JP2010206277A - Communication method, communication system and processing program of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system capable of reducing power consumption when utilizing authentication and encryption using a nonce on a radio access network having a power saving function. <P>SOLUTION: The communication system includes: a random number generation means provided in a terminal for generating a temporary nonce; a transmission means provided in the terminal for transmitting prescribed information to a server using the generated temporary nonce; a random number sequence request means provided in the terminal for requesting the nonce generated in the server; a random number sequence generation means provided in the server for returning the nonce generated in the server corresponding to the request from the terminal; a random number sequence conversion table processing means provided in the terminal for generating the conversion table of the temporary nonce and the nonce and sending it to the server; and a random number sequence collation means provided in the server for specifying the temporary nonce corresponding to a received message from the received conversion table and performing authentication or decoding using the specified temporary nonce. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication method, a communication system, and a processing program therefor, and more particularly, to one that can contribute to power saving by reducing the frequency of receiving packets for nonce reception in authentication and encryption procedures.

  Conventionally, this type of power-saving communication system collects information from a terminal device such as a sensor constituting a PAN (Personal Area Network) or a HAN (Home Area Network), or controls the terminal device. It is used for authentication and encryption. PAN and HAN are composed of terminal devices such as sensors, gateway devices such as broadband routers and portable terminals that connect a plurality of terminal devices by wireless communication means, and server devices connected to the gateway devices. The server device is configured to collect information from the terminal device via the gateway device.

In general, a message uniqueness confirmation method using a nonce is used to prevent replay attack or spoofing in an authentication protocol or the like. A nonce is a numerical value or character string that is used only once, and is generally generated based on random numbers, time information, or the like.
The server device generates a nonce and sends it to the terminal. The terminal that receives the nonce includes the value when sending the packet to the server next time, or sends the packet encrypted using the value to the server. I am trying to send it. Since only the server that issued the nonce knows the nonce used by the next packet to be received, the received packet and the uniqueness of the terminal that sent it can be confirmed. SIP Tag (Entity tag: entity identification tag) is also used for device identification in the same manner.

Patent Document 1 also discloses a communication system for preventing replay attack and impersonation. That is, this Patent Document 1 includes an ID code storage unit that stores an ID code that identifies itself, a time code generation unit that generates a time code that is updated each time it is transmitted, and an ID stored in the ID code storage unit. A portable device comprising a code and a data generating means for generating control data based on the time code generated by the time code generating section, a receiving means for receiving control data, and a control received by the receiving means ID code determination means for determining whether or not the ID code included in the data is a regular ID code, and the time code included in the control data including the regular ID code received last time is stored as a comparative time code The time code storage means for comparison, the time code included in the control data received this time, and the ratio stored in the time code storage means for comparison A time code determining means for comparing the time clock codes and determining whether the time code is correct, and a control means for controlling the device when the determination results of the ID code determining means and the time code determining means are both correct. A communication system including a parent device including
According to Patent Document 1, by adding a time code, the control data is updated every time it is transmitted from the portable device. Therefore, the control data is temporarily copied, and the copied control data is used for the master unit. Even if a control command is sent, it is determined that the timing code is not correct.

  In addition, wireless communication means represented by IEEE 802.15 often have a function for the purpose of power saving and the like. As the power saving function, the following operation is assumed. The circuit of the wireless interface part is basically kept in a power-off state. Packet transmission is performed as follows. That is, when the terminal transmits a packet, the circuit is turned on, and the terminal is turned off immediately after the transmission is completed. Packet reception is performed as follows. That is, the circuit of the wireless interface portion is periodically turned ON, and it is confirmed whether or not packets addressed to the terminal itself are stagnating with the base station apparatus (gateway). If the packet remains, the reception process is performed, and the wireless interface is turned off after the reception process is completed. As described above, transmission can be performed at an arbitrary timing, but reception is performed by periodic polling.

  An operation example in the case where it is attempted to guarantee the uniqueness of a terminal or a message using a nonce on the communication interface having the power saving function described above will be described with reference to the message flow diagram of FIG. Here, a case where the sensor terminal periodically notifies the server of information such as temperature will be described as an example. Also in this example, reception is performed by periodic polling.

