JP4781910B2 - Remote operation method and remote operation system - Google Patents

Description

  The present invention relates to an RFID (Radio Frequency IDentification) tag, also referred to as an IC tag, a real-world-oriented interface technology that utilizes IDs (identifiers) read from QR (Qujck Response) codes, barcodes, and the like for control of network terminals. is there.

  As a remote operation of a network terminal, a remote operation service for operating an air conditioner, lighting, electric lock, etc. from a mobile phone or a personal computer connected to the Internet is provided (see Non-Patent Document 1, for example). Such a remote control service can be operated anytime, anywhere, by inputting a 12-digit customer number and a 4-digit password.

  On the other hand, there is a hash function as one of cryptographic techniques. The hash function calculates a fixed-length hash value from an arbitrary-length message, and has a property that the message cannot be calculated backward from the hash value (see Non-Patent Document 2, for example). And it becomes possible to judge whether two messages are equal only by comparing hash values. This is an effective technique for detecting tampering and can confirm the authenticity of the message. Also, it is extremely difficult to find another message that has the same hash value as a message (weak collision resistance), and it is very difficult to find two different messages that have the same hash value (strong collision). Tolerance). Further, when the message is rewritten by 1 bit, about half of the hash value changes with high probability, and no matter how many bits are rewritten, about half of the hash value changes with high probability.

  In addition, a distributed hash table (hereinafter referred to as DHT: Distributed Hash Table) using a hash function as a search technique performs a search on a hash value generated from data (see, for example, Non-Patent Document 3). In the search by DHT, a hash value of data is calculated, and mapping between the hash value and a position where the actual state of the data exists (node hash value) is performed. The feature of DHT is that the registration destinations are not fixed as in the index server, and a plurality of registration destinations exist and are distributed. Each of these distributed index nodes determines its own responsibility and holds a table of data location information (a set of hash value and location). In DHT, a hash value is also generated from index node information (IP address, URL, etc.). Defining the closeness between hash values is a fundamental part of DHT and differs depending on the algorithm. The index node takes care of the location information of data having a hash value close to its own hash value.

  The DHT has an ad hoc property that allows a search system to be constructed with only the collected nodes by dynamically processing a query while maintaining scalability by having distributed indexes.

The home gateway device (Home Gateway) refers to a device (system) that plays a role in connecting a plurality of different networks in a home and absorbing differences between the networks (for example, see Non-Patent Document 4). The home gateway device is generally disposed between the Internet and a home (home) network, and has functions such as a home router, protocol conversion, and a firewall. There is also a concept of including a so-called set top box such as a broadcast receiving function in the home gateway device.
Tokyo Gas (Remote Plus), [Search April 12, 2006], Internet <URL: http://home.tokyo-gas.co.jp/tes/remote/service1.html> and <URL: http: / /home.tokyo-gas.co.jp/tes/remote/qa.html> Hiroyuki Yuki, “Introduction to Cryptographic Technology”, Softbank Publishing Co., Ltd., September 27, 2003, p. 166-172 Shinichi Iwata, “Book that understands P2P”, Ohm Co., Ltd., October 20, 2005, p. 72-77 Home Gateway (Home Network), [Search April 12, 2006], Internet <URL: http://dictionary.rbbtoday.com/Details/term789.html>

  The remote control service that operates the air conditioner, lighting, electric lock, etc., described in the prior art from a mobile phone or a personal computer connected to the Internet, can be used by anyone at any time by entering a 12-digit customer number and 4-digit password. There is a problem that it can be operated from anywhere, and the risk of remote operation by impersonation of a third party is unavoidable. Remote operation by a malicious third party on a network terminal is not just for operating an air conditioner or lighting, but for psychological damage such as inability to receive remote operation services with confidence, or for remote operation of electric locks. , Which also allows third parties to invade, and involves the danger of threatening safe living.

There are two main factors that cause spoofing by a third party.
1) A 12-digit customer number and a 4-digit password are intangible information that can be easily executed by a third party if the information is known regardless of the length of the number of digits.
2) Remote operation via a network, which can be executed from any terminal connected to the network, and it is difficult to identify or monitor the crime scene by a third party. ,

  The present invention has been made in view of such problems, and an object of the present invention is to derive a command that is an instruction content to a specific network terminal using an ID already distributed in the city. It is another object of the present invention to provide a remote operation method and a remote operation system that can perform remote operation simply and safely.

