JP7404220B2 - Wireless transmission system and wireless transmission method - Google Patents

Description

Embodiments of the present invention relate to a wireless transmission system and wireless transmission method for wirelessly transmitting communication data.

In recent years, the use of wireless communication technology has expanded significantly, and mobile terminals, wearable sensors, and various IoT sensors are being applied at various sites in factories and plants. However, since these wireless devices communicate with wireless base stations using radio waves, the communication area is within the range of radio waves.

One method of expanding the communication area is multi-hop network technology that uses wireless base stations as relay stations. With this multi-hop network technology, in addition to being able to expand the communication area because wireless base stations relay radio waves, relay stations can be freely placed within the range that radio waves can reach. ) has the advantage that wireless communication is possible even in places where there is no line of sight.

However, as the reach of radio waves expands, concerns about information leaks and unauthorized intrusion into networks due to the spread of radio waves also increase. In recent years, the demand for security measures for digital equipment and network equipment has increased, and various security measures have been implemented in multi-hop network technology.

As a security measure for such multi-hop network technology, for example, as shown in FIG. A wireless transmission system is known that includes an authenticator generation unit 102 that calculates an authenticator for data using a private key that is shared in advance, and a parity tag generator 103 that generates a parity tag from the authenticator. ing.

Note that a plurality of nodes 101 are installed, and the six shown in the figure are an example. A parity tag is generated at each node 101, and this parity tag is attached to data and transmitted to the next node 101, and finally to the server 100. The server 100 can identify the occurrence of a security event such as spoofing or data tampering by comparing the authenticator and the parity tag.

Also, a wireless transmission system is known in which the risk of security events itself is reduced by making the transmission route of the node 101 different for upstream and downstream data.

International Publication No. 2014/076911 International Publication No. 2018/056387

However, in the wireless transmission system described above, each node 100 adds a parity tag to the data, which increases the amount of data. Therefore, when the amount of communication is large, there is a problem in that quality such as communication speed deteriorates.

The embodiments of the present invention have been made in consideration of the above-mentioned circumstances, and aim to provide a wireless transmission system and a wireless transmission method that can identify the occurrence of a security event while suppressing the deterioration of quality such as communication speed. purpose.

A wireless transmission system according to an embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay means that relays the communication data wirelessly transmitted from the wireless device, and a relay means that relays the communication data that is wirelessly transmitted from the wireless device. A wireless transmission system comprising: an access point that receives the communication data; and an inspection unit that is connected to the access point to acquire the communication data from the wireless device and perform a test regarding the wireless device and the communication data. , the wireless device uses the secret information and the measurement data to obtain an authentication code, adds the authentication code to the measurement data, and wirelessly transmits the communication data as the communication data, and the relay means relays the communication data. At this time, the authenticator is newly calculated and rewritten, and the inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and extracts the authenticator from the communication data acquired by the access point, and extracts the authenticator from the communication data acquired by the access point, and extracts the authenticator from the communication data acquired by the access point. A verification value of the rewritten authenticator is obtained using the number of relay means, and the rewritten authenticator is compared with the verification value to authenticate the wireless device and confirm the soundness of the measurement data. It is characterized in that it is configured to perform.

Further, the wireless transmission system according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that relays the communication data that is wirelessly transmitted from the wireless device. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and inspection means connected to the access point to acquire the communication data from the wireless device and perform a test regarding the wireless device and the communication data. In the system, the wireless device uses the secret information and the measurement data to obtain an authentication code, adds this authentication code to the measurement data, and wirelessly transmits it as the communication data, and the relay means is configured to transmit the authentication code wirelessly as the communication data. The inspection means includes a storage means for storing secret information, and when the communication data is relayed, the authentication code added with the secret information of the relay means is newly calculated and rewritten; Extracting the rewritten authenticator from the communication data, and using the secret information shared with each of the wireless device and the relay means and the relayed route of the relay means to obtain a verification value of the rewritten authenticator. The wireless device is configured to authenticate the wireless device and confirm the soundness of the measurement data by comparing the rewritten authentication code with the verification value.

Further, the wireless transmission system according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that relays the communication data that is wirelessly transmitted from the wireless device. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and a verification unit that is connected to the access point to acquire the communication data from the wireless device and performs verification regarding the wireless device and the communication data. In the system, the wireless device includes a cryptographic processing means for obtaining an authenticator using an asymmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data. , the relay means includes a key storage means for storing an asymmetric encryption key of the relay means, and when relaying the communication data, encrypts and rewrites the authenticator using the asymmetric encryption key of the relay means, The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the asymmetric encryption key that is paired with each of the asymmetric encryption keys shared with the wireless device and the relay means. By repeating decryption of the authenticator using the encryption key, the decrypted measurement data and the decrypted asymmetric encryption key of the wireless device are obtained, and the decrypted measurement data and the extracted measurement data are verified. and further configured to authenticate the wireless device and confirm the soundness of the measurement data by comparing the decrypted asymmetric encryption key of the wireless device with the asymmetric encryption key of the wireless device. That is.

Furthermore, the wireless transmission system according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that uses the relay unit to relay the communication data that is wirelessly transmitted from the wireless device. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and a verification unit that is connected to the access point to acquire the communication data from the wireless device and performs verification regarding the wireless device and the communication data. In the system, the wireless device includes a cryptographic processing means for obtaining an authenticator using a symmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data. , the relay means includes a key generation means for generating and storing a symmetric encryption key of the relay means, and encrypts the authentication code using the symmetric encryption key of the relay means when relaying the communication data. The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and uses the respective symmetric encryption keys shared with the wireless device and the relay means. By repeating the decryption of the authenticator, the decrypted measurement data and the decrypted symmetric encryption key of the wireless device are obtained, the decrypted measurement data and the extracted measurement data are compared, and the The wireless device is characterized in that it is configured to authenticate the wireless device and confirm the soundness of the measurement data by comparing the decrypted symmetric encryption key of the wireless device with the symmetric encryption key of the wireless device. be.

A wireless transmission method according to an embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay means that relays the communication data wirelessly transmitted from the wireless device, and a relay means that relays the communication data that is wirelessly transmitted from the wireless device. A wireless transmission method comprising: an access point that receives the communication data; and an inspection unit connected to the access point to acquire the communication data from the wireless device and perform a test regarding the wireless device and the communication data. , in the wireless device, the step of obtaining an authentication code using secret information and the measurement data, adding this authentication code to the measurement data and wirelessly transmitting it as the communication data, and in the relay means, the communication data is In the step of newly calculating and rewriting the authenticator when relaying, the inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and extracts the rewritten authenticator from the communication data acquired by the access point, and checks the secret information to be shared with the wireless device. The verification value of the rewritten authenticator is calculated using the number of the relay means relayed, and the rewritten authenticator is compared with the verification value, thereby authenticating the wireless device and verifying the measurement data. This method is characterized by carrying out each step of confirming soundness.

Further, the wireless transmission method according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that relays the communication data that is wirelessly transmitted from the wireless device. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and inspection means connected to the access point to acquire the communication data from the wireless device and perform a test regarding the wireless device and the communication data. In the method, the wireless device obtains an authentication code using the secret information and the measurement data, adds the authentication code to the measurement data, and wirelessly transmits it as the communication data; The inspection means includes a storage means for storing secret information of the access point, and when relaying the communication data, the inspection means includes a step of newly calculating and rewriting an authenticator including the secret information of the relay means. extracts the rewritten authenticator from the communication data acquired by the user, and extracts the rewritten authenticator using the secret information shared with each of the wireless device and the relay means and the relayed route of the relay means. The device is characterized in that the wireless device is authenticated and the measured data is verified to be sound by determining a verification value of the wireless device and comparing the rewritten authentication code with the verification value. It is.

Further, the wireless transmission method according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that relays the communication data that is wirelessly transmitted from the wireless device. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and a verification unit that is connected to the access point to acquire the communication data from the wireless device and performs verification regarding the wireless device and the communication data. In the method, the wireless device includes a cryptographic processing means for obtaining an authenticator using an asymmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data. The relay means includes a key storage means for storing an asymmetric encryption key of the relay means, and when the communication data is relayed, the authentication code is encrypted using the asymmetric encryption key of the relay means. In the rewriting step, the verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point. By repeating decryption of the authenticator using a paired asymmetric encryption key, the decrypted measurement data and the decrypted asymmetric encryption key of the wireless device are obtained, and the decrypted measurement data and the extracted measurement data are obtained. authenticating the wireless device and confirming the soundness of the measurement data by comparing the decrypted asymmetric encryption key of the wireless device with the asymmetric encryption key of the wireless device; Each of them is characterized by its implementation.

