JP7000925B2 - Data processing system and encryption key sharing method - Google Patents

Description

The present invention relates to a data processing system and an encryption key sharing method.

In recent years, various devices have been connected to a network to collect data, and the collected data has been analyzed using AI (Artificial Intelligence). On the other hand, since various devices are exposed to the threat of cyber attacks by connecting to the network, security measures are required. In particular, from the viewpoint of utilization of sensor data, data security that can safely deliver the sensing data collected from the end devices to the cloud is required.

Patent Document 1 describes that transmission information is encrypted using a common key or a public key to generate encrypted information.

In Patent Document 2, the terminal transmits the encrypted data obtained by encrypting the data using the encryption key and the encryption key share to the data center, and the data center stores the encrypted data and the encryption key share in association with each other. Is described.

In Patent Document 3, the client 1 transfers the encrypted content and the half key of the common key to which the common key ID (IDentification) is given to the client 2. The client 2 requests the key management server 3 to transfer the half key together with the ID of the common key and its own client ID. The key management server 3 checks whether the requesting client is a legitimate client from the common key ID and the client ID indicating the delivery destination, and then encrypts and transmits the common key registered with the public key of the requested client 2. do. The client 2 synthesizes a common key from the half key of the common key decrypted with its own private key and the other half key from the client 1, and decrypts the encrypted content using the common key. ..

Japanese Unexamined Patent Publication No. 2016-142608 Japanese Unexamined Patent Publication No. 2008-219178 Japanese Unexamined Patent Publication No. 2007-089098

Data encryption is known as a measure for ensuring data security. There are two types of encryption methods: common key cryptography and public key cryptography.

The common key cryptosystem is a method in which the key to be encrypted and the key to be decrypted are equal. Therefore, in the case of the common key cryptosystem, it is necessary to share the key in advance between the encryption side and the decryption side.

The public key cryptosystem uses two types of keys, a private key known only to the owner and a public key that is widely disclosed. In public key cryptography, a public key is used when encrypting, and a private key is used when decrypting.

The public key cryptosystem has an advantage in that it is not necessary to share the key in advance, but the common key cryptosystem is superior in terms of implementability and processing performance. In particular, the capacity of the ROM (Read Only Memory) and RAM (Random Access Memory) of the microcomputer used to control the sensor device, and the capacity of the CPU (Central Processing Unit) are generally very small compared to personal computers. It is powerless. In such an environment, it is appropriate to adopt a common key cryptosystem in order to securely transmit sensing data.

However, when adopting the common key cryptosystem, it is necessary to overcome the following problems.

Sensor devices and the like are shipped with the OS (Operating System) and applications written in ROM, and are basically not rewritten after shipment. Therefore, when implementing the encryption function of the common key encryption method, the encryption key is written in the ROM before shipment. At this time, in order to decrypt the data encrypted by this sensor device, the same encryption key is required in the decryption side system, but it must be implemented in the decryption side system without leaking the encryption key. However, although the manufacturing vendor of the sensor device can know the encryption key, the problem is how to implement the encryption key when a third party other than the manufacturing vendor uses the sensor device. Once the encryption key is leaked, it takes a lot of labor and cost to update the key on the sensor device side, so it is not possible to easily teach the encryption key. In this way, when a third party builds a secure data processing system using an arbitrary sensor device, the encryption key is securely supplied to the decryption side system and complicated development is not required. It is requested to do.

Furthermore, there are cases where the same key is used for each lot or product as the key embedded in mass-produced sensor devices. For this reason, a situation occurs in which the same key is used between systems that are completely unrelated to each other. In such a case, if the key used in one system is leaked, the encrypted data of another system will be decrypted by a malicious third party.

It is difficult to solve the above-mentioned problems of the common key cryptosystem with the techniques described in Patent Documents 1-3.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a data processing system capable of reducing the risk of leakage of an encryption key, and an encryption key sharing method.

