JP2003283480A - Wireless communication system, wireless communication method, recording medium, and program - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a wireless communication system capable of performing data communication with high confidentiality. SOLUTION: A secret key transmitting means for transmitting a secret key when a transmitting side transmits a transmission request signal 401, and a secret key when transmitting a transmission permission signal 402, Response signal transmitting means for transmitting a response signal of acceptance is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system, a wireless communication method, a recording medium and a program, and more particularly to a method for increasing the confidentiality of communication for avoiding eavesdropping in a wireless section.

[0002]

2. Description of the Related Art Conventionally, as a method of concealing data to be communicated in a wireless communication system for performing digital data communication, particularly in a wireless LAN system, WEP (Wired Equi)
There was a method called valentPrivacy). This is a method in which a secret key for concealing communication data is stored in advance in a wireless client terminal and a wireless access point, which communicate with each other, and the data is thereby concealed.

As a technique for concealing communication data, there is a method described in Japanese Patent Registration No. 2601983.
In this prior art, a server of a communication network increases confidentiality by transmitting coded information depending on an initial user key, a group key, and a temporary key for authentication that the user sends to the server to the user. .

Similarly, as a technique for concealing communication data, there is a method described in Japanese Patent Laid-Open No. 11-331147. This prior art is a method of establishing a communication channel after performing communication for transmitting and receiving a public key and a secret key between a client and a server on a network.

[0005]

As described above, the conventional method of providing confidentiality to the wireless communication data is a method of presetting the confidential key as an initial value in the access point and the client terminal which perform wireless communication. It was Therefore, once the secret key is set, the secret key does not change unless the user changes it, which is weak in terms of the confidentiality of data, that is, the strength against eavesdropping.

Further, conventionally, in wired communication, there has been a method of setting a secret key when starting data communication between a server and a client terminal which perform communication. Even with this method, since the secret key is not changed after the secret key is set at the start of communication, the confidentiality of the data was low. In addition, wireless communication is more likely to be tapped than wire communication, so that in order to perform highly confidential communication, it is necessary to change the confidential key frequently.

In view of such circumstances, an object of the present invention is to provide a highly confidential wireless communication system, wireless communication method, recording medium and program.

[0008]

According to another aspect of the present invention, there is provided a wireless communication system having a plurality of wireless communication devices, which transmits information used for data concealment processing when a transmitting side transmits a transmission request signal. And a confidentiality processing means for performing confidentiality processing on the data communicated between the transmitting side and the receiving side using the information transmitted by the transmitting means.

Further, the wireless communication system of the present invention is a wireless communication system having a plurality of wireless communication devices, in which the transmitting side transmits a transmission request signal to the receiving side, the receiving side returns a transmission permission signal, and then the transmitting side transmits the signal. Transmitting means for transmitting information used for data confidentiality processing, and confidentiality processing means for performing confidentiality processing on the data communicated between the transmitting side and the receiving side using the information transmitted by the transmitting means. , Are included.

Further, the wireless communication method of the present invention is, in the wireless communication method between wireless communication devices, a transmitting step of transmitting information used for data concealment processing when the transmitting side transmits a transmission request signal, A confidentiality processing step of performing a confidentiality process on data communicated between the transmitting side and the receiving side using the information transmitted in the transmitting step.

The wireless communication method of the present invention is a wireless communication method between wireless communication devices, in which the transmitting side transmits a transmission request signal to the receiving side, the receiving side returns a transmission permission signal, and then the transmitting side transmits data. A transmitting step of transmitting information used for the confidentiality processing, and a confidentiality processing step of performing confidentiality processing on data communicated between the transmitting side and the receiving side by using the information transmitted in the transmitting step. It is characterized by having.

Further, the program of the present invention is for causing a computer to function as each unit of any of the above wireless systems.

The program of the present invention is for causing a computer to execute each procedure of any of the above-mentioned wireless methods.

According to the present invention, it is possible to flexibly change the secret key used for the confidential processing of data in wireless communication.
Data communication with enhanced confidentiality becomes possible.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1. FIG. 1 is a system configuration diagram of a wireless communication system according to an embodiment of the present invention. In the figure, 101 is a network, to which wireless access points 102 to 104 are connected. A wireless access point 104 is set to be connectable to the wireless client 105, and is connected to the wireless client 105 wirelessly. In addition, as a wireless system used in the following description, for example, IEEE 802.11,
IEEE802.11b and IEEE802.11a and the like, and as a method of concealing with a secret key, for example, WEP and the like defined in IEEE802.11 is used.