  When the terminal first notifies the server of information, the terminal turns on the wireless interface circuit (“wakeup” operation in FIG. 3), and a request message including the information is transmitted to the server via the gateway. When the transmission is completed, the wireless interface circuit is turned off (“sleep” operation in FIG. 3). When the server receives the request message, it generates a random number (nonce), and the generated random number is returned together with the response message. The response message is stuck at the gateway. The terminal is “wakeup” for message reception polling in the next reception cycle, and the presence or absence of a received message is confirmed. If there is a received message addressed to the terminal itself, it is picked up. Then, after the reception is completed, “sleep” is set.

  When the terminal notifies the server of the information in the next transmission cycle, the terminal is “Wakeup”, and the request message encrypted with the previously received random number or the previously received random number is sent via the gateway together with the transmitted information. Sent to the server. When the transmission is completed, the terminal is set to “sleep”. When the server receives the request message, the server generates a random number, and the generated random number is returned together with the response message. The response message is stuck at the gateway. The terminal is “Wakeup” for message reception polling in the next reception cycle, and the presence or absence of a received message is confirmed. If there is a received message addressed to the terminal itself, it is picked up. It is set to “sleep” after completion of reception. Thereafter, the same operation is repeated.

JP 2003-314108 A

However, in the conventional power-saving communication system described above, when authentication or encryption using a nonce is performed on a communication interface having a power-saving function, the number and time of turning on the wireless interface increase, and power consumption Had the problem of increasing. When the terminal notifies the server of the information, the server returns a response message including a nonce, but the terminal must receive the message each time. For this reception, the wireless interface is turned on each time. Because it must be done.
Further, the terminal has a problem that a message can be transmitted only in a reception cycle. This is because, when reception is performed periodically, a nonce can be received only in that period, and therefore a transmission packet including a nonce can be generated only in that period.

  Therefore, the present invention has been made to solve the above-described drawbacks, and its purpose is to reduce power consumption when using authentication and encryption using a nonce on a radio access network having a power saving function. Another object of the present invention is to provide a communication method, a communication system, and a processing program therefor, which can be reduced and the terminal can transmit a message at an arbitrary timing.

In order to achieve the above object, a communication method according to the present invention is a communication method involving an authentication procedure or an encryption procedure in communication between a terminal and a server, using a temporary nonce generated by the terminal. It is characterized in that predetermined information is transmitted to the server, and then the provisional nonce and the nonce generated by the server are collated to decode the information.
The communication method according to the present invention generates a temporary nonce at a terminal, transmits predetermined information to the server using the generated temporary nonce, and transmits the predetermined information from the terminal to the server at the server. Requesting the generated nonce, transmitting the nonce generated at the server in response to the request of the terminal at the server, generating a correspondence table between the temporary nonce and the nonce received from the server at the terminal; The generated correspondence table is transmitted to the server, the temporary nonce corresponding to the received message is specified from the correspondence table received at the server, and authentication or decryption is performed using the specified temporary nonce. It is a feature.
Furthermore, the communication method according to the present invention is characterized in that a nonce request to the server is made after a predetermined information is transmitted to the server a plurality of times using a temporary nonce at the terminal.

In order to achieve the above object, a communication system according to the present invention transmits random information to a server using random number generation means provided in a terminal that generates a temporary nonce and the generated temporary nonce. A transmission means provided in the terminal; a random number sequence request means provided in the terminal that requests a nonce generated by the server; and a nonce generated by the server in response to a request from the terminal From the random number sequence generating means provided in the server, the random number correspondence table processing means provided in the terminal that generates a temporary nonce and nonce correspondence table and sends it to the server, and the received correspondence table, It is characterized by comprising a random number collation means provided in the server for identifying a corresponding temporary nonce and performing authentication or decryption using the specified temporary nonce.
The communication system according to the present invention is characterized in that the correspondence table is generated by a random number correspondence table processing means provided in the terminal.
Furthermore, the communication system according to the present invention is characterized in that a nonce request to the server is made after a predetermined information is transmitted to the server a plurality of times using a temporary nonce at the terminal.
The communication system according to the present invention is characterized in that a gateway having a buffer is provided between the terminal and the server.

