Data relay system

Abstract

To allow an insurance company to set an insurance bill of cyber insurance to an appropriate sum.SOLUTION: When relaying data communicated between an internal terminal and an external terminal within a network by a data repeating device, the data are also transmitted from the data repeating device to a block data transmission device. The block data transmission device generates block data in a block chain format by using the received data, and stores the data in a block chain network by transmitting the data to a node of the block chain network. In this manner, data communicated between an internal terminal in the network and an external terminal can be stored in the block chain network, the causes of intrusion, presence / absence of responsibility, and the like can be clarified by examining the data even if the network is intruded. Therefore, an insurance company can set an insurance bill to an appropriate sum that is considered to be appropriate according to a cyber risk estimated at the time of contract.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a technique for relaying data communicated between a plurality of processing terminals by interposing between processing terminals capable of communicating data with each other within a network or between processing terminals outside the network. [Background technology]

[0002] Thanks to advances in computer technology and information and communication technology, various server devices and processing terminals are now connected in a state in which they can communicate with each other, forming a network system as a whole. Furthermore, these network systems (simply called "networks") are connected in a state in which they can communicate with external processing terminals and other networks via the Internet. While this makes it possible to collect and utilize a large amount of various information, it also creates the risk of significant damage (hereinafter referred to as cyber risk) due to external intrusion into the network, the extraction of confidential information, or the falsification or destruction of important information.

[0003] To prepare for such cyber risks, insurance companies offer cyber insurance. Cyber ​​insurance is an insurance whereby, by making a contract with an insurance company in advance and paying a premium, if damage occurs due to an external intrusion into the network, the insurance company will compensate for part or all of the damage. The amount of the premium paid to the insurance company depends on the magnitude of the cyber risk (the possibility of damage occurring and the extent of the damage) and the level of compensation when damage occurs, but the magnitude of the cyber risk is difficult to estimate accurately because it depends heavily on the communication conditions between the network and the outside. For this reason, insurance companies inevitably overestimate the cyber risk, and as a result, they are forced to set the amount of the premium high.

[0004] In response to this, a technology has been proposed in which an insurance company monitors the communication status of the network that is the subject of the contract for a certain period of time before accepting a cyber insurance contract, and uses the results to estimate the magnitude of the cyber risk, thereby setting the insurance premium at an appropriate amount (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7276480 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned conventional technology, there is still a problem that it is difficult to set the cyber insurance premium at an appropriate amount. The reason is as follows. First, after signing a contract for cyber insurance, the network manager is likely to have low awareness of defense against cyber risks because even if damage occurs, the insurance company will compensate for part or all of the damage. Therefore, measures to prevent intrusion and measures to prevent the damage from spreading after intrusion are likely to be neglected, and there is a possibility that signing a contract for cyber insurance will increase the cyber risk. In addition, if damage actually occurs due to an external intrusion, the insurance company needs to confirm whether or not the cyber insurance policyholder (in most cases, the network administrator) is negligent before compensating for the damage, and if negligence is found, the compensation will be reduced. For this reason, the cyber insurance policyholder may minimize the information provided to the insurance company or hide inconvenient information, and the insurance company may have to compensate even for damage caused by the negligence of the cyber insurance policyholder. As such, cyber insurance companies are still forced to overestimate cyber risks and set higher premiums because there is a possibility that cyber risks may increase after the policy is taken out, and because they may also have to compensate for losses caused by the policyholder's negligence.

[0007] The present invention has been made to solve the above-mentioned problems associated with the conventional technology, and aims to provide technology that enables insurance companies to set cyber insurance premiums at appropriate amounts. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the data relay system of the present invention employs the following configuration. A data relay system that is interposed between a plurality of internal terminals, which are processing terminals capable of communicating data with each other within a network, and an external terminal, which is a processing terminal outside the network, and relays data communicated between the internal terminals and the external terminals, a data relay device that relays the data between the internal terminal and the external terminal; a block data transmission device that is connected to the data relay device and at least one of a plurality of nodes that form a blockchain network outside the network, receives the data relayed by the data relay device, generates block data in a blockchain format, and transmits the block data to the node of the blockchain network; The present invention is characterized by comprising:

[0009] In the data relay system of the present invention, data communicated between an internal terminal and an external terminal is transmitted from the data relay device to the block data transmission device, which then uses the received data to generate block data in a blockchain format and transmits it to a node in the blockchain network, thereby storing it in the blockchain network.

[0010] In this way, data communicated between an internal terminal in the network and an external terminal is stored in the blockchain network. Since it is known that data stored in the blockchain network is extremely difficult to tamper with, even if the network is invaded, the cause of the intrusion and the presence or absence of responsibility can be clarified by examining the data stored in the blockchain network. Therefore, if an insurance company makes it a condition of the contract that the data relay system of the present invention is provided when contracting cyber insurance, it can avoid a situation where it has to compensate for damages caused by the negligence of the policyholder. In addition, since the policyholder cannot receive sufficient compensation if damage occurs due to his / her own negligence, even after contracting cyber insurance, the awareness of preparing for cyber risks and the awareness of trying to minimize damages even after the network is invaded are less likely to fade, and as a result, the tendency for cyber risks and damages to increase after contracting cyber insurance can be suppressed. For these reasons, the insurance company can set the insurance premium at an appropriate amount that it considers appropriate according to the cyber risk estimated at the time of contracting cyber insurance.

[0011] In addition, in the data relay system of the present invention described above, data communicated between an internal terminal and another internal terminal may also be relayed by the data relay device, and the data may be transmitted to the block data transmitting device, and the generated block data including the data may be transmitted to the node.

[0012] After a network is infiltrated, damage often occurs or spreads due to communication between internal terminals in the network. Therefore, if data communicated between internal terminals after a network is infiltrated is also transmitted to a block data transmission device and stored in the blockchain network, it becomes possible to clarify the cause of the spread of damage and whether there is any responsibility, as well as the cause of the damage and whether there is any responsibility.

