JP2018042081A - Data transmitting/receiving method and sensing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform secure data communication even when a transmission-side device operates in one-way communication.SOLUTION: A transmission-side sensor terminal 10 transmits to a reception side an authentication message Ma which contains signature information Ds generated by encrypting a hash value Hd of data D to be transmitted with a transmission-side secret key Kss, encryption information Dc generated by encrypting the data D with a transmission-side encryption key Ksc, and key information Dk generated by encrypting the transmission-side encryption key Ksc with a reception-side public key Krp. A reception-side processing unit 20 acquires the transmission-side encryption key Ksc by decrypting the key information Dk in the received authentication message Ma with a reception-side secret key Krs, acquires the data D by decrypting the encryption information Dc in the authentication message Ma with the transmission-side encryption key Ksc, and acquires the hash value Hd by decrypting the signature information Ds in the authentication message Ma with a transmission-side public key Ksp, and compares the hash value Hd with a hash value Hd' calculated from the data D so as to authenticate and determine the transmission side and reception side authenticity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a data transmission / reception technique for encrypting and transmitting various types of data from a transmission-side device connected via a communication network to a reception-side device.

A sensing system is a system that collects data from sensors installed in remote locations in a processing device such as a server using a communication network. Recently, it has also been used for health care and monitoring using human biological information. Consideration is progressing.
In such a system, in order to ensure security, it is necessary to confirm that the sensor terminal and the processing device that access the network are valid, or to conceal the sensor value depending on the application. For example, in personal computers and smartphones, mutual authentication using electronic certificates and encrypted communication using private key encryption are performed (see, for example, Non-Patent Document 1).

"Basics of Network Learning by Illustration: SSL", Nikkei NETWORK, June 2007, page 78

  In such a conventional encrypted communication technique, it is necessary to perform authentication processing by performing bidirectional communication based on a predetermined sequence between the transmission side device and the reception side device. However, the sensor terminal of the sensing system is actually a sensor terminal that supports only one-way communication, or actually reduces power consumption even if it supports two-way communication due to restrictions on the communication method and terminal control. For this reason, a sensor terminal or the like that is operated by one-way communication may be used. Therefore, such a sensing system has a problem that the conventional encrypted communication technology cannot be applied.

  An object of the present invention is to provide a data transmission / reception technique capable of performing secure data communication even when a transmission side device operates in one-way communication.

  In order to achieve such an object, a data transmission / reception method according to the present invention is a data used when various data is encrypted and transmitted from a transmission-side device connected via a communication network to a reception-side device. A transmission / reception method in which a transmission side device calculates a hash value of data and encrypts the data with a transmission side secret key by encrypting the data with a transmission side encryption key Encryption information generation step for generating encryption information, key information generation step for generating key information by encrypting the transmission-side encryption key with the reception-side public key, signature information, encryption information, and key information as 1 A transmission step of storing the message in one message and transmitting the message to the reception side device, wherein the reception side device receives the message from the transmission side device; The key information decrypting step for obtaining the transmitting side encryption key by decrypting the key information to be received with the receiving side private key, and obtaining the data by decrypting the encryption information included in the message with the transmitting side encryption key. An encryption information decryption step, a signature information decryption step of obtaining a hash value by decrypting the signature information included in the message with the transmission side public key, and calculating a hash value of the data obtained by decryption, And an authentication determination step for authenticating the authenticity of the transmission side device and the reception side device by comparing with the hash value obtained by decryption.

  Also, in one configuration example of the data transmission / reception method according to the present invention, when the transmission step sequentially transmits data to the receiving side device, usually only the cryptographic information related to the data generated in the cryptographic information generation step is received. Sends to the side device, generates and sends a message about the data at a predetermined transmission frequency or transmission time interval, and when only the encryption information is received from the sending side device, the encryption information decryption step is acquired by the message so far The encrypted information is decrypted with the transmitted encryption key.

  Also, in one configuration example of the data transmission / reception method according to the present invention, the transmission step changes a transmission frequency or a transmission time interval for transmitting a message in accordance with communication traffic between the transmission side device and the reception side device. It is what I did.

  Also, one configuration example of the data transmission / reception method according to the present invention is such that the encryption information generation step changes the transmission side encryption key at an arbitrary frequency when the data is encrypted with the transmission side encryption key. is there.

  Also, one configuration example of the data transmission / reception method according to the present invention is that, when the encryption information generation step encrypts data with the transmission side encryption key, the transmission side encryption is performed according to the transmission frequency of the data transmitted from the transmission side device. The change frequency of the key is changed.

  The sensing system according to the present invention is a sensing system that encrypts and transmits various types of data from a sensor terminal connected via a communication network to a processing device, and is based on any one of the data transmission / reception methods described above. Thus, data is transmitted from the sensor terminal to the processing device.

  Another sensing system according to the present invention is a sensing system that encrypts and transmits various types of data from a sensor terminal connected via a communication network to a processing device, and transmits data transmitted from the sensor terminal. A relay device that relays and transfers to the processing device is provided, and data is transmitted from the relay device to the processing device based on any of the data transmission / reception methods described above.

