Data communication system, data communication device, host device, data communication method, and data communication program

Abstract

A data communication system (1) is provided with at least one data communication device (10) and a host device (20) capable of communicating with the at least one data communication device (10). Each of the at least one data communication device (10) transmits, to the host device (20), encryption information pertaining to an encryption scheme predetermined corresponding to the data communication device (10). The host device (20) receives encrypted information from each of the at least one data communication device (10). The host device (20) performs data communication with each of the at least one data communication device (10) on the basis of the encrypted information.

Description

Technical Field

[0001] The present disclosure relates to a data communication system, a data communication device, a host device, a data communication method, and a data communication program. Background Art

[0002] Conventionally, there is known a data communication system in which a host device acquires data detected by a sensor and transmits the acquired data to a central processing unit. In such a data communication system, at least one sensor can be connected to the host device, but the at least one sensor may contain a mixture of sensors for processing data with low confidentiality to the user and sensors for processing data with high confidentiality to the user.

[0003] Data with high confidentiality requires a higher security level in data communication than data with low confidentiality. However, sensors that can ensure a high security level need to perform high-speed processing in data encryption, etc., which may cause the built-in processor to be large and expensive, and power consumption to increase. Therefore, in the case of performing encryption processing such as ensuring a high security level for all sensors connected to the host device in accordance with the sensor for processing data with high confidentiality, even the sensor for processing data with low confidentiality needs to be equipped with an overly high-performance processor, which may lead to a large and high-cost data communication system as a whole, and increase power consumption. In addition, in the host device, when high-speed processing is performed in encryption of data communication between all connected sensors, power consumption may also increase.

[0004] In this regard, Japanese Patent Application Laid-Open No. 2017-211850 (Patent Document 1) discloses a system that partially encrypts data from a sensor in order to keep the data detected by the sensor confidential with a small processing burden.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-211850 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The system disclosed in Patent Document 1 does not consider whether each of the multiple sensors connected to the processing device is a sensor for processing data with low confidentiality or a sensor for processing data with high confidentiality, but is configured so that all sensors connected to the processing device perform encryption processing at the same security level. Therefore, even in the system disclosed in Patent Document 1, when encryption processing is performed such that all sensors connected to the processing device have a high security level in accordance with sensors for processing data with high confidentiality, even sensors for processing data with low confidentiality need to be equipped with an overly high-performance processor, which may result in a large and high-cost system as a whole, and increased power consumption.

[0010] The present disclosure has been made to solve such a problem, and an object of the present disclosure is to provide a technology capable of ensuring the security of data communication while suppressing an increase in size, cost, and power consumption.

[0011] Solutions for solving problems

[0012] According to a certain aspect of the present disclosure, a data communication system comprises: at least one data communication device; and a host device capable of communicating with the at least one data communication device. Each of the at least one data communication device sends encryption information related to a predetermined encryption method corresponding to the data communication device to the host device. The host device receives the encryption information from each of the at least one data communication device. The host device and each of the at least one data communication device perform data communication based on the encryption information.

[0013] According to another aspect of the present disclosure, a data communication device comprises: a control device; and a communication interface for communicating with a host device. The control device receives query information related to a query of an encryption method from the host device, and in response to receiving the query information, sends encryption information related to a predetermined encryption method to the host device, and performs data communication with the host device based on the encryption information.

[0014] According to another aspect of the present disclosure, a host device comprises: a control device; and a communication interface for communicating with at least one data communication device. The control device sends query information related to a query of a predetermined encryption method corresponding to the data communication device to each of the at least one data communication device, receives encryption information related to the encryption method corresponding to the data communication device from each of the at least one data communication device, and performs data communication with each of the at least one data communication device based on the encryption information.

[0015] According to another aspect of the present disclosure, a data communication method includes the following steps: receiving query information related to a query on an encryption method from a host device; sending encryption information related to a predetermined encryption method to the host device in response to receiving the query information; and communicating data with the host device based on the encryption information.

[0016] According to another aspect of the present disclosure, a data communication method includes the following steps: sending query information related to a query corresponding to a predetermined encryption method of the data communication device to each data communication device in at least one data communication device; receiving encryption information related to the encryption method corresponding to the data communication device from each data communication device in at least one data communication device; and performing data communication with each data communication device in at least one data communication device based on the encryption information.

[0017] Effects of the Invention

[0018] According to the present disclosure, the host device and each of the at least one data communication device perform data communication based on encryption information related to the encryption method predetermined corresponding to the data communication device. Therefore, each of the at least one data communication device only needs to install a control device that can perform encryption processing that matches the respective security level. Compared with installing a control device that can perform encryption processing that matches the highest security level in all data communication devices, the data communication system as a whole can ensure the security of data communication while suppressing the increase in size, cost, and power consumption. In addition, in the host device, high-speed processing is not performed in the encryption of data communication between all connected data communication devices, so the increase in power consumption can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing an overview of a data communication system according to an embodiment.

[0020] Figure 2 It is a diagram showing the structure of a data communication system involved in the embodiment.

[0021] Figure 3 This is a diagram for explaining the structure of data transmitted and received between a host device and a data communication device.

[0022] Figure 4 This is a diagram showing an example of data communication performed by a host device and a data communication device.

[0023] Figure 5 This is a diagram showing an example of data retransmission from a data communication device to a host device.

[0024] Figure 6This is a diagram showing another example of data retransmission from the data communication device to the host device.

[0025] Figure 7 This is a diagram showing an example of function sharing in a data communication system. DETAILED DESCRIPTION

[0026] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings, and their description will not be repeated.

[0027] [Overview of Data Communication System]

[0028] Reference Figure 1 An overview of a data communication system 1 according to the embodiment will be described. Figure 1 It is a diagram showing an overview of a data communication system 1 according to the embodiment.

[0029] like Figure 1 As shown, the data communication system 1 includes at least one data communication device 10A, 10B, 10C, 10D (hereinafter also collectively referred to as “data communication device 10 ”) and a host device 20 .