The data processing system of the present invention includes a data transmission device for transmitting encrypted data, a data collection device for receiving and decrypting the encrypted data, and a confidential information database, and the data transmission device. Stores in advance the identification information that identifies the data transmission device and the first secret information that, when a plurality of the data transmission devices are present, has different values for each of the data transmission devices and is not an encryption key. Each time a communication connection with the data collection device is established, a temporary key, which is an encryption key having a random value, is generated, and the generated temporary key is multiplied by the first secret information. Confidential information is generated, and the identification information and the third confidential information are transmitted to the data collection device. The confidential information database has the identification information and the first secret for each of the plurality of data transmission devices. The second secret information, which is the reverse source of the information, is stored in association with the second secret information, and the data collecting device searches the secret information database using the received identification information as a key, and the second secret information corresponding to the received identification information is searched. The secret information is specified, and the temporary key is calculated from the specified second secret information and the received third secret information.

The encryption key sharing method of the present invention is an encryption key sharing method in a data processing system including a data transmission device for transmitting encrypted data and a data collection device for receiving and decrypting the encrypted data. Therefore, in the secret information database, for each of the plurality of data transmission devices, the identification information for identifying the data transmission device and the first secret having different values for each of the plurality of data transmission devices and not an encryption key. The second secret information, which is the reverse source of the information, is stored in association with each other, and the data transmission device stores the identification information and the first secret information in advance, and a communication connection between the data collection device and the data collection device is established. Each time it is established, a temporary key which is an encryption key having a random value is generated, a third secret information is generated by multiplying the generated temporary key and the first secret information, and the identification information and the third secret are generated. Information is transmitted to the data collection device, and the data collection device searches the secret information database using the received identification information as a key, identifies the second secret information corresponding to the received identification information, and identifies the second secret information. It is characterized in that the temporary key is calculated from the specified second secret information and the received third secret information.

According to the present invention, it is possible to reduce the risk of leakage of the encryption key.

It is a block diagram which shows the structural example of the data processing system which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation example (encryption key sharing method) of the data processing system shown in FIG. 1, and in detail, is the flowchart which shows the operation example of the data transmission device shown in FIG. It is a flowchart which shows the operation example (encryption key sharing method) of the data processing system shown in FIG. 1, and more specifically, is the flowchart which shows the operation example of the data collection device shown in FIG. It is a block diagram which shows the structural example of the data processing system which concerns on 2nd Embodiment of this invention. An example of the data structure of the confidential information database shown in FIG. 4 is shown. It is a sequence chart which shows the 1st operation example (encryption key sharing method) of the data processing system shown in FIG. It is a sequence chart which shows the 2nd operation example (encryption key sharing method) of the data processing system shown in FIG. It is a block diagram which shows the structural example of the data processing system which concerns on 3rd Embodiment of this invention. It is a sequence chart which shows the operation example (encryption key sharing method) of the data processing system shown in FIG.

[First Embodiment]
(Explanation of configuration)
FIG. 1 is a block diagram showing a configuration example of the data processing system 10 according to the first embodiment of the present invention.

The data processing system 10 includes a data transmission device 12 for transmitting encrypted data, a data collection device 14 for receiving and decrypting encrypted data, and a confidential information database 16.

The data transmission device 12 stores in advance the identification information for identifying the data transmission device 12 and the first secret information. The first secret information is secret information having a different value in each of the data transmission devices 12 and not an encryption key when a plurality of data transmission devices 12 are present. The data transmission device 12 generates a temporary key, which is an encryption key having a random value, every time a communication connection with the data collection device 14 is established, and the generated temporary key is multiplied by the first secret information. Generate third confidential information. The data transmission device 12 transmits the previously recorded identification information and the generated third secret information to the data collection device 14.

The secret information database 16 stores the identification information and the second secret information in association with each other for each of the plurality of data transmission devices 12. The second secret information is an inverse element of the first secret information stored by each of the plurality of data transmission devices 12. For example, the second secret information is a multiplicative inverse element of the first secret information. Specifically, the first secret information and the second secret information are elements on a finite field, respectively, and when they are multiplied by each, they become 1.

The data collection device 14 searches the secret information database 16 using the identification information received from the data transmission device 12 as a key. The data collecting device 14 identifies the second secret information corresponding to the received identification information, and calculates a temporary key from the specified second secret information and the received third secret information.