[0013] Furthermore, in the data relay system of the present invention described above, when the block data transmission device generates block data, it may generate the block data by selecting data from the data transmitted from the data relay device in the following manner. That is, when the block data transmission device receives data from the data relay device, it judges whether the data is predetermined storage interruption data. Then, it stores the received data until it receives storage interruption data, and if it judges that the received data is storage interruption data, it interrupts data storage and generates block data using the stored data. After the data storage is interrupted, it judges whether the data is predetermined storage resumption data every time it receives data from the data relay device, and if the received data is storage resumption data, it stores the data until it receives storage interruption data again.

[0014] Data communicated between multiple processing terminals may contain confidential information, and cyber insurance policyholders may feel reluctant to store block data containing such information in a blockchain network. When attempting to transmit data that may be confidential, it is normal to transmit the data (original data to be transmitted) containing confidential information (original data) to the other processing terminal after confirming that the other processing terminal can receive the data by transmitting and receiving procedural data in advance. Therefore, between multiple processing terminals, there is a tendency for the original data to be transmitted in succession after the procedural data is transmitted and received in succession. Therefore, data at which the procedural data ends and data at which the procedural data starts are stored in the block data transmission device as storage interruption data and storage restart data, respectively. Then, among the data transmitted one after another from the data relay device, block data is generated using data from the storage restart data to the storage interruption data, and stored in the blockchain network. In this way, confidential information is not stored in the blockchain network, and even if the network is invaded, it is possible to clarify the cause and the presence or absence of responsibility by examining the data stored in the blockchain network. Furthermore, by a simple process of generating block data using data from storage resume data to storage interruption data from among data transmitted in sequence from the data relay device, it is possible to generate block data including necessary data while eliminating data that may be classified as confidential. In addition, it is only necessary to determine whether the data received from the data relay device corresponds to storage interruption data while data storage is in progress, and whether the data corresponds to storage resume data while data storage is interrupted. This makes it possible to make a simpler and faster determination than when determining whether all data should be stored.

[0015] In addition, in the data relay system of the present invention described above, in which a processing terminal initiates communication with another processing terminal after establishing a connection with the other processing terminal, if a new connection is established while a connection is already established, the block data transmitting device may accumulate data for each connection, generate block data, and transmit it to the node.

[0016] In this way, even if multiple connections are established between internal terminals within the network, or between an external terminal and an internal terminal, it is possible to generate block data containing the necessary data and store it in the blockchain network while eliminating potentially confidential data for each connection.

[0017] In the data relay system of the present invention described above, the data relay device may select data and transmit it to the block data transmission device, instead of the block data transmission device selecting data from the data transmitted from the data relay device. That is, when relaying data to an internal terminal in the network or an external terminal outside the network, the data relay device judges whether the data is predetermined interruption data or not. Then, the data is also transmitted to the block data transmission device until the interruption data is relayed, and when the interruption data is relayed, the transmission of data to the block data transmission device is interrupted. After interrupting the transmission to the block data transmission device, each time data is relayed to an internal terminal or an external terminal, the data is judged whether the data is predetermined resume data or not, and if the data is resume data, the data is transmitted to the block data transmission device until the interruption data is received again.

[0018] Even in this way, necessary data can be stored in the blockchain network while preventing potentially confidential information from being stored in the blockchain network. Therefore, even if the network is invaded, it is possible to clarify the cause and responsibility by examining the data stored in the blockchain network. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an explanatory diagram showing an overview of a data relay system 10 according to a first embodiment. [Diagram 2] 1 is a sequence diagram showing the operation of the data relay system 10 of the first embodiment to store block data in a node 51a of a blockchain network 50. FIG. [Diagram 3] 1 is an explanatory diagram showing how the block data transmission device 30 of the first embodiment generates block data and stores it in multiple nodes 51a to 51d of the block chain network 50. FIG. [Figure 4] FIG. 11 is a block diagram showing the internal structure of a block data transmission device 30 in the data relay system 10 of the second embodiment. [Diagram 5] 13 is a flowchart of a block data transmission process executed by a block data transmission device 30 of the second embodiment. [Figure 6] 13 is a sequence diagram showing the operation of the data relay system 10 according to the second embodiment to store block data in a node 51a of a block chain network 50. FIG. [Figure 7] 13 is a sequence diagram showing the operation of the data relay system 10 according to the second embodiment to store block data in a node 51a of a block chain network 50. FIG. [Figure 8] 13 is a flowchart of a block data generation process executed by a block data transmission device 30 of the second embodiment. [Figure 9] FIG. 11 is a block diagram showing the internal structure of a data relay device 20 mounted on a data relay system 10 according to another aspect of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A. First Example: FIG. 1 is an explanatory diagram showing an overview of a data relay system 10 of a first embodiment. As shown in the figure, the data relay system 10 includes a data relay device 20 and a block data transmission device 30. The data relay device 20 is communicably connected to a plurality of processing terminals 2A-2E and a server device 3. Therefore, the plurality of processing terminals 2A-2E and the server device 3 can transmit and receive data to and from the other processing terminals 2A-2E and the server device 3 via the data relay device 20, and the whole forms a LAN network 1. The data relay device 20 is also connected to the Internet 5, and the plurality of processing terminals 2A-2E and the server device 3 in the LAN network 1 can transmit and receive data to and from the processing terminals 6A-6C and the server device 7 connected to the Internet 5 via the data relay device 20.

[0021] In order to distinguish between the processing terminals 2A-2E and the server device 3 inside the LAN network 1 and the processing terminals 6A-6C and the server device 7 outside the LAN network 1, hereinafter, the processing terminals 2A-2E and the server device 3 inside the LAN network 1 are referred to as "internal terminals", and the processing terminals 6A-6C and the server device 7 outside the LAN network 1 are referred to as "external terminals". When it is necessary to distinguish between the processing terminals 2A-2E and the server device 3 among the internal terminals, they may be written as the internal terminals 2A-2E or the internal server device 3. Similarly, when it is necessary to distinguish between the processing terminals 6A-6C and the server device 7 among the external terminals, they may be written as the external terminals 6A-6C or the external server device 7.