[0030] At least one data communication device 10 is a device that detects data and sends the detected data (hereinafter also referred to as "detection data") to the host device 20. For example, Figure 1 In the example of , the data communication device 10A is a CO2 sensor capable of detecting carbon dioxide (hereinafter also referred to as "CO2") in the target space where the data communication device 10A is installed, and the data communication device 10A sends the detected CO2 data to the host device 20. The data communication device 10B is a temperature and humidity sensor capable of detecting the temperature and humidity in the target space where the data communication device 10B is installed, and the data communication device 10B sends the detected temperature and humidity data to the host device 20. The data communication device 10C is a sound sensor capable of detecting sounds (e.g., human voices, etc.) emitted in the target space where the data communication device 10C is installed, and the data communication device 10C sends the detected sound data to the host device 20. The data communication device 10D is a camera device including a camera capable of photographing a target (e.g., a person or an object, etc.) in the target space where the data communication device 10D is installed, and the data communication device 10D sends the image data obtained by photographing to the host device 20.

[0031] Furthermore, the data communication device 10 is not limited to being applied to devices capable of detecting CO2, temperature, humidity, sound, and images, but can also be applied to devices capable of detecting any data such as air pressure, acceleration, angular velocity, or illumination in the target space where the data communication device 10 is installed. Figure 1In the example, four data communication devices are connected to one host device 20, but one data communication device may be connected to one host device 20, or another number of data communication devices may be connected. At least one data communication device 10 connected to one host device 20 may be a device capable of detecting data of the same type or a device capable of detecting data of different types.

[0032] The data communication device 10 is connected to the host device 20 in a communicable manner. For example, the data communication device 10 includes an insertion-side connector 130 that complies with the USB (Universal Serial Bus) standard. On the other hand, the host device 20 includes a reception-side connector 230 that complies with the USB standard. The data communication device 10 can perform data communication with the host device 20 via the USB connection by inserting the insertion-side connector 130 into the reception-side connector 230 of the host device 20.

[0033] In addition, the data communication device 10 and the host device 20 are not limited to performing data communication via USB connection, and data communication may be performed via wireless connection such as Bluetooth (registered trademark). In the data communication system 1, at least one data communication device 10 connected to the host device 20 via USB connection and at least one data communication device 10 connected to the host device 20 via wireless connection may be mixed.

[0034] When the data communication device 10 and the host device 20 are configured to communicate via a USB connection, the communicated data is less likely to be lost than when they are configured to communicate via a wireless connection, and the settings required for a wireless connection are not required. In addition, the data communication device 10 can receive power from the host device 20 via a USB connection.

[0035] When the data communication device 10 and the host device 20 are configured to be able to communicate via a wireless connection, data communication can be performed while the data communication device 10 is installed at a location physically far from the host device 20. Therefore, when the data communication device 10 and the host device 20 are configured to be able to communicate via a wireless connection, the degree of freedom in configuring the data communication device 10 can be increased compared to when the data communication device 10 and the host device 20 are configured to be able to communicate via a USB connection.

[0036] The host device 20 acquires data transmitted from at least one data communication device 10 connected in a communicable manner. The host device 20 is configured to be able to wirelessly communicate with the central processing device 30 via the network 50. For example, the host device 20 may be connected to the network 50 via an access point (not shown) using a Wi-Fi (registered trademark) connection, or may be connected to the network 50 using a cellular line such as LTE (Long Term Evolution) or 5G. The host device 20 transmits the data acquired from the data communication device 10 to the central processing device 30 via the network 50.

[0037] In addition, the host device 20 and the central processing unit 30 are not limited to performing data communication via wireless connection, and may perform data communication via wired connection. Furthermore, the host device 20 may also have the function of the central processing unit 30.

[0038] The central processing device 30 accumulates data acquired from the data communication device 10 via the host device 20, performs processing such as calculation or analysis using the data, and transmits control data based on the processing result to the terminal device 40. For example, the central processing device 30 uses the CO2 data acquired from the data communication device 10 to analyze the CO2 concentration in the target space over time, and transmits control data for displaying the analysis result to the terminal device 40. In addition, the central processing device 30 may also be a server or a cloud, and may also be integrated with the host device 20 to constitute a PC (Personal Computer) or a terminal device.

[0039] The terminal device 40 is an information terminal that performs predetermined information processing, such as a desktop PC, a laptop computer, a smartphone, a smart watch, a wearable device, or a tablet PC. For example, the terminal device 40 displays the CO2 concentration in the target space over time on a display (not shown) based on control data from the central processing unit 30.

[0040] [Structure of data communication system]

[0041] Reference Figure 2 The configuration of the data communication system 1 according to the embodiment will be described in detail. Figure 2 It is a diagram showing the configuration of a data communication system 1 according to the embodiment.

[0042] like Figure 2 As shown, the data communication device 10 includes a control device 11 , a storage unit 12 , a communication interface 13 , and a data detection unit 14 .

[0043] The control device 11 is a computer such as a processor. The processor is composed of, for example, a microcontroller, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). In addition, the processor has the function of performing various processes by executing a program, but part or all of these functions can also be implemented using a dedicated hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). "Processor" is not limited to a processor in a narrow sense that performs processes in a stored program manner such as a CPU or MPU, and can include hard-wired circuits such as ASIC or FPGA. Therefore, the processor can also be renamed as a processing circuit (Processing Circuitry) in which the processing is predefined by a computer-readable code and / or a hard-wired circuit. In addition, the control device 11 can be composed of one chip or multiple chips.

[0044] The storage unit 12 includes a RAM (Random Access Memory) and a storage device. The RAM is a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), and functions as a work memory that temporarily stores data processed by a processor. In addition, the RAM may be included in the control device 11, or may be configured separately from the control device 11. The storage device is a non-volatile memory such as a ROM (Read Only Memory) or a flash memory, and stores programs or various data used in the programs.

[0045] In the data communication device 10 according to the embodiment, the storage unit 12 stores a control program 120 and setting data 125. The control program 120 is an example of a "data communication program". The control program 120 is executed by the control device 11 and defines processing procedures related to the detection of data in the target space and the transmission and reception of data with the host device 20 (for example, the following description). Figures 4 to 6The data communication device 10 may also obtain the control program 120 stored in the recording medium from a recording medium such as a memory card or a USB (Universal Serial Bus) memory. The setting data 125 includes information related to the detection of data in the object space and the transmission and reception of data with the host device 20 (for example, encryption information and hash information described later).

