relaying the customer information transmitted from the slave unit 201. It becomes possible.

  Here, the child device 202 does not store the public keys of the parent devices 101 and 102 in the memory 22, but only the public key of the parent device 101 when the parent device 101 is the transmission destination of customer information. When the machine 101 is the customer information transmission destination, only the public key of the parent machine 102 is stored in the memory 22. That is, when the transmission destination of the customer information is changed, the child device 2 discards the public key of the parent device 1 stored in the memory 22 and newly becomes the transmission destination of the customer information. Is obtained in the above procedure and stored in the memory 22.

  Next, a specific example of the operation of the communication system will be described with reference to FIGS. Here, the slave device 201 of the customer 401 uses the communication route of the slave device 202 of the consumer 402 as the parent device 1 from the slave device 202 of the customer 402 → the slave device 203 of the consumer 203 →. The case where it transmits to the apparatus 1 is illustrated.

  First, the child device 201 uses the common key K1 stored in its own memory 22 in advance (before transmitting the customer information of the customer 401 to the parent device 1), and the child device 202 as an adjacent node and Distribute to the management device 301 of the same consumer 401. That is, the child device 201 encrypts the common key K1 by the second encryption unit 241 using the public key Ka2 issued by the child device 202 that is an adjacent node (S1 in FIG. 4), and the encrypted common key K1. Is transmitted to the handset 202 (S2). When receiving the encrypted common key K1, the slave unit 202 obtains the common key K1 by decrypting the common key K1 with the second decryption unit 242 using the secret key Kb2 paired with the public key Ka2. S3).

  Further, the slave unit 201 encrypts the common key K1 by the second encryption unit 241 using the public key Ka3 issued by the management device 301 of the same customer 401 (S4), and manages the encrypted common key K1. It transmits to the apparatus 301 (S5). When the management device 3 receives the encrypted common key K1, the second decryption unit 342 decrypts the common key K1 using the public key Ka3 and the paired secret key Kb3, thereby obtaining the common key K1 ( S6).

  Further, the slave unit 202 receives a hello message including the public key Ka1 of the master unit 1 from the slave unit 203 which is an adjacent node (S7). Thereby, the slave unit 202 acquires the public key Ka1 of the master unit 1 (S8) and stores it in the memory 22.

  On the other hand, when transmitting the customer information of the customer 401 to the parent device 1, the slave device 201 that is the transmission source of the first hop first stores the customer information of the customer 401 in the first encryption unit. In 231, encryption is performed using the common key K 1 (S 11). Then, the subunit | mobile_unit 201 transmits the customer information encrypted with the common key K1 to the subunit | mobile_unit 202 which is an adjacent node (S12). At this time, the slave unit 201 is also encrypted with the common key K1 in the management device 301 provided in the same customer 401 and the management device 300 provided in the neighboring customer 400 of the customer 401. Customer information is transmitted simultaneously (S13, S14).

  The slave device 202 that is the transmission source of the second hop decrypts the customer information received from the slave device 201 using the common key K1 in the first decryption unit 232 (S15), and further the second encryption unit In 241, encryption is performed using the public key Ka 1 of the parent device 1 (S 16). Then, the subunit | mobile_unit 202 transmits the customer information encrypted with public key Ka1 to the subunit | mobile_unit 203 which is an adjacent node (S17). At this time, the subunit | mobile_unit 202 transmits simultaneously the customer information encrypted with public key Ka1 also to the management apparatus 302 provided in the same customer 402 (S18).

  Further, the management apparatus 301 of the same customer 401 as that of the slave unit 201 decrypts the customer information received from the slave unit 201 using the common key K1 in the first decryption unit 332 (S19). A process such as visualization of the power usage amount is executed (S20). On the other hand, since the management apparatus 300 of the customer 400 does not have the common key K1 common to the child device 201, the customer information received from the child device 201 cannot be decrypted (S21).

  The slave unit 203 serving as the transmission source of the third hop acquires transfer destination information from the header portion of the packet received from the slave unit 202 (S22). And the subunit | mobile_unit 203 transmits the customer information encrypted with the public key Ka1 received from the subunit | mobile_unit 202 to an adjacent node or the main | base station 1 without performing a decoding or encryption process especially (S23). ). On the other hand, since the management device 302 of the customer 402 does not have the secret key Kb1 for decrypting the data encrypted with the public key Ka1 of the parent device 1, it decrypts the customer information received from the child device 202. It cannot be done (S24).