[0022] Furthermore, the data relay device 20 of the first embodiment is connected to the block data transmitting device 30, and every time it relays data transmitted and received between internal terminals in the LAN network 1, it transmits the data to the block data transmitting device 30. Similarly, when relaying data transmitted and received between an internal terminal in the LAN network 1 and an external terminal outside the LAN network 1, it also transmits the data to the block data transmitting device 30.

[0023] The block data transmission device 30 is also connected to a blockchain node (hereinafter, simply referred to as a node) 51a that forms a blockchain network 50. Here, the blockchain network is a distributed network formed by multiple computers, and is a network that realizes a blockchain database. Note that a distributed network is a network in which there is no central computer and multiple computers are connected on an equal basis. In addition, the multiple computers that form the blockchain network are called blockchain nodes. Furthermore, a blockchain database is a database in which data stored in the database is collected into a collection of data called block data and stored in a blockchain format. Here, the blockchain format is a format in which multiple block data are linked in a row like a chain by adding information for specifying the previous block data (usually the hash value of the previous block data) to the multiple block data.

[0024] In a blockchain database, since a plurality of block data are connected in a row, when a certain data in a block data is to be changed later, it is necessary to change the information added to the block data immediately after the block data (herein referred to as the subsequent block data) so that the subsequent block data specifies the previous block data (block data whose internal data has been changed). When the information specifying the previous block data is changed for the subsequent block data, it is necessary to change the information specifying the previous block data for the block data following the subsequent block data. In the end, when a certain data in a block data is to be changed later, it is necessary to change all the block data following the block data, so that data tampering is difficult. Furthermore, since the same contents are stored in a blockchain database in a plurality of blockchain nodes (hereinafter, nodes), even if all the block data stored in one node is changed, it is necessary to change the block data stored in other nodes (at least half of the total number of nodes) as well to know that the data has been changed. For this reason, the blockchain database is known to be a database in which data tampering is extremely difficult.

[0025] The block data transmission device 30 receives data every time the data relay device 20 relays the data, and generates block data using the data and transmits it to the node 51a. When the node 51a receives block data from the block data transmission device 30, it stores the block data and transfers it to the other nodes 51b to 51d that form the blockchain network 50. As a result, the same block data as that of the node 51a is also stored in the other nodes 51b to 51d. In this way, the data relayed by the data relay device 20 is stored in the multiple nodes 51a to 51d of the blockchain network 50 in a blockchain format. Note that, although the blockchain network 50 is formed here by four nodes 51a to 51d, it may be formed by more nodes.

[0026] Fig. 2 is a sequence diagram showing the operation of the data relay system 10 of the first embodiment to store block data in node 51a of the blockchain network 50. Fig. 2 shows how the data relay device 20 relays six pieces of data a to f, and the block data transmitting device 30 receives the data a to f and transmits block data BDa and block data BDb to node 51a.

[0027] 2 is data a transmitted from any one of the external terminals 6A to 6C, 7 to the internal terminal 2A. After this data a is received by the data relay device 20, it is transmitted from the data relay device 20 to the internal terminal 2A. When relaying the data a, the data relay device 20 also transmits the data a to the block data transmission device 30. Moreover, data b is data transmitted by the internal terminal 2A, which received the data a, to the external terminal that transmitted the data a. The data b is received by the data relay device 20 and transmitted from the data relay device 20 to the external terminal. When relaying the data b, the data relay device 20 also transmits the data b to the block data transmission device 30.

[0028] Data c is data transmitted from the internal terminal 2B to one of the external terminals 6A-6C, 7, data d is data transmitted from an external terminal that received data c to the internal terminal 2B, data e is data transmitted from the internal terminal 2A to the internal terminal 2B, and data f is data transmitted from the internal terminal 2B that received data e to the internal terminal 2A. The data relay device 20 also transmits these data c to data f to the block data transmitting device 30 when relaying them.

[0029] The block data transmitting device 30 accumulates data transmitted from the data relay device 20, and when a predetermined condition is met, it aggregates the accumulated data to generate block data. The predetermined condition can be, for example, that the number of pieces of data accumulated in the block data transmitting device 30 reaches a predetermined accumulated number. In the example shown in FIG. 2, the accumulated number is set to three, and in response to this, when the block data transmitting device 30 receives data c, it generates block data BDa using three pieces of data a to c, including data a and data b that have already been received, and transmits the block data BDa to the node 51a. Similarly, when it receives data f, it generates block data BDb using three pieces of data d to f, including data d and data e that have already been received, and transmits the block data BDb to the node 51a.

[0030] FIG. 3 is an explanatory diagram showing how the block data transmission device 30 of the first embodiment generates block data and stores it in multiple nodes 51a to 51d of the blockchain network 50. As shown in FIG. 3, three memory areas 30a to 30c are prepared inside the block data transmission device 30 of the first embodiment. One of these memory areas, the memory area 30a, is a memory area for storing data received from the data relay device 20, and is capable of storing a predetermined number of pieces of data (here, three pieces). The memory area 30b is a memory area for storing a hash value for specifying previously generated block data. The memory area 30c is a memory area for temporarily holding the hash value of the generated block data. Here, the hash value is a value obtained by performing a special operation called a hash function on any data. In addition, the hash function converts data of any size into a hash value of the same data length, and if even a part of the data before the conversion is different, the converted hash value becomes a completely different value. Therefore, a one-to-one relationship is established between the hash value and the original data, and the hash value may be considered to uniquely represent the data before the conversion. Incidentally, a hash value has the property that it is not possible to restore the data before conversion from the hash value.

[0031] The data supplied from the data relay device 20 is stored in the memory area 30a of the block data transmission device 30, and when the number of stored data reaches a predetermined number (here, three), the data and the hash value stored in the memory area 30b are combined to generate block data. When the block data is generated, the hash value of the block data is calculated and stored in the memory area 30c. When the block data transmission device 30 generates the block data in this way, it transmits the block data to the node 51a, and then initializes the memory area 30a and overwrites the hash value stored in the memory area 30c in the memory area 30b. As a result, the hash value of the block data generated immediately before is always stored in the memory area 30b.