[0046] The communication interface 13 is an interface for performing data communication with the host device 20 via a USB connection or a wireless connection such as Bluetooth (registered trademark).

[0047] The data detection unit 14 includes a structure such as a sensor for detecting various data such as CO 2 , temperature, humidity, sound, and image.

[0048] The host device 20 includes a control device 21 , a storage unit 22 , a communication interface 23 , and a communication device 24 .

[0049] The control device 21 is a computer such as a processor, and has the same structure as the control device 11 of the data communication device 10. The processor is composed of, for example, a microcontroller, a CPU, an MPU, an ASIC, an FPGA, etc., and can also be referred to as a processing circuit. In addition, the control device 21 can be composed of one chip or a plurality of chips.

[0050] The storage unit 22 includes a RAM (DRAM or SRAM) and a storage device (ROM or flash memory), and has the same structure as the storage unit 12 of the data communication device 10 .

[0051] In the host device 20 according to the embodiment, the storage unit 22 stores a control program 220. The control program 220 is an example of a "data communication program". The control program 220 is executed by the control device 21 and defines a process related to the transmission and reception of data with the data communication device 10 (for example, the following description). Figures 4 to 6 The host device 20 may also obtain the control program 220 stored in a recording medium such as a memory card or a USB memory from the recording medium.

[0052] The communication interface 23 is an interface for performing data communication with the data communication device 10 via a USB connection or a wireless connection such as Bluetooth (registered trademark).

[0053] The communication device 24 has a function for wirelessly communicating with the central processing device 30 via the network 50 .

[0054] According to the data communication system 1 configured as described above, data communication can be performed between the data communication device 10 and the host device 20 , and detection data detected by the data communication device 10 can be transmitted to the central processing device 30 via the host device 20 .

[0055] Here, in at least one data communication device 10 that can be connected to the host device 20, there are sometimes a mixture of data communication devices 10 for processing data with low confidentiality for the user and data communication devices 10 for processing data with high confidentiality for the user. For example, the voice data detected by the data communication device 10C and the image data detected by the data communication device 10D are more likely to be data related to the privacy of a person existing in the target space or to contain confidential matters than the CO2 data detected by the data communication device 10A and the temperature and humidity data detected by the data communication device 10B. Therefore, from the viewpoint of protecting the privacy or confidential matters of the person existing in the target space, the voice data sent from the data communication device 10C to the host device 20 and the image data sent from the data communication device 10D to the host device 20 need to have a higher security level in data communication than the CO2 data sent from the data communication device 10A to the host device 20 and the temperature and humidity data sent from the data communication device 10B to the host device 20.

[0056] In the case where the host device 20 performs encryption processing such that a high security level is ensured for the data communication devices 10A and 10B for processing data with low confidentiality in accordance with the data communication devices 10C and 10D for processing data with high confidentiality, even the data communication devices 10A and 10B for processing data with low confidentiality need to be equipped with an overly high-performance control device 11, which may lead to a large and high-cost data communication system 1 as a whole, and increase power consumption. In addition, in the case where the host device 20 performs high-speed processing in encryption of data communication with all connected data communication devices 10, power consumption may also increase.

[0057] Therefore, in the data communication system 1, whether to encrypt data, the encryption method when encrypting, whether to add a hash value to the data, and the hash method when adding the hash value are determined in advance corresponding to each of the at least one data communication device 10 connected to the host device 20. Then, the host device 20 and each of the at least one data communication device 10 perform data communication using the encryption method corresponding to the data communication device 10, or perform data communication using the hash method corresponding to the data communication device 10.

[0058] Thus, in order for the host device 20 to perform data communication with each of the at least one data communication device 10 using the encryption method and hash method predetermined for each of the at least one data communication device 10, each of the at least one data communication device 10 only needs to install the control device 11 capable of performing encryption processing that matches the respective security levels. That is, the data communication device 10A and the data communication device 10B for processing data with low confidentiality do not need to install an overly high-performance control device 11 in accordance with the data communication device 10C and the data communication device 10D for processing data with high confidentiality, so that it is possible to suppress the increase of high performance, high cost, and power consumption that is beyond necessity. Therefore, compared with the data communication device 10A and the data communication device 10B for processing data with low confidentiality, the control device 11 capable of performing encryption processing that matches the security level of the data communication device 10C and the data communication device 10D for processing data with high confidentiality is installed, and the security of data communication can be ensured while suppressing the increase of size, high cost, and power consumption in the data communication system 1 as a whole. Furthermore, since the host device 20 does not execute high-speed processing such as encryption of data communications with all the connected data communication devices 10 , it is also possible to suppress an increase in power consumption.

[0059] [An example of data structure]

[0060] Reference Figure 3 The structure of data transmitted and received between the host device 20 and the data communication device 10 will be described. Figure 3 2 is a diagram for explaining the structure of data transmitted between the host device 20 and the data communication device 10. Figure 3 In the following, the structure of data transmitted from the data communication device 10 to the host device 20 and the structure of data transmitted from the host device 20 to the data communication device 10 are collectively described.

[0061] like Figure 3 As shown, the data structure includes fields indicating data items and the content of data corresponding to each field. The fields include IV (Initial Value), DATA, HASH, and EOD (End Of Data).

[0062] IV includes an initial value, a data length, a counter, and a data format. In addition, the data length, the counter, and the data format may not be included in IV, but may be included in a field different from the initial value.

[0063] The initial value is a random value indicating the initial value of the data to be sent once. The initial value is composed of, for example, 16 bytes and is used to encrypt data. The data length indicates the number of valid bytes of the data body. For example, the data body is composed of 16*N bytes (N is a natural number). The counter is a value that is incremented each time data is sent, so that the receiving side does not repeatedly receive data received in the past, or is used to determine the presence or absence of data defects caused by data reception errors described later.

[0064] The data format includes encryption information related to the encryption method predetermined for the data communication device 10 and hash information related to the hash method predetermined for the data communication device 10. The encryption information includes information indicating whether the data is encrypted and the encryption method when the encryption is performed. The hash information includes information indicating whether the IV and the data body are calculated by the hash method and the hash method when the calculation is performed.