Further, the wireless transmission method according to the embodiment of the present invention includes a wireless device that wirelessly transmits communication data including measurement data, a relay unit that relays the communication data wirelessly transmitted from the wireless device, and a relay unit that transmits communication data including measurement data. wireless transmission comprising: an access point that receives the communication data sent to the wireless device; and a verification unit that is connected to the access point to acquire the communication data from the wireless device and performs verification regarding the wireless device and the communication data. In the method, the wireless device includes a cryptographic processing means for obtaining an authenticator using a symmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data. The relay means includes key generation means for generating and storing a symmetric encryption key of the relay means, and when relaying the communication data, the authentication code is generated using the symmetric encryption key of the relay means. In the step of encrypting and rewriting, the collation means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data from the communication data acquired by the access point, By repeating decryption of the authenticator using the encryption key, the decrypted measurement data and the decrypted symmetric encryption key of the wireless device are obtained, and the decrypted measurement data and the extracted measurement data are verified. and further performing the steps of authenticating the wireless device and confirming the soundness of the measurement data by comparing the decrypted symmetric encryption key of the wireless device with the symmetric encryption key of the wireless device. It is characterized by:

According to the embodiments of the present invention, it is possible to identify the occurrence of a security event while suppressing deterioration in quality such as communication speed.

FIG. 1 is a block diagram showing a wireless transmission system according to a first embodiment. FIG. 2 is a block diagram showing a wireless transmission system according to a second embodiment. FIG. 3 is a block diagram showing a wireless transmission system according to a third embodiment. FIG. 7 is a block diagram showing a wireless transmission system according to a fourth embodiment. FIG. 1 is a block diagram showing a conventional wireless transmission system.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing.
[A] First embodiment (Figure 1)
FIG. 1 is a block diagram showing a wireless transmission system according to a first embodiment. The wireless transmission system 10 shown in FIG. 1 includes a wireless device 11 that wirelessly transmits communication data A including measurement data s, and relay means 13a, b, c that relays the communication data A wirelessly transmitted from the wireless device 11. , d, e, f, g, an access point 12 that receives the communication data A relayed by the relay means 13a, b...g, and an access point 12 that receives the communication data A from the wireless device 11 connected to this access point 12. and inspection means 14 for inspecting the wireless device 11 and the communication data A. In this wireless transmission system 10, a plurality of relay means 13a, b...g are installed, and a plurality of transmission paths for communication data A are set between the wireless device 11 and the access point 12.

The wireless device 11 includes various sensors and a communication device (or a device with a communication function such as a mobile terminal or a portable terminal). Sensors include GPS (Global Positioning System), acceleration sensor, gyro sensor, optical sensor, image sensor, temperature sensor, pressure sensor, magnetic sensor, ultrasonic sensor, displacement sensor, odor sensor, switch sensor, CT type (Current Transformer). ), various types of sensors such as current sensors and voltage sensors that measure 4-20 mA can be applied. The communication device uses the secret information x shared with the inspection means 14, the one-way function H, and the measurement data s of the sensor, and adds the authentication code y ₀ shown in equation (1) to the measurement data s. The data is assigned and communicated wirelessly as communication data A. As the one-way function H, functions such as SHA and MD5 are known.

As the communication method of the communication device, various methods in PAN (Personal Area Network), LAN (Local Area Network), MAN (Metropolitan Area Network), and WAN (Wide Area Network) are applicable. Examples include communication systems in series such as IEEE 802.11, IEEE 802.15.1, and IEEE 802.15.4. Furthermore, terminals equipped with communication methods such as IEEE 802.11, IEEE 802.15.1, and IEEE 802.15.4 can be applied to mobile terminals and portable terminals. A plurality of communication methods can be applied to the wireless device 11.

The access point 12 receives communication data A from the relay means 13e, f, g, etc. and transmits it to the inspection means 14. The communication data A is received by various antennas such as a dipole antenna, a monopole antenna, a chip antenna, a pattern antenna, a parabolic antenna, and a horn antenna, and is converted into digital data and transmitted to the inspection means 14. Note that it is also possible to limit the wireless devices 11 by setting the access point 12 with an ID and password that are shared with the wireless devices 11.

The relay means 13a, b...g receive radio waves (communication data A), process the communication data A, set a destination route, and amplify and transmit the radio waves as necessary. Similar to the access point 12, various antennas such as dipole antennas, monopole antennas, chip antennas, pattern antennas, parabolic antennas, and horn antennas provided in the relay means 13a, b...g can be used for transmitting and receiving radio waves (communication data A). It is.

The relay means 13a, b...g use the one-way function H when relaying the authentication code relayed from the wireless device 11 or the preceding relay means 13a, b...g, and perform the following equation (2). As shown in the figure, the n-th (nth number of relays) authentication code y _n is newly calculated and rewritten to this authentication code y _n . Note that the number of relays N (N≧1) is shared with the inspection means 14 in advance.

The subsequent relay route is set using a reactive method that searches for a route set in advance during communication, a proactive method that generates a route by constantly exchanging connection information, or the like. The radio waves (communication data A) transmitted from the relay means 13a, b...g are amplified by an amplifier circuit as necessary and then transmitted. Here, the number and arrangement of the relay means 13a, b...g are not limited and can be freely set.

The inspection means 14 includes the secret information x shared in advance with the wireless device 11, the one-way function H, the number of relays N, the measurement data s of the wireless device 11 transmitted from the access point 12, and the authenticator _y after rewriting. Then, the wireless device 11 is authenticated and the soundness of the measurement data is confirmed. That is, the inspection means 14 extracts the rewritten authenticator _yN from the communication data A acquired by the access point 12, and then extracts the secret information x shared in advance with the wireless device 11, the one-way function H, and the relay In addition to the number of times N, the transmitted measurement data s is used to calculate the verification value y _NN of the authenticator y _N after rewriting from equations (1) and (2). The inspection means 14 further compares this verification value y _NN with the transmitted authenticator y _N after rewriting. When y _NN =y _N , the one-way function H is a function with weak collision resistance, so that the secret information x, the measurement data s, and the number of relays N are the authenticator y _N and the verification value y. It is determined that they match with _NN . When y _NN ≠ y _N , it is determined that some or all of the secret information x, measurement data s, and number of relays N are inconsistent between the authenticator y _N and the verification value y _NN .

Next, the action will be explained.
The wireless device 11 calculates the authenticator y _o from equation (1) using the secret information x shared with the inspection means 14 for the measurement data s. The wireless device 11 adds an authentication code y _o to the measurement data s and wirelessly transmits the data as communication data A to the relay means 13a.

The relay means 13a receives the communication data A, obtains the authenticator _y1 using equation (2), rewrites the authenticator _yo to the authenticator _y1 , and uses the above-mentioned reactive or proactive method. The next transmission route is selected and the communication data A including the rewritten authenticator _y1 is wirelessly transmitted to any of the relay means 13b, c, and d. In any of the transmitted relay means 13b, c, and d, the authentication code _y2 is similarly obtained using equation (2), and the authentication code _y1 is rewritten as the authentication code _y2 . Thereafter, in the same way, formula (2) is repeated every time the relay is performed, the authenticator y _n-1 is rewritten to the authenticator y _n , and the communication data A (rewritten N times) is relayed through the N relay means 13a, b...g. (including the rewritten authenticator _yN ) is received by the access point 12 and transmitted to the inspection means 14.

The inspection means 14 obtains the measurement data s and the rewritten authentication code _yN each time the communication data A is received. Furthermore, the inspection means 14 shares the secret information x, the one-way function H, and the number of relays N with the wireless device 11 in advance. Therefore, the inspection means 14 calculates the verified value y of the authenticator y _N after rewriting using equations (1) and (2) from these shared values x, H, N and the received measurement data s. Find _NN . The inspection means 14 compares this verification value y _NN with the received authenticator y _N after rewriting.