FIG. 2 is a block diagram of the wireless access point 104 of this wireless communication system. In the figure,
Reference numeral 201 denotes a radio unit that transmits and receives radio, and includes a transmission unit 210,
The receiver 211 and the antenna 212 are included. 202 detects the received signal and converts it into a digital signal,
It is a signal processing unit that modulates a digital signal sent from the data processing unit 203 for wireless transmission. Also,
The signal processing unit 202 attaches a header or the like for making the data for wireless transmission to the data sent from the data processing unit 203, and for the received data,
It has a function of removing the header and the like and sending it to the data processing unit 203. A data processing unit 203 includes a transmission data processing unit 205 that performs a concealment process on the data from the network interface 208, and a reception data processing unit 206 that has a function of canceling the concealment of the concealed data.
Consists of. A network interface 208 is an interface with the network 101. Two
Reference numeral 04 is a control unit that includes a timer necessary for communication and controls the entire wireless access point. To change the secret key,
This is performed by the control unit 204 notifying the data processing unit 203 of the secret key to be changed. A storage unit 207 stores the initial value of the secret key.

FIG. 3 is a block diagram of the wireless client 105 of this wireless communication system. In FIG. 3, the same reference numerals as those in FIG. 2 indicate the same or corresponding portions, and thus the description thereof will be omitted. Reference numeral 301 is a data communication interface for connecting to an information processing device such as a personal computer and performing data communication.

Next, the operation will be described. The transmission and reception timings of the wireless access point 104 and the wireless client 105 are shown in FIG. 4, and the operation flow is shown in FIG.

As shown in FIG. 5, the transmission side control section 204
Monitors for a transmission request from the network interface 208 or the data communication interface 301 during the normal operation (step S601) (step S602). When there is a transmission request, the transmission side adds a secret key for concealing data to the transmission request (RTS) signal (step S603) and transmits it (steps S604, 401).

Here, the transmitting side sets the timer in the control unit 204 (step S605), and the CT from the receiving side is set.
Start monitoring whether the S signal can be received. The receiving side determines whether or not the RTS signal from the transmitting side is received (step S606). When the receiving side receives the RTS signal, it sends a transmission permission (CT) from the receiving side back to the transmitting side.
S) signal with the secret key reception response signal added (step S
607), the CTS signal is transmitted (step S608,
402).

The transmitting side monitors the reception of the CTS signal (step S609), but if the CTS signal cannot be received and the previously set timer times out (step S614), the transmitting side further resends. It is determined whether there is a request (step S615), and if there is a retransmission request, the RTS signal is transmitted again (step S60).
3). When there is no request for resending, it returns to the normal state.

Even when the receiving side cannot receive the RTS signal sent by the transmitting side, the transmitting side cannot receive the CTS signal, and therefore the same processing as the above processing is performed. That is, when the timer times out (step S612),
Further, the transmitting side determines whether or not there is a resend request (step S613).
The S signal is transmitted (step S603). When there is no request for resending, it returns to the normal state.

On the transmitting side, C including the secret key reception response signal
When the TS signal is received, the transmitting side transmits the data concealed by the concealing key notified to the receiving side (steps S610 and 403). The receiving side decrypts the received anonymized data using the confidential key notified from the transmitting side (step S611).

As described above, according to the first embodiment,
Since the transmitting side notifies the receiving side of the secret key when making a transmission request, the secret key can be changed every data transmission, and the confidentiality of data communication is enhanced.

Embodiment 2. In this embodiment, in the operation of the wireless access point 104 and the wireless client 105, after the transmitting side transmits a transmission request and the receiving side sends back a transmission permission, the transmitting side changes the secret key together with the secret key change notification. The key is transmitted, and in response, the receiving side changes the secret key and transmits a response signal for accepting the secret key. The other configuration is the same as that of the first embodiment.

The transmission and reception timings at the wireless access point 104 and the wireless client 105 are shown in FIG. 6, and the operation flow is shown in FIG.

As shown in FIG. 7, the transmission side control unit 204
Monitors for a transmission request from the network interface 208 or the data communication interface 301 during the normal operation (step S701) (step S702). When there is a transmission request, the transmission side transmits a transmission request (RTS) signal (step S703, step S703).
501).

Here, the transmitting side sets the timer in the control unit 204 (step S704), and the CT from the receiving side is set.
Start monitoring whether the S signal can be received. The receiving side determines whether or not the RTS signal from the transmitting side has been received (step S705). If you receive an RTS signal,
The reception side transmits a transmission permission (CTS) signal to be returned to the transmission side (steps S706 and 502).

The transmitting side monitors the reception of the CTS signal (step S707), but if the CTS signal cannot be received and the previously set timer times out (step S717), the transmitting side further resends. It is determined whether there is a request (step S718), and if there is a retransmission request, the RTS signal is transmitted again (step S70).
3). When there is no request for resending, it returns to the normal state.