As mentioned above, the first secret information itself is not an encryption key. The second secret information, which is the reverse source of the first secret information, and the third secret information obtained by multiplying the temporary key and the first secret information are not encryption keys like the first secret information. Therefore, even if these confidential information is leaked, the temporary key cannot be identified immediately.
(Explanation of operation)
2 and 3 are flowcharts showing an operation example (encryption key sharing method) of the data processing system 10 shown in FIG. In detail, FIG. 2 is a flowchart for explaining an operation example of the data transmission device 12. FIG. 3 is a flowchart for explaining an operation example of the data acquisition device 14.

As a premise of the operation described below, it is assumed that the data transmission device 12 stores the identification information and the first secret information in advance. Further, in the secret information database 16, the identification information and the second secret information are stored in association with each other for each of the plurality of data transmission devices 12.

As shown in FIG. 2, the data transmission device 12 determines whether or not a communication connection with the data collection device 14 is established (step S1). If the communication connection is not established (No in step S1), the process of step S1 is executed again.

When a communication connection with the data acquisition device 14 is established (Yes in step S1), the data transmission device 12 generates a temporary key (step S2). The data transmission device 12 multiplies the generated temporary key with the first secret information to generate the third secret information (step S3). The data transmission device 12 transmits the identification information and the third secret information to the data collection device 14 (step S4).

The data transmission device 12 encrypts predetermined data (for example, sensing data) with the temporary key generated in step S2 (step S5). The data transmission device 12 transmits the encrypted data to the data collection device 14 (step S6).

As shown in FIG. 3, the data acquisition device 14 determines whether or not the identification information and the third secret information have been received from the data transmission device 12 (step S10). If the identification information and the third secret information are not received (No in step S10), the process of step S10 is executed again.

When the identification information and the third secret information are received (Yes in step S10), the data collection device 14 searches the secret information database 16 using the received identification information as a key, and the second secret information corresponding to the received identification information. (Step S11). The data acquisition device 14 calculates the temporary key by multiplying the specified second secret information and the received third secret information (step S12).

By the above processing, the data collection device 14 can share the temporary key with the data transmission device 12 as an encryption key.

After that, the data acquisition device 14 determines whether or not the encrypted data has been received from the data transmission device 12 (step S13). If the encrypted data is not received (No in step S13), the process of step S13 is executed again.

When the encrypted data is received (Yes in step S13), the data acquisition device 14 decrypts the encrypted data using the temporary key calculated in step S12 (step S14). As a result, the data collection device 14 can obtain predetermined data.
(Explanation of effect)
In the first embodiment described above, the encryption key (temporary key of the present embodiment) used at the time of decryption in the data collection device 14 which is the system on the side of decrypting the encrypted data is itself. It is calculated based on the second secret information and the third secret information, which are meaningless information, not the encryption key.

Further, in the communication performed for sharing the encryption key between the data transmission device 12 and the data collection device 14, the third secret information is transmitted instead of the temporary key, so that the third secret information is assumed. Even if is intercepted, the temporary key will not be identified immediately.

Further, as shown in FIGS. 2 and 3, the temporary key is updated every time a communication connection is established between the data transmitting device 12 and the data collecting device 14. This is because, as mentioned above, the temporary key is a random value.

That is, according to the first embodiment, it is possible to reduce the risk of leakage of the encryption key. By reducing the risk of leakage, the work when the encryption key is leaked (for example, updating the encryption key in the system on the encryption side) becomes unnecessary or reduced.

Further, it is not necessary for the developer of the data transmission device 12 to disclose the encryption key to a third party who uses the data transmission device 12. Furthermore, the third party does not have to be aware of the encryption key. Therefore, it is possible to smoothly develop each device.

The search of the confidential information database 16 may be directly executed by the data collection device 14 as in the first embodiment, or may be executed by another device (confidential information management) as in the second embodiment described later. The device 103) may be instructed to search and receive only the result.