  According to the communication system of the present embodiment described above, when the slave unit 2 transmits the customer information of the customer 4 to the master unit 1 by multi-hop communication, not only the slave unit 2 at the hop destination but also the same. It transmits also to the management apparatus 3 provided in the consumer 4. Therefore, the subunit | mobile_unit 2 can reduce the frequency | count of transmission of customer information compared with the case where customer information is separately transmitted to each of the main | base station 1 and the management apparatus 3. FIG. In short, according to the communication system of the present embodiment, the management device 3 can acquire customer information from the child device 2, but the number of transmissions of customer information in the child device 2 does not increase. As a result, the slave unit 2 can reduce at least the load factor applied to the first conversion unit 23 that performs encryption, and the customer information is transmitted to the master unit 1 and the management device 3 by the same communication method (in this embodiment, wireless communication). When transmitting customer information, it is possible to reduce the load factor applied to the communication system when transmitting customer information.

  Moreover, the child device 2 that is the transmission source of the first hop is common to the child device 2 that is the adjacent node and the management device 3 of the same customer 4 that is common to the management device 3 of these adjacent node and the same customer 4. The customer information encrypted with the key is transmitted at the same time. Therefore, even if the customer information transmitted from the handset 2 that is the transmission source of the first hop may be received by the management device 3 of the neighboring customer 4, the management device 3 of the neighboring customer 4 Since the customer information cannot be decrypted, the customer information does not leak to the neighboring customer 4.

  Further, since the slave unit 2 serving as the transmission source after the second hop transfers the customer information encrypted using the public key Ka1 of the master unit 1, the master unit 1 is transmitted after the second hop. Thus, the customer information is transmitted in such a manner that the customer information can be decrypted only by. Therefore, even if the customer information transmitted from the slave unit 2 which is the transmission source after the second hop is received by the management device 3 of the same customer 4 as that of the slave unit 2 or the neighboring customer 4, the management is performed. Since the device 3 cannot decrypt the customer information, the customer information does not leak.

  As a result, it is possible to realize secure communication while suppressing the number of times customer information is transmitted by the slave unit 2.

  Furthermore, in the present embodiment, the slave unit 2 transmits the common key encrypted with the public key of the adjacent node to the adjacent node, and the common key encrypted with the public key of the management device 3 of the same customer 4 is the same. By transmitting to the management apparatus 3, the common key is distributed. Therefore, the handset 2 can distribute the common key only to the target partner (the adjacent node and the management device 3 of the same customer 4), and the common key leaks to the other handset 2 or the management device 3. You can avoid that.

  Moreover, since the main | base station 1 distributes own public key using the hello message with respect to the subunit | mobile_unit 2 on the communication route in which self is contained, in the subunit | mobile_unit 2, it becomes a transmission destination of customer information. Even if the parent device 1 is changed, the public key of the changed parent device 1 can be acquired. Accordingly, the handset 2 can acquire only the public keys necessary for the occasion from the base unit 1 without storing the public keys of the plurality of base units 1 in the memory 22 in advance. As a result, the handset 2 can keep the capacity occupied by the public key in the memory 22 small.

  In the above-described embodiment, a case has been described in which the communication between the child devices 2 and between the child device 2 and the parent device 1 and the communication between the child device 2 and the management device 3 are both realized by wireless communication. However, the present invention is not limited to this configuration. That is, for example, communication between the child devices 2 and between the child device 2 and the parent device 1 may be realized by wireless communication, and communication between the child device 2 and the management device 3 may be realized by wired communication such as power line carrier communication. .

  In this case, the slave unit 2 includes, as the communication unit 21, a wireless communication unit for communicating with the other slave units 2 and the master unit 1, and a wired communication unit for communicating with the management device 3. And the subunit | mobile_unit 2 which is a transmission source of the 1st hop transmits the customer information encrypted using the common key which is common with the adjacent node and the management apparatus 3 of the same customer 4 to the subunit | mobile_unit 2 which is an adjacent node. On the other hand, it transmits from the wireless communication unit to the management device 3 of the same customer 4 from the wired communication unit. Even in this case, the slave unit 2 can reduce the number of times the customer information is transmitted compared to the case where the customer information is individually transmitted to the master unit 1 and the management device 3, and the first conversion for performing encryption is performed. The load factor applied to the unit 23 can be reduced.