In order to achieve the above object, a communication processing program according to the present invention includes a step of generating a temporary nonce at a terminal, a step of transmitting predetermined information to a server using the generated temporary nonce, and the terminal Requesting a nonce generated at the server from the server to the server, transmitting a nonce generated at the server in response to a request of the terminal at the server, and a temporary nonce and the server at the terminal Generating a correspondence table with the nonce received from the terminal, transmitting the correspondence table generated at the terminal to the server, and identifying a temporary nonce corresponding to the received message from the correspondence table received at the server And performing authentication or decryption using the specified temporary nonce It is.
In the communication processing program according to the present invention, the step of requesting a nonce generated by the server from the terminal to the server uses the temporary nonce at the terminal to transmit predetermined information to the server a plurality of times. It is characterized by being performed.

Since the communication method according to the present invention can be transmitted to the server using the temporary nonce generated by the terminal, the number of times the terminal receives a message including the nonce can be reduced, and the power consumption required for message reception Can be reduced.
Moreover, since the communication system according to the present invention can transmit the message to the server using the temporary nonce generated by the terminal, the number of times the terminal receives a message including the nonce can be reduced. That is, the communication system according to the present invention reduces the number of receptions when exchanging messages between a terminal and a server, rather than performing nonce collation for each message, rather than collating multiple nonces. Power consumption required for message reception can be reduced. Moreover, since the terminal does not wait for the nonce to be received from the server and transmits using the temporary nonce generated by the terminal, the terminal can send a message to the server at an arbitrary timing. Can be reduced.
When the communication program according to the present invention notifies the server of the information obtained by the terminal, the temporary nonce generated by the server and the temporary nonce generated by the terminal are used using the temporary nonce generated by the terminal. Can be periodically performed at a frequency lower than the information notification frequency, so that it is possible to reduce power consumption required for message reception.

It is a block diagram which shows schematic structure of the communication system which concerns on one embodiment of this invention. It is a message flow figure which shows operation | movement of the communication system which concerns on one embodiment of this invention. It is a message flow figure which shows operation | movement of the conventional communication system.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention. This communication system includes a terminal a, a gateway b, and a server c.

  The terminal a includes a timer 11, a request message transmission unit 12 corresponding to the transmission unit of the present invention, a random number generation unit 13 corresponding to the random number generation unit of the present invention, and the random number sequence of the present invention. A random number sequence correspondence table processing unit 14 corresponding to a table processing means and a random number sequence request unit 15 are included. Among them, the timer 11 periodically collects predetermined information such as temperature information (hereinafter, “information is described as“ temperature information ”) from a temperature sensor (not shown) and notifies the server c of the information. It is configured to be able to generate a trigger.

  The request message transmission unit 12 is configured to create a temporary nonce given from the collected temperature information by the random number generation unit 13, that is, a message encrypted by the temporary nonce, and transmit the message to the server c. . Here, the nonce is a numerical value or character string that is used only once, and generally refers to a value generated based on a random number, time information, or the like.

As described above, the random number generation unit 13 is configured to generate a predetermined temporary nonce, and the generated temporary nonce can be notified to the request message transmission unit 12 and the random number sequence correspondence table processing unit 14. It is configured as follows.
The random number sequence correspondence table processing unit 14 creates a correspondence table between the temporary nonce generated by the random number generation unit 13 and sent together with the request message, and the normal nonce from the server c received via the random number sequence request unit 15. The created correspondence table can be notified to the server c.
The random number sequence request unit 15 is configured to periodically request a nonce sequence from the server c and receive the nonce sequence generated by the server c via the gateway b.

  The gateway b includes a buffer 21. The buffer 21 stores the message received from the server c. When there is a reception polling from the terminal a, if the message addressed to the terminal a is stored, the buffer 21 sends the message to the terminal a. It is configured as follows.