[0032] When the block data transmission device 30 generates block data for the first time, the block data generated immediately before does not exist, so the hash value is not stored in the storage area 30b, and the block data generated for the first time does not include a hash value. When generating block data, the block data transmission device 30 may encrypt the data stored in the storage area 30a before generating the block data. If the block data is encrypted, even if the block data contains confidential data, the data can be stored in the multiple nodes 51a to 51d of the blockchain network 50 while maintaining the confidentiality. Alternatively, the block data may be generated after attaching a signature of the administrator of the LAN network 1 formed by the data relay device 20 to the data stored in the storage area 30a. In this way, it is possible to clarify that the administrator of the LAN network 1 has generated the block data of his / her own will. As a method for attaching a signature, a well-known method such as an asymmetric key method can be used.

[0033] The node 51a that receives the block data from the block data transmission device 30 stores the block data and transmits it to the other nodes 51b to 51d that form the block chain network 50, so that the other nodes 51b to 51d also store the block data. FIG. 3 shows how the block data DBa, block data DBb, and block data BDc are stored in each of the nodes 51a to 51d in this manner. The block data DBb contains a hash value indicating the block data DBa, and the block data DBc contains a hash value indicating the block data DBb. Therefore, if the block data is stored in the nodes 51a to 51d in this manner, the block data will be stored in the block chain format.

[0034] In this way, the data relay system 10 of the first embodiment stores the data relayed by the data relay device 20 in the nodes 51a to 51d of the blockchain network 50. This allows insurance companies to set cyber insurance premiums at appropriate amounts. This point will be described below.

[0035] As mentioned above, one of the reasons why insurance companies are unable to set cyber insurance premiums at an appropriate level is that policyholders become complacent when they take out cyber insurance, which in turn increases cyber risks and damages. In addition, when damage occurs, even if the insurance company tries to confirm whether the policyholder was at fault, it may not be able to obtain sufficient cooperation from the policyholder, which may result in the insurance company compensating for damages caused by the policyholder's negligence. This is another reason why insurance companies are unable to set insurance premiums at an appropriate level.

[0036] However, when an insurance company contracts cyber insurance, if the contract requires that the LAN network 1 has the data relay system 10 of the first embodiment described above, the data relayed by the data relay device 20 can be stored in the blockchain network 50. Data stored in the blockchain network 50 is extremely difficult to tamper with, and in addition, the data is stored in a state in which the order in which it was generated (and therefore the order in which it was communicated via the data relay device 20) is maintained. Therefore, if damage occurs after the cyber insurance contract is made, the insurance company can check the data stored in the blockchain network 50 to confirm the circumstances and cause of the damage, and can easily determine whether the policyholder was negligent.

[0037] In addition, the data stored in the blockchain network 50 is data transmitted to the node 51a of the blockchain network 50 by the block data transmission device 30 in the LAN network 1 managed by the contractor, and is therefore data stored under the contractor's management and responsibility. Therefore, even if the contractor is negligent, if the negligence is pointed out based on such data, it will be more convincing to the contractor. In this sense, it is possible to easily determine whether the contractor is negligent by examining the data stored in the blockchain network 50 after the occurrence of damage.

[0038] In addition, if the policyholder experiences damage due to his / her own negligence, his / her negligence will be discovered if the data stored in the blockchain network 50 is examined, and the policyholder will not be able to receive adequate compensation. Therefore, even after taking out cyber insurance, the policyholder will be less likely to lose his / her awareness of preparing for cyber risks and of trying to minimize damage even after the network is infiltrated. As a result, the tendency for cyber risks and damage to increase after taking out cyber insurance can be suppressed. For these reasons, insurance companies can set cyber insurance premiums to an appropriate amount that they consider appropriate at the time of taking out cyber insurance by making it a condition for taking out cyber insurance that the target network has the data relay system 10 of the first embodiment.

[0039] B. Second Example: In the above-mentioned first embodiment, it has been described that all data relayed by the data relay device 20 is transmitted to the block data transmission device 30 and stored in each node 51a to 51d of the blockchain network 50. However, the data relayed by the data relay device 20 may contain confidential information. For this reason, when contracting cyber insurance, it is considered that the data including confidential information is stored in each node 51a to 51d of the blockchain network 50, which becomes an obstacle and the contract is not concluded. Therefore, the data stored in each node 51a to 51d of the blockchain network 50 may not contain confidential information. In the second embodiment described below, it is possible to easily realize such a thing.

[0040] B-1. Overview of data relay system 10 according to the second embodiment: Fig. 4 is an explanatory diagram showing an overview of the data relay system 10 of the second embodiment. Like the data relay system 10 of the first embodiment described above, the data relay system 10 of the second embodiment also includes a data relay device 20 and a block data transmission device 30. Although not shown in Fig. 4, an internal terminal is connected to the data relay device 20, and an external terminal is connected to the Internet 5. And like the data relay device 20 of the first embodiment described above using Fig. 1, the data relay device 20 of the second embodiment also transmits data transmitted between internal terminals or between an internal terminal and an external terminal to the block data transmission device 30 every time it relays the data.

[0041] As shown in FIG. 4, the block data transmission device 30 of the second embodiment includes a data accumulation unit 31, a storage unit 32, a block data generation unit 33, and a block data transmission unit 34. These "units" are abstract concepts that represent functions installed in the block data transmission device 30 of the second embodiment, and do not indicate the existence of parts that correspond to these "units." These "units" can be realized as software programs executed by a microcomputer built into the block data transmission device 30, or as hardware such as an LSI or IC. Furthermore, they may be realized by combining a software program and hardware. Although the block data transmission device 30 shown in FIG. 4 also includes a data transfer unit 35, the data transfer unit 35 is not necessarily required.