  In another configuration example of the sensing system according to the present invention, the sensor terminal divides and generates any one or a plurality of pieces of information among signature information, encryption information, and key information. When transmitting a message, among the signature information, encryption information, and key information, the information generated by the sensor terminal and the remaining information generated by itself are stored in one message and transmitted to the processing device. It is a thing.

  According to the present invention, the data to be transmitted is encrypted by the public key encryption method on the transmission side, the hash value of the data is encrypted by the common key encryption method on the transmission side, and further the common key encryption method on the transmission side. The transmission side encryption key (common key) to be used is encrypted by the reception side public key encryption method, and these are transferred from the transmission side to the reception side by one message. For this reason, by decoding this message on the receiving side, it is possible to authenticate and determine the authenticity of the transmitting side and the receiving side, and it is possible to ensure confidentiality regarding data.

  Therefore, even if the sending side only supports one-way communication, or actually supports two-way communication, due to limitations in the communication method and terminal control, such as sensor terminals of sensing systems, it is actually consumed. Secure data communication can be performed even when operating in one-way communication to reduce power consumption. As a result, the processing load and circuit configuration on the transmission side can be reduced, and the cost of the entire system can be greatly reduced.

It is a block diagram which shows the structure of the sensing system concerning 1st Embodiment. It is explanatory drawing which shows the encryption process concerning 1st Embodiment. It is a sequence diagram which shows the data transfer process concerning 1st Embodiment. It is a flowchart which shows the transmission side process of the sensor terminal concerning 1st Embodiment. It is a flowchart which shows the receiving side process of the processing apparatus concerning 1st Embodiment. It is a sequence diagram which shows the data transfer process concerning 2nd Embodiment. It is a block diagram which shows the structure of the sensing system concerning 3rd Embodiment. It is explanatory drawing which shows the encryption process concerning 3rd Embodiment. It is a sequence diagram which shows the data transfer process concerning 3rd Embodiment. It is a block diagram which shows the structure of the sensing system concerning 4th Embodiment. It is explanatory drawing which shows the encryption process concerning 4th Embodiment. It is a sequence diagram which shows the data transfer process concerning 4th Embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a sensing system 1 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a sensing system according to the first embodiment.

  In the sensing system 1, a plurality of sensor terminals 10 are connected to a processing device 20 via a communication network NW, and sensor values detected by the sensor terminals 10 are collected by the processing device 20 via the communication network NW. System.

  When the sensor terminal 10 transmits data such as a sensor value detected by the sensor to the processing device 20 via the communication network NW, the sensor terminal 10 performs an encryption process based on the data to be transmitted and various preset encryption keys. Thus, it has a function of generating various kinds of authentication information for authenticating and concealing data of the sensor terminal 10 and the processing device 20, and storing them in one message.

  The processing device 20 is composed of an information processing device such as a server device as a whole, acquires each authentication information from the message from the sensor terminal 10 received via the communication network NW, and uses various encryption keys set in advance. By performing the decryption processing based on this, it has a function of authenticating the sensor terminal 10 and the processing device 20 and decrypting the concealed original data.

  In the present embodiment, a case will be described as an example where the sensor terminal 10 is a transmission-side device, the processing device 20 is a reception-side device, and the sensor terminal 10 has only a message transmission function. However, the sensor terminal 10 may have a message reception function.

  In FIG. 1, the configuration in which the sensor terminal 10 and the processing device 20 directly perform data communication via the communication network NW is described as an example. However, the configuration is not limited thereto. 10 and the communication network NW may be provided with relay devices so that messages from a plurality of sensor terminals 10 may be aggregated and transferred to the processing device 20.

  FIG. 2 is an explanatory diagram of encryption processing according to the first embodiment. In the present embodiment, a transmission side public encryption key composed of a pair of a transmission side private key Kss and a transmission side public key Ksp is set in advance in the sensor terminal 10 on the transmission side. In addition, a receiving side public encryption key composed of a pair of a receiving side secret key Krs and a receiving side public key Krp is set in advance in the processing device 20 on the receiving side. The transmission side public encryption key and the reception side public encryption key are composed of general public encryption keys.

In the present embodiment, the transmission side public key Ksp of the sensor terminal 10 is set in the processing device 20 in advance, and the reception side public key Krp of the processing device 20 is set in the sensor terminal 10 in advance. . As a cryptographic algorithm, a general method such as RSA or ElGamal may be used.
The sensor terminal 10 is preset with a transmission side encryption key Ksc consisting of a common encryption key, and is updated at a predetermined timing.
The storage and encryption processing of these keys are safely performed in tamper-resistant hardware installed in the sensor terminal 10 or the processing device 20.

As shown in FIG. 2, in the sensor terminal 10, the transmission side secret key Kss, the transmission side encryption key Ksc, and the reception side public key Krp are used to encrypt the hash value Hd, the data D, and the transmission side encryption key Ksc, respectively. Used.
In the processing device 20, the reception side secret key Krs, the transmission side encryption key Ksc, and the transmission side public key Ksp are used to decrypt the transmission side encryption key Ksc, the data D, and the hash value Hd, respectively.