The server c includes a request message receiving unit 31, a random number sequence matching unit 32 corresponding to the random number sequence matching unit of the present invention, and a random number sequence generation unit 33 corresponding to the random number sequence generation unit of the present invention. ing. Among these, the request message receiving unit 31 is configured to receive from the terminal a and pass the received message to the random number sequence matching unit 32.
From the nonce generated by the random number sequence generation unit 33 and the random number sequence correspondence table received from the terminal a (see the list of provisional random number and random number pairs shown at the bottom of FIG. 2). The corresponding temporary nonce is identified, and the received message is decrypted using the specified temporary nonce.
The random number sequence generation unit 33 is configured to generate a nonce sequence in response to a request from the terminal a and send it to the terminal a via the gateway b. This nonce string is a nonce string generated every time a temporary nonce is received from the terminal a.

  Next, the operation of the communication system according to the above embodiment will be described with reference to the message flow of FIG. In FIG. 2, the temporary nonce is shown as a temporary random number, and the nonce is shown as a random number.

  Now, the request message transmission unit 12 given the trigger from the timer 11 turns on the wireless interface (“Wakeup”), and the temperature information is collected. Then, the random number generation unit 13 encrypts the message using the generated temporary nonce, and the encrypted message is transmitted to the server c via the gateway b. After the transmission is completed, the wireless interface is turned off (“sleep”) (step 201. Hereinafter, the step is set to “S”).

  Similar to the above, temperature information is transmitted to the server c at a predetermined interval set in the timer 11 (S202, S203). After the above-described information transmission is repeated a fixed number of times (three times in the illustrated example), the random number sequence request unit 15 requests the server c for a nonce sequence (S210). The random number sequence generation unit 33 of the server c generates and issues a nonce sequence in response to the request, and the issued nonce sequence is sent to the terminal a (S211).

  After a predetermined time has elapsed, the random number sequence request unit 15 of the terminal a is “wake up”, and a polling operation for confirming whether there is a received message is performed. By the polling operation, the nonce sequence is received by the random number sequence request unit 15 via the buffer 21 of the gateway b. After completion of the reception, the random number sequence request unit 15 is set to “sleep” (S212). Thereafter, the random number sequence request unit 15 is “Wakeup” again, and the random number sequence correspondence table processing unit 14 creates a correspondence table between the temporary nonce created by the random number generation unit 13 and used for encrypting the message and the nonce received from the server c. (See the list of temporary random number and random number pairs shown in the lower part of FIG. 2), and the generated correspondence table is sent from the terminal a to the server c (S213).

  The random number sequence matching unit 32 of the server c identifies the temporary nonce corresponding to each received message from the nonce generated by the random number sequence generating unit 33 and the correspondence table received from the terminal a, and uses this to identify the received message. Decoding is performed (S214). Thereafter, similarly, the terminal a periodically collects temperature information, and the collected temperature information is transmitted to the server c (S201).

  The communication system configured as described above includes a random number generation unit 13 that generates a temporary nonce, a random number sequence request unit 15 that requests a plurality of regular nonces from the server c, and a random number sequence generation unit 33 that returns a nonce sequence in response to the request. And a random number correspondence table processing unit 14 that generates a correspondence table between the temporary nonce and the regular nonce and sends it to the server c, and identifies the temporary nonce corresponding to the received message from the received correspondence table, and uses it Since it has a random number sequence collation unit 32 that enables authentication or decryption, when notifying the server c of the temperature information obtained by the terminal a, the temporary nonce generated by the terminal a is used, The regular nonce and the nonce can be collated periodically at a frequency lower than the temperature information notification frequency. Therefore, when performing authentication or encryption using a nonce on the wireless access network, the number of times that the terminal a receives a message including the nonce can be reduced, and power consumption required for message reception can be reduced. .