[0042] When the data storage unit 31 receives data transmitted from the data relay device 20, it refers to information stored in the storage unit 32 to determine whether or not to store the received data, and stores the data that it has determined to store in a storage area (not shown) for storing data (hereinafter referred to as the storage area). The storage unit 32 stores data called "storage interruption data" and data called "storage restart data". The data storage unit 31 does not need to store only one piece of storage interruption data or storage restart data, and can store multiple pieces of data. If the data received from the data relay device 20 corresponds to the storage interruption data, the data storage unit 31 determines not to store data received thereafter, and if the data received thereafter from the data relay device 20 corresponds to the storage restart data, it determines to resume storage from that data. The data storage unit 31 can prevent data containing confidential information from being stored by such a simple method. The reason for this will be described later.

[0043] Then, every time data accumulation is interrupted, the data accumulation unit 31 outputs the data accumulated in an accumulation area (not shown) to the block data generation unit 33. Furthermore, if the block data transmission device 30 is equipped with a data transfer unit 35, the data accumulation unit 31 also outputs the same data to the data transfer unit 35. Note that, although the explanation here is that the accumulated data is output to the block data generation unit 33 every time data accumulation is interrupted, similarly to the first embodiment described above, it is also possible to output the data to the block data generation unit 33 every time the number of accumulated data reaches a predetermined accumulated number.

[0044] When the block data generation unit 33 receives data stored in the data storage unit 31, it generates block data in the blockchain format. That is, it stores information (here, a hash value) for specifying the previously generated block data, and when it receives new data from the data storage unit 31, it generates new block data by adding the stored hash value to the data. In addition, when new block data is generated, it calculates and stores the hash value of the block data. Then, it outputs the new block data to the block data transmission unit 34.

[0045] When the block data transmission unit 34 receives the block data, it transmits it to node 51a forming the blockchain network 50. Node 51a stores the received block data and also transfers the block data to other nodes 51b to 51d forming the blockchain network 50. As a result, the block data is stored in the blockchain format in each of nodes 51a to 51d of the blockchain network 50.

[0046] Furthermore, if the block data transmission device 30 is equipped with a data transfer unit 35, when the data storage unit 31 stores data in a storage area (not shown), it also outputs the data to the data transfer unit 35. Note that the data storage unit 31 may also output data to the data transfer unit 35 when outputting data to the block data generation unit 33, rather than outputting the data to the data transfer unit 35 every time it stores the data.

[0047] A data analysis device 40 is connected to the data transfer unit 35. The data analysis device 40 has a function of extracting suspicious communications suspected of attempting to intrude into the network from outside the network, or suspicious communications suspected of preparing an attack after infiltrating the network, by analyzing the data relayed by the data relay device 20. If such suspicious communications can be extracted, it is possible to prevent intrusion into other networks and prevent damage caused by attacks, so information that enables the extraction of suspicious communications has great economic value. Therefore, the data analysis device 40 extracts such useful information by analyzing the data received from the data transfer unit 35.

[0048] However, advanced and specialized technology is required to analyze the data relayed by the data relay device 20 and extract such useful information. Therefore, in reality, it is difficult to extract useful information unless the company is specialized in data analysis, but on the other hand, the data relayed by the data relay device 20 contains confidential information, and there is strong resistance to providing such data to other companies. However, the data stored by the data storage unit 31 is data that does not contain confidential information but from which useful information can be extracted, for reasons described below. Therefore, when the data transfer unit 35 receives such data from the data storage unit 31, it transfers it to the data analysis device 40. Although the data analysis device 40 is owned by a company that specializes in analysis, there is no problem with confidentiality even if data is transferred to the data analysis device 40. Therefore, by analyzing the data transferred from the data transfer unit 35 with the data analysis device 40, it becomes possible to extract useful information to reduce cyber risks. The data analysis device 40 may be installed within a network centered on the data relay device 20, but it may also be installed outside the network.

[0049] B-2. Block data transmission process: FIG. 5 is a flowchart of a process in which the block data transmission device 30 of the second embodiment transmits block data to the node 51a of the block chain network 50. As shown in FIG. 5, the block data transmission device 30 of the second embodiment first judges whether data has been received from the data relay device 20 (STEP 10). As a result, if data has not been received from the data relay device 20 (STEP 10: no), the determination of STEP 10 is repeated, and the device enters a standby state until data is received. If data has been received (STEP 10: yes), the device judges whether the received data is storage interruption data (STEP 11). As described above with reference to FIG. 4, the block data transmission device 30 of the second embodiment stores storage interruption data in advance, and judges whether the data received from the data relay device 20 corresponds to storage interruption data. The storage interruption data will be described later.

[0050] If the received data does not correspond to the storage interruption data (STEP 11: no), the received data is stored in a storage area (not shown) (STEP 12), and then the process returns to the beginning to determine whether data has been received from the data relay device 20 (STEP 10). If data has been received (STEP 10: yes), it is again determined whether the data corresponds to the storage interruption data (STEP 11). While repeating such operations, if it is determined that the data received from the data relay device 20 corresponds to the storage interruption data (STEP 11: yes), the data is stored in the storage area (STEP 13), and then a block data generation process (described later) is started to generate block data using the data stored in the storage area (STEP 20). Here, the storage interruption data is the following data.

[0051] In general, when one of two internal terminals belonging to the same network is going to send data to the other internal terminal, procedural data is sent to the other internal terminal before sending the data to be sent, so that the data that is really wanted to be sent will surely reach the other internal terminal. This procedural data includes information indicating the internal terminal that sends the data and the internal terminal that receives the data, information indicating the method of sending the data and the type of data to be sent, etc. Hereinafter, this information included in the procedural data will be referred to as "procedural information". The same is also done when an internal terminal in a network and an external terminal connected to the Internet send and receive data. In this way, a state in which data can be reliably sent and received between two internal terminals or between an internal terminal and an external terminal by sending and receiving procedural data is called a "connection established state". In order to establish a connection, it is necessary to send and receive multiple pieces of data in a predetermined order between the internal terminal or external terminal that is the other party of the connection. Then, the data sent and received after the connection is established is considered to be data that includes the information that is really wanted to be sent (i.e., information that may be classified). In the following, the information that one actually wants to send is referred to as "substantial information."