[Sensor terminal]
Next, with reference to FIG. 1, the structure of the sensor terminal 10 concerning this Embodiment is demonstrated in detail.
The sensor terminal 10 includes a sensor 11, a signature information generation unit 12, an encryption information generation unit 13, a key information generation unit 14, and a transmission unit 15 as main functional units.

The sensor 11 has a function of detecting and outputting a sensor value from a target.
The signature information generation unit 12 calculates the hash value Hd for the data D such as the sensor value detected by the sensor 11 and encrypts the obtained hash value Hd with the transmission side secret key Kss to thereby obtain the signature information Ds. It has a function to generate.

The encryption information generation unit 13 has a function of generating the encryption information Dc by encrypting the data D with the transmission side encryption key Ksc. At this time, a general method such as AES or Camellia may be used as the encryption algorithm.
The key information generation unit 14 has a function of generating key information Dk by encrypting the transmission side encryption key Ksc with the reception side public key Krp.
The transmission unit 15 has a function of storing authentication information including the signature information Ds, the encryption information Dc, and the key information Dk in one authentication message Ma and transmitting the authentication information Ma to the processing device 20 via the communication network NW. .

[Processing equipment]
Next, the configuration of the processing apparatus 20 according to the present embodiment will be described in detail with reference to FIG.
The processing device 20 includes a reception unit 21, a key information decryption unit 22, an encryption information decryption unit 23, a signature information decryption unit 24, and an authentication determination unit 25 as main functional units.

  The receiving unit 21 has a function of receiving the authentication message Ma transmitted from the sensor terminal 10 and acquiring authentication information including the stored signature information Ds, encryption information Dc, and key information Dk. .

The key information decryption unit 22 has a function of acquiring the transmission side encryption key Ksc by decrypting the key information Dk included in the authentication message Ma with the reception side secret key Krs.
The encryption information decryption unit 23 has a function of acquiring the data D by decrypting the encryption information Dc included in the authentication message Ma with the transmission side encryption key Ksc obtained by the key information decryption unit 22. Yes.

The signature information decryption unit 24 has a function of acquiring the hash value Hd by decrypting the signature information Ds included in the authentication message Ma with the transmission side public key Ksp.
The authentication determination unit 25 has a function of calculating the hash value Hd ′ of the data D obtained by decryption by the encryption information decryption unit 23 and a hash value Hd obtained by decryption by the signature information decryption unit 24 By comparing with the value Hd ′, it has a function of authenticating and determining the authenticity of the sensor terminal 10 and the processing device 20.

[Operation of First Embodiment]
Next, the data transfer operation of the sensing system 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a sequence diagram illustrating data transfer processing according to the first embodiment.
As shown in FIG. 3, the sensing system 1 intermittently performs an authentication message transfer process (steps) according to a preset transfer timing in a data transfer process for transferring data D from the sensor terminal 10 to the processing device 20. 100).

  First, the sensor terminal 10 performs authentication processing based on new data D to be transmitted and various encryption keys set in advance, thereby obtaining authentication information composed of signature information Ds, encryption information Dc, and key information Dk. The authentication message Ma is generated (step 101), and the authentication message Ma in which the authentication information Ds, Dc, Dk is stored is transmitted to the processing device 20 (step 102).

  The processing device 20 receives the authentication message Ma from the sensor terminal 10, and decrypts the authentication information Ds, Dc, Dk acquired from the authentication message Ma based on various preset encryption keys (step 103). In response to the successful authentication of the authenticity relating to the sensor terminal 10 and the processing device 20, the obtained data D is output, and the series of authentication message transfer processing (step 100) is terminated.

[Operation of sensor terminal]
Next, with reference to FIG. 4, the transmission side operation in the sensor terminal 10 in the data transfer operation will be described. FIG. 4 is a flowchart illustrating a transmission side process of the sensor terminal according to the first embodiment.
The sensor terminal 10 executes the transmission side process of FIG. 4 in the data transfer operation.

First, the signature information generation unit 12 calculates a hash value Hd for new data D such as a sensor value detected by the sensor 11 (step 110), and encrypts the obtained hash value Hd with the transmission side secret key Kss. Thus, signature information Ds is generated (step 111).
Also, the encryption information generation unit 13 generates encryption information Dc by encrypting the data D with the transmission side encryption key Ksc (step 112), and the key information generation unit 14 discloses the transmission side encryption key Ksc to the reception side disclosure. The key information Dk is generated by encrypting with the key Krp (step 113).

  Thereafter, the transmission unit 15 stores the authentication information including the signature information Ds, the encryption information Dc, and the key information Dk in one authentication message Ma (step 114), and then transmits the authentication information to the processing device 20 via the communication network NW. (Step 115), and a series of authentication message transmission processing ends.

[Processing unit operation]
Next, with reference to FIG. 5, the reception side operation in the processing device 20 in the data transfer operation will be described. FIG. 5 is a flowchart illustrating a reception-side process of the processing device according to the first embodiment.
The processing device 20 executes the reception side process of FIG. 5 in the data transfer operation.