In order to achieve the above object, the present invention enables remote control of a tag storing an ID, a plurality of readers for reading the ID stored in one or a plurality of tags, and a server device including a hash table. A system remote control method comprising a network terminal, wherein the reader has a step of converting a combination of one or a plurality of tag IDs and reader IDs into a hash value, and the server device is converted A remote operation comprising: storing the hash value associated with the address and command of the network terminal as a hash table; and deriving the address and command of the network terminal according to the hash table using the converted hash value as an input In the method, the reader comprises one or more tags. A step of generating a hash value C from a combination of a hash value A converted from a combination of a group ID or a reader ID and a value B already held, and a value B already held as the hash value A or the hash value The server device further includes a step of replacing C, and a step of transmitting the hash value A and the hash value C, and the server device obtains the hash value C from the combination of the received hash value A and the value B ′ already held on the receiving side. Generating ', checking that the hash value C' is equal to the hash value C sent from the transmission side, and replacing the already-stored value B 'with the hash value A or the hash value C And a step of replacing .

Further, the present invention includes a tag storing an ID, a plurality of readers for reading out IDs stored in one or a plurality of tags, a server device including a hash table, and a network terminal capable of remote control. The reader has a means for converting a combination of one or more tag IDs and reader IDs into a hash value, and the server device converts the converted hash value into the network terminal. In the remote operation system, the reader has a means for storing the hash value in association with an address and a command, and a means for deriving the address and command of the network terminal according to the hash table using the converted hash value as an input. A set of one or more tag IDs or reader IDs Means for generating a hash value C from a combination of a hash value A converted from the combination and a value B already held; means for replacing the value B already held with the hash value A or the hash value C; Means for transmitting a hash value A and a hash value C, wherein the server device generates a hash value C ′ from a combination of the received hash value A and a value B ′ already held on the receiving side; And means for checking that the hash value C ′ is equal to the hash value C sent from the transmission side, and means for replacing the already held value B ′ with the hash value A or the hash value C. It is characterized by that.

In addition, the present invention provides a tag storing ID, a plurality of readers for reading ID stored in one or a plurality of tags, a home gateway device including a hash table, and a network terminal capable of remote control. A remote control system configured, wherein the reader has means for converting a combination of one or more tag IDs and reader IDs into a hash value, and the home gateway device converts the converted hash value into the hash value In the remote operation system, comprising: means for storing the hash value in association with an address and a command of a network terminal; and means for deriving the address and command of the network terminal according to the hash table using the converted hash value as an input. The reader can have one or more tag I Alternatively, a means for generating a hash value C from a combination of a hash value A converted from a combination of reader IDs and a value B already held, and a value B already held as the hash value A or the hash value C The home gateway device further includes a means for replacing and a means for transmitting the hash value A and the hash value C, and the home gateway device determines the hash value C ′ from the combination of the received hash value A and the value B ′ already held on the receiving side. Generating means, a means for checking that the hash value C ′ is equal to the hash value C sent from the transmission side, and a value B ′ already held as the hash value A or the hash value C. It further has a means for replacing .

  The present invention has the following effects regarding storage and communication of customer numbers and passwords. Copying can be made difficult by using RFID fixed to solid rather than intangible information. Only a legitimate user can hold an ID by setting a tag ID corresponding to the key at home and treating it with the key at home. Since the data transmitted from the reader is a hash value, it is difficult to guess a combination of one or a plurality of tag IDs and reader IDs even if they are eavesdropped on an intermediate communication path. Since the data transmitted from the reader is a hash value, effective tampering is difficult.

  In addition, the present invention has the following effects against the threat of impersonation by a third party. If readers that can read tag IDs are limited and not only tag IDs but also reader IDs are combined and converted into hash values, impersonation of tag IDs alone is invalid. In particular, it is more effective to use a device that is not shared with others, such as a mobile phone with a built-in reader, and to limit reading only from the reader. If a step of converting to a hash value in combination with the previous hash value is added, unauthorized use can be detected.

  Moreover, this invention has the following effects regarding the improvement of safety | security. If all the commands received by the network terminal are routed through the home gateway device of the present invention, the danger of the network terminal receiving an illegal command can be avoided and safety can be maintained. Since it is possible to issue a command transmission instruction using a metaphor that only the person knows (a thing attached with an RFID represents a right or a target), confidentiality is high. It is also possible to send a command limited to a specific reader, time and place. By combining a tag that is valid only by the user with a tag that is attached to something that only the user has (for example, an ID card or key), it can also be used for user authentication. Increasing the number of tags further improves safety.

