JP7231291B1 - Information processing system, information processing method, server, blockchain node, and program - Google Patents

Abstract

The object of the present invention is to verify that there is no fraudulent transaction of raw materials contained in an item while keeping the quantity of the raw materials contained in the item secret.
An information processing system (10) includes a server (14), a plurality of blockchain nodes (16), and a plurality of terminals (12). Each of the plurality of blockchain nodes 16 reads each of the first transaction data, which is past transaction data linked to the second transaction data broadcast by the server 14, from the blockchain. Each of the plurality of blockchain nodes 16 generates a second It verifies whether or not the item of transaction data is composed of raw materials included in the source item of the first transaction data.
[Selection drawing] Fig. 1

Description

The present invention relates to an information processing system, an information processing method, a server, a blockchain node, and a program.

Conventionally, there is known a technique for recording tracking information of an item on a blockchain while reducing the data amount of the tracking information of the item to be moved (for example, Patent Document 1). In the technology disclosed in Patent Document 1, when a server receives a request signal including identification information of an item to be tracked, a sequence of transaction data in which an item corresponding to the identification information included in the request signal has been moved is generated. and the series of accumulators corresponding to the series of transaction data from the blockchain. Then, the server verifies whether or not the identification information of the tracked item is stored in each accumulator in the acquired series of accumulators, and outputs the verification result.

Japanese Patent Application Laid-Open No. 2021