Further, the processes of steps S5 and S6 in FIG. 2 and the processes of steps S13 and S14 in FIG. 3 are not necessarily the processes necessary for achieving the problem.
[Second Embodiment]
(Explanation of configuration)
FIG. 4 is a block diagram showing a configuration example of the data processing system 100 according to the second embodiment of the present invention. The data processing system 100 includes a configuration based on the data processing system 10 shown in FIG. The data processing system 100 includes a data transmission device 101, a data collection device 102, and a confidential information management device 103. The connection between each device and the connection within each device in FIG. 4 are merely examples.

The data transmission device 101 is typically a device, for example, a sensor device, in which the capacity of the ROM or RAM of the microcomputer used for control and the capacity of the CPU are lower than those of a general personal computer. In the following, a case where the data transmission device 101 is a sensor device will be described as an example. The data transmission device 101 is provided in a device to be sensed (not shown in FIG. 1). The data transmission device 101 acquires data on a predetermined physical quantity of the device to be sensed, for example, data on temperature / humidity, vibration, sound, and video. The data transmission device 101 includes a communication unit 1011, a sensor unit 1012, an encryption unit 1013, a RAM 1016, and a storage unit 1017.

Confidential information A (an example of first confidential information) and product information (an example of identification information) are stored in the storage unit 1017. The secret information A is information that has a different value for each data transmission device 101 and is not an encryption key when a plurality of data transmission devices 101 exist. The product information is unique information for identifying the data transmission device 101. The product information is, for example, a manufacturing vendor, a product name, or an ID associated with the manufacturing vendor.

The sensor unit 1012 outputs the measured data as sensor data. The sensor unit 1012 is, for example, a temperature / humidity sensor, a vibration sensor, an acoustic sensor, a camera, or the like.

The encryption unit 1013 generates a temporary key, which is an encryption key of a random value, every time a communication connection is formed between the data transmission device 101 and the data collection device 102. The temporary key is stored in, for example, RAM 1016.

The encryption unit 1013 generates the secret information C (an example of the third secret information) by multiplying the generated temporary key and the secret information A stored in the storage unit 1017. The encryption 1013 transmits the generated secret information C and the product information stored in the storage unit 1017 to the data collection device 102 via the communication unit 1011.

Further, the encryption unit 1013 encrypts the sensor data input from the sensor unit 1012 using the temporary key recorded in the RAM 1016. The encryption unit 1013 transmits the encrypted sensor data to the data collection device 102 via the communication unit 1011.

The communication unit 1011 transmits / receives data to / from the data collection device 102.

The data acquisition device 102 may exist on the same local network as the data transmission device 101, or in the cloud on the Internet.

The data collecting device 102 includes a communication unit 1021, an analysis unit 1022, a key generation unit 1023, a decoding unit 1024, a RAM 1025, and a storage unit 1026.

The communication unit 1021 transmits / receives data to / from the data transmission device 101 and the confidential information management device 103.

The key generation unit 1023 calculates a temporary key. The calculated temporary key is recorded in the RAM 1025. The method of calculating the temporary key will be described later.

The decryption unit 1024 obtains the sensor data by decoding the encrypted sensor data received from the data transmission device 101 via the communication unit 1021 using the temporary key recorded in the RAM 1025. The decoded sensor data is stored in, for example, the storage unit 1026.

The RAM 1025 is a volatile memory. That is, when the power supply to the data acquisition device 102 is stopped, the data recorded in the RAM 1025, for example, the temporary key is lost.

The analysis unit 1022 analyzes the decoded sensor data. The analysis unit 1022 stores the analysis result in the storage unit 1026 as needed.

The secret information management device 103 is configured separately from the data collection device 102, and exists in the cloud on the Internet or in the same local network as the data collection device 102.

The secret information management device 103 includes a communication unit 1031, a search unit 1032, and a secret information database 1033.

The communication unit 1031 transmits / receives data to / from the data collection device 102.