That is, in the communication system configured as described above, when a message is exchanged between the terminal a and the server c, nonce verification is not performed for each message, but a plurality of nonce verifications are performed collectively. This can reduce power consumption required for message reception.
Since terminal a does not wait for reception of a nonce from server c and transmits using the temporary nonce generated by terminal a, terminal a can send a message to server c at an arbitrary timing. This can also reduce power consumption.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to the above-described embodiment, and design changes and the like can be made without departing from the scope of the present invention. Is possible.
For example, in the above description, the information transmitted from the terminal a to the server c is the temperature information, but other information such as pressure may be used. That is, the communication system according to the present invention can be applied to uses such as authentication and encryption of a message transmitted from a terminal that must continue to operate for a long time with low power consumption such as a sensor net.

  Further, the communication system according to the present invention can apply the encryption method using nonce to the exchange part of the random number sequence of S210 to S214 and the exchange part of the correspondence table. In this case, eavesdropping and impersonation can be further prevented. Furthermore, a sequence number may be given to a message transmitted from the terminal a to the server c. In this case, even if the message transmitted from the terminal a to the server c is lost for some reason, it can be correctly decoded.

  Each device such as the above-described terminal, gateway, and server has a computer system therein. Each process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing the program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  a terminal, 11 timer, 12 request message transmission unit, 13 random number generation unit, 14 random number correspondence table processing unit, 15 random number request unit, b gateway, 21 ... buffer, c ... server, 31 ... request message receiving unit, 32 ... random number sequence collating unit, 33 ... random number sequence generating unit

Claims (9)

A communication method involving an authentication procedure or an encryption procedure for communication between a terminal and a server,
Using the temporary nonce generated by the terminal to transmit predetermined information to the server, and then comparing the temporary nonce and the nonce generated by the server to decode the information. Communication method. A temporary nonce is generated at the terminal, and predetermined information is transmitted to the server using the generated temporary nonce,
Requesting a nonce generated at the server from the terminal to the server;
In response to a request from the terminal, the server sends a nonce generated by the server,
A correspondence table between the temporary nonce and the nonce received from the server is generated at the terminal, and the generated correspondence table is transmitted to the server.
From the correspondence table received at the server, the temporary nonce corresponding to the received message is specified, and authentication or decryption is performed using the specified temporary nonce.
A communication method characterized by the above. The communication method according to claim 2, wherein the nonce request to the server is made after transmitting predetermined information to the server a plurality of times using a temporary nonce at the terminal. Random number generation means provided in a terminal for generating a temporary nonce;
A transmission means provided in the terminal for transmitting predetermined information to the server using the generated temporary nonce;
A random number sequence request means provided in the terminal for requesting a nonce generated by the server;
A random number sequence generating means provided in the server for returning a nonce generated in the server in response to a request from the terminal;
A random number correspondence table processing means provided in the terminal for generating a temporary nonce and a nonce correspondence table and sending it to the server;
A temporary nonce corresponding to the received message is identified from the received correspondence table, and a random number sequence collation means provided in the server that performs authentication or decryption using the identified temporary nonce,
A communication system comprising:   5. The communication system according to claim 4, wherein the correspondence table is generated by a random number correspondence table processing unit provided in the terminal. The communication system according to claim 4 or 5, wherein the nonce request to the server is made after transmitting predetermined information to the server a plurality of times using the temporary nonce at the terminal.   The communication system according to claim 4, wherein a gateway having a buffer is provided between the terminal and the server. Generating a temporary nonce at the terminal;
Transmitting predetermined information to the server using the generated temporary nonce;
Requesting a nonce generated at the server from the terminal to the server;
Sending a nonce generated at the server in response to a request of the terminal at the server;
Generating a correspondence table between the temporary nonce and the nonce received from the server at the terminal;
Transmitting the correspondence table generated in the terminal to the server;
Identifying a temporary nonce corresponding to the received message from the correspondence table received at the server, and performing authentication or decryption using the specified temporary nonce;
A communication processing program characterized by comprising:   The step of requesting a nonce generated at the server from the terminal to the server is performed after transmitting predetermined information to the server a plurality of times using the temporary nonce at the terminal. The communication processing program according to claim 8.

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