  Furthermore, this invention has the following effects regarding the improvement of simplicity. Command transmission to an information device such as a network terminal can be executed simply by holding an object over a reader or carrying it. Since the RFID tag affixed to an object that is a metaphor set by the user is used, the operation is easy to memorize and can be executed unconsciously. An infinite number of instruction contents can be expressed by a combination of tags. Accurate instructions can be reproduced without ambiguity. It is also possible to give a command transmission instruction without being limited to a specific reader, time, or place. The display destination of the transmission result can also be specified by the same interface.

  Moreover, this invention has the following effects regarding the improvement of expandability. Since an existing tag can be used, no new cost is generated for the tag. The platform can handle ID and application independently. Since the ID stored in the tag is valid only for the server device or home gateway device that has passed through a series of flows, if the condition can be cleared, it should be used even if the tag is owned by another person. Can be flexible.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a service image in the remote control system of the present invention. This example is activated by the order in which a user reads one ID by a plurality of readers ((a) and (b)) or a combination ((c)) by which a plurality of IDs are read by one reader. It will change the service. (A) is a case where the user is worried about things left behind at home, and the video from the network camera installed in his / her seat is transmitted to the portable terminal of the user who can display the video, (b) Suppose you want to start up your personal computer automatically when you go to work. Both are activated based on the order of readers to read the admission card ((a) is the order of the entrance to the entrance gate → (b) is the order of the entrance gate → the entrance to the entrance). (C) assumes the situation of a child at home, holding up the “home key” with a legitimate reader (for example, a reader built in the user's mobile phone) When the photograph is held over, a video from a network camera capable of remote control installed in the child room of the user's home is transmitted to the mobile phone at hand of the user.

  The metaphor to which the tag is attached is a pseudo representation of an instruction content to be transmitted or an authority that the user has, using an object that can be easily understood by the user. In this example, “home key” is a metaphor indicating that the object to be instructed is at home and that the user has the authority to operate the object. “Children's photo” is used as a metaphor indicating a network camera in a children's room. The metaphor may be anything as long as it is easy for the user to understand and remember, and the feature of the present invention is that an ID already distributed in the city can be freely selected. Here, the server apparatus inputs a hash value generated from a combination of one or a plurality of tag IDs and reader IDs as a hash table in association with a network terminal address and a command, and the converted hash value As a means for deriving the address and command of the network terminal according to the hash table.

  FIG. 2 shows an operation flow of the remote operation system shown in FIG. 1, and a service image will be described according to this operation flow. The reader reads the tag ID attached to the one or more metaphors, converts the combination of the one or more tag IDs and the reader ID into a hash value, and transmits the hash value to the server device. If the address and command of the network terminal corresponding to the hash value received by the server apparatus exist, the command is transmitted to the network terminal and the operation is completed. When operating by receiving hash values from a plurality of readers, the current state is held and input from the readers is awaited. If there is no network terminal address and command corresponding to the hash value received by the server device, the operation is completed.

  FIG. 3 shows system components of the remote control system shown in FIG. As shown in FIG. 3, the system components include a tag 10 attached to an object (a tag ID is stored), a reader 20 for reading the tag ID, and a server connected to the reader 20 via a network. It comprises a device 30 and a network terminal 40 connected to the server device 30 via a network and a home gateway device.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples. FIG. 4 shows an example of the configuration of the remote control system of the present invention. In this example, a system configuration along the flow until a command is transmitted to a network terminal is extracted. The tag 10 is attached to some object and stores a tag ID that can uniquely identify the object. It comprises a reader 20 that reads a tag ID stored in one or more tags, a server device 30 connected to a network, and a network terminal 40 that can be remotely controlled.

  Below, each processing means with which a tag, a reader, a server device, and a network terminal are provided will be described. Each of these processing means can also be realized by a computer program except for storage means such as a temporary storage unit. This computer program Is provided by being recorded in a suitable computer-readable storage medium or provided via a network, and is installed when the present invention is carried out to operate on a control means such as a CPU. Will do.