[0052] As is clear from the above explanation, the stored interruption data in the second embodiment is the last data transmitted and received to establish a connection. If the data relayed by the data relay device 20 is stored interruption data, the data transmitted and received thereafter contains entity information that may be confidential, so the data should not be stored. Note that there may be multiple methods for establishing a connection, but no matter which method is used to establish a connection, multiple pieces of data must be transmitted and received in a predetermined order, so the data transmitted last is determined for each method of establishing a connection. Therefore, it is sufficient to store that data as stored interruption data.

[0053] In STEP 11 of the block data transmission process shown in Fig. 5, it is determined whether the data received from the data relay device 20 corresponds to the above-mentioned storage interruption data. If the received data corresponds to the storage interruption data (STEP 11: yes), the received data is stored in a storage area (STEP 13), and then block data is generated using the stored data (STEP 20). Details of the process of generating block data will be described later, but once the block data is generated, the data stored in the storage area is erased.

[0054] Next, after transmitting the generated block data to node 51a of the block chain network 50 (STEP 14), it is determined whether data has been received from the data relay device 20 (STEP 15). If no data has been received (STEP 15: no), the determination in STEP 15 is repeated to enter a standby state, and if data is received (STEP 15: yes), it is determined whether the data is accumulation resume data (STEP 16). Here, accumulation resume data is the following data.

[0055] As described above, in order to establish a connection, it is necessary to transmit and receive a plurality of data in a predetermined order between the internal terminal or external terminal of the other party. Similarly, when terminating an established connection, it is necessary to transmit and receive a plurality of data in a predetermined order between the internal terminal or external terminal of the other party. When the first data transmitted and received to terminate an established connection is transmitted, it is considered that the data transmitted and received thereafter does not include any entity information that may be a confidential matter. As is clear from this, the accumulation resume data in the second embodiment is the first data transmitted and received to terminate an established connection. Note that, although there may be a plurality of methods for terminating an established connection, it is necessary to transmit and receive a plurality of data in a predetermined order regardless of the method of termination, so the data transmitted first is determined for each method of terminating a connection. Therefore, it is sufficient to store these data as accumulation resume data.

[0056] In STEP 16 of the block data transmission process shown in Fig. 5, it is determined whether the data received from the data relay device 20 corresponds to the above-mentioned storage restart data. If the received data does not correspond to the storage restart data (STEP 16: no), the received data is not stored in the storage area, and the process returns to STEP 15 again to determine whether data has been received from the data relay device 20, and then the above-mentioned operation is repeated. On the other hand, if the received data corresponds to the storage restart data (STEP 16: yes), the received data is stored in the storage area (STEP 17), and then the process returns to the beginning of the process to determine whether data has been received from the data relay device 20 (STEP 10). Then, the above-mentioned operation is repeated.

[0057] 6 and 7 are sequence diagrams showing how block data is stored in the node 51a of the blockchain network 50 by the block data transmission device 30 of the second embodiment executing the block data transmission process described above. The data a shown in FIG. 6 is data transmitted by one of the external terminals 6A to 6C, 7 to the internal terminal 2A requesting the establishment of a connection. This data a includes connection information 1 such as information requesting the establishment of a connection, information identifying the external terminal making the request, information identifying the internal terminal 2A that is the other party, and information indicating the transmission method. The data a transmitted from the external terminal is relayed to the internal terminal 2A by the data relay device 20. The internal terminal 2A that receives the data a transmits data b including the predetermined connection information 2 corresponding to the data a to the external terminal that transmitted the data a. This data b is also relayed to the external terminal by the data relay device 20. Furthermore, the external terminal that receives the data b transmits data c including the connection information 3 corresponding to the data b to the internal terminal 2A. This data c is also relayed to the internal terminal 2A by the data relay device 20. In this way, the connection is established by transmitting and receiving the three pieces of data a to c between the external terminal and the internal terminal 2A. After the connection is established, data d, data e, and data g, each containing entity information, are transmitted from the external terminal to the internal terminal 2A. Note that, like data f illustrated in Fig. 6, the internal terminal 2A may return procedural data containing procedural information indicating failure in reception (or success in reception) between receiving data d, data e, and data g, each containing entity information.

[0058] The external terminal transmits data including entity information in this manner, and when it has transmitted the last data, it transmits data to the internal terminal 2A to terminate the connection established with the internal terminal 2A. Data h shown in FIG. 7 is the last data including entity information, and data i is data to terminate the connection. Data i includes connection information 4 such as information requesting termination of the connection, information identifying the requesting external terminal, and information identifying the other internal terminal 2A. The internal terminal 2A that receives data i returns data j including predetermined connection information 5 corresponding to data i. These data i and data j are also relayed by the data relay device 20. The established connection is terminated by transmitting and receiving data i and data j in this manner.

[0059] In the example shown in FIG. 7, one of the external terminals 6A to 6C, 7 then requests the internal terminal 2B to establish a connection and transmits data k. This data k also contains the connection information 1 described above. The data a transmitted from the external terminal is relayed to the internal terminal 2A by the data relay device 20. The internal terminal 2B that receives the data k transmits data l including the connection information 2 corresponding to the data k to the external terminal that transmitted the data k. Then, the external terminal that receives the data l transmits data m including the connection information 3 corresponding to the data l to the internal terminal 2B, thereby establishing a connection between the external terminal and the internal terminal 2B. Then, after the connection is established, data n including entity information is transmitted from the external terminal to the internal terminal 2B. The data relay device 20 also relays these data k to n. Then, the data relay device 20 transmits the data to the block data transmitting device 30 every time it relays data.