The secret information database 1033 is a secret information B (an example of a second secret information) which is the reverse source of the product information and the secret information A stored in each of the data transmission devices 101 for each of the plurality of data transmission devices 101. And memorize in association with. For example, the secret information B is a multiplicative inverse element of the secret information A recorded in the data transmission device 101. Specifically, the secret information A and the secret information B are elements on a finite field, respectively, and when they are multiplied by each, they become 1.

FIG. 5 shows an example of a data structure of the secret information database 1033. In FIG. 5, the product information is composed of a vendor name and a device name. For example, the secret information B of the product information data transmission device 101 whose vendor name is "Company A" and whose device name is "W" is "3746". In this way, the secret information database 1033 records the vendor name and device name and the secret information B in association with each other.

The search unit 1032 searches the secret information database 1033 via the communication unit 1031 using the product information received from the data collection device 102 as a key.
(Explanation of the first operation example)
FIG. 6 is a sequence chart showing a first operation example (encryption key sharing method) of the data processing system 100 shown in FIG. In this sequence chart, from the time when the communication connection is established between the data transmission device 101 and the data collection device 102 until the temporary key is shared between the data transmission device 101 and the data collection device 102. It explains the operation. Therefore, please refer to FIGS. 2 and 3 for the determination of the establishment of the communication connection, the encryption of the data, the transmission / reception of the encrypted data, and the decryption of the encrypted data.

The security of communication between the data collection device 102 and the confidential information management device 103 is ensured by an encryption protocol such as TSL (Transport Layer Security).

The encryption unit 1013 of the data transmission device 101 generates a temporary key when a communication connection is formed between the data transmission device 101 and the data collection device 102 (step S20). The encryption unit 1013 generates the secret information C by multiplying the generated temporary key and the secret information A (step S21). Then, the encryption unit 1013 transmits the product information and the confidential information C to the data collection device 102 via the communication unit 1011 (step S22).

The key generation unit 1023 of the data collection device 102 records the secret information C in the RAM 1025. Further, the key generation unit 1023 transmits a secret information request including product information to the secret information management device 103 via the communication unit 1021 (step S23).

When the search unit 1032 of the confidential information management device 103 receives the confidential information request, the search unit 1032 searches the confidential information database 1033 using the product information included in the confidential information request as a key, and determines whether or not the received product information is registered. (Step S24). If the product information is registered, the search unit 1032 acquires the corresponding confidential information B.

The search unit 1032 transmits the collation result to the data collection device 102 via the communication unit 1031 (step S25). When the product information is registered, the collation result includes the OK (registered) status and the confidential information B acquired from the confidential information database 1033. If the product information is not registered, the collation result includes only the NG (no registration) status.

When the collation result including the OK status is received, the key generation unit 1023 of the data collection device 102 calculates the temporary key by multiplying the secret information C recorded in the RAM 1025 and the secret information B included in the collation result. (Step S26).

Here, when the secret information A is SA, the secret information C is SC, the secret information B is SB (that is, 1 / SA), and the temporary key is KT, the key generation unit 1023 sets (Equation 1). By calculating, the temporary key KT generated by the data transmission device 101 can be restored. The restored temporary key KT is recorded in the RAM 1025.

SC x SB = (SA x KT) x 1 / SA = KT (Equation 1)
The key generation unit 1023 transmits shared OK or shared NG to the data transmission device 101 (step S27). When the key generation unit 1023 receives the collation result including the OK status from the secret information management device 103, the key generation unit 1023 transmits a shared OK to the data transmission device 101 and outputs the collation result including the NG status from the secret information management device 103. When it is received, the shared NG is transmitted to the data transmission device 101.

In the case of sharing OK, sharing of the temporary key between the data transmitting device 101 and the data collecting device 102 is completed. Therefore, thereafter, the data transmission device 101 encrypts the sensor data with the temporary key and transmits the data to the data collection device 102, and the data collection device 102 uses the temporary key recorded in the RAM 1025 by the decoding unit 1024 to encrypt the data. Can be decrypted.

On the other hand, in the case of sharing NG, sharing of the temporary key between the data transmitting device 101 and the data collecting device 102 is not completed. Therefore, it is impossible for the data acquisition device 102 to decode the sensor data. That is, the data acquisition device 102 cannot use the sensor data.
(Explanation of effect)
According to the second embodiment described above, it is possible to obtain the same effect as that of the first embodiment.