  The tag 10 mainly includes a tag ID storage unit 11, a message transmission unit 12, and a communication control unit 13. The tag ID storage unit 11 has a function of storing a symbol for uniquely identifying each tag (that is, the item to which the tag is attached). In the present invention, any symbol can be used as long as it can uniquely identify an object or a place. The message transmission unit 12 outputs the tag ID stored in the tag ID storage unit 11 in a message format that can be received by the reader 20 by an external instruction via the communication control unit 13 or its own periodic operation. It has a function. The communication control unit 13 has a function of establishing communication with the communication control unit of the reader 20.

  The reader 20 mainly includes a message reception unit 21, a temporary storage unit 22, a reader ID storage unit 23, a hash value generation unit 24, a message transmission unit 25, and a communication control unit 26. The message receiving unit 21 has a function of extracting the tag ID from the message of the tag 10 received via the communication control unit 26 and storing it in the temporary storage unit 22. The temporary storage unit 22 has a function of temporarily storing the tag ID. The reader ID storage unit 23 has a function of storing a reader ID that is unique to each reader and that can uniquely identify the reader as a whole system. The hash value generation unit 24 has a function of generating a hash value for a combination of a tag ID and a reader ID. The message transmission unit 25 has a function of outputting the hash value generated by the hash value generation unit 24 in a message format that can be received by the server device 30. The communication control unit 26 has a function of establishing communication with the communication control unit 13 of the tag 10 and the communication control unit of the server device 30.

  The server device 30 mainly includes a message reception unit 31, a storage server extraction unit 32, a hash table 33, an input waiting hash value derivation unit 34, a temporary storage unit 35, an address and command derivation unit 36, a command transmission unit 37, and a message transmission unit. 38 and a communication control unit 39. The message receiving unit 31 has a function of extracting a hash value from the message of the reader 20 received via the communication control unit 39. The storage server extraction unit 32 has a function of extracting a storage server based on the extracted hash value when the hash table is distributed and arranged in a plurality of storage servers. The hash table 33 has a function of storing hash values in association with addresses and commands of network terminals. The input waiting hash value deriving unit 34 is generated from a combination of a tag ID and a reader ID to be read next when changing a service to be activated according to an order in which one or a plurality of tag IDs are read by a plurality of readers. The hash value is derived from the hash table 33. The temporary storage unit 35 has a function of temporarily storing the hash value derived by the input waiting hash value deriving unit 34. The address and command deriving unit 36 has a function of deriving the address and command of the network terminal 40 according to the hash table 33 with the hash value as an input. The command sending unit 37 sends the same derived command to the message transmitting unit 38 for the address and the address of the network terminal 40 derived by the command deriving unit 36. The message transmission unit 38 has a function of outputting a command output from the command transmission unit 37 in a message format that can be received by the communication control unit of the network terminal 40. The communication control unit 39 has a function of establishing communication with the communication control unit 26 of the reader 20 and the communication control unit of the network terminal 40.

  The network terminal 40 is mainly a part that provides an original function as a home appliance, but the part directly related to the present invention mainly includes a message receiving unit 41, an executing unit 42, and a communication control unit 43. Is done. The message receiving unit 41 has a function of extracting a command from the message of the server device 30 received via the communication control unit 43 and outputting the command to the execution unit 42. The execution unit 42 has a function of executing an operation according to the command. The communication control unit 43 has a function of establishing communication with the communication control unit 39 of the server device 30.

  Hereinafter, the operation flow in the system configuration example of FIG. 4 will be specifically described with reference to the drawings along the flow until the command is transmitted to the network terminal. FIG. 5 is a diagram for explaining the operations of the storage process and the derivation process in the server device and the inspection process in the server device and the home gateway device. FIG. 6 explains the configuration of the hash table of the server device and the home gateway device. FIG.

The storage process is started from the user's personal computer via the network. One or more pairs A _n tag ID and the reader ID, and the hash value C _n obtained by conversion using the hash function, the set B _n of the address and command of the network terminal 40 for providing a service corresponding to the A _n Is stored in the server device 30 as the hash table 33. Here, when the service to be activated is changed according to the order of a plurality of A, instead of B, hash values C _{n + 1} and C _n generated from the combination of tag ID and reader ID A _{n + 1} to be read next are used. The hash value C _z of the set of C _{n + 1} and C _n and the address of the network terminal 40 providing the corresponding service and the command set Bz are stored in the server device 30 as the hash table 33 as B _n of the hash table. When the hash table 33 is distributed and arranged in a plurality of storage servers, the storage server D is determined based on the hash value C.