First, the receiving unit 21 acquires authentication information including signature information Ds, encryption information Dc, and key information Dk stored in the received authentication message Ma (step 120).
Next, the key information decryption unit 22 obtains the transmission side encryption key Ksc by decrypting the key information Dk included in the authentication message Ma with the reception side secret key Krs (step 121), and the encryption information decryption unit 23 obtains the original data D by decrypting the encryption information Dc included in the authentication message Ma with the transmission side encryption key Ksc obtained by the key information decryption unit 22 (step 122).

Further, the signature information decryption unit 24 obtains the hash value Hd by decrypting the signature information Ds included in the authentication message Ma with the transmission side public key Ksp (step 123).
Thereafter, the authentication determination unit 25 calculates the hash value Hd ′ of the data D obtained by decryption by the encryption information decryption unit 23 (step 124), and is obtained by decryption by the signature information decryption unit 24. The hash value Hd is compared with the hash value Hd ′ (step 125).

  Here, when the hash value Hd and the hash value Hd ′ match (step 125: YES), the authentication determination unit 25 determines that the authentic authentication of the sensor terminal 10 and the processing device 20 is successful (step 126). Then, the data D obtained by the encryption information decryption unit 23 is output to the subsequent processing (step 127), and the series of authentication message reception processing is terminated. Thereby, the authenticity regarding the sensor terminal 10 and the processing apparatus 20 can be confirmed, and the confidentiality regarding the data D can also be ensured.

  On the other hand, when the hash value Hd and the hash value Hd ′ do not match (step 125: NO), the authentication determination unit 25 determines that the authentication failure of authenticity related to the sensor terminal 10 and the processing device 20 (step 128). ), The data D obtained by the encryption information decryption unit 23 is discarded (step 129), and the series of authentication message reception processing ends. Thereby, the authenticity regarding the sensor terminal 10 and the processing apparatus 20 could not be confirmed.

[Effect of the first embodiment]
As described above, in the present embodiment, in the sensor terminal 10 on the transmission side, the signature information Ds generated by encrypting the hash value Hd of the data D to be transmitted with the transmission side secret key Kss and the data D are transmitted on the transmission side encryption key. The encryption information Dc generated by encrypting with Ksc and the key information Dk generated by encrypting the transmission side encryption key Ksc with the reception side public key Krp are stored in the authentication message Ma and transmitted to the reception side, and the reception side In the processing device 20, the key information Dk of the received authentication message Ma is decrypted with the reception side secret key Krs to obtain the transmission side encryption key Ksc, and the encryption information Dc of the authentication message Ma is decrypted with the transmission side encryption key Ksc. The data D is acquired, the signature information Ds of the authentication message Ma is decrypted with the transmission side public key Ksp to obtain the hash value Hd, and the hash value Hd ′ calculated from the data D is compared. More, it is the authenticity of the sender and receiver that so as to authentication determination.

  As a result, the data D is encrypted by the transmission side public key cryptosystem, and the hash value Hd of the data D is encrypted by the transmission side common key cryptosystem, and further transmitted by the transmission side common key cryptosystem. The side encryption key (common key) is encrypted by the public key cryptosystem on the reception side, and these are transferred from the transmission side to the reception side by one message Ma. For this reason, by decoding this message Ma on the receiving side, it is possible to authenticate and determine the authenticity of the transmitting side and the receiving side, and it is also possible to ensure confidentiality regarding data.

  Therefore, as in the case of the sensor terminal 10 of the sensing system 1, when the transmission side only supports one-way communication or due to restrictions on the communication method or terminal control, or even if it supports two-way communication, Can perform secure data communication even when operating in one-way communication to reduce power consumption. As a result, the processing load and circuit configuration on the transmission side can be reduced, and the cost of the entire system can be greatly reduced.

[Second Embodiment]
Next, the sensing system 1 concerning the 2nd Embodiment of this invention is demonstrated.
In the first embodiment, the case where the authentication message transfer process (step 100) is executed each time the data D is transferred in the data transfer process has been described as an example. Here, when the transfer interval of the data D is short, it may not be necessary to execute the authentication message transfer process every time the data D is transferred. In the present embodiment, a case will be described in which encrypted message transfer processing is performed in which data D is normally encrypted and transferred, and authentication message transfer processing is executed at a constant transmission frequency or transmission time interval.

  In the present embodiment, when the transmission unit 15 of the sensor terminal 10 sequentially transmits data to the processing device 20, the encryption unit normally stores only the encryption information Dc related to the data D generated by the encryption information generation unit 13. It has a function of transmitting to the processing device 20 by the message Md and a function of generating and transmitting an authentication message Ma related to the data D at a predetermined transmission frequency or transmission time interval.

  At this time, as for the transmission of the authentication message Ma, the authentication message Ma may be transmitted at a transmission frequency for the encryption message Md set in advance, for example, once every tens of thousands of encryption messages Md. For example, the authentication message Ma may be transmitted at a transmission time interval such as once every several hours.

Further, the transmission side encryption key Ksc may be updated every time the authentication message Ma is transmitted, or at a constant transmission frequency for the authentication message Ma. Thereby, the security against the decryption of the data D by a malicious third party can be enhanced.
For the authentication message Ma, pseudo dummy data may be used instead of the data D to be collected by the processing device 20. Thereby, even if new data D to be collected does not exist, the authentication message Ma can be transmitted at an arbitrary timing.