[0065] For example, in the data form, encryption information and hash information are included in a manner corresponding to six identifiers "0" to "5" in order of security level from low to high. When the identifier is "0", the encryption process and the operation process using the hash method are the simplest and the security level is the lowest, and when the identifier is "5", the encryption process and the operation process using the hash method are the most complex and the security level is the highest.

[0066] Specifically, when the data format indicates "0", the data body is not encrypted and the IV and the data body are not hashed, and the data is sent in plain text. No hash value is added to the data to be sent or received.

[0067] When the data format indicates "1", the data body is encrypted by encryption method A without computing the IV and the data body by hashing. No hash value is added to the data being sent or received. Encryption method A is, for example, an encryption method that encrypts data using a 40-bit to 256-bit shared key using the RC4 (Rivest Cipher 4) (registered trademark) encryption algorithm. No hash value is added to the data being sent or received.

[0068] When the data format indicates "2", the data body is encrypted by encryption method B without computing the IV and the data body by hashing. No hash value is added to the data being sent or received. Encryption method B is, for example, an encryption method that encrypts data using a 128-bit shared key using the AES (Advanced Encryption Standard) encryption algorithm.

[0069] When the data format indicates "3", the data body is encrypted by encryption method C and the IV and data body are not hashed. No hash value is added to the data being sent or received. Encryption method C is an encryption method that encrypts data using a 256-bit shared key using the AES encryption algorithm, for example.

[0070] When the data format indicates "4", IV and the data body are calculated by hash method A, and the data body and the hash value obtained by the calculation using the hash method A are encrypted by the above-mentioned encryption method B, and then the data body is sent. Hash method A is a hash method that calculates data using a hash function of MD5 (Message Digest Algorithm 5), for example.

[0071] When the data format indicates "5", the data body is sent by calculating IV and the data body by hash method A, and the data body and the hash value obtained by the calculation using the hash method A are encrypted by the above-mentioned encryption method B. The hash method B is, for example, a hash method for calculating data by a hash function of SHA256 (Secure Hash Algorithm 256).

[0072] As described above, in the data format, it is specified that in the case of the identifier 0 with the lowest security level, encryption and hash value addition are not performed and data is sent in plain text, and it is specified that encryption and hash value addition are performed as the security level becomes higher, and it is also specified that the encryption security level is increased.

[0073] In addition, the encryption method and hash method specified by the data format are not limited to Figure 3 The example shown in the data structure. Other encryption methods and hash methods can also be used. For example, the encryption method is not limited to the shared key (common-key) encryption method, and the public key (public-key) encryption method can also be used. A hybrid key encryption method obtained by combining the shared key encryption method and the public key encryption method can also be used.

[0074] Furthermore, in the embodiments, data communication based on encryption information includes a case where data is sent and received in plain text without encrypting the data body and a case where data is sent and received after being encrypted by a predetermined encryption method. In addition, data communication based on hash information includes a case where data is sent and received without using a hash method to calculate the IV and the data body and a case where data is sent and received by using a hash method to calculate the IV and the data body and attaching a hash value as a result of the calculation to the data.

[0075] DATA indicates the data body. HASH indicates a hash value, which is the result of the operation obtained by operating the data in the hash method specified in the data format. The hash value is used to detect whether the data has been tampered with. EOD (End Of Data) is a fixed value indicating the end of the data sent once.

[0076] [An example of data communication]

[0077] Reference Figure 4 Data communication performed by the host device 20 and the data communication device 10 will be described. Figure 4 1 is a diagram showing an example of data communication performed by the host device 20 and the data communication device 10. In addition, the data communication device 10 performs communication with the host device 20 by executing the control program 120 by the control device 11. Figure 4 , described later Figure 5 and Figure 6 In addition, the host device 20 executes the control program 220 by the control device 21 to perform the processing related to the data communication shown. Figure 4 , described later Figure 5 and Figure 6 The data communication related processing is shown.

[0078] exist Figure 4 , the processing related to data communication performed when the host device 20 detects the data communication device 10 is shown. Figure 4 As shown, when the insertion-side connector 130 of the data communication device 10 is inserted into the reception-side connector 230 of the host device 20 , the data communication device 10 is detected by the host device 20 .

[0079] When the host device 20 detects the data communication device 10, the host device 20 requests communication from the data communication device 10. Specifically, the host device 20 sends inquiry information related to the inquiry of the data form (encryption information and hash information) to the data communication device 10. At this time, in the data of the inquiry information related to the communication request from the host device 20 to the data communication device 10, the command data for requesting communication is set in the data body, "1" indicating the first transmission is set in the counter, and "0" is set in the data form. That is, when the data communication is requested from the host device 20 to the data communication device 10 for the first time, since the data form (encryption information and hash information) has not been notified from the data communication device 10, the host device 20 sends the data related to the communication request to the data communication device 10 in plain text and inquires about the data form (encryption information and hash information).

[0080] When receiving the inquiry information related to the communication request from the host device 20, the data communication device 10 responds to the communication request. At this time, in the data related to the communication response from the data communication device 10 to the host device 20, the command data for responding to the communication is included in the data body, "1" indicating the first transmission is set in the counter, and "5" is set in the data format. That is, when the data communication device 10 responds to the communication request of the host device 20, the data communication device 10 specifies the encryption information and hash information predetermined corresponding to the data communication device 10 in the data format, and encrypts the data related to the communication response based on the encryption information and hash information, and sends it after adding the hash value. In addition, the data communication device 10 stores the encryption information and hash information specified to the host device 20 in advance as the setting data 125 in the storage unit 12.

[0081] exist Figure 4 In the case of the example, the data communication device 10 sets "5" in the data format, encrypts the data related to the communication response by the encryption method B, calculates the IV and the data body related to the communication response by the hash method B, and sends the hash value as the calculation result to the host device 20 after adding it. As a result, the host device 20 can identify the encryption information and hash information corresponding to the data communication device 10 by referring to the data format included in the IV in the data received from the data communication device 10. In the case of this example, the host device 20 can recognize that the encryption method and hash method corresponding to the data format "5" are used for data communication with the data communication device 10 as the communication destination.