If y _NN = y _N , since the one-way function H is a function with weak collision resistance, the secret information x, the measurement data s, and the number of relays N are the authenticator y _N after rewriting and the verification value y _NN This results in a match. The fact that the secret information x of the wireless device 11 matches the authenticator y _N after rewriting and the verification value y _NN indicates that the transmitting device of the communication data A is the same regarding the secret information x. Further, the fact that the measured data s matches the authenticator y _N after rewriting and the verification value y _NN indicates that the measured data s has not changed during the process. Furthermore, the fact that the number of relays N matches the authenticator _yN after rewriting and the verification value _yNN indicates that there is no mistake in the number of relay means 13a, b...g. From these, it can be seen that the measurement data s acquired by the inspection means 14 is transmitted from the designated wireless device 11, that the measurement data s is not tampered with and is sound, and that the number of relays is the same as the set number of times.

Conversely, if y _NN ≠ y _N , since the one-way function H is a function with weak collision resistance, some or all of the secret information x, measurement data s, and number of relays N are authenticated after being rewritten. There is a mismatch between the child _yN and the verification value _yNN , indicating that security events such as spoofing, falsification of measurement data s, and an abnormality in the number of relays have occurred.

With the above configuration, the main body embodiment provides the following effects (1) and (2).
(1) The wireless device 11 obtains an authentication code _y0 from the secret information x and the measurement data s, adds this authentication code _y0 to the measurement data s, wirelessly transmits it as communication data A, and transmits it wirelessly to the respective relay means 13a and b. Every time g relays communication data A, it rewrites the authentication codes y _{0 and} y _n and wirelessly transmits them to the access point 12. Since the authentication codes y _{0 and} y _n are rewritten, the amount of communication data A is constant regardless of the number of relays, and the capacity is small. The inspection means 14 connected to the access point 12 authenticates the wirelessly transmitted measurement data s using the secret information x, the one-way function H, and the number of relays N shared in advance with the wireless device 11 after rewriting. A verification value y _NN of the child y _N is obtained, and this verification value y _NN is compared with the wirelessly transmitted authenticator y _N after rewriting.

Since the one-way function H applied to the calculation of the authenticator _yN and the verification value _yNN after rewriting is a function with weak collision resistance, the inspection means 14 checks the measured data when the verification matches. It can be confirmed that s is transmitted from the wireless device 11 that shares the secret information x and is sound without tampering, and that the number of relays by the relay means 13a, b...g is the set number of times, and the verification does not match. In this case, it can be determined that a security event such as the measurement data s being unhealthy has occurred. As a result, the occurrence of a security event can be identified without deteriorating quality such as communication speed by keeping the amount of communication data A constant.

(2) Since there are multiple transmission paths from the wireless device 11 to the access point 12, when the relay means 13a, b...g select the relay means to be the next transmission path and wirelessly transmit the communication data A. , the amount of communication data A in each of the relay means 13a, b...g can be suppressed and wirelessly transmitted to the access point 12. Furthermore, since the authentication codes y _{0 and} y _n included in the communication data A are rewritten, the data amount of the communication data A is constant regardless of the number of relays by the relay means 13a, b...g, and the capacity is small. For these reasons, the amount of communication data A in each of the relay means 13a, b, .

[B] Second embodiment (Figure 2)
FIG. 2 is a block diagram showing a wireless transmission system according to a second embodiment. In this second embodiment, the same parts as in the first embodiment are given the same reference numerals as those in the first embodiment to simplify or omit the explanation.

The wireless transmission system 20 shown in FIG. 2 includes a plurality of wireless devices 21 that wirelessly transmit communication data B, and a plurality of relay means 23a, b, and c that relay the communication data B by setting a plurality of transmission paths for the communication data B. , d, e, f, and g, an access point 12, and an inspection means 24 that acquires communication data B from the access point 12 and performs an inspection regarding the wireless device 21 and communication data B. Ru.

The wireless device 21 obtains the authenticator _y0 using the secret information x, the communication setting information (communication setting information) c, and the measurement data s included in the communication data B, as shown in equation (3) below. , this authentication code _y0 is added to the measurement data s, and it is wirelessly transmitted as communication data B.

That is, the wireless device 21 is equipped with a communication device or a communication function, and stores the communication setting information c such as frequency and communication time interval, which are setting items for communication. Although the settings of this communication setting information c can be changed, it is shared with the inspection means 24 in advance. The communication device of the wireless device 21 uses the secret information x of the wireless device 21, the measurement data s, and the communication setting information c to obtain the authenticator z ₀ shown in equation (3) from the one-way function H, and uses the measurement data s and wirelessly communicates as communication data B.

Each of the relay means 23a, b...g has storage means 26a, b, c, which stores the secret information r _i (i=a, b...g) and communication setting information rc _i of each relay means 23a, b...g. d, e, f, and g, respectively. Of these, the relay means connected to the wireless device 21, for example, the relay means 23a, further includes a connection number measuring means 25 that measures the number of connections co of the wireless device 21 to the relay means 23a.

When the relay means 23a connected to the wireless device 21 relays the communication data B, the relay means 23a adds the number of connections co of the wireless devices 21, the secret information r _a of the relay means 23a, and the communication setting information rc _a to create an authenticator _z1. is newly calculated, and the authenticator z ₀ is rewritten to the authenticator z ₁ . Further, each of the relay means 23b, c...g that is not connected to the wireless device 21, when relaying the communication data B, uses the secret information r _i and the communication setting information rc _i ( A new authentication code z _n (n is the number of relays) is calculated by adding i=a, b, c, d, e, f, g) and rewritten to this authentication code z _n .

That is, the connection number measuring means 25 is provided in the relay means 23a, and measures the number co of connections of the wireless devices 21 to the relay means 23a. The connection number measuring means 25 is equipped with various antennas, measures radio waves, and grasps the number co of wireless devices 21 connected to the relay means 23a. The number of connections co can also be the number of connections after filtering by IP address or MAC address, or after authenticating the wireless device 21. The number of connections co is shared with the inspection means 24 in advance.

The relay means 23a uses the authenticator _z0 and the number of connections co transmitted from the wireless device 21 to calculate a new authenticator _z1 from the one-way function H as shown in equation (4), and performs authentication. Rewrite child z ₀ to authentication child z ₁ . Further, the relay means 23a adds an authentication code _z1 to the measurement data s, and wirelessly transmits it as measurement data B to the subsequent relay means 13ba, c...g.

Each of the storage means 26a, b...g is a storage device provided in each of the relay means 23a, b...g, and includes a cache memory, a RAM (Random Access Memory), a ROM (Read Only Memory), a Flash Memory, and various types of storage. It consists of etc. Each of the storage means 26a, b...g stores secret information r _i (i=a, b...g) of each relay means 23a, b...g shared with the inspection means 24, and communication settings. Items such as communication setting information rc _i (i=a, b...g) such as frequency and communication time interval are stored. Although the communication setting information rc _i can be changed, it is shared with the inspection means 24 in advance.

The relay means 23b, c, d, e, f, and g that are not connected to the wireless device 21 apply a one-way function H to the authenticator zn _-1 transmitted from the preceding relay means. Using this method, the authenticator z _n is newly calculated as shown in equation (5), and the authenticator z _n-1 is rewritten to the authenticator z _n . The relay route is shared with the inspection means 24 in advance. Here, n in formula (5) is an integer of 2 or more, and i is b, c, d, e, f, and g.

The inspection means 24 extracts the measurement data s and the rewritten authenticator _zN from the communication data B acquired by the wireless point 12. Furthermore, the inspection means 24 checks the secret information x, r _i , the communication setting information c, r _i , the one-way relationship H, and the wireless device 21 shared with each of the wireless device 21 and the relay means 23a, b...g. Using the number co of connections to the relay means 23a, the relay route by the relay means 23a, b...g, and the measurement data s, a verification value _zNN of the authenticator _zN after rewriting is determined. The inspection means 24 then authenticates the wireless device 21 and confirms the soundness of the measurement data s by comparing the authenticator _zN after rewriting with the verification value _zNN .