The derivation process is started when the reader reads the tag ID and the reader 20 sends the hash value C _n obtained by converting one or a plurality of tag ID and reader ID pairs An using a hash function to the server device 30. Is done.

When the input waiting hash value C _{m + 1} stored in the temporary storage unit 35 of the server device 30 does not match the input hash value C _n , the storage server D is extracted based on C _n and the hash of the storage server D is obtained. B _n corresponding to C _n is extracted from the table. When B _n is a set of an address and a command, B _n is output to the command sending unit. When B _n is not a pair of address and command but a pair of input waiting hash values C _{n + 1} and C _n , the pair of input waiting hash values C _{n + 1} and C _n is stored in the temporary storage unit.

When the input waiting hash value C _{m + 1} stored in the temporary storage unit 35 of the server apparatus 30 matches the input hash value C _n (see FIG. 7), a set of C _n (that is, C _{m + 1} ) and C _m the extracts storage server D based on the hash value C _z converted using a hash function, extracts a B _z corresponding to C _z from the hash table of the storage server D. If _Bz is a combination of an address and a command, _Bz is output to the command sending unit. When _Bz is not a pair of address and command but a pair of input waiting hash values C _{l + 1} and C _l , the pair of input waiting hash values C _{l + 1} and C _l is stored in the temporary storage unit.

FIG. 7 is a diagram for explaining a derivation process depending on the order of readers. In FIG. 7, C _{n + 1} is a hash value waiting for input, C _n is a hash value to be received immediately before C _{n + 1} , C _z is a hash value of a pair of C _{n + 1} and C _n , When C _{n + 1} is received next to C _n , the service is activated (B _z command is issued to B _z address).

When C _n is received, a set of C _{n + 1} and C _n is stored in the temporary storage unit. Next, if C _{n + 1} is received, it matches C _{n + 1} of the temporary storage unit, so a hash value C _z is generated from a set of C _{n + 1} and C _n . Then, to derive a set of addresses and commands is from C _z B _z. When C _{n + 1} is received without receiving C _n , if B _{n + 1} corresponding to C _{n + 1} exists, that B _{n + 1} is executed.

  The inspection process is effective in a system composed of a specific reader and a specific home gateway device. Both the reader 20 and the home gateway device hold the same hash value C ′. A new hash value C ″ is generated from the set of the value C ′ and the current hash value C, and the new hash value C ″ is transmitted to the home gateway device together with the current hash value C. The home gateway device generates a new hash value from the received current hash value C and the hash value already held by itself, and the value is equal to the received hash value C ″ together with the current hash value C. The hash value C ′ may be a fixed value or may be replaced with C or C ″ every time.

  As shown in FIGS. 5 and 6, the hash table in the server device stores a hash value C and a set B of an address and a command corresponding to the hash value C, or a hash value C and a hash value C itself.

  The hash table in the home gateway device is obtained by adding a hash value C ′ held in advance for the inspection process to the hash table in the server device. C ′ may be different for each hash value C, or may be one for each home gateway device.

  If all commands received by the network terminal are routed through the server device of the present invention and security measures such as SSL (Secure Socket Layer) are applied between the server device and the network terminal, the risk of the network device receiving an illegal command is avoided. And safe.

  As described above, the safe remote control method and apparatus of the present invention realizes a new real-world-oriented human computer interaction (HCI) technique using RFID. ID information typified by RFID links real world objects (objects and events) and data on a computer, and has a possibility of realizing various applications depending on usage.

  In addition, with the above-described safe remote operation method and apparatus using RFID, it is possible to construct a rational business model in which remote operation for network terminals is a business. In this business model, a user who wants to control a network terminal using an ID is guaranteed that a legitimate ID has been read from a legitimate reader, and a fee for deriving an address and a command is collected from the ID user. You will build a business.

  FIG. 8 shows a business model that can be realized by the present invention. A service that collects the user who wants to control the network terminal using the ID, the user who wants to control the network terminal using the ID, and the price that resolves the address and command from the user, assuring that the ID is read from the legitimate reader There are three communication network providers that provide a network that reliably communicates an ID transmitted from a provider and a reader and a command to a network terminal.

  There are four business models, a relay model, a housing model, a hosting model, and a direct management model, depending on the dependency relationship between the service provider and the communication network provider. In the relay model, a service provider prepares a place and a server, and only a line is borrowed from a communication network provider. In the housing model, a service provider prepares a server and borrows a location from a communication network provider. In the hosting model, a service provider prepares only software, and a location and a server are borrowed from a communication network provider. In the direct management model, the communication network provider is the service provider.