[0082] In addition, although not shown in the figure, for example, when the data communication device 10 is a data communication device 10 for processing data with low confidentiality, such as the data communication device 10A and the data communication device 10B, the data communication device 10 sets encryption information and hash information with a relatively low security level, such as "1" or "2", in the data format. On the other hand, when the data communication device 10 is a data communication device 10 for processing data with high confidentiality, such as the data communication device 10C and the data communication device 10D, the data communication device 10 sets encryption information and hash information with a relatively high security level, such as "4" or "5", in the data format. Thus, the host device 20 can recognize that data communication is performed for each of the at least one data communication device 10 as the communication destination using the encryption method and hash method predetermined corresponding to the data communication device 10.

[0083] When the host device 20 receives data related to the communication response from the data communication device 10, it requests the data communication device 10 for detection data detected by the data communication device 10. At this time, in the data related to the data request from the host device 20 to the data communication device 10, the command data for requesting data is included in the data body, "2" indicating the second transmission is set in the counter, and "5" is set in the data format. That is, when requesting the detection data from the data communication device 10, the host device 20 encrypts and / or adds a hash value to the data related to the data request based on the encryption information and hash information corresponding to the data format "5" specified by the data communication device 10 in the communication response, and then sends it.

[0084] When the data communication device 10 receives data related to the data request from the host device 20, it transmits the detection data to the host device 20. At this time, in the data related to the data response from the data communication device 10 to the host device 20, the detection data is included in the data body, "2" indicating the second transmission is set in the counter, and "5" is set in the data format. That is, when transmitting the detection data to the host device 20, the data communication device 10 encrypts the detection data based on the encryption information and hash information corresponding to the data format "5" specified for the data communication device 10 in the communication response, and then transmits it after adding a hash value.

[0085] In contrast, the host device 20 allows acceptance of data only when receiving data that has been encrypted based on encryption information corresponding to the data form “5” specified by the data communication device 10 at the time of the communication response and to which a hash value as a result of a hash operation based on the hash information corresponding to the data form “5” is attached. On the other hand, the host device 20 prohibits acceptance of data when receiving data sent in plain text, or when receiving data encrypted by an encryption method different from the encryption method of the encryption information corresponding to the data form “5” specified by the data communication device 10 at the time of the communication response, or when a hash value obtained by a hash operation based on the IV and the data body received by the host device 20 by the hash operation corresponding to the data form “5” is different from the hash value sent from the data communication device 10.

[0086] When host device 20 requests data communication device 10 to periodically transmit detection data every time a predetermined time has passed in a data request to data communication device 10, data communication device 10 periodically transmits detection data to host device 20 every time a predetermined time has passed as a data response.

[0087] For example, the data communication device 10 measures the time elapsed since the detection data was sent for the n-1th time. When the measured time reaches a predetermined time, the data communication device 10 detects the data again and sends the detection data as the nth data response to the host device 20. At this time, in the data related to the data response from the data communication device 10 to the host device 20, the nth detection data is included in the data body, "n" indicating the nth transmission is set in the counter, and "5" is set in the data format.

[0088] Furthermore, the data communication device 10 measures the time elapsed since the detection data was sent for the nth time. When the measured time reaches the predetermined time, the data communication device 10 detects the data again and sends the detection data as the n+1th data response to the host device 20. At this time, in the data related to the data response from the data communication device 10 to the host device 20, the n+1th detection data is included in the data body, "n+1" indicating the n+1th transmission is set in the counter, and "5" is set in the data format.

[0089] In this way, the data communication device 10 periodically sends to the host device 20 detection data that is encrypted using an encryption method corresponding to a data format "5" predetermined corresponding to the data communication device 10 and to which is attached a hash value that is a result of a hash calculation using a hash method corresponding to the data format "5" in accordance with a data request from the host device 20.

[0090] When the host device 20 receives and accepts the detection data periodically sent from the data communication device 10, it sends the acquired detection data to the central processing device 30 via the network 50. Data communication is performed between the host device 20 and the central processing device 30 by encrypting the detection data using a specific encryption method such as HTTPS (HyperText Transfer Protocol Secure). That is, the host device 20 encrypts the detection data acquired from each of the at least one data communication device 10 using a specific encryption method predetermined independently of the at least one data communication device 10 and sends the encrypted data to the central processing device 30.

[0091] Thus, the central processing unit 30 can obtain the detection data from each data communication device 10 among at least one data communication device 10 connected to the host device 20 from the host device 20 after encrypting it using a predetermined specific encryption method. Therefore, no matter which data communication device 10 the detection data is obtained from, the same decryption process can be performed, which can reduce the processing burden related to decryption.

[0092] In addition, the host device 20 may also send the detection data acquired from each of the at least one data communication device 10 to the central processing device 30 in a state of being encrypted by an encryption method predetermined by the data communication device 10. That is, the host device 20 may also send the detection data acquired from each of the at least one data communication device 10 to the central processing device 30 as it is without decrypting or encrypting.

[0093] Thus, even when the host device continuously receives data from each of at least one data communication device 10, it only needs to send the data as it is to the central processing unit 30, thereby reducing the processing burden related to decryption and encryption.

[0094] As described above, the host device 20 and each of the at least one data communication device 10 perform data communication using the encryption method and hash method predetermined for each of the at least one data communication device 10, so each of the at least one data communication device 10 only needs to be equipped with a control device 11 capable of performing encryption processing that matches the respective security level. As a result, compared with installing a control device 11 capable of performing encryption processing that matches the highest security level in all data communication devices 10, it is possible to ensure the security of data communication while suppressing an increase in size, cost, and power consumption.

[0095] The host device 20 can perform encryption processing according to the security level of at least one data communication device 10 connected, and add a hash value as a result of the operation using the hash method, so it is possible to flexibly support data communication devices 10 of various security levels. As a result, in the host device 20, high-speed processing is not performed in encryption of data communication with all the connected data communication devices 10, so an increase in power consumption can be suppressed.

[0096] The data communication device 10 only needs to include a control device 11 corresponding to a predetermined security level. In particular, a data communication device 10 such as a sensor that does not require security can use an inexpensive and small control device 11, thereby reducing the cost and power consumption of the data communication device 10.

[0097] The host device 20 encrypts the data and adds a hash value according to the encryption information and hash information specified by the data communication device 10, but the encryption method and hash method cannot be specified from the host device 20. Therefore, the encryption method and hash method cannot be specified to the data communication device 10 from an illegal host device disguised as a legitimate host device 20, so the confidentiality of the data in the data communication between the host device 20 and the data communication device 10 can be ensured.

