JP2005020350A - Radio communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication apparatus in which the distance between radio communication apparatuses is used for the key of authentication, interception by undesired radio communication equipment is made impossible so as to prevent leakage of a communication content, and the secrecy and safety of communication using a radio wave is improved. <P>SOLUTION: The distance between a radio communication apparatus 10a and radio communication apparatus 10b which are to make communication is measured and communication ciphered by the distance is performed. Authentication is established between the radio communication apparatus 10a and the objective radio communication apparatus 10b and communication is realized. However, authentication is not established between the radio communication apparatus 10a and an unintended radio communication apparatus 10c, and communication cannot be performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless communication apparatus.
[0002]
[Prior art]
Conventionally, as an authentication system in wired communication, IPv4 (Internet Protocol version 4) adopted in the IEEE1394 system is known, and products corresponding to the next version IPv6 with an expanded address space are also being released. In addition, a security system called IPSEC (IP security protocol), including a protocol such as an authentication header, IP packet encryption, and key exchange, has been formulated by the IETF (Internet Engineering Force).
[0003]
However, in a communication method such as USB (Universal Serial Bus), since there is no authentication between connected devices, a movie company in the United States is a major problem in information transmission of images that require content protection.
[0004]
On the other hand, in a wireless communication system with a charge that is managed by a telecommunications carrier, authentication can be made by a closed system configuration. However, in the case of a wireless LAN in which an individual is an administrator, malicious Can intervene relatively easily. WEP (Wired Equivalent Privacy), which is one of the encryption technologies used for wireless LANs, has been put into practical use, but the current situation is that the ciphers are being decrypted one after another.
[0005]
In response to the current state of such a wireless communication system, a proposal has been made to perform authentication based on device position information (see, for example, Patent Document 1). This is intended to measure the position of an accurate device using GPS (Global Positioning System) and use the position information for an authentication system.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-183188
[Problems to be solved by the invention]
By the way, although the positional information measured using GPS has nothing to do with originally performed communication, there is a problem that a new GPS facility must be provided in order to use GPS.
In measurement using GPS, normally, 4 to 12 artificial satellites (NAVSTAR) can be seen from the ground regardless of day or night, and the phases of radio waves (differences in reception timing) transmitted from the satellites can be determined. The position is calculated and triangulated between the receiver and the satellite. Therefore, one measurement error is about 30 to 100 m. Recently, in order to realize more accurate measurement, a differential GPS (DGPS) using a radio wave from an artificial satellite and a ground wave (about 300 kHz) has appeared. In Japan, a system using a radio wave band for a mobile phone has been in operation since 1996. However, the measurement error of DGPS is still about 10 m, and the measurement accuracy is rough.
[0008]
Furthermore, when the communication device is installed indoors, there is a problem in that it is difficult to obtain radio waves from the artificial satellite, and accurate position information cannot be obtained.
[0009]
The present invention has been made in view of the above points. In the Ultra Wideband wireless transmission system, the propagation distance of radio waves is used as a key for authentication, and communication can be performed by making it impossible to intercept communication by an unintended wireless communication device. It is an object of the present invention to provide a wireless communication device that makes it impossible to leak content and enhances the confidentiality and safety of communication using radio waves.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention comprises the following means 1) to 2).
That is,
1) Before performing wireless communication, a test signal is transmitted from the receiving device to the transmitting device or from the transmitting device to the receiving device, and the radio wave propagation distance between the transmission and reception is measured from the test signal, and then measured. An ultra wideband wireless communication apparatus configured to encrypt communication data using data corresponding to the radio wave propagation distance as an encryption key for authentication of communication,
Test signal transmitting means for transmitting the test signal;
Distance measuring means for receiving the test signal and measuring a radio wave propagation distance;
Storage means for storing radio wave propagation distance data obtained by the distance measuring means;
An encryption key generating means for generating an encryption key for communication authentication using the radio wave propagation distance data read from the storage means;
Data transmission means for encrypting and transmitting communication data using the encryption key generated by the encryption key generation means;
Receiving means for receiving encrypted communication data;
Data decrypting means for decrypting the received encrypted communication data from the encrypted communication data received by the receiving means and the encryption key generated by the encryption key generating means;
A wireless communication apparatus comprising:
2) An ultra-wideband wireless communication apparatus that encrypts communication data using radio wave propagation distance data from a transmission-side apparatus to a reception-side apparatus as an encryption key for communication authentication,
Area encryption key generating means for generating a communication encryption key using predetermined radio wave propagation distance data determined in advance;
Area data transmitting means for encrypting and transmitting communication data using the area encryption key generated by the area encryption key generating means;
Area data receiving means for receiving encrypted area data;
Data decrypting means for decrypting the encrypted area data received from the encrypted area data received by the receiving means and the area encryption key generated by the area encryption key generating means, and A wireless communication apparatus that selectively communicates with a counterpart wireless communication apparatus located at a predetermined radio wave propagation distance.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the wireless communication apparatus according to the present invention will be described.