Further, in the second embodiment, the temporary key is stored in the RAM 1025 in the data acquisition device 102. Since the RAM 1025 is a volatile memory, the temporary key recorded in the RAM 1025 is lost when the power supply to the data acquisition device 102 is stopped. That is, even if the data collection device 102 is activated next time, the temporary key does not exist until a new communication connection is established. Therefore, since the state in which the temporary key is maintained unnecessarily is further reduced, the risk of the temporary key being leaked can be further reduced.
(Explanation of the second operation example)
FIG. 7 is a sequence chart showing a second operation example (encryption key sharing method) of the data processing system 100 shown in FIG.

If the temporary key is not correctly shared between the data transmitting device 101 and the data collecting device 102, the data collecting device 102 cannot correctly decode the received data.

Therefore, FIG. 7 shows a second operation example as a countermeasure against this problem. The feature of the second operation example is that it has a phase of confirming whether or not the temporary keys match the exact values. The processing from step S20 to step S26 in FIG. 7 is the same as that in FIG.

The key generation unit 1023 of the data collection device 102 generates challenge data (step S40). Challenge data is a disposable random number. The key generation unit 1023 transmits the challenge data to the data transmission device 101 (step S41).

The encryption unit 1013 of the data transmission device 101 encrypts the received challenge data with a temporary key to create response data (step S42). The encryption unit 1013 transmits the response data to the data collection device 102 (step S43).

The key generation unit 1023 decodes the received response data with its own temporary key, and verifies whether the decoding result matches the challenge data (step S44). If they match, it can be confirmed that the same temporary key can be shared, and if they do not match, sharing has failed. The key generation unit 1023 transmits a verification result (OK or NG) to the data transmission device 101 (step S45).

As described above, by adding the processes of steps S40 to S45 to the operation of FIG. 6, it is possible to confirm whether or not the temporary key sharing is successful, so that the data collection device 102 collects data. The processing can be carried out reliably.
<Modification example>
In the second embodiment, the product information is given as an example of the identification information, but the identification information may be any information as long as it can identify the data transmission device 101.

Further, in the second embodiment, the case where the data transmission device 101 is a sensor device is taken as an example, but the data transmission device 101 is any device as long as it is a device that encrypts and transmits predetermined data. May be good.
[Third Embodiment]
FIG. 8 is a block diagram showing a configuration example of the data processing system 200 according to the third embodiment. The difference between the data processing system 200 and the data processing system 100 shown in FIG. 4 is that the data processing system 200 further includes an edge device 104.

The edge device 104 is installed for the purpose of reducing the processing load of the data collection device 102. The edge device 104 is provided between the data transmission device 101 and the data collection device 102.

Since the data is once decrypted by the edge device 104, it is necessary to share the temporary key. Further, when the data processed by the edge device 104 is transmitted to the data collection device 102, the data is encrypted again and decrypted by the data collection device 102, so that the data collection device 102 also needs to share the temporary key.

FIG. 9 is a sequence chart illustrating the processing at this time. As shown in FIG. 9, the edge device 104 transfers the data (product information and confidential information C) received from the data transmission device 101 to the data collection device 102 (step S50). Further, the data collecting device 102 transfers the collation result received from the secret information management device 103 to the edge device 104 (step S55). By the above operation, the edge device 104 and the data collection device 102 can share the same temporary key.

According to the data processing system 200 of the third embodiment described above, it is possible to reliably perform the data collection processing in the data collection device 102 while reducing the processing load of the data collection device 102.
[Fields where the invention can be used]
The first to third embodiments described above can be applied to systems in all fields such as a system connected to a network and collecting information from a remote device. The above system is, for example, a system for monitoring the operating status of industrial machines installed in factories, a system for monitoring the deterioration status of social infrastructure and important infrastructure, a security camera system, a system for collecting biological information, and the like. ..