  Further, the transmission frequency or transmission time interval for transmitting the authentication message Ma may be changed according to the communication traffic related to the communication path between the sensor terminal 10 and the processing device 20. For example, the transmission frequency (transmission time interval) is reduced / increased according to the increase / decrease of the network traffic such as the communication network NW, the relay device located on the communication path, and further the communication traffic notified from the processing device 20 ( Extension / reduction). Thereby, the network load can be reduced.

  Further, when only the encryption information Dc is received from the sensor terminal 10 by the encryption message Md from the sensor terminal 10, the encryption information decryption unit 23 of the processing device 20 obtains the encryption information Dc by the transmission side encryption key Ksc acquired by the authentication message Ma so far. It has a function of acquiring data D by decoding.

[Operation of Second Embodiment]
Next, the operation of the sensing system 1 according to the present embodiment will be described with reference to FIG. FIG. 6 is a sequence diagram illustrating data transfer processing according to the second embodiment.

As shown in FIG. 3, in the data transfer process for transferring the data D from the sensor terminal 10 to the processing device 20, the sensing system 1 first executes an authentication message transfer process (step 100) to obtain the sensor terminal 10. Notifies the processing device 20 of the transmitting side encryption key Ksc.
Thereafter, the encryption message transfer process (step 200) is repeatedly executed until the processing timing of the authentication message transfer process arrives based on a predetermined transmission frequency or transmission time interval.

  In the encryption message transfer process (step 200), the sensor terminal 10 first generates encryption information Dc by encrypting new data D with the transmission side encryption key Ksc by the encryption information generation unit 13 (step 201). The transmitting unit 15 transmits the encrypted message Mc storing only the encrypted information Dc to the processing device 20 (step 202). At this time, after the transmission side encryption key Ksc is updated by the encryption information generation unit 13, the encryption information Dc may be generated.

  The processing device 20 receives the encrypted message Mc from the sensor terminal 10 by the receiving unit 21, and the encrypted information Dc acquired from the encrypted message Mc is obtained by the encrypted message transfer process (step 100) executed so far. Decryption processing is performed based on the transmission side encryption key Ksc (step 203), and the obtained data D is output in response to successful authentication of the sensor terminal 10 and the processing device 20, and a series of encryption message transfer processing ( Step 200) is terminated.

In addition, instead of the authentication message Ma in FIG. 6, a key message Mk for notifying the updated transmitting side encryption key may be transmitted.
In this case, the relay device 30 is obtained by encrypting the encryption information Dc obtained by encrypting the data D with the updated new transmission side encryption key Ksc and the new transmission side encryption key Ksc with the reception side public key Krp. The key information Dk may be stored in one key message Mk and transmitted to the processing device 20.

  The processing device 20 decrypts the key information Dk acquired from the received key message Mk with the reception-side secret key Krs to acquire a new transmission-side encryption key Ksc, and then acquires the encryption information acquired from the received key message Mk. Data D may be obtained by decrypting Dc with the new transmission-side encryption key Ksc.

[Effect of the second embodiment]
As described above, according to the present embodiment, in the sensor terminal 10 on the transmission side, usually only the encryption information Dc related to the data D generated by the encryption information generation unit 13 is transmitted to the reception side by the encryption message Mc, and a predetermined transmission frequency is obtained. Alternatively, when the authentication message Ma related to the data D is generated and transmitted at a transmission time interval, and the encryption information decryption unit 23 receives the encryption message Mc storing only the encryption information from the transmission side in the processing device 20 on the reception side, Data D is acquired by decrypting the encryption information Dc with the transmission side encryption key Ksc acquired by the authentication message Ma until then.

  Thereby, since the data D is normally transferred by the encryption message Mc having a data length shorter than that of the authentication message Ma, the frequency of transmitting the authentication message Ma is reduced. Therefore, it is possible to reduce the processing load on the transmitting-side sensor terminal 10 and further the processing load on the receiving-side processing device 20 while ensuring a certain level of security.

In the present embodiment, in the sensor terminal 10 on the transmission side, the transmission frequency or the transmission time interval for transmitting the authentication message Ma may be changed according to the communication traffic between the transmission side and the reception side. Good.
As a result, when communication traffic is relatively low, data D can be transmitted at a higher frequency, and when communication traffic increases, the transmission frequency of data D is reduced to avoid adverse effects on communication traffic. Can do.

In the present embodiment, instead of the authentication message Ma at a certain rate, the encryption information Dc obtained by the updated transmission side encryption key Ksc and the key information obtained by encrypting the updated transmission side encryption key Ksc. Dk may be stored in one key message Mk and transmitted to the processing device 20.
Thereby, the transmission side encryption key Ksc is updated while further reducing the frequency of transmitting the authentication message Ma. Therefore, it is possible to reduce the processing load on the transmitting-side sensor terminal 10 and further the processing load on the receiving-side processing device 20 while ensuring a certain level of security.

[Third Embodiment]
Next, with reference to FIG. 7, the sensing system 1 concerning the 3rd Embodiment of this invention is demonstrated. FIG. 7 is a block diagram illustrating a configuration of a sensing system according to the third embodiment.