The Ultra Wideband (hereinafter referred to as UWB) wireless transmission system is a system in which communication data is converted into a discontinuous impulse train and transmitted using a very narrow pulse having a width of only 1 nsec or less. Since this pulse wave contains a very wide range of frequency components, it is called the Ultra Wideband system as the name suggests because it is a system that uses a very wide frequency width of several GHz on the frequency axis. It is. Currently being studied in IEEE 802.15.3TG3a, it implements bidirectional communication using a time division duplex transmission (TDD). In the case of TDD transmission, the communication frequency and the communication band are the same, and transmission and reception can be performed using a time difference.
[0012]
FIG. 1 shows a time waveform of the UWB wireless transmission system. This figure shows the impulse train of the UWB wireless transmission system with time on the horizontal axis, and uses a very narrow pulse having a width of only 1 nsec or less. Since this pulse wave contains a very wide range of frequency components, the system uses a very wide frequency width of several GHz when viewed on the frequency axis. In UWB, information is added by changing the position, waveform, and phase of the pulse wave on the time axis. That is, the baseband signal waveform is directly converted into a pulse wave for transmission. What is output from the antenna is a discontinuous pulse wave. By using this method, it is possible to realize a high data transfer rate with less power consumption compared to conventional wireless communication.
[0013]
The measurement of the propagation distance of communication radio waves between communication devices will be described using FIG. As shown in the figure, the propagation distance of communication radio waves is measured between the wireless communication device 10a and the wireless communication device 10b that are to communicate. In the present embodiment, an example will be described in which a distance obtained by communication radio waves is used as an encryption key. After measuring the distance to the target wireless communication device, the measured result is stored in each of the wireless communication devices 10a and 10b for use in authentication of the communication device and information on the encryption key of the communication data.
In the case of TDD transmission, the communication frequency and the communication band are the same, and transmission and reception can be performed using a time difference. Therefore, if the wireless communication device does not move, the wireless propagation distance can be regarded as the same although there is a time difference.
[0014]
As can be seen from FIG. 1, UWB is suitable for distance measurement because the arrival time of a pulse wave having a time width of only 1 nsec can be measured with an accuracy of several psec. Since distance measurement between objects using time difference can be performed with high accuracy, the difference in position of only 1 inch can be grasped in real time at a distance of 100 m if the above-mentioned measurement accuracy is used. It is.
[0015]
Next, the transmission of information that is difficult to leak will be described with reference to FIG. As shown in the figure, the transmitting-side radio communication device 10a encrypts information to be transmitted using the distance from the partner radio communication device 10b measured earlier as a key. The encryption uses a known encryption technique such as adding a key packet that stores distance information or arranging communication data based on the key. Since the receiving-side wireless communication device 10b has the same distance information as the transmitting-side wireless communication device 10a, a key is generated based on the previously stored distance information and decryption is performed. The wireless communication device 10c located at a different distance from the counterpart wireless communication device 10b cannot generate a key based on the distance information of the wireless communication device 10a on the transmitting side and cannot decrypt the code, so communication is not established. .
By doing so, it is possible to significantly reduce the chance of information loss to a third party in wireless communication.
[0016]
In each of the above-described embodiments, the distance information is measured by both the wireless communication apparatuses that perform communication. However, encryption is performed based on the encryption generated by generating the encryption key based on the predetermined distance. Send data. At the time of reception, a configuration may be adopted in which the decrypted received data is recognized as valid data by decrypting with the encryption key used at the time of transmission.
[0017]
The other embodiment will be described with reference to FIG. In this method, authentication between wireless communication apparatuses is performed using distance information within a predetermined range. As shown in the figure, a distance range in which authentication of the wireless communication device 10a on the transmission side is set in advance is set, and communication is enabled when the partner wireless communication device is located in a range in which authentication is enabled. It may be configured. When the wireless communication device 10a distributes information, if there is a wireless communication device at the position of the wireless communication device 10c, authentication is not established and the communicated information cannot be recognized. When it is at the position of the wireless communication device 10b, since it is within the effective range of the wireless communication device 10a, authentication is established, and the communicated information can be decoded.
In this way, information can be prevented from being distributed to other than the intended wireless communication device, and can be applied to uses such as information communication in a local area such as an office.
[0018]
Next, the process of encrypting information using the distance as a key will be described with reference to FIG. In each of the above-described embodiments, the radio communication device 10a transmits a radio wave propagation measurement signal (S501), receives a radio wave propagation measurement signal from the opposite radio communication device 10b, and determines the radio wave propagation distance. Measure (S502). Based on the measurement result, the distance between the wireless communication device 10a and the wireless communication device 10b is stored (S503), and an encryption key for communication with the wireless communication device 10b is generated (S504). Thereafter, data encrypted based on the generated encryption is transmitted (S505).
[0019]
Similarly to the radio communication device 10a, the radio communication device 10b transmits a radio wave propagation measurement signal (S511), receives a radio wave propagation measurement signal from the opposite radio communication device 10a, and receives the radio wave propagation distance. Is measured (S512). Based on the measurement result, the distance between the wireless communication device 10a and the wireless communication device 10b is stored (S513), and an encryption key for communication with the wireless communication device 10a is generated (S514). Then, after receiving the data encrypted based on the generated encryption (S515), the encrypted data signal received with the self-generated encryption key is decrypted (S520).