[0098] [An example of retransmission data]

[0099] Reference Figure 5 The retransmission of data from the data communication device 10 to the host device 20 will be described. Figure 5 This is a diagram showing an example of data retransmission from the data communication device 10 to the host device 20 .

[0100] As described above, in the data communication system 1 , the host device 20 is configured to periodically receive detection data from the data communication device 10 . However, the host device 20 may fail to receive the detection data from the data communication device 10 due to some abnormality.

[0101] For example, Figure 5 As shown, after the data communication device 10 sends the detection data as the nth data response to the host device 20, after a predetermined time has passed, the data communication device 10 sends the detection data as the n+1th data response to the host device 20, but there is a case where due to some abnormality, the host device 20 does not normally receive the n+1th data response even after the predetermined time has passed. In this case, the host device 20 requests the data communication device 10 to resend the n+1th detection data.

[0102] Specifically, when the host device 20 does not receive the EOD of the data related to the data response for the n+1th time sent from the data communication device 10 and times out, it resends the request information for requesting the retransmission of the n+1th detection data to the data communication device 10. At this time, the data of the request information related to the data retransmission request from the host device 20 to the data communication device 10 includes command data for requesting the retransmission of the n+1th detection data, "m" indicating the mth transmission is set in the counter, and "5" is set in the data format. That is, when requesting the data communication device 10 to retransmit the detection data, the host device 20 encrypts the data related to the data retransmission request based on the encryption information and hash information corresponding to the data format "5" specified by the data communication device 10 at the time of the communication response, and sends it after adding a hash value.

[0103] When the data communication device 10 receives the request information related to the data retransmission request from the host device 20, it retransmits the n+1th detection data to the host device 20. At this time, in the data related to the data retransmission response from the data communication device 10 to the host device 20, the n+1th detection data is included in the data body, "n+1" indicating the n+1th transmission is set in the counter, and "5" is set in the data format. That is, when retransmitting the detection data to the host device 20, the data communication device 10 encrypts the detection data based on the encryption information and hash information corresponding to the data format "5" specified for the data communication device 10 in the communication response, and retransmits it after adding a hash value.

[0104] Thereafter, when the time elapsed from the retransmission of the detection data for the n+1th time reaches the prescribed time, the data communication device 10 detects the data again and transmits the detection data as the n+2th data response to the host device 20. At this time, in the data related to the data response from the data communication device 10 to the host device 20, the n+2th detection data is included in the data body, "n+2" indicating the n+2th transmission is set in the counter, and "5" is set in the data format.

[0105] Thus, when the host device 20 fails to receive detection data from the data communication device 10, it can request the data communication device 10 to retransmit data and obtain detection data again from the data communication device 10. Thus, the host device 20 can obtain detection data sent from the data communication device 10 without losing it.

[0106] [Another example of resending data]

[0107] Reference Figure 6 Another example of retransmitting data from the data communication device 10 to the host device 20 will be described. Figure 6 This is a diagram showing another example of data retransmission from the data communication device 10 to the host device 20 .

[0108] like Figure 6 As shown, after the data communication device 10 sends the detection data as the nth data response to the host device 20, after a predetermined time has passed, the data communication device 10 sends the detection data as the n+1th data response to the host device 20, but there is a case where the n+1th data response is not normally received by the host device 20 due to some abnormality, while the next n+2th data response is normally received by the host device 20. In this case, the host device 20 requests the data communication device 10 to resend the n+1th detection data and the n+2th detection data.

[0109] Specifically, when the host device 20 does not receive the EOD of the data related to the n+1th data response sent from the data communication device 10, but receives the EOD of the data related to the next n+2th data response and receives the EOD of the data related to the next n+3th data response, it again sends the request information for requesting the retransmission of the n+1th detection data and the n+2th detection data to the data communication device 10. In addition, the host device 20 regards that the n+3th data response has been received normally.

[0110] The data of the request information related to the data retransmission request from the host device 20 to the data communication device 10 includes command data for requesting the retransmission of the n+1th detection data and the n+2th detection data, "m" indicating the mth transmission is set in the counter, and "5" is set in the data format. That is, when requesting the data communication device 10 to retransmit the detection data, the host device 20 encrypts the data related to the data retransmission request based on the encryption information and hash information corresponding to the data format "5" specified by the data communication device 10 at the time of the communication response, and transmits it after adding a hash value.

[0111] When the data communication device 10 receives the request information related to the data retransmission request from the host device 20, it retransmits the n+1th detection data to the host device 20. At this time, in the data related to the data retransmission response from the data communication device 10 to the host device 20, the n+1th detection data is included in the data body, "n+1" indicating the n+1th transmission is set in the counter, and "5" is set in the data format. That is, when retransmitting the detection data to the host device 20, the data communication device 10 encrypts the detection data based on the encryption information and hash information corresponding to the data format "5" specified for the data communication device 10 in the communication response, and retransmits it after adding a hash value.

[0112] Furthermore, the data communication device 10 retransmits the n+2th detection data to the host device 20 in response to the data retransmission request from the host device 20. At this time, in the data related to the data retransmission response from the data communication device 10 to the host device 20, the n+2th detection data is included in the data body, "n+2" indicating the n+2th transmission is set in the counter, and "5" is set in the data format. That is, when retransmitting the detection data to the host device 20, the data communication device 10 encrypts the detection data based on the encryption information and hash information corresponding to the data format "5" specified for the data communication device 10 in the communication response, and retransmits it after adding a hash value.

[0113] Thereafter, when the time elapsed from the retransmission of the detection data for the n+2th time reaches the prescribed time, the data communication device 10 detects the data again and transmits the detection data as the n+4th data response to the host device 20. At this time, in the data related to the data response from the data communication device 10 to the host device 20, the n+4th detection data is included in the data body, "n+4" indicating the n+4th transmission is set in the counter, and "5" is set in the data format.

[0114] Thus, when the host device 20 fails to receive detection data from the data communication device 10, it can obtain detection data from the data communication device 10 again by requesting the data communication device 10 to retransmit data. Thus, the host device 20 can obtain detection data sent from the data communication device 10 without losing it.