Even when the receiving side cannot receive the RTS signal sent by the transmitting side, the transmitting side cannot receive the CTS signal, and therefore the same processing as the above processing is performed. That is, when the timer times out (step S715),
Further, the transmitting side judges whether or not there is a resend request (step S716).
The S signal is transmitted (step S703). When there is no request for resending, it returns to the normal state.

Next, the transmitting side transmits a notification signal to the effect that the secret key is changed and the secret key information to be changed (steps S708, 503). Here, the transmitting side resets the timer (step S709) and starts monitoring whether or not the secret key reception response signal from the receiving side can be received. The receiving side determines whether or not the secret key change notification and the secret key information from the transmitting side have been received (step S71).
0). If received, the reception side transmits a secret key reception response signal to the transmission side (steps S711 and S50).
4).

The transmitting side monitors whether or not the secret key reception response signal is received (step S712), but if the reception response signal cannot be received and the previously set timer times out (step S721). The sender further determines whether or not there is a resend request (step S
722), if there is a resend request, the secret key change notification and the secret key information are transmitted again (step S708).
When there is no request for resending, it returns to the normal state.

Even when the receiving side cannot receive the secret key change notification and the secret key information signal sent by the transmitting side, the transmitting side cannot receive the response signal, and therefore the same processing as the above processing is performed. That is, if the timer times out (step S719), the sender further determines whether or not there is a retransmission request (step S720). If there is a retransmission request, the secret key change notification and the secret key information are again sent. It is transmitted (step S708). When there is no request for resending, it returns to the normal state.

When the transmitting side receives the secret key reception response signal, the transmitting side uses the secret key notified to the receiving side as a new secret key, and transmits the data concealed with this secret key (step S713). , 505). The reception side decrypts the received concealed data using the secret key notified from the transmission side (step S714).

As described above, according to the second embodiment, the secret key can be changed after the transmission between the transmitting side and the receiving side is permitted, and the confidentiality of the data communication is improved.

Embodiment 3. Embodiment 1 and Embodiment 2
In the above, the key for actually concealing is transmitted as the data of the concealing key transmitted in steps S604 and S708, respectively, but in the third embodiment, the concealing key is initialized and the data of the difference from this initial value is transmitted. . Other configurations are similar to those of the first and second embodiments.

The method of sending the difference from the initial value in this embodiment will be described below. In this case, the secret key is handled as follows. First, in the initial state, the transmitting side,
The same secret key that has been initialized is stored in the storage unit 207 on the receiving side. The transmitting side generates difference data for generating a new secret key to be changed from the initially set secret key, transmits the difference data to the receiving side, and stores it by the processing of the control unit 204. A transmission data processing unit 2 that generates a new secret key based on the initial secret key and the difference data and performs the secret processing on the information.
It sends to 05 and makes data confidential.

The receiving side generates a new secret key by the processing of the control unit 204 from the secret key of the initial value stored in the storage unit 207 and the difference data sent from the transmitting side. Then, the information is sent to the received data processing unit 206 that performs the process of removing the confidentiality of the received data, and the confidentiality of the data is released. By operating as described above, the concealment process using the difference data of the concealment key becomes possible.

Further, if the transmission side control unit 204 is provided with a random number generation function and the like and has a function of changing the secret key every time it is transmitted, data communication with a different secret key for each data packet becomes possible. The confidentiality can be improved.

The specific embodiment of the present invention has been described above, but the configuration of the present invention is not limited to this.
For example, in the first to third embodiments, one wireless access point and one wireless client have been described, but as the configuration of the present invention, the wireless access point 1 is used.
Alternatively, there may be multiple wireless clients.

That is, the wireless LA used in the above embodiment
In the N system, a transmission request signal and a transmission permission signal are used for communication competition control, and a wireless client terminal other than the communication partner who receives the transmission request signal and the transmission permission signal transmits for a certain period of time. It is supposed to be impossible.

Therefore, the wireless client terminal that has transmitted the RTS signal to send one wireless packet can occupy the wireless access point until it has sent the data packet. Similarly, the wireless access point transmitting the RTS signal does not perform communication other than the designated wireless client until the data packet is transmitted. That is,
Until the communication with one secret key is completed, the communication with other secret keys is not performed. Therefore, even if the system has multiple wireless clients for one wireless access point, the system is changed. The same effect can be obtained without doing.

The wireless communication system and the wireless communication method according to the first to third embodiments as described above can be realized by operating a program stored in the RAM or ROM of the computer. This program and a computer-readable storage medium recording the program are included in the embodiments of the present invention.

Specifically, the program is, for example, a CD
-Recorded in a recording medium such as a ROM, or provided to a computer via various transmission media. As the recording medium for recording the program, a flexible disk, a hard disk, a magnetic tape, a magneto-optical disk, a non-volatile memory card, or the like can be used in addition to the CD-ROM. On the other hand, as a transmission medium of the above-mentioned program, a communication medium (a wired line such as an optical fiber or the like) in a computer network (LAN, WAN such as the Internet, a wireless communication network, etc.) system for propagating and supplying the program information as a carrier wave. Wireless line) can be used.