Next, the effect will be explained.
Each wireless device 21 calculates an authenticator z ₀ from equation (3) for the measurement data s using the secret information x and communication setting information c shared with the inspection means 24 . The inspection means 24 adds an authentication code z ₀ to the measurement data s to form communication data B, and wirelessly transmits the communication data B from the wireless device 21 to the relay means 23a. Thereby, the authenticator z ₀ can include the communication setting information c in addition to the measurement data s and the secret information x of the wireless device 21 .

The relay means 23a receives the communication data B, obtains the number of connections co measured by the number of connections measuring means 25, and further obtains the secret information r _a and communication setting information rc _a of the relay means 23a from the storage means 26a. . This relay means 23a obtains the authenticator _z1 using equation (4), and rewrites the authenticator _z0 to the authenticator _z1 . Thereby, the authenticator z ₁ can include information regarding the number of connections co to the relay means 23a in addition to the authenticator z ₀ . The relay means 23a adds the authentication code _z1 to the measurement data s, selects the next transmission route as the communication data B, and wirelessly transmits the data to one of the relay means 23b, c, and d.

In any of the transmitted relay means 23b, c, d, the secret information r _i (i=b, c, d) and Using the communication setting information rc _i (i=b, c, d), the authenticator z ₂ is calculated from equation (5), and the authenticator z ₁ is rewritten to the authenticator z ₂ . Thereafter, the relay means similarly repeats equation (5) every time communication data B is relayed to rewrite the authentication code, and transfers communication data B that has been relayed N times (including the authenticator z after being rewritten and rewritten _N times). ) is transmitted to the inspection means 24 via the access point 12. Thereby, the authenticator z _N after rewriting can include the secret information r _i and the communication setting information rc _i of the relay means 23a, b...g in addition to the authenticator z _N-1 .

The inspection means 24 acquires the measurement data s and the rewritten authentication code _zN each time the communication data B is received via the access point 12. The inspection means 24 also checks the secret information x and communication setting information c of the wireless device 21, the one-way function H, the number co of connections of the wireless device 21 to the relay means 23a, and the secret information r _i of the relay means 23a, b...g. The communication setting information rc _i and the relay route by the relay means 23a, b...g are shared with the wireless device 21 in advance. Therefore, the inspection means 24 calculates equations (3) to (5) from these shared values (x, c, H, co, r _i , r c _i, relay route) and the received measurement data s. is used to obtain the verification value _zNN of the authenticator _zN after rewriting. Then, the inspection means 24 compares the created verification value z _NN with the rewritten authenticator z _N received from the access point 12 .

Even if the number of calculation parameters of the one-way function H increases, if z _NN =z _N , the one-way function H is a function with weak collision resistance, so the secret information x, communication setting information c , the measurement data s, the number co of wireless devices 21 connected, the secret information r _i , the communication setting information r c _i , and the relay route will match the authenticator z _N and the verification value z _NN after rewriting. As a result, since the authenticator _zN and the verification value _zNN after rewriting have the same secret information x and communication setting information c, it is confirmed that the wireless device 21 is correct and the measurement data s has not changed during the process. In addition, it becomes possible to specify the number co of wireless devices 21 connected to the relay means 23a, the relay means 23a, b...g, and their relay routes. As a result, the measurement data s acquired by the inspection means 24 is transmitted from the specified wireless device 21 and is untampered and sound, and there is no connection other than the setting to the relay means 23a, b...g, and It can be seen that the information is routed through relay means 23a, b...g.

Conversely, if z _NN ≠ z _N , since the one-way function H is a function with weak collision resistance, secret information x, communication setting information c, measurement data s, number co of connected wireless devices 21, secret Some or all of the information r _i , communication setting information rc _i , and relay route may be mismatched between the authenticator z _N after rewriting and the verification value z _NN , resulting in spoofing, falsification of measurement data s, and designated relay means 23a. , b...g has occurred.

With the above configuration, the second embodiment provides the following effects (3) and (5).
(3) The wireless device 21 obtains an authenticator _z0 by adding the secret information x, the measurement data s, and the communication setting information c, adds this authenticator _z0 to the measurement data s, and wirelessly transmits it as the communication data B. Each time the relay means 23a, b...g relay communication data B, the relay means 23a, b...g add the secret information r _i to obtain the authenticator _zn , and use the authenticator _zn-1 as the authenticator. Finally, _the authenticator _zN that has been rewritten N times is wirelessly transmitted to the access point 12. Since the authentication code z _n is rewritten, the amount of communication data B is constant regardless of the number of relays, and in addition to having a small capacity, the authentication code z n is a relay shared in advance with the relay means 23a, b...g. Secret information r _i of means 23a, b...g can be included.

The inspection means 24 connected to the access point 12 collects the wirelessly transmitted measurement data s, in addition to the secret information x shared in advance with the wireless device 21, the secret information r of each relay means 23a, b...g. A verification value z _NN of the authenticator z _N after being wirelessly transmitted using _i is obtained, and this verification value z _NN is compared with the authenticator z _N after being rewritten.

Since the one-way function H applied to calculate the authenticator _zN after rewriting and the verification value _zNN is weakly collision resistant, the inspection means 24 calculates the difference between the authenticator _zN after rewriting and the verification value _zNN . If the verification matches, the measurement data s is transmitted from the wireless device 21 that shares the secret information x and is sound without being tampered with, and furthermore, the measurement data s is transmitted from the wireless device 21 that shares the secret information _x . High reliability can be confirmed from the fact that If the authenticator _zN after rewriting and the verification value _zNN do not match, the inspection means 24 knows that a security event such as the measurement data s is not sound has occurred. As a result, the occurrence of a security event can be identified without reducing the quality of communication speed or the like by keeping the amount of communication data B constant.

(4) In response to the communication data B transmitted from some wireless devices 21, a relay means connected to the wireless device 21, for example, the relay means 23a, uses a connection number measuring means 25 that measures the number of connections co of the wireless devices 21. Equipped with When relaying the communication data B, the relay means 23a calculates the authenticator _z1 by adding information about the number co of wireless devices 21 connected to the relay means 23a, and converts the authenticator _z0 into the authenticator _z1 . rewrite. Thereafter, the relay means 23b, c...g sequentially rewrite the authentication code _z1 to the authentication code _zn and wirelessly transmit it to the access point 12. Since the authenticators z ₁ and z _n are rewritten, the amount of communication data B remains constant regardless of the number of relays, and in addition to having a small capacity, they also include information on the number co of wireless devices 21 connected. be able to.

The inspection means 24 connected to the access point 12 calculates, for the wirelessly transmitted measurement data s, the number co of wireless devices 21 connected to the relay means 23a, in addition to the secret information x shared in advance with the wireless devices 21. Using the information, a verification value z _NN of the wirelessly transmitted authenticator z _N after being rewritten is determined, and this verification value z _NN is compared with the authenticator z _N after being rewritten.

Since the one-way function H applied to calculate the authenticator _zN after rewriting and the verification value _zNN is a function with weak collision resistance, the inspection means 24 calculates the verification value _zNN and the authenticator z after rewriting. If the comparison with _N matches, the measurement data s is transmitted from the wireless device 21 that shares the secret information x and is sound without being tampered with, and the number of connections co of the wireless device 21 is as set. , high reliability can be confirmed. If the verification value _zNN and the authenticator _zN after rewriting do not match, the inspection means 24 knows that a security event such as the measurement data s being unsound has occurred. As a result, the occurrence of a security event can be identified without reducing the quality of communication speed or the like by keeping the amount of communication data B constant.

(5) For communication data B transmitted from the wireless device 21, each of the relay means 23a, b...g transmits the communication setting information rc _i of the relay means 23a, b...g each time it relays the communication data B. In addition, the authenticator z _n is calculated, the authenticator z _n-1 is rewritten to the authenticator z _n , and finally the rewritten authenticator z _N , which has been rewritten N times, is wirelessly transmitted to the access point 12. Since the authentication code z _n is rewritten, the amount of communication data B remains constant regardless of the number of relays, and in addition to having a small capacity, it also changes the communication settings of the wireless device 21 and relay means a, b... Information c, rc _i can be included.

The inspection means 24 connected to the access point 12 uses secret information x, r _i and communication setting information c, r _i shared in advance with the wireless device 21 to perform wireless transmission on the wirelessly transmitted measurement data s. A verification value z _NN of the authenticator z _N after being rewritten is determined, and this verification value z _NN is compared with the authenticator z _N after being rewritten.