[0060] The block data transmitting device 30 generates block data using data transmitted from the data relay device 20 by executing the block data transmission process described above with reference to Fig. 5. For example, if the data received from the data relay device 20 is data a or data b shown in Fig. 6, the data is not storage interruption data (last data transmitted and received to establish a connection), so the answer is determined as "no" in STEP 11 of Fig. 5 and the data is stored in the storage area (STEP 12). After that, when data c is received from the data relay device 20, the answer is determined as "yes" in STEP 11 of Fig. 5 because the data c is storage interruption data, and the data c is stored in the storage area (STEP 13), and then the block data BDa is generated using the data stored in the storage area (STEP 20 of Fig. 5) and transmitted to the node 51a. The method of generating the block data BDa will be described later.

[0061] After transmitting block data BDa to node 51a, each time data is received from data relay device 20, it is determined whether the data is storage restart data (initial data transmitted and received to terminate connection) (STEP 16 in FIG. 5). Data d, e, and g shown in FIG. 6 and data h shown in FIG. 7 are data for transmitting entity information, and therefore are not storage restart data. Therefore, the determination is "no" in STEP 16 in FIG. 5, and these data are not stored in the storage area. Moreover, data f shown in FIG. 6 is procedural data for transmitting procedural information, but is not storage restart data, and therefore this data is also not stored in the storage area.

[0062] However, when the data i shown in FIG. 7 is received, the answer is determined as "yes" in STEP 16 in FIG. 5. Then, by storing the data i in the storage area, data storage is resumed (STEP 17), and thereafter, the received data is stored in the storage area unless the data received from the data relay device 20 corresponds to the storage interruption data (STEP 12 in FIG. 5). After that, when the data m corresponding to the storage interruption data is received, the answer is determined as "yes" in STEP 11 in FIG. 5, and the data m is stored in the storage area (STEP 13), and the block data BDb is generated using the data stored in the storage area (STEP 20 in FIG. 5) and transmitted to the node 51a. The block data transmitting device 30 generates the block data as described above and transmits it to the node 51a by executing the block data transmission process in FIG. 5. Then, the node 51a transmits the received block data to the other nodes 51b to 51d, and the block data is stored in each of the nodes 51a to 51d in the blockchain network 50.

[0063] B-3. ​​Block data generation process: Finally, a brief description will be given of the process of generating block data by the block data transmission device 30. Fig. 8 is a flowchart of the block data generation process executed by the block data transmission device 30 to generate block data. This process is executed after the data received during the block data transmission process shown in Fig. 5 is stored in the storage area when the data is storage interruption data.

[0064] When the block data generation process is started, first, all data stored in the storage area is read (STEP 21). Next, the hash value of the previously generated block data is read (STEP 22). As will be described later, every time new block data is generated, the hash value of that block data is calculated and stored.

[0065] Then, new block data is generated by adding the hash value of the previous block data to all the read data, and then stored in a storage area other than the accumulation area in which the data received from the data relay device 20 is accumulated (STEP 23). Next, a hash value of the newly generated block data is calculated and stored in a storage area other than the accumulation area (STEP 24). After storing the new block data and the hash value in this way, all data accumulated in the accumulation area is erased in preparation for generating the next block data (STEP 25), and the block data generation process of Fig. 8 is terminated, and the process returns to the block data transmission process of Fig. 5. Then, in STEP 14 of the block data transmission process, the block data stored in the storage area in STEP 23 of Fig. 8 is read out and transmitted to node 51a.

[0066] The block data transmission device 30 of the second embodiment generates block data as described above and stores it in each of the nodes 51a to 51d of the block chain network 50. As described above with reference to Figs. 6 and 7, the block data generated by the block data transmission device 30 of the second embodiment includes procedural information, but does not include entity information that may be confidential. This makes it possible to prevent a situation in which the storage of block data in each of the nodes 51a to 51d of the block chain network 50 becomes an obstacle and a contract is not reached. On the other hand, the procedural information stored in the block data includes information indicating the internal terminal or external terminal transmitting and receiving data, information regarding the method of transmitting and receiving data, information regarding the type of data transmitted and received, and information regarding the order in which the data was transmitted and received. Therefore, in the event of damage caused by an external intrusion into the network, the process and cause of the damage can be confirmed by examining the block data.

[0067] In addition, the block data transmission device 30 can generate block data including data necessary for confirming the process and cause of the damage while eliminating data including information that may be confidential, by a simple process of determining whether the data received from the data relay device 20 corresponds to storage interruption data or storage restart data. That is, data including information that may be confidential can also be eliminated by registering all procedural data that does not include substance information, and judging whether the data corresponds to the registered procedural data each time data is received from the data relay device 20. However, in the above-mentioned second embodiment, it is sufficient to judge whether the data corresponds to storage interruption data while the data is being stored, and whether the data corresponds to storage restart data while the data storage is suspended. This makes it possible to eliminate data including information that may be confidential very easily and quickly.

[0068] 6 and 7, it has been described that a new connection is established between the external terminal and the internal terminal 2B after the connection established between the external terminal and the internal terminal 2A is terminated. However, in a state where a connection is established between the external terminal and the internal terminal 2A, for example, a new connection may be established between another external terminal and the internal terminal 2B. In such a case, the block data transmission process shown in FIG. 5 may be executed for each connection. That is, when data transferred from the data relay device 20 is received, it is identified which connection the data belongs to based on the header information of the data. Then, the process shown in FIG. 5 may be executed for each connection. In this way, it is possible to generate block data for each connection when multiple connections are established.

[0069] In the above-mentioned second embodiment, the data relay device 20 transmits all data to be relayed to the block data transmission device 30, and the block data transmission device 30 selects the data to be stored. However, data may be selected on the data relay device 20 side and transmitted to the block data transmission device 30. Other aspects of such a second embodiment will be described below.

[0070] Fig. 9 is an explanatory diagram illustrating a data relay system 10 of another aspect of the second embodiment. Like the data relay system 10 of the first or second embodiment described above, the data relay system 10 of another aspect of the second embodiment also includes a data relay device 20 and a block data transmission device 30. Note that, like Fig. 4 described above, although not shown, Fig. 9 also has an internal terminal connected to the data relay device 20 and an external terminal connected to the Internet 5. The data relay device 20 relays data transmitted between the internal terminals and data transmitted between the internal terminals and the external terminal.