In the sensing system 1, when a large number of sensor terminals 10 are connected to the processing device 20, a relay device 30 is provided between the sensor terminal 10 and the processing device 20, and data from the sensor terminal 10 is transmitted by the relay device 30. In some cases, the data is aggregated and relayed to the processing device 20.
In the present embodiment, a case will be described as an example in which the relay device 30 is used as a transmission side device instead of the sensor terminal 10 and the encrypted communication technology is applied between the relay device 30 and the processing device 20. Here, although the case where there is one relay device 30 will be described as an example, a plurality of relay devices 30 may be provided, and a plurality of sensor terminals 10 may be accommodated in each. Note that the configuration of the processing device 20 is the same as that of the first embodiment, and a detailed description thereof is omitted here.

In the present embodiment, the relay device 30 is composed of a network device such as a gateway device as a whole, is connected between each sensor terminal 10 and the communication network NW, aggregates data from the sensor terminal 10, and then encrypts the data. It has a function of relaying and transferring to the processing device 20 by using the communication technology.
The relay device 30 includes a receiving unit 31, a signature information generation unit 32, an encryption information generation unit 33, a key information generation unit 34, and a transmission unit 35 as main functional units.

The receiving unit 31 generates data D to be transmitted to the processing device 20 by performing a function of receiving terminal data notified from the subordinate sensor terminal 10 and data processing such as aggregation on the terminal data. It has the function to do.
The signature information generation unit 32 has a function of calculating the hash value Hd for the data D generated by the reception unit 31, and a function of generating the signature information Ds by encrypting the obtained hash value Hd with the transmission side secret key Kss. have.

The encryption information generation unit 33 has a function of generating encryption information Dc by encrypting the data D generated by the reception unit 31 with the transmission-side encryption key Ksc. At this time, a general method such as AES or Camellia may be used as the encryption algorithm.
The key information generation unit 34 has a function of generating key information Dk by encrypting the transmission side encryption key Ksc with the reception side public key Krp.
The transmission unit 35 has a function of storing authentication information including the signature information Ds, the encryption information Dc, and the key information Dk in one authentication message Ma and transmitting the authentication information Ma to the processing device 20 via the communication network NW. .

  FIG. 8 is an explanatory diagram of an encryption process according to the third embodiment. In the present embodiment, a transmission side public encryption key composed of a pair of a transmission side private key Kss and a transmission side public key Ksp is set in advance in the relay device 30 on the transmission side. In addition, a receiving side public encryption key composed of a pair of a receiving side secret key Krs and a receiving side public key Krp is set in advance in the processing device 20 on the receiving side. The transmission side public encryption key and the reception side public encryption key are composed of general public encryption keys.

In the present embodiment, the transmission side public key Ksp of the relay device 30 is set in the processing device 20 in advance, and the reception side public key Krp of the processing device 20 is set in the relay device 30 in advance. . In addition, a transmission side encryption key Ksc consisting of a common encryption key is preset in the relay device 30, and is updated at a predetermined timing.
Storage of these keys and encryption processing are performed safely in tamper-resistant hardware installed in the relay device 30 or the processing device 20. As a cryptographic algorithm, a general method such as RSA or ElGamal may be used.

As shown in FIG. 8, in the relay device 30, the transmission side secret key Kss, the transmission side encryption key Ksc, and the reception side public key Krp are used to encrypt the hash value Hd, the data D, and the transmission side encryption key Ksc, respectively. Used.
In the processing device 20, the reception side secret key Krs, the transmission side encryption key Ksc, and the transmission side public key Ksp are used to decrypt the transmission side encryption key Ksc, the data D, and the hash value Hd, respectively.

[Operation of Third Embodiment]
Next, a data transfer operation of the sensing system 1 according to the present embodiment will be described with reference to FIG. FIG. 9 is a sequence diagram illustrating data transfer processing according to the third embodiment.
As shown in FIG. 9, the sensing system 1 intermittently performs an authentication message transfer process (step (step)) in a data transfer process for transferring data D from the relay apparatus 30 to the processing apparatus 20 in accordance with a preset transfer timing. 300).

  First, the relay device 30 receives terminal data from the subordinate sensor terminal 10 and generates new data D to be transmitted (step 301), and based on the obtained data D and various encryption keys set in advance. By performing encryption processing, authentication information composed of signature information Ds, encryption information Dc, and key information Dk is generated (step 302), and an authentication message Ma storing these authentication information Ds, Dc, Dk is processed by the processing device. 20 (step 303).

  The processing device 20 receives the authentication message Ma from the relay device 30, and decrypts the authentication information Ds, Dc, Dk acquired from the authentication message Ma based on various preset encryption keys (step 304). In response to successful authentication of the authenticity relating to the sensor terminal 10 and the processing device 20, the obtained data D is output, and the series of authentication message transfer processing (step 300) is terminated.

The detailed transmission side processing in the relay device 30 is the same as the transmission side processing related to the sensor terminal 10 in FIG. 4 described above, and a detailed description thereof is omitted here.
Further, the detailed reception side processing in the processing device 20 is the same as the above-described reception side processing in FIG. 5, and detailed description thereof is omitted here.
Note that the second embodiment may be applied to the present embodiment to reduce the transmission frequency of the authentication message transfer process, and the same effect as described above can be obtained.