Since the one-way function H applied to calculate the authenticator _zN after rewriting and the verification value _zNN is a function with weak collision resistance, the inspection means 24 calculates the verification value _zNN and the authenticator z after rewriting. If the comparison with _N is a match, the measurement data s is transmitted from the wireless device 21 that shares the secret information x and is sound without being tampered with, and furthermore, the communication between the wireless device 21 and the relay means a, b...g is confirmed. Since there are no errors in the setting information c and rc _i , high reliability can be confirmed. If the verification value _zNN and the authenticator _zN after rewriting do not match, the inspection means 24 knows that a security event such as the measurement data s being unsound has occurred. As a result, the occurrence of a security event can be identified without reducing the quality of communication speed or the like by keeping the amount of communication data B constant.

[C] Third embodiment (Figure 3)
FIG. 3 is a block diagram showing a wireless transmission system according to a third embodiment. In the third embodiment, the same parts as in the first embodiment are given the same reference numerals as in the first embodiment, so that the explanation will be simplified or omitted.

The wireless transmission system 30 shown in FIG. 3 includes a wireless device 31 that wirelessly transmits communication data C, and a plurality of relay means 33a, b, c, and d that relay the communication data C by setting a plurality of transmission paths for the communication data C. , e, f, and g, an access point 12, and a verification means 34 that acquires communication data C from the access point 12 and performs verification regarding the wireless device 31 and the communication data C. .

The wireless device 31 uses the asymmetric encryption key k ₀ of the wireless device 31 and the measurement data s included in the communication data C to obtain the authenticator w ₀ using the cryptographic processing means 35 as shown in equation (6) below. This authentication code w ₀ is added to the measurement data s and wirelessly transmitted as communication data C.

That is, the cryptographic processing means 35 cryptographically processes the measurement data s of the sensor in the wireless device 31 and the asymmetric cryptographic key _k0 whose pair is shared between the wireless device 31 and the collation means 34, and formula (6) Find the authenticator w ₀ shown in . As the encryption method En, various asymmetric encryption methods such as RSA (Rivest-Shamir-Adleman) and elliptic curve cryptography are applied.

Each of the relay means 33a, b...g includes a key storage means 36a, which stores the asymmetric encryption key k _i (i=a, b, c, d, e, f, g) of each relay means 33a, b...g. b, c, d, e, f, g, and when relaying the communication data C, the asymmetric encryption key k _i of each relay means 33a, b...g is used as shown in equation (7) below. The authenticator w _n (n: integer) is encrypted and obtained, and the authenticator w _n-1 is rewritten to the authenticator w _n .

That is, the key storage means 36a, b...g stores the asymmetric encryption keys k _i of the relay means 33a, b...g whose pairs are shared between the relay means 33a, b...g and the verification means 34 ( i=a, b...g) are stored. Note that the verification means 34 stores an asymmetric encryption key that is paired with this asymmetric encryption key k _i .

When the relay means 33a, b...g relay the communication data C to the authentication codes w ₀ and w _n-1 transmitted from the wireless device 31 or the previous stage, the relay means 33a, b... As shown, the authenticator w _n is encrypted and obtained, and the authenticator w _n-1 is rewritten to the authenticator w _n . Here, the relay route by the relay means 33a, b...g is shared with the verification means 34 in advance.

The verification means 34 first extracts the authenticator _wN that has been rewritten N times and the measurement data s from the communication data C acquired by the access point 12. Next, the verification means 34 uses the asymmetric encryption keys paired with the respective asymmetric encryption keys k ₀ , k _i shared with the wireless device 31 and the relay means 33a, b...g to obtain the authenticators w _N , w _{n .} , w ₀ is repeated to obtain the decrypted measurement data ss and the decrypted asymmetric encryption key k ₀₀ of the wireless device 31. Next, the collation means 34 collates the decrypted measurement data ss and the extracted measurement data s, and further collates the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 with the asymmetric encryption key k ₀ of the wireless device 31. By comparing the data, the authentication of the wireless device 31 and the soundness of the measurement data s are confirmed.

That is, the verification means 34 authenticates the wireless device 31 and confirms the soundness of the measurement data s based on the measurement data s of the wireless device 31 transmitted from the access point 12 and the rewritten authenticator _wN . Since the relay route by the relay means 33a, b...g is shared with the wireless device 31 in advance, the verification means 34 performs authentication using the asymmetric cryptographic key paired with the asymmetric cryptographic key k _i in the reverse order of the relay route. The children w _n and w _N are sequentially decoded.

Note that since the asymmetric encryption key paired with the asymmetric encryption key k _i has a one-to-one correspondence, even if the relay route by the relay means 33a, b...g is unknown, decryption is possible by sequentially trying. Thereafter, the authenticator w ₀ is decrypted using the asymmetric encryption key paired with the asymmetric encryption key k ₀ to obtain the decrypted measurement data ss and the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 . Then, the measurement data s is compared with the decrypted measurement data ss, and furthermore, the asymmetric encryption key k ₀ of the wireless device 31 is compared with the decrypted asymmetric encryption key k ₀₀ of the wireless device 31. The decrypted asymmetric encryption key k ₀₀ of the wireless device 31 can be verified by storing the asymmetric encryption key k ₀ of the wireless device 31 in advance in the verification means 34, and can also be verified using the paired asymmetric encryption key applied for decryption. By verifying the cryptographic processing, it becomes possible to verify the asymmetric encryption key _k0 without storing it in the verification means 34 in advance.

Next, the effect will be explained.
The wireless device 31 combines the measurement data s with the asymmetric encryption key k ₀ of the wireless device 31 and calculates the authenticator w ₀ using equation (6). This wireless device 31 adds an authentication code w ₀ to the measurement data s to generate communication data C, and wirelessly transmits this communication data C from the wireless device 31 to the relay means 33a.

The relay means 33a receives the communication data C, uses the asymmetric encryption key _{k a} stored in the key storage means 36a to obtain the authenticator w ₁ from equation (7), and sets the authenticator w ₀ to the authenticator w ₁ Rewrite it to . Further, the relay means 33a selects the next transmission route and wirelessly transmits the communication data C including the rewritten authenticator _w1 to one of the relay means 33b, c, and d.

In any of the transmitted relay means 33b, c, and d, the authentication code _w2 is similarly obtained using equation (7), and the authentication code _w1 is rewritten to the authentication code _w2 . Similarly, the subsequent relay means rewrites the authentication code w _n using equation (7) every time it is relayed, and converts the communication data C relayed N times (measurement data s and the rewritten authentication code rewritten N times) w _N ) is transmitted to the verification means 34 via the access point 12.

The verification means 34 obtains the measurement data s and the rewritten authentication code _wN each time the communication data C is received. Since the verification means 34 shares the relay route of the relay means 33a, b...g with the wireless device 31 in advance, the verification means 34 performs authentication using the asymmetric cryptographic key paired with the asymmetric cryptographic key k _i in the reverse order of the relay route. The children w _N and w _n are sequentially decoded. Thereafter, the authentication code w ₀ is decrypted, and the decrypted measurement data ss and the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 are obtained. The collation means 34 collates the measurement data s and the decrypted measurement data ss, and further collates the asymmetric encryption key k ₀ of the wireless device 31 with the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 .

If s=ss and k ₀ =k ₀₀ , the verification means 34 determines that the measurement data s has been transmitted from the specified wireless device 31 and is sound without falsification, and the relay means 33a, b...g It is determined that there is no error in the relay route. Conversely, if s≠ss or k ₀ ≠ k ₀₀ , the verification means 34 determines that some or all of the measurement data s, the asymmetric encryption key k ₀ , and the asymmetric encryption key k _i are abnormal, and the measurement data It is determined that a security event such as falsification of s or an abnormality in the relay route has occurred.