[0115] [Modifications]

[0116] In the data communication system 1 according to the modification, the host device 20 may be configured to perform encryption processing or calculate the IV and the data body based on a hash method in data communication with the data communication device 10 when controlling the data communication device 10.

[0117] For example, the data communication device 10 connected to the host device 20 may be a control device that controls a device not shown in the figure according to control data from the host device 20. For example, the control device may be configured to open and close a door according to control data from the host device 20.

[0118] Then, the host device 20 may also obtain the encryption information and hash information using the data format included in the data related to the communication response from the data communication device 10 as the control device, and transmit the control data encrypted based on the encryption information and hash information and attached with the hash value to the data communication device 10. The data communication device 10 may also control the device according to the data obtained by decrypting the control data obtained from the host device 20. For example, the data communication device 10 may also be configured to open and close the door based on the control data obtained from the host device 20.

[0119] The data communication system 1 according to the embodiment and the modified example is described above, but the data communication system 1 may also be configured as follows: Figure 7 The model shown here comes from the sharing of functions among the devices. Figure 7 This is a diagram showing an example of function sharing in the data communication system 1 .

[0120] like Figure 7As shown, the main functions related to the data communication system 1 include a data acquisition function for acquiring data such as CO2 from an object space, a data collection function for collecting data acquired by each data communication device 10 in at least one data communication device 10, an operation function for using the collected data to analyze the CO2 concentration in the object space over time, a control data generation function for generating control data for displaying the analysis results, and an action function for displaying the CO2 concentration over time according to the control data.

[0121] In the function sharing mode 1, the data communication device 10 has a data acquisition function, the host device 20 has a data collection function, the central processing unit 30 has a calculation function and a control data generation function, and the terminal device 40 has an operation function.

[0122] In the function sharing mode 2, the data communication device 10 has the data acquisition function, the host device 20 has the data collection function and the calculation function, the central processing unit 30 has the control data generation function, and the terminal device 40 has the operation function.

[0123] In mode 3 of function sharing, the data communication device 10 has a data acquisition function, the host device 20 has a data collection function, a calculation function, and a control data generation function, and the terminal device 40 has an action function. In addition, in the case of mode 3, the host device 20 is integrally configured with the central processing unit 30. The device in which the host device 20 and the central processing unit 30 are integrally configured can be a PC, a server, or a cloud.

[0124] In addition, the range of functions of the data communication system 1 can also be distinguished by modes A to D. For example, in mode A, the data communication system 1 has a data acquisition function and a data collection function. In mode B, the data communication system 1 has a data acquisition function, a data collection function, and a calculation function. In mode C, the data communication system 1 has a data acquisition function, a data collection function, a calculation function, and a control data generation function. In mode D, the data communication system 1 has a data acquisition function, a data collection function, a calculation function, a control data generation function, and an action function.

[0125] <Method>

[0126] (Item 1) A data communication system (1) according to one embodiment comprises: at least one data communication device (10); and a host device (20) capable of communicating with the at least one data communication device. Each of the at least one data communication device sends encryption information related to an encryption method predetermined corresponding to the data communication device to the host device. The host device receives the encryption information from each of the at least one data communication device. The host device and each of the at least one data communication device perform data communication based on the encryption information.

[0127] (Item 2) In the data communication system described in Item 1, the host device and each of the at least one data communication device distinguish whether to encrypt data in the data communication based on the encryption information.

[0128] (Item 3) In the data communication system described in Item 1 or Item 2, each of the at least one data communication device sends hash information related to a predetermined hash method corresponding to the data communication device to the host device. The host device receives the hash information from each of the at least one data communication device. The host device and each of the at least one data communication device perform data communication based on the hash information.

[0129] (Item 4) In the data communication system described in Item 3, the host device and each of the at least one data communication device distinguish whether to attach a hash value of the data in the data communication based on the hash information.

[0130] (Item 5) In the data communication system described in any one of Items 1 to 4, each of at least one data communication device sends data to the host device based on encryption information related to an encryption method corresponding to the data communication device.

[0131] (Item 6) In the data communication system described in any one of Items 1 to 5, when the host device fails to receive data from at least one data communication device, the host device sends request information for requesting retransmission of data to the at least one data communication device. In response to receiving the request information, the at least one data communication device retransmits the data to the host device.

[0132] (Item 7) In the data communication system described in any one of Items 1 to 6, the host device sends data to each of at least one data communication device based on the encryption information related to the encryption method corresponding to the data communication device.

[0133] (Item 8) In the data communication system described in any one of Items 1 to 7, at least one data communication device includes at least one of a sensor device for detecting data, a camera device for photographing a target, and a control device for controlling the device.

[0134] (Item 9) The data communication system described in any one of Items 1 to 8 further comprises a central processing unit (30) capable of communicating with a host device. The host device encrypts data acquired from each of the at least one data communication device using a specific encryption method predetermined independently of the at least one data communication device and transmits the encrypted data to the central processing unit.

[0135] (Item 10) The data communication system described in any one of Items 1 to 8 further comprises a central processing unit (30) capable of communicating with a host device. The host device transmits data acquired from each of the at least one data communication device to the central processing unit in an encrypted state using an encryption method corresponding to the data communication device.

[0136] (Item 11) In the data communication system described in any one of Items 1 to 10, at least one data communication device and the host device can communicate via a connector (130, 230) compliant with the USB standard or via a wireless connection.

[0137] (Item 12) A data communication device (10) according to one embodiment comprises: a control device (11); and a communication interface (13) for communicating with a host device. The control device receives inquiry information related to an inquiry about an encryption method from the host device, and in response to receiving the inquiry information, the control device sends encryption information related to a predetermined encryption method to the host device, and the control device performs data communication with the host device based on the encryption information.

[0138] (Item 13) A host device (20) according to one embodiment comprises: a control device (21); and a communication interface (23) for communicating with at least one data communication device. The control device sends inquiry information related to an inquiry about a predetermined encryption method corresponding to the data communication device to each of the at least one data communication device, receives encryption information related to the encryption method corresponding to the data communication device from each of the at least one data communication device, and performs data communication with each of the at least one data communication device based on the encryption information.