[Effect of the third embodiment]
As described above, in this embodiment, the transmission side according to the first embodiment is replaced with the relay device 30 instead of the sensor terminal 10, and the first embodiment is provided between the relay device 30 and the processing device 20. The data transmission / reception method according to the above is applied.
Thereby, the encryption process in the sensor terminal 10 can be omitted, and the processing load in the sensor terminal 10 can be greatly reduced. Therefore, the configuration of the sensor terminal 10 can be simplified, or the existing sensor terminal 10 can be applied, and the cost of the entire sensing system 1 can be reduced.

[Fourth Embodiment]
Next, a sensing system 1 according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a block diagram illustrating a configuration of a sensing system according to the fourth embodiment.

  In the first embodiment, a case in which all transmission side processing is executed by the sensor terminal 10 will be described as an example. In the third embodiment, a case in which all transmission side processing is executed by the relay device 30 will be described as an example. did. In the present embodiment, a case will be described in which transmission-side processing is shared between the sensor terminal 10 and the relay device 30 and executed.

  FIG. 10 illustrates, as a specific example, a case in which the generation of the signature information Ds is executed by the sensor terminal 10 and the generation of the encryption information Dc and the key information Dk is executed by the relay device 30 in the transmission side process. Has been. Note that the processing sharing between the sensor terminal 10 and the relay device 30 is not limited to this, and can be arbitrarily replaced. Note that the configuration of the processing device 20 is the same as that of the first embodiment, and a detailed description thereof is omitted here.

In the present embodiment, the sensor terminal 10 includes a sensor 11, a signature information generation unit 12, and a transmission unit 15 as main functional units.
The transmission unit 15 stores the signature information Ds generated by the signature information generation unit 12 and the data D in the signature message Ms based on the new data D such as the sensor value detected by the sensor 11, and relays the data. 30. The sensor 11 and the signature information generation unit 12 are the same as those described in the first embodiment, and a detailed description thereof is omitted here.

The relay device 30 includes a reception unit 31, an encryption information generation unit 33, a key information generation unit 34, and a transmission unit 35 as main functional units.
The receiving unit 31 has a function of receiving the signature message Ms from the subordinate sensor terminal 10 and acquiring the signature information Ds and the data D.
The encryption information generation unit 33 has a function of generating the encryption information Dc by encrypting the data D from the reception unit 31 with the transmission side encryption key Ksc.
The key information generation unit 34 and the transmission unit 35 are the same as those described in the third embodiment, and a detailed description thereof is omitted here.

  FIG. 11 is an explanatory diagram of encryption processing according to the fourth embodiment. In the present embodiment, a transmission side public encryption key composed of a pair of a transmission side private key Kss and a transmission side public key Ksp is set in advance in the sensor terminal 10 on the transmission side. In addition, a receiving side public encryption key composed of a pair of a receiving side secret key Krs and a receiving side public key Krp is set in advance in the processing device 20 on the receiving side. The transmission side public encryption key and the reception side public encryption key are composed of general public encryption keys.

In the present embodiment, the transmission side public key Ksp of the sensor terminal 10 is set in the processing device 20 in advance, and the reception side public key Krp of the processing device 20 is set in the relay device 30 in advance. . In addition, a transmission side encryption key Ksc consisting of a common encryption key is preset in the relay device 30, and is updated at a predetermined timing.
Storage of these keys and encryption processing are performed safely in tamper-resistant hardware installed in the sensor terminal 10, the relay device 30, and the processing device 20. As a cryptographic algorithm, a general method such as RSA or ElGamal may be used.

As shown in FIG. 11, in the sensor terminal 10, the transmission side secret key Kss is used for encryption of the hash value Hd. In the relay device 30, the transmission side encryption key Ksc and the reception side public key Krp are the data D and Used to encrypt the transmission side encryption key Ksc.
In the processing device 20, the reception side secret key Krs, the transmission side encryption key Ksc, and the transmission side public key Ksp are used to decrypt the transmission side encryption key Ksc, the data D, and the hash value Hd, respectively.

[Operation of Fourth Embodiment]
Next, the data transfer operation of the sensing system 1 according to the present embodiment will be described with reference to FIG. FIG. 12 is a sequence diagram illustrating data transfer processing according to the fourth embodiment.
As shown in FIG. 12, the sensing system 1 intermittently according to a preset transfer timing in a data transfer process of transferring data D from the sensor terminal 10 to the processing device 20 via the relay device 30. An authentication message transfer process (step 400) is executed.

  First, the sensor terminal 10 generates signature information Ds by performing encryption processing based on the new data D to be transmitted and the preset transmission-side secret key Kss (step 401), and the signature information Ds and the data The signature message Ms in which D is stored is transmitted to the relay device 30 (step 402).

  The relay device 30 receives the signature message Ms from the subordinate sensor terminal 10, and generates the encryption information Dc by encrypting the data D acquired from the signature message Ms with the transmission side encryption key Ksc (step 403). Also, the key information Dk is generated by encrypting the transmission side encryption key Ksc with the reception side public key Krp (step 404), the signature information Ds obtained from the signature message Ms, and the encryption information Dc generated by the relay device 30. And the key information Dk are stored in one authentication message Ma and transmitted to the processing device 20 (step 405).