With the above configuration, the third embodiment provides the following effect (6).
(6) The wireless device 31 includes a cryptographic processing means 35 that obtains an authenticator _w0 from the measurement data s and the asymmetric encryption key _k0 , adds the obtained authenticator _w0 to the measurement data s, and wirelessly transmits it as communication data C. do. Each time the relay means 33a, b...g relay the communication data C, the relay means 33a, b...g use the asymmetric encryption key k _i stored in the key storage means 36a, b...g of the relay means 33a, b...g. _wn is encrypted and rewritten, and the rewritten authenticator _wN and measurement data s are wirelessly transmitted to the access point 12 as communication data C. Since the authenticators w _n and w _N are rewritten by encryption, the data amount of the communication data C is constant regardless of the number of relays, and furthermore, the asymmetric encryption keys k _i of the relay means 33a, b...g can be included. Since the asymmetric encryption key k _i cannot be used for decryption, the communication data C will not be decrypted even if the asymmetric encryption key k _i is leaked.

The verification means 34 connected to the access point 12 uses the wirelessly transmitted rewritten authenticator _wN to determine the respective asymmetric encryption keys k ₀ , which are shared in advance with the wireless device 31 and the relay means 33a, b...g. Since the relay route by the relay means 33a, b...g is shared with the wireless device 31 in advance using the asymmetric encryption key paired with k _i , the authenticators w _n , w _N are used in the reverse order of the relay route. is decrypted to obtain the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 and the decrypted measurement data ss. This decrypted measurement data ss is compared with the wirelessly transmitted measurement data s, and the decrypted asymmetric encryption key k ₀₀ of the wireless device 31 is the asymmetric encryption key k ₀ of the wireless device 31 shared in advance, or this The asymmetric encryption key k ₀ is compared with the asymmetric encryption key of the wireless device 31 paired with it.

If the above-mentioned verification matches, the verification means 34 determines that the measurement data s has been transmitted from the wireless device 31 that shares the asymmetric encryption key _k0 and is sound without being tampered with, and that the relay means 33a, b...g Since the relay route is as set, high reliability can be confirmed. Furthermore, if the verification results do not match, the verification means 34 can determine that a security event has occurred, such as that the measurement data s is not sound. Thereby, the occurrence of a security event can be identified without causing a deterioration in quality such as communication speed by keeping the amount of communication data s constant.

[D] Fourth embodiment (Fig. 4)
FIG. 4 is a block diagram showing a wireless transmission system according to a fourth embodiment. In the fourth embodiment, the same parts as in the first embodiment are given the same reference numerals as in the first embodiment to simplify or omit the explanation.

The wireless transmission system 40 shown in FIG. 4 includes a wireless device 41 that wirelessly transmits communication data D, and a plurality of relay means 43a, b, c, and d that relay the communication data D by setting a plurality of transmission paths for the communication data D. , r, f, and g, an access point 12, and a verification means 44 that acquires communication data D from the access point 12 and performs verification regarding the wireless device 41 and the communication data D. .

The wireless device 41 uses the symmetric encryption key p ₀ of the wireless device 41 and the measurement data s included in the communication data D to generate the authentication code u ₀ using the cryptographic processing means 45, as shown in equation (8) below. This symmetric encryption key p ₀ is added to the measurement data s and wirelessly transmitted as communication data D. That is, the cryptographic processing means 45 performs cryptographic processing on the measurement data s and the symmetric cryptographic key p ₀ shared with the collation means 44, and generates the authenticator u ₀ shown in equation (8). Various symmetric encryption methods such as AES (Advanced Encryption Standard) and 3DES (3Data Encryption Standard) are applied to the encryption method Em.

Each of the relay means 43a, b...g has a symmetric encryption key q _i ^j (i=a, b, c, d, r, f, g, j: time or number of relays). The key generation means 46a, b, c, d, r, f, and g are provided to generate and store the symmetric encryption keys q _i ^j of each relay means 43a, b... The authenticator u _n (n: integer) is encrypted and obtained using the authenticator u n -1, and the authenticator u _n-1 is rewritten to the authenticator u _n .

In other words, the key generation means 46a, b...g generate a symmetric encryption key q _i ^j (i= a, b...g, j: time or number of relays) are newly generated and stored. This symmetric encryption key q _i ^j is shared with the verification means 44 . The key generation means 46a, b...g are composed of pseudo-random number generators, and by making the initial values of the pseudo-random numbers individual, the key generation means 46a, b...g can have different symmetric encryption keys, and , it is also possible to use a common symmetric encryption key for the key generation means 46a, b...g by making the initial value common.

The relay means 43a, b...g perform encryption as shown in equation (9) using the encryption method Em when relaying the authentication codes u ₀ and u _n-1 transmitted from the wireless device 41 or the previous stage. , obtains the authenticator u _n , and rewrites the authenticator u _n-1 to the authenticator u _n . Here, the relay routes by the relay means a, b, . . . g are shared with the verification means 44 in advance.

The collation means 44 first extracts the authenticator u _N that has been rewritten N times and the measurement data s from the communication data D acquired by the access point 12 . Next, the verification means 44 uses each symmetric encryption key p ₀ shared with the wireless device 41 and the relay means 43a, b...g,
By repeating the decoding of the authenticators u _N , u _n , and u ₀ using q _i ^j , the decrypted measurement data ss and the decrypted symmetric encryption key p ₀₀ of the wireless device 41 are obtained.

Next, the collation means 44 collates the decrypted measurement data ss and the extracted measurement data s, and further verifies the decrypted symmetric encryption key p ₀₀ of the wireless device 41 and the symmetric encryption key p ₀ of the wireless device 41. By comparing the data, the wireless device 41 is authenticated and the measurement data 1 is verified to be sound.

In other words, the verification means 44 authenticates the wireless device 41 and confirms the soundness of the measurement data s based on the measurement data s of the wireless device 41 transmitted from the access point 12 and the transmitted authenticator _uN after rewriting. . In the verification means 44, the relay route by the relay means 43a, b...g is shared with the wireless device 41 in advance. Further, the collation means 44 shares the symmetric encryption key p ₀ of the wireless device 41 with the wireless device 41, and transmits the symmetric encryption keys q _i ^j generated by the key generation means 46 a, b...g to the relay means 43a, b...g. is shared with. Therefore, the collation means 44 sequentially decrypts the authenticators u _N and u _n in the reverse order of the relay route by the relay means 43a, b...g using the symmetric encryption key q _i ^j determined by time or the number of times of use (relay). do. Finally, the authenticator u ₀ is decrypted to obtain the decrypted measurement data ss and the decrypted symmetric encryption key p ₀₀ of the wireless device 41 . Then, the collation means 44 collates the measurement data s and the decrypted measurement data ss, and further collates the symmetric encryption key p ₀ of the wireless device 41 and the decrypted symmetric encryption key p ₀₀ of the wireless device 41. .

Next, the effect will be explained.
The wireless device 41 calculates the authenticator u ₀ from equation (8) by combining the measurement data s with the symmetric encryption key p ₀ of the wireless device 41 . This wireless device 41 adds an authentication code u ₀ to the measurement data s to generate communication data D, and wirelessly transmits this communication data D from the wireless device 41 to the relay means 43a.

The relay means 43a receives the communication data D, uses the symmetric encryption key q _a ^j in the key generation means 46a to obtain the authenticator u ₁ from equation (9), and converts the authenticator u ₀ into the authenticator u _1. rewrite. Further, the relay means 43a selects the next transmission route and wirelessly transmits the communication data D including the rewritten authenticator _u1 to one of the relay means 43b, c, and d. The symmetric encryption key q _i ^j is generated based on time or the number of times communication data is relayed, but the symmetric encryption key q _i ^j can also be changed for each relay means.

In any of the transmitted relay means 43b, c, or d, the authentication code _u2 is similarly obtained using equation (9), and the authentication code _u1 is rewritten to the authentication code _u2 . Similarly, the subsequent relay means repeats equation (9) every time it is relayed and rewrites it to the authenticator u _n , and transfers the communication data D relayed N times (measured data s and the rewritten authentication code rewritten N times). including the child _uN ) to the verification means 44 via the access point 12.

The collation means 44 obtains the measurement data s and the rewritten authenticator _uN each time the communication data D is received. The collation means 44 shares the relay route by the relay means 43a, b...g with the wireless device 41 in advance, and also shares the symmetric encryption key _p0 of the wireless device 41 with the wireless device 41, and furthermore, the key generation means 46a, The symmetric encryption keys q _i ^j generated by b...g are shared with the relay means 43a, b...g. Therefore, the collation means 44 specifies the symmetric encryption key q _i ^j from time or the number of relays, sequentially decrypts the authenticators u _N and u _n , and then decrypts the authenticator u ₀ to obtain the decrypted measurement information. The data ss and the decrypted asymmetric encryption key p ₀₀ of the wireless device 41 are obtained. Then, the collation means 44 collates the measurement data s and the decrypted measurement data ss, and collates the asymmetric encryption key p ₀ of the wireless device 41 with the decrypted asymmetric encryption key p ₀₀ of the wireless device 41 .