Although the present invention has been described above using each embodiment, the technical scope of the present invention is not limited to the description of each of the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to each of the above embodiments. Therefore, it is needless to say that such modified or improved forms are also included in the technical scope of the present invention. Further, the numerical values and the names of the respective configurations used in the above-described embodiments are exemplary and can be changed as appropriate.

10 Data processing system 12 Data transmission device 14 Data collection device 100 Data processing system 101 Data transmission device 102 Data collection device 103 Confidential information management device 104 Edge device 200 Data processing system 1011 Communication unit 1012 Sensor unit 1013 Encryption unit 1016 RAM
1017 Storage unit 1021 Communication unit 1022 Analysis unit 1023 Key generation unit 1024 Decoding unit 1025 RAM
1026 Storage unit 1031 Communication unit 1032 Search unit 1033 Confidential information database

Claims (10)

A data transmitter that sends encrypted data, and
A data collection device that receives and decrypts the encrypted data, and
Equipped with a confidential information database
The data transmission device includes identification information that identifies the data transmission device, and first secret information that, when a plurality of the data transmission devices are present, has different values for each of the data transmission devices and is not an encryption key. , Are stored in advance, a temporary key that is an encryption key of a random value is generated each time a communication connection with the data collection device is established, and the generated temporary key is multiplied by the first secret information. The combined third secret information is generated, and the identification information and the third secret information are transmitted to the data collection device.
The secret information database stores the identification information and the second secret information, which is the inverse element of the first secret information, in association with each of the plurality of data transmission devices.
The data collecting device searches the secret information database using the received identification information as a key, identifies the second secret information corresponding to the received identification information, and receives the specified second secret information. A data processing system characterized in that the temporary key is calculated from the third secret information. The secret information database is included in a secret information management device that is configured separately from the data collection device.
The confidential information management device receives a confidential information request including the identification information from the data collection device, searches the confidential information database using the received identification information as a key, and corresponds to the received identification information. The data processing system according to claim 1, wherein the second secret information is specified and the collation result including the specified second secret information is transmitted to the data collecting device. It is a device for reducing the processing load of the data collection device, and further includes an edge device provided between the data transmission device and the data collection device.
The edge device receives the identification information and the third secret information from the data transmission device, and transmits the received identification information and the third secret information to the data collection device.
The data processing system according to claim 2, wherein the data collecting device receives the collation result from the secret information management device and transfers the received collation result to the edge device. The data processing system according to claim 2 or 3, wherein the communication between the data collecting device and the confidential information management device is secured by using a predetermined encryption protocol. After calculating the temporary key, the data acquisition device transmits challenge data, which is a disposable random number, to the data transmission device.
The data transmission device encrypts the received challenge data with the temporary key to create response data, and transmits the response data to the data collection device.
One of claims 1 to 4, wherein the data acquisition device decodes the received response data with the temporary key, and verifies whether or not the decrypted result matches the challenge data. The data processing system described in Section. The data processing system according to any one of claims 1-5, wherein the inverse element is a multiplicative inverse element. The data processing system according to any one of claims 1 to 6, wherein the data collecting device records the calculated temporary key in a volatile memory. The data processing system according to any one of claims 1 to 7, wherein the data transmission device acquires sensor data. The data processing system according to any one of claims 1 to 8, wherein the identification information is product information. A method for sharing an encryption key in a data processing system including a data transmission device for transmitting encrypted data and a data collection device for receiving and decrypting the encrypted data.
In the secret information database, the reverse of the identification information that identifies the data transmission device for each of the plurality of data transmission devices and the first secret information that has a different value for each of the plurality of data transmission devices and is not an encryption key. Store it in association with the original second secret information,
The data transmitting device stores the identification information and the first secret information in advance, and generates a temporary key which is an encryption key having a random value each time a communication connection is established with the data collecting device. , Generates a third secret information by multiplying the generated temporary key and the first secret information, and transmits the identification information and the third secret information to the data collection device.
The data collecting device searches the secret information database using the received identification information as a key, identifies the second secret information corresponding to the received identification information, and receives the specified second secret information. A method for sharing an encryption key, which comprises calculating the temporary key from the third secret information.

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