  The processing device 20 receives the authentication message Ma from the sensor terminal 10 and decrypts the authentication information Ds, Dc, Dk acquired from the authentication message Ma based on various preset encryption keys (step 406). In response to the successful authentication of the authenticity relating to the sensor terminal 10 and the processing device 20, the obtained data D is output, and the series of authentication message transfer processing (step 400) is terminated.

[Effect of the fourth embodiment]
As described above, in the present embodiment, the sensor terminal 10 generates one or more pieces of information among the signature information Ds, the encryption information Dc, and the key information Dk, and the relay device 30 Of the signature information Ds, the encryption information Dc, and the key information Dk, the information generated by the sensor terminal 10 and the information generated by itself are stored in one message and transmitted to the processing device 20. It is what I did.

Thereby, compared with 1st Embodiment, the processing burden of a transmission side process can be disperse | distributed from the sensor terminal 10 to the relay apparatus 30, the processing burden of the sensor terminal 10 can be reduced, and the structure of the sensor terminal 10 is demonstrated. Can be simplified.
Further, the sharing of the transmission side processing may be determined according to the scale and specifications of the sensing system 1 such as the number of connections of the sensor terminal 10 and the data D collection interval, and the sensing system with extremely good cost performance. 1 can be realized.

[Extended embodiment]
The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. In addition, each embodiment can be implemented in any combination within a consistent range.

  DESCRIPTION OF SYMBOLS 1 ... Sensing system, 10 ... Sensor terminal, 11 ... Sensor, 12 ... Signature information generation part, 13 ... Encryption information generation part, 14 ... Key information generation part, 15 ... Transmission part, 20 ... Processing apparatus, 21 ... Reception part, DESCRIPTION OF SYMBOLS 22 ... Key information decryption part, 23 ... Encryption information decryption part, 24 ... Signature information decryption part, 25 ... Authentication determination part, 30 ... Relay apparatus, 31 ... Reception part, 32 ... Signature information generation part, 33 ... Encryption Information generating unit 34... Key information generating unit 35 35 Transmitting unit NW Communication network

Claims (8)

A data transmission / reception method used when encrypting and transmitting various types of data from a transmission side device connected via a communication network to a reception side device,
The sending device is
A signature information generation step for generating signature information by calculating a hash value of the data and encrypting the data with a transmission side private key;
An encryption information generation step for generating encryption information by encrypting data with a transmission side encryption key;
A key information generation step for generating key information by encrypting the transmission side encryption key with the reception side public key;
Including a signature step, encryption information, and key information stored in one message and transmitted to the receiving device,
The receiving device
A receiving step of receiving a message from the transmitting device;
A key information decryption step for obtaining a transmission side encryption key by decrypting the key information included in the message with the reception side private key;
An encryption information decryption step for obtaining data by decrypting the encryption information included in the message with the transmission side encryption key;
A signature information decryption step for obtaining a hash value by decrypting the signature information included in the message with the transmission side public key;
An authentication determination step for calculating the hash value of the data obtained by decryption and comparing the hash value obtained by the decryption to authenticate the authenticity of the transmission side device and the reception side device. A data transmission / reception method characterized by the above. The data transmission / reception method according to claim 1,
In the transmission step, when data is sequentially transmitted to the reception side device, normally, only the encryption information related to the data generated in the encryption information generation step is transmitted to the reception side device, and the data is transmitted at a predetermined transmission frequency or transmission time interval. Generate and send a message about
In the encryption information decryption step, when only the encryption information is received from the transmission side device, data is obtained by decrypting the encryption information with the transmission side encryption key obtained by the message so far. Method. The data transmission / reception method according to claim 2,
A transmission step is a data transmission / reception method characterized by changing a transmission frequency or a transmission time interval for transmitting a message in accordance with communication traffic between a transmission side device and a reception side device. In the data transmission / reception method in any one of Claims 1-3,
An encryption information generating step is characterized in that, when data is encrypted with a transmission side encryption key, the transmission side encryption key is changed at an arbitrary frequency. The data transmission / reception method according to claim 4,
The encryption information generation step, when encrypting data with a transmission side encryption key, changes the transmission side encryption key change frequency according to the transmission frequency of data transmitted from the transmission side device. A sensing system that encrypts and transmits various data to a processing device from a sensor terminal connected via a communication network,
6. A sensing system that transmits data from a sensor terminal to a processing device based on the data transmission / reception method according to claim 1. A sensing system that encrypts and transmits various data to a processing device from a sensor terminal connected via a communication network,
A relay device that relays and forwards data transmitted from the sensor terminal to the processing device,
6. A sensing system, comprising: transmitting data from a relay device to a processing device based on the data transmission / reception method according to claim 1. The sensing system according to claim 7,
The sensor terminal divides and generates any one or more of signature information, encryption information, and key information,
When transmitting a message, the relay device stores the information generated by the sensor terminal and the remaining information generated by itself among the signature information, encryption information, and key information in one message and sends it to the processing device. A sensing system characterized by transmitting.

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