  The business model with remote operation for network terminals as a business hinders the spread of remote command transmissions to network terminals due to concerns over misoperation, falsification by third parties, and impersonation beyond their convenience. However, in the present invention, the security can be maintained by the server device or the home gateway device, and the network terminal can be easily controlled, so that the business model can be constructed as a rational one. become.

It is a figure which shows the service image in the remote control system of this invention. It is a figure which shows the operation | movement flow of the remote control system of this invention. It is a figure which shows the system component of the remote control system of this invention. It is a figure which shows an example of a structure of the remote control system of this invention. It is a figure explaining the operation | movement of the storage process and derivation | leading-out process in a server apparatus, and the test | inspection process in a home gateway apparatus. It is a figure explaining the structure of the hash table of a server apparatus and a home gateway apparatus. It is a figure explaining the derivation process depending on the order of a reader. It is a figure which shows the business model which can be implement | achieved by this invention.

Explanation of symbols

10 tag 11 tag ID storage unit 12, 25, 38 message transmission unit 13, 26, 39, 43 communication control unit 20 reader 21, 31, 40 message reception unit 22, 35 temporary storage unit 23 reader ID storage unit 24 hash value generation Unit 30 server device 32 storage server extraction unit 33 hash table 34 input waiting hash value derivation unit 36 address and command derivation unit 37 command transmission unit 40 network terminal 42 execution unit

Claims (3)

Remote operation of a system comprising a tag storing an ID, a plurality of readers for reading out an ID stored in one or more tags, a server device having a hash table, and a network terminal capable of remote control The reader includes a step of converting a combination of one or more tag IDs and reader IDs into a hash value, and the server device converts the converted hash value into an address and a command of the network terminal. In the remote operation method, the method includes the steps of: storing as a hash table in association with; and deriving an address and a command of the network terminal according to the hash table using the converted hash value as an input ,
The reader generates a hash value C from a combination of a hash value A converted from one or a plurality of tag IDs or a combination of reader IDs and a value B already held, and a value B already held Further replacing the hash value A or the hash value C, and transmitting the hash value A and the hash value C,
The server device generates a hash value C ′ from the combination of the received hash value A and the value B ′ already held on the receiving side, and the hash value sent from the transmitting side. The remote operation method further comprising the steps of checking that the value is equal to C and replacing the already held value B ′ with the hash value A or the hash value C. A remote control system comprising a tag storing ID, a plurality of readers for reading ID stored in one or a plurality of tags, a server device having a hash table, and a network terminal capable of remote control The reader has means for converting a combination of one or more tag IDs and reader IDs into a hash value, and the server device associates the converted hash value with the address and command of the network terminal. A remote operation system having means for storing as a hash table and means for deriving an address and a command of the network terminal according to the hash table, using the converted hash value as an input ,
The reader generates a hash value C from a combination of a hash value A converted from one or a plurality of tag IDs or a combination of reader IDs and a value B that is already held, and a value B that is already held And means for replacing the hash value A or the hash value C, and means for transmitting the hash value A and the hash value C,
The server device generates a hash value C ′ from a combination of the received hash value A and a value B ′ already held on the receiving side, and a hash value sent from the transmitting side. The remote control system further comprising means for checking that the value is equal to C, and means for replacing the already held value B ′ with the hash value A or the hash value C. A remote operation system comprising a tag storing an ID, a plurality of readers for reading out the ID stored in one or more tags, a home gateway device having a hash table, and a network terminal capable of remote control The reader has means for converting a combination of one or more tag IDs and reader IDs into a hash value, and the home gateway device converts the converted hash value into an address and a command of the network terminal. A remote operation system having means for associating and storing as a hash table, and means for deriving an address and a command of the network terminal according to the hash table using the converted hash value as input ,
The reader generates a hash value C from a combination of a hash value A converted from one or a plurality of tag IDs or a combination of reader IDs and a value B that is already held, and a value B that is already held And means for replacing the hash value A or the hash value C, and means for transmitting the hash value A and the hash value C,
The home gateway device generates a hash value C ′ from a combination of the received hash value A and a value B ′ already held on the receiving side, and a hash from which the hash value C ′ is sent from the transmitting side The remote operation system further comprising means for checking that the value is equal to the value C, and means for replacing the already held value B ′ with the hash value A or the hash value C.