If s=ss and p ₀ = p ₀₀ , the verification means 44 determines that the measurement data s has been transmitted from the designated wireless device 41 and that the measurement data s has not been tampered with and is sound, and the relay means 43a, b...g It is determined that there is no error in the relay route. On the other hand, if s≠ss or p ₀ ≠ p ₀₀ , the verification means 44 determines that some or all of the measurement data s, the symmetric encryption key p ₀ and the symmetric encryption key q _i ^j are abnormal, and the measurement data is falsified or measured. It is determined that a security event such as falsification of data s or an abnormality in the relay route has occurred.

As configured as above, the fourth embodiment provides the following effects (7) and (8).
(7) The wireless device 41 includes a cryptographic processing means 45 that obtains an authenticator _u0 from the measurement data s and the symmetric encryption key _p0 , adds the obtained authenticator _u0 to the measurement data s, and wirelessly transmits it as communication data D. do. Each time the relay means 43a, b...g relay communication data D, the relay means 43a, b...g generate an authenticator using the symmetric encryption keys q _i ^j generated by the key generation means 46a, b...g of the relay means 43a, b...g. It encrypts and rewrites the authentication code _uN and measurement data s as communication data D, and wirelessly transmits the rewritten authentication code _uN and measurement data s to the access point 12. Since the authenticator _un is rewritten by encryption, the amount of communication data D is constant regardless of the number of relays, and the symmetric encryption keys q _i ^j of the relay means 43a, b...g can be included. can.

The verification means 44 connected to the access point 12 uses each symmetric encryption key p ₀ , which is shared in advance with the wireless device 41 and the relay means 43a, b...g, for the wirelessly transmitted authenticator U _N after rewriting. Since the relay route by the relay means 43a, b...g is shared with the wireless device 41 in advance using q _i ^j , the authenticators u _N and u _n are decrypted in the reverse order of the relay route. The decrypted symmetric encryption key p ₀₀ of the wireless device 41 and the decrypted measurement data ss are obtained. The decrypted measurement data ss is compared with the wirelessly transmitted measurement data s, and the decrypted symmetric encryption key p ₀₀ is compared with the symmetric encryption key p ₀ shared in advance.

If the above-mentioned verification matches, the verification means 44 determines that the measurement data s has been transmitted from the wireless device 41 that shares the symmetric encryption key _p0 and is sound without being tampered with, and that the measurement data s has been transmitted by the relay means 43a, b...g. Since the relay route is as set, high reliability can be confirmed. Further, if the above-mentioned verification results do not match, the verification means 44 can determine that a security event such as the measurement data s is not sound has occurred. Thereby, the occurrence of a security event can be identified without reducing the quality of communication speed or the like by keeping the amount of communication data D constant.

(8) Each time the communication data D transmitted from the wireless device 41 is relayed by each of the relay means 43a, b...g, the key generation means 46a, b of each relay means 43a, b...g The authenticator U _N is encrypted using the symmetric encryption key q _i ^j generated in g, the authenticator is rewritten, and the rewritten authenticator U _N is wirelessly transmitted to the access point 12 . Since the authentication code _un is rewritten, the amount of communication data D remains constant regardless of the number of relays, and in addition to having a small capacity, it is shared in advance with the relay means 43a, b...g, and is It is possible to include secret information x that changes depending on the number of (relays). As a result, even if the symmetric encryption key q _i ^j is leaked, the change will not affect anything other than the target symmetric encryption key q _i ^j .

The verification means 44 connected to the access point 12 uses each symmetric encryption key p ₀ shared in advance with each of the wireless device 41 and the relay means 43a, b...g for the wirelessly transmitted authenticator _uN after rewriting. , q _i ^j , the relay route is shared with the wireless device 41 in advance, and the time and the number of times of use (relay) are also shared with the wireless device 41. Therefore, the authenticators u _N and u _n are decrypted. The symmetric encryption key p ₀₀ of the wireless device 41 and the decrypted measurement data ss are obtained. The measurement data ss is compared with the wirelessly transmitted measurement data s, and the decrypted symmetric encryption key p ₀₀ of the wireless device 41 is compared with the symmetric encryption key p ₀ of the wireless device 41 that is shared in advance.

If the above-mentioned verification matches, the verification means 44 determines that the measurement data s has been transmitted from the wireless device 41 that shares the symmetric encryption key _p0 and is sound without being tampered with, and that the relay means 43a, b...g Since the relay route and time or number of times of use (relay) are as set, high reliability can be confirmed. Further, if the above-mentioned verification results do not match, the verification means 44 can determine that a security event such as the measurement data s being unsound has occurred. Thereby, the occurrence of a security event can be identified without reducing the quality of communication speed or the like by keeping the amount of communication data D constant.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention, and those substitutions and changes can be made. are included within the scope and gist of the invention, and are included within the scope of the invention described in the claims and its equivalents.

For example, in the wireless transmission system 20 of the second embodiment, the secret information x of the wireless device 21 is the communication setting information C of the wireless device 21, and the secret information r _i (i=a, b... g) may be configured to include communication setting information rc _i (i=a, b...g) of the relay means 23a, b...g, respectively.

Further, in the first to fourth embodiments, the secret information x of the wireless devices 11, 21, the asymmetric encryption key k ₀ of the wireless device 31, and the symmetric encryption key p ₀ of the wireless device 41 are stored in one wireless device 11, 21, A plurality of 31 and 41 may be provided. Similarly, the secret information r _i of the relay means 23a, b...g, the asymmetric encryption key k _i of the relay means 33a, b...g, and the symmetric encryption key q _i ^j of the relay means 43a, b...g are each transmitted by one relay. A plurality of devices may be provided in the means.

Furthermore, in the first to fourth embodiments, the secret information x of the wireless devices 11 and 21, the asymmetric encryption key k ₀ of the wireless device 31, and the symmetric encryption key p ₀ of the wireless device 41 change with time or the number of times of use. Similarly, the secret information r _i of the relay means 23a, b...g, the asymmetric encryption key k _i of the relay means 33a, b...g, and the symmetric encryption key q _i ^j of the relay means 43a, b...g may be configured to change with time or number of uses.

10...Wireless transmission system, 11...Wireless device, 12...Access point, 13a, b...g...Relay means, 14...Inspection means, 20...Wireless transmission system, 21...Wireless device, 23a, b...g...Relay means, 24... Inspection means, 25... Connection number counting means, 26a, b... g... Storage means, 30... Wireless transmission system, 31... Wireless device, 33a, b... g... Relay means, 34... Verification means, 35... Encryption processing Means, 36a, b...g...Key storage means, 40...Wireless transmission system, 41...Wireless device, 43a, b...g...Relay means, 44...Verification means, 45...Encryption processing means, 46a, b...g...Key Generation means, A, B, C, D...Communication data, s...Measurement data, x...Secret information, _y0 , _yn ...Authenticator, _yN ...Authenticator after rewriting, _yNN ...Verification value, c... Communication setting information, ri _... confidential information, co...number of connections, rc _i ...communication setting information, _z0 , _z1 , _zn ...authenticator, _zN ,...authenticator after rewriting, _zNN ...verification value, _k0 , _ki ...Asymmetric encryption key, _w0 , _wn ...Authenticator, _wN ...Authenticator after rewriting, ss...Decrypted measurement data, _k00 ...Decrypted asymmetric encryption key of the wireless device, p ₀ , q _i ^j ... Symmetric encryption key, u ₀ , u _n ... Authenticator, u _N ... Authenticator after rewriting, p ₀₀ Decrypted symmetric encryption key of the wireless device