[0139] (Item 14) A data communication method involves the following steps: receiving query information related to a query on an encryption method from a host device (20); sending encryption information related to a predetermined encryption method to the host device in response to receiving the query information; and communicating data with the host device based on the encryption information.

[0140] (Item 15) A data communication method involves the following steps: sending query information related to a query corresponding to a predetermined encryption method of the data communication device to each data communication device (10) in at least one data communication device (10); receiving encryption information related to the encryption method corresponding to the data communication device from each data communication device in at least one data communication device; and performing data communication with each data communication device in at least one data communication device based on the encryption information.

[0141] (Item 16) A data communication procedure involves the following steps: receiving query information related to a query on an encryption method from a host device (20); sending encryption information related to a predetermined encryption method to the host device in response to receiving the query information; and communicating data with the host device based on the encryption information.

[0142] (Item 17) A data communication procedure involves the following steps: sending query information related to a query regarding a predetermined encryption method corresponding to the data communication device to each data communication device (10) in at least one data communication device (10); receiving encryption information related to the encryption method corresponding to the data communication device from each data communication device in at least one data communication device; and performing data communication with each data communication device in at least one data communication device based on the encryption information.

[0143] Although the embodiment and the modified examples have been described above, the features of each of the embodiment and the modified examples can be appropriately combined within a range where no contradiction occurs.

[0144] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present disclosure is indicated by the claims rather than the description of the embodiments described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0145] Description of Reference Numerals

[0146] 1: data communication system; 10, 10A, 10B, 10C, 10D: data communication device; 11, 21: control device; 12, 22: storage unit; 13, 23: communication interface; 14: data detection unit; 20: host device; 24: communication device; 30: central processing unit; 40: terminal device; 50: network; 120, 220: control program; 125: setting data; 130: insertion side connector; 230: receiving side connector.

Claims

1. A data communication system comprising: at least one data communication device; and a host device capable of communicating with the at least one data communication device, in, Each of the at least one data communication device sends encryption information related to a predetermined encryption method corresponding to the data communication device to the host device, The host device receives the encrypted information from each of the at least one data communication device, The host device performs data communication with each of the at least one data communication device based on the encryption information.

2. The data communication system according to claim 1, wherein: The host device and each of the at least one data communication device distinguish whether to encrypt data in data communication based on the encryption information.

3. The data communication system according to claim 1 or 2, wherein: Each of the at least one data communication device sends hash information related to a predetermined hash method corresponding to the data communication device to the host device, The host device receives the hash information from each of the at least one data communication device, The host device performs data communication with each of the at least one data communication device based on the hash information.

4. The data communication system according to claim 3, wherein: The host device and each of the at least one data communication device distinguish whether to add a hash value of data in data communication based on the hash information.

5. The data communication system according to any one of claims 1 to 4, wherein: Each of the at least one data communication device transmits data to the host device based on the encryption information related to the encryption method corresponding to the data communication device.

6. The data communication system according to any one of claims 1 to 5, wherein: The host device, when failing to receive data from the at least one data communication device, transmits request information for requesting retransmission of data to the at least one data communication device, The at least one data communication device retransmits data to the host device in response to receiving the request information.

7. The data communication system according to any one of claims 1 to 6, wherein: The host device transmits data to each of the at least one data communication device based on the encryption information related to an encryption method corresponding to the data communication device.

8. The data communication system according to any one of claims 1 to 7, wherein: The at least one data communication device includes at least one of a sensor device for detecting data, a camera device for photographing a target, and a control device for controlling a device.

9. The data communication system according to any one of claims 1 to 8, wherein: Also provided is a central processing unit capable of communicating with the host device, The host device encrypts the data acquired from each of the at least one data communication device using a specific encryption method predetermined independently of the at least one data communication device and transmits the encrypted data to the central processing device.

10. The data communication system according to any one of claims 1 to 8, wherein: Also provided is a central processing unit capable of communicating with the host device, The host device transmits the data acquired from each of the at least one data communication device to the central processing device in a state of being encrypted by an encryption method corresponding to the data communication device.

11. The data communication system according to any one of claims 1 to 10, wherein: The at least one data communication device can communicate with the host device via a connector conforming to the USB standard or via a wireless connection.

12. A data communication device for communicating with a host device, the data communication device comprising: Control devices; and a communication interface for communicating with the host device, in, The control device receives inquiry information related to the inquiry in the encrypted manner from the host device, In response to receiving the query information, the control device sends encryption information related to a predetermined encryption method to the host device, The control device performs data communication with the host device based on the encrypted information.

13. A host device for communicating with at least one data communication device, the host device comprising: Control devices; and a communication interface for communicating with the at least one data communication device, in, The control device sends inquiry information related to the inquiry corresponding to the predetermined encryption method of the data communication device to each of the at least one data communication device, The control device receives encryption information related to the encryption method corresponding to each of the at least one data communication device from the data communication device. The control device performs data communication with each of the at least one data communication device based on the encrypted information.

14. A data communication method, which is a data communication method performed by a computer for a data communication device to communicate with a host device, comprising the following steps: receiving query information related to the encrypted query from the host device; In response to receiving the query information, sending encryption information related to a predetermined encryption method to the host device; as well as Data is communicated with the host device based on the encrypted information.

15. A data communication method, which is a data communication method performed by a computer for a host device to communicate with at least one data communication device, comprising the following steps: sending inquiry information related to an inquiry corresponding to a predetermined encryption method of the data communication device to each of the at least one data communication device; receiving, from each of the at least one data communication device, encryption information related to an encryption method corresponding to the data communication device; as well as Data communication is performed with each of the at least one data communication device based on the encryption information.

16. A data communication program is a data communication program executed by a computer for a data communication device to communicate with a host device, comprising the following steps: receiving query information related to the encrypted query from the host device; In response to receiving the query information, sending encryption information related to a predetermined encryption method to the host device; as well as Data is communicated with the host device based on the encrypted information.

17. A data communication program, which is executed by a computer and is used for a host device to communicate with at least one data communication device, comprising the following steps: sending inquiry information related to an inquiry corresponding to a predetermined encryption method of the data communication device to each of the at least one data communication device; receiving, from each of the at least one data communication device, encryption information related to an encryption method corresponding to the data communication device; as well as Data communication is performed with each of the at least one data communication device based on the encryption information.

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