[0071] As shown in Fig. 9, the data relay device 20 of the modified example of the second embodiment includes a data relay unit 21, a data selection and transmission unit 22, and a storage unit 23. These "units" are also abstract concepts that represent functions provided in the data relay device 20 of another aspect of the second embodiment, and do not indicate the existence of parts that correspond to these "units." These "units" can be realized as software programs, or as hardware such as LSIs or ICs.

[0072] The data relay unit 21 is connected to an internal terminal (not shown) and the Internet 5, and relays data transmitted and received between internal terminals and between internal terminals and external terminals, and outputs the relayed data to the data selection and transmission unit 22.

[0073] When the data selection transmitting unit 22 receives data output from the data relay unit 21, it judges whether the data corresponds to the predetermined "interrupted data" or the predetermined "resume data" stored in the storage unit 23. The interrupted data can be the same data as the stored interrupted data described above, and the resumed data can be the same data as the stored resumed data described above. Then, depending on the result of the judgment, the data selection transmitting unit 22 switches between a state in which data is transmitted to the block data transmission device 30 and a state in which no transmission is performed. That is, when the data received from the data relay unit 21 is in a state in which the data is transmitted to the block data transmission device 30, if the data received from the data relay unit 21 is judged to correspond to the interrupted data, the data received thereafter is not transmitted to the block data transmission device 30 (a state in which transmission is interrupted). Also, when the data received from the data relay unit 21 is judged to correspond to the resumed data in a state in which transmission is interrupted, the data received thereafter is transmitted to the block data transmission device 30, including the data. Also, when the data selection transmitting unit 22 transmits data to the block data transmission device 30, the data selection transmitting unit 22 may also transmit the same data to the data analyzing device 40. Incidentally, the data selection and transmission unit 22 of another aspect of the second embodiment corresponds to the "data transmission unit" of the present invention.

[0074] The block data transmitting device 30 generates block data using the data received from the data selecting and transmitting unit 22, and outputs the block data to the node 51a of the block chain network 50. The block data transmitting device 30 of another aspect of the second embodiment may generate block data each time the received data reaches a predetermined accumulated number, similar to the block data transmitting device 30 of the first embodiment described above, or may generate block data using the data accumulated up to that point each time interruption data is transmitted from the data relay device 20, similar to the block data transmitting device 30 of the second embodiment described above.

[0075] Furthermore, in the case of the data relay device 20 of another aspect of the second embodiment described above, when a plurality of connections are established, data may be selected for each connection and transmitted to the block data transmitting device 30. In this case, the block data transmitting device 30 does not necessarily need to generate block data for each connection, but may generate block data for each connection.

[0076] In this other aspect of the data relay system 10 of the second embodiment, the data relayed by the data relay device 20 is stored in each node 51a to 51d of the blockchain network 50, so that it is possible to obtain the same effect as the data relay system 10 of the second embodiment described above.

[0077] Although the data relay system 10 according to various embodiments has been described above, the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0078] 1...LAN network, 2A to 2E...internal terminal, 3...server device, 5...Internet, 6A~6C...External terminal, 7...Server device, 10... data relay system, 20... data relay device, 21... data relay unit, 22: data selection and transmission unit; 23: storage unit; 30: block data transmission device; 30a to 30c... storage area, 31... data storage section, 32... storage section, 33: block data generation unit; 34: block data transmission unit; 35...data transfer unit, 40...data analysis device, 50...blockchain network, 51a~51d...nodes.

Claims

1. A data relay system that is interposed between a plurality of internal terminals, which are processing terminals capable of communicating data with each other within a network, and an external terminal, which is a processing terminal outside the network, and relays data communicated between the internal terminals and the external terminals, a data relay device that relays the data between the internal terminal and the external terminal; a block data transmission device that is connected to the data relay device and at least one of a plurality of nodes that form a blockchain network outside the network, receives the data relayed by the data relay device, generates block data in a blockchain format, and transmits the block data to the node of the blockchain network; A data relay system comprising:

2. 2. The data relay system according to claim 1, the data relay device also relays data communicated between the internal terminal and another internal terminal, The block data transmission device generates the block data including the data to be communicated between the internal terminal and another internal terminal, and transmits the block data to the node. A data relay system comprising:

3. 3. The data relay system according to claim 1, The block data transmission device includes: a data storage unit that stores the data received from the data relay device; a block data generation unit that generates the block data by using the data stored in the data storage unit; a block data transmission unit that transmits the block data generated by the block data generation unit to the node; a storage unit that stores predetermined storage interruption data, which is the data for which the data storage unit should interrupt storage of the data, and predetermined storage resumption data, which is the data for which the data storage unit should resume storage of the interrupted data; It is equipped with The data storage unit includes: When the storage interruption data is received from the data relay device, the storage of the data is interrupted and the stored data is output to the block data generation unit; When the storage restart data is received from the data relay device while the storage of the data is interrupted, the storage of the data is restarted. A data relay system comprising:

4. 4. The data relay system according to claim 3, the processing terminal establishes a connection with another processing terminal prior to starting communication with the other processing terminal, and then the processing terminals with which the connection has been established communicate with each other; When a new connection is established while the connection is established, the block data transmission device accumulates the data for each connection, generates the block data for each connection, and transmits the block data to the node for each connection. A data relay system comprising:

5. 3. The data relay system according to claim 1, The data relay device includes: a data transmission unit that transmits the data to the block data transmission device when relaying the data; a storage unit that stores predetermined interruption data, which is data for interrupting transmission of the data to the block data transmission device, and predetermined resume data, which is data for resuming transmission of the interrupted data; Equipped with The data transmission unit is If the data to be relayed is the interrupted data, interrupt the transmission of the data to the block data transmission device; If the data relayed while the transmission of the data was interrupted is the resume data, the transmission of the data to the block data transmission device is resumed. A data relay system comprising:

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