Claims (13)

a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission system comprising: an inspection unit connected to an access point to acquire the communication data from the wireless device and perform an inspection regarding the wireless device and the communication data,
The wireless device uses the secret information and the measurement data to obtain an authentication code, adds the authentication code to the measurement data, and wirelessly transmits the measurement data as the communication data,
The relay means newly calculates and rewrites the authenticator when relaying the communication data,
The inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and extracts the rewritten authenticator from the communication data acquired by the access point, and uses the secret information shared with the wireless device and the number of relay means relayed. A wireless transmission system characterized in that the wireless transmission system is configured to authenticate the wireless device and confirm the soundness of the measurement data by determining a verification value of and comparing the rewritten authenticator with the verification value. . 2. The wireless transmission system according to claim 1, wherein a plurality of said relay means are arranged so that a plurality of communication data transmission paths are set between a wireless device and an access point. a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission system comprising: an inspection unit connected to an access point to acquire the communication data from the wireless device and perform an inspection regarding the wireless device and the communication data,
The wireless device uses the secret information and the measurement data to obtain an authentication code, adds the authentication code to the measurement data, and wirelessly transmits the measurement data as the communication data,
The relay means includes a storage means for storing secret information of the relay means, and when relaying the communication data, calculates and rewrites a new authenticator to which the secret information of the relay means is added,
The inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and checks the secret information shared with each of the wireless device and the relay means and the relayed route of the relay means. is configured to authenticate the wireless device and confirm the soundness of the measurement data by determining the verification value of the rewritten authenticator using the rewritten authentication code, and comparing the rewritten authenticator with the verification value. A wireless transmission system characterized by: The relay means connected to the wireless device includes connection number measuring means for measuring the number of connections of the wireless device to the relay means, and adds information on the number of connections of the wireless device when relaying the communication data. Calculate and rewrite the authenticator that was created,
The inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and uses the secret information shared with each of the wireless device and the relay means and the number of connections of the wireless device. The wireless device is configured to authenticate the wireless device and confirm the soundness of the measurement data by obtaining a verification value of the rewritten authenticator and comparing the rewritten authenticator with the verification value. The wireless transmission system according to claim 3, characterized in that: a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission system comprising: a verification unit connected to an access point to acquire the communication data from the wireless device and perform verification regarding the wireless device and the communication data,
The wireless device includes a cryptographic processing means for obtaining an authenticator using the asymmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data,
The relay means includes a key storage means for storing an asymmetric encryption key of the relay means, and when relaying the communication data, encrypts and rewrites the authentication code using the asymmetric encryption key of the relay means,
The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the asymmetric encryption key that is paired with each of the asymmetric encryption keys shared with the wireless device and the relay means. By repeating decryption of the authenticator using the encryption key, the decrypted measurement data and the decrypted asymmetric encryption key of the wireless device are obtained, and the decrypted measurement data and the extracted measurement data are verified. and further configured to authenticate the wireless device and confirm the soundness of the measurement data by comparing the decrypted asymmetric encryption key of the wireless device with the asymmetric encryption key of the wireless device. wireless transmission system. a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission system comprising: a verification unit connected to an access point to acquire the communication data from the wireless device and perform verification regarding the wireless device and the communication data,
The wireless device includes a cryptographic processing means for obtaining an authenticator using the symmetric encryption key of the wireless device and the measurement data, and adds the authentication code to the measurement data and wirelessly transmits it as the communication data,
The relay means includes a key generation means for generating and storing a symmetric encryption key of the relay means, and encrypts the authenticator using the symmetric encryption key of the relay means when relaying the communication data. rewrite,
The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and performs the authentication using the respective symmetric encryption keys shared with the wireless device and the relay means. By repeating the decryption of the child, the decrypted measurement data and the decrypted symmetric encryption key of the wireless device are obtained, the decrypted measurement data and the extracted measurement data are compared, and the decrypted measurement data is A wireless transmission system characterized in that the system is configured to authenticate the wireless device and confirm the soundness of the measurement data by comparing a symmetric encryption key of the wireless device with a symmetric encryption key of the wireless device. 5. The secret information of each of the wireless device and the relay means is configured to include communication setting information of each of the wireless device and the relay means, according to any one of claims 1 to 4. wireless transmission system. The wireless device and the relay means each have a plurality of secret information, an asymmetric encryption key, or a symmetric encryption key, respectively, in one wireless device or in one relay means. A wireless transmission system according to any one of claims 1 to 7. 9. The secret information, asymmetric encryption key, and symmetric encryption key of each of the wireless device and the relay means are configured to change with time or the number of times of use. wireless transmission system. a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission method comprising: an inspection unit connected to an access point to acquire the communication data from the wireless device and perform an inspection regarding the wireless device and the communication data,
In the wireless device, the step of obtaining an authentication code using secret information and the measurement data, adding the authentication code to the measurement data, and wirelessly transmitting it as the communication data,
In the relay means, the step of newly calculating and rewriting the authenticator when relaying the communication data,
The inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and extracts the rewritten authenticator from the communication data acquired by the access point, and uses the secret information shared with the wireless device and the number of relay means relayed to the rewritten authenticator. The wireless device is characterized in that the steps of authenticating the wireless device and confirming the soundness of the measurement data are performed by determining a verification value of the wireless device and comparing the rewritten authenticator with the verification value. Transmission method. a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission method comprising: an inspection unit connected to an access point to acquire the communication data from the wireless device and perform an inspection regarding the wireless device and the communication data,
In the wireless device, the step of obtaining an authentication code using secret information and the measurement data, adding the authentication code to the measurement data, and wirelessly transmitting it as the communication data,
The relay means includes a storage means for storing secret information of the relay means, and when relaying the communication data, the step of calculating and rewriting a new authenticator to which the secret information of the relay means is added,
The inspection means extracts the rewritten authenticator from the communication data acquired by the access point, and checks the secret information shared with each of the wireless device and the relay means and the route of the relay means that relayed the information. the step of authenticating the wireless device and confirming the soundness of the measurement data by determining a verification value of the rewritten authenticator using the rewritten authentication code and comparing the rewritten authenticator with the verification value, A wireless transmission method characterized by carrying out. a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission method comprising: a verification unit connected to an access point to acquire the communication data from the wireless device and perform verification regarding the wireless device and the communication data,
The wireless device includes a cryptographic processing means for obtaining an authentication code using the asymmetric encryption key of the wireless device and the measurement data, and the step of adding the authentication code to the measurement data and wirelessly transmitting it as the communication data,
The relay means includes a key storage means for storing an asymmetric encryption key of the relay means, and the step of encrypting and rewriting the authenticator using the asymmetric encryption key of the relay means when relaying the communication data. ,
The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and extracts the rewritten authentication code and the measurement data, and extracts the asymmetric encryption key that is paired with each of the asymmetric encryption keys shared with the wireless device and the relay means. By repeating decryption of the authenticator using the encryption key, the decrypted measurement data and the decrypted asymmetric encryption key of the wireless device are obtained, and the decrypted measurement data and the extracted measurement data are verified. and further performing the steps of authenticating the wireless device and confirming the soundness of the measurement data by comparing the decrypted asymmetric encryption key of the wireless device with the asymmetric encryption key of the wireless device. A wireless transmission method characterized by: a wireless device that wirelessly transmits communication data including measurement data; a relay means that relays the communication data wirelessly transmitted from the wireless device; an access point that receives the communication data relayed by the relay means; A wireless transmission method comprising: a verification unit connected to an access point to acquire the communication data from the wireless device and perform verification regarding the wireless device and the communication data,
The wireless device includes a cryptographic processing means for obtaining an authenticator using the symmetric encryption key of the wireless device and the measurement data, and the step of adding the authentication code to the measurement data and wirelessly transmitting it as the communication data,
The relay means includes a key generation means for generating and storing a symmetric encryption key of the relay means, and encrypts the authenticator using the symmetric encryption key of the relay means when relaying the communication data. Steps to rewrite
The verification means extracts the rewritten authenticator and the measurement data from the communication data acquired by the access point, and performs the authentication using the respective symmetric encryption keys shared with the wireless device and the relay means. By repeating the decryption of the child, the decrypted measurement data and the decrypted symmetric encryption key of the wireless device are obtained, the decrypted measurement data and the extracted measurement data are compared, and the decrypted measurement data is A wireless transmission method characterized by performing the steps of authenticating the wireless device and confirming the soundness of the measurement data by comparing a symmetric encryption key of the wireless device with a symmetric encryption key of the wireless device. .

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