Further, not only the functions of the above-described embodiments are realized by the computer executing the supplied program, but also the OS (operating system) or other application software running the program on the computer. In the case where the functions of the above-described embodiments are realized in cooperation with the above, or all or part of the processing of the supplied program is performed by the function expansion board or function expansion unit of the computer, the functions of the above-described embodiments are realized. However, such a program is also included in the embodiment of the present invention.

For example, FIG. 8 is a schematic diagram showing the internal structure of a general personal user terminal device. In FIG. 8, reference numeral 1200 is a computer PC. PC12
Reference numeral 00 denotes a CPU 1201, which executes device control software stored in the ROM 1202 or the hard disk (HD) 1211 or supplied from the flexible disk drive (FD) 1212, and comprehensively controls each device connected to the system bus 1204. To control.

[0048]

As described above, according to the present invention, it is possible to flexibly change the secret key used for the confidential processing of data in wireless communication, and it is possible to perform data communication with enhanced confidentiality.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a wireless communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a wireless access point in the wireless communication system according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a wireless client in the wireless communication system according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing transmission and reception timings in the wireless communication system according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing an operation procedure of the wireless communication system according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram showing transmission and reception timings in the wireless communication system according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing an operation procedure of the wireless communication system according to the second embodiment of the present invention.

FIG. 8 is a schematic diagram showing an internal configuration of a general personal computer terminal device.

[Explanation of symbols]

101 network, 102-104 wireless access points 105 wireless client 201 Wireless unit 202 signal processing unit 203 data processing unit 204 control unit 205 Transmission data processing unit (concealment processing means) 206 Received data processing unit 207 memory 208 network interface 210 transmitter (secret key transmission means) 211 Receiver (Response signal transmitter) 212 antenna

Claims (13)

[Claims] 1. In a wireless communication system having a plurality of wireless communication devices, when a transmitting side transmits a transmission request signal, transmitting means for transmitting information used for data concealment processing, and said transmitting means. A wireless communication system comprising: a confidentiality processing unit that performs confidentiality processing on data communicated between a transmitting side and a receiving side using information. 2. In a wireless communication system having a plurality of wireless communication devices, the transmitting side transmits a transmission request signal to the receiving side, the receiving side returns a transmission permission signal, and then the transmitting side uses the data for concealing processing. A transmission means for transmitting information, and a confidentiality processing means for performing confidentiality processing on data communicated between the transmission side and the reception side by using the information transmitted by the transmission means. Wireless communication system. 3. The wireless communication system according to claim 1 or 2, wherein the information transmitted by the transmitting side is a secret key used for a confidential process of data. 4. The wireless communication system according to claim 1 or 2, wherein the information transmitted by the transmitting side is a difference from a secret key set by an initial value. . 5. The wireless communication system according to any one of claims 1 to 4, wherein the transmitting side has a function of changing a secret key to be transmitted each time a data packet is transmitted. Wireless communication system. 6. The wireless communication system according to any one of claims 1 to 5, wherein communication methods are IEEE 802.11 and IEEE 80.
2. A wireless communication system, characterized in that the wireless communication system is one of 2.11b and IEEE 802.11a. 7. The wireless communication system according to any one of claims 1 to 6, wherein a method of concealing with a secret key is IEEE802.1.
1. A wireless communication system characterized by being WEP (Wired Equivalent Privacy) defined in 1. 8. A wireless communication method between wireless communication devices, comprising a transmitting step of transmitting information used for data concealment processing when a transmitting side transmits a transmission request signal, and information transmitted in the transmitting step. And a confidentiality processing step of performing a confidentiality process on data communicated between the transmitting side and the receiving side, using the wireless communication method. 9. A wireless communication method between wireless communication devices, wherein a transmitting side transmits a transmission request signal to a receiving side, and after the receiving side returns a transmission permission signal, information used by the transmitting side for concealing data is transmitted. A wireless communication characterized by comprising: a transmitting step of transmitting, and a confidential processing step of performing a confidential processing on data communicated between a transmitting side and a receiving side using the information transmitted in the transmitting step. Method. 10. A computer-readable recording medium having recorded thereon a program for causing a computer to function as each unit of the wireless communication system according to claim 1. 11. A computer-readable recording medium in which a program for causing a computer to execute each procedure of the wireless communication method according to claim 8 is recorded. 12. A program for causing a computer to function as each unit of the wireless communication system according to claim 1. 13. A program for causing a computer to execute each of the steps of the wireless communication method according to claim 8.