1, 101, 102 ... Base unit 2, 201, 202 ... Slave unit (communication terminal)
22 Memory (storage unit)
231 1st encryption unit 232 1st decryption unit 241 2nd encryption unit 3,301,302 ... management device (customer device)
32 Memory (storage unit)
332 First decryption unit 4, 401, 402...

Claims (5)

A master unit that collects customer information from a plurality of consumers, a plurality of slave units each provided in a plurality of consumers and having a function of transmitting the customer information of each consumer to the master unit, and demand A consumer device that is installed in a house and acquires the consumer information of the consumer from the slave unit, wherein one of the plurality of slave units is a multi-hop with another slave unit as a repeater A communication system for transmitting the customer information to the parent device by communication,
Each of the plurality of slave units is
A common key that is common between the adjacent node that is a slave unit that can receive customer information without relaying other slave units and the consumer device of the same consumer, and a public key of the master unit are stored. A storage unit;
A first encryption unit that encrypts data using the common key in the storage unit;
A first decryption unit for decrypting data using the common key in the storage unit;
A second encryption unit that encrypts data using the public key in the storage unit,
When transmitting the customer information to the parent device, the slave device of the transmission source of the first hop is encrypted by the first encryption unit for the customer device of the adjacent node and the same customer A communication system, wherein customer information is transmitted, and a slave unit of a transmission source after the second hop is configured to transmit the customer information encrypted by the second encryption unit. The slave unit transmits the common key encrypted with the public key of the adjacent node to the adjacent node, and transmits the common key encrypted with the public key of the customer device of the same consumer to the customer device. The communication system according to claim 1, wherein the common key is distributed by transmission. The slave unit can select the master unit as a transmission destination of the customer information from a plurality of master units, and periodically determines a communication route with the master unit as a transmission destination. Are exchanging Hello messages,
The communication system according to claim 1 or 2, wherein the master unit distributes the public key of the master unit to the slave unit on the communication route including the master unit by using the hello message. . A master unit that collects customer information from a plurality of consumers, a plurality of slave units each provided in a plurality of consumers and having a function of transmitting the customer information of each consumer to the master unit, and demand A consumer device that is installed in a house and acquires the consumer information of the consumer from the slave unit, wherein one of the plurality of slave units is a multi-hop with another slave unit as a repeater A communication terminal used as the slave unit in a communication system that transmits the customer information to the master unit by communication,
A common key that is common between the adjacent node that is a slave unit that can receive customer information without relaying other slave units and the consumer device of the same consumer, and a public key of the master unit are stored. A storage unit;
A first encryption unit that encrypts data using the common key in the storage unit;
A first decryption unit for decrypting data using the common key in the storage unit;
A second encryption unit that encrypts data using the public key in the storage unit,
When transmitting the customer information to the base unit, when it becomes the transmission source of the first hop, the first encryption unit encrypts the customer device of the adjacent node and the same customer A communication terminal configured to transmit customer information when the customer information is transmitted and becomes a transmission source after the second hop, the customer information encrypted by the second encryption unit. A master unit that collects customer information from a plurality of consumers, a plurality of slave units each provided in a plurality of consumers and having a function of transmitting the customer information of each consumer to the master unit, and demand A consumer device that is installed in a house and acquires the consumer information of the consumer from the slave unit, wherein one of the plurality of slave units is a multi-hop with another slave unit as a repeater In a communication system that transmits the customer information to the parent device by communication, a management device used as the customer device,
A storage unit for storing a slave unit of the same consumer and a common key that is common to adjacent nodes that are slave units capable of receiving customer information from the slave unit without relaying other slave units;
A first decryption unit that decrypts data using the common key in the storage unit,
When a slave device of the same consumer transmits the customer information to the master device, the slave device is configured to receive the consumer information that is encrypted with the common key and transmitted to the adjacent node. Management device characterized.

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