[0020]
FIG. 6 shows a configuration example of the wireless communication apparatus. In order to acquire the radio wave propagation distance information with the counterpart wireless communication device, the test signal transmission unit 607 transmits a radio wave propagation distance measurement test signal 611. The test signal transmitted from the counterpart wireless communication device is supplied to the radio wave propagation distance measurement unit 601 as the received radio wave propagation distance measurement test signal 613. The radio wave propagation distance information unique to the facing wireless communication device obtained by the radio wave propagation distance measurement unit 601 is supplied to and stored in the radio wave propagation distance storage unit 602. Based on the encryption key stored in the radio wave propagation distance storage unit 602, the encryption key generation unit 603 generates an encryption key.
The input communication data 610 is transmitted to the partner wireless communication apparatus as encrypted communication data 612 after the input communication data 610 is encrypted based on the encryption key generated by the encryption key generation unit 603 in the data transmission unit 606. To do.
On the other hand, the encrypted communication data 614 received from the counterpart wireless communication device is received by the data receiving unit 604 and decrypted by the data decrypting unit 605 based on the encryption key generated by the encryption key generating unit 603, and the original data The signal 620 restored to
[0021]
In each of the above-described embodiments, the radio wave propagation distance is used as the encryption key for communication. However, the amplitude, the number of receptions, the time interval of TDD transmission, information on noise reflected by the radio wave on the obstacle, and the like may be used as the encryption key. Moreover, it is good also as a structure which uses these combining.
[0022]
【The invention's effect】
As described above in detail, according to the present invention, since it is possible to perform highly accurate distance measurement using the UWB system, it is not necessary to incorporate a system for acquiring position information in a wireless communication device, and communication is performed. In an environment in which communication is established between wireless communication devices, it is possible to provide a wireless communication device in which communication authentication is also established.
Furthermore, wireless communication is possible even in environments where radio waves from satellites do not reach, such as indoors and underground facilities when using GPS, and without installing or operating a base station for accurate distance measurement. In an environment where communication is established between communication devices, it is possible to provide a wireless communication device in which communication authentication is also established.
[0023]
In addition, according to the present invention, since distance information can be acquired in a wireless communication device, external communication means required when an external system is used is not required, and communication between wireless communication devices that perform communication can be performed. It is possible to provide a wireless communication apparatus that is authenticated.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a time waveform of a UWB system signal.
FIG. 2 is a diagram for explaining distance measurement between wireless communication apparatuses applied to the embodiment;
FIG. 3 is a diagram illustrating cryptographic communication applied to the present embodiment. FIG. 4 is a diagram illustrating cryptographic communication applied to the present embodiment with a constant distance. FIG. It is the figure which showed an example of the flowchart for demonstrating operation | movement of the radio | wireless communication apparatus applied to FIG.
FIG. 6 is a schematic block diagram of a wireless communication apparatus applied to this embodiment.
[Explanation of symbols]
10a, 10b, 10c ... wireless communication device 601 ... radio wave propagation distance measurement unit 602 ... radio wave propagation distance storage unit 603 ... encryption key generation unit 604 ... communication data reception unit 605 ... data decryption unit 606 ... data transmission unit 607 ... test signal transmission Part

Claims (2)

Before performing wireless communication, after transmitting a test signal from the receiving device to the transmitting device or from the transmitting device to the receiving device and measuring a radio wave propagation distance between transmission and reception from the test signal, the measured radio wave An ultra wideband wireless communication apparatus that encrypts communication data using data according to a propagation distance as an encryption key for authentication of communication,
Test signal transmitting means for transmitting the test signal;
Distance measuring means for receiving the test signal and measuring a radio wave propagation distance;
Storage means for storing radio wave propagation distance data obtained by the distance measuring means;
An encryption key generating means for generating an encryption key for communication authentication using the radio wave propagation distance data read from the storage means;
Data transmission means for encrypting and transmitting communication data using the encryption key generated by the encryption key generation means;
Receiving means for receiving encrypted communication data;
Data decrypting means for decrypting the received encrypted communication data from the encrypted communication data received by the receiving means and the encryption key generated by the encryption key generating means;
A wireless communication apparatus comprising: An ultra wideband wireless communication device that encrypts communication data using radio wave propagation distance data from a transmission side device to a reception side device as an encryption key for communication authentication,
Area encryption key generating means for generating a communication encryption key using predetermined radio wave propagation distance data determined in advance;
Area data transmitting means for encrypting and transmitting communication data using the area encryption key generated by the area encryption key generating means;
Area data receiving means for receiving encrypted area data;
Data decrypting means for decrypting the encrypted area data received from the encrypted area data received by the receiving means and the area encryption key generated by the area encryption key generating means, and A wireless communication apparatus that selectively communicates with a counterpart wireless communication apparatus located at a predetermined radio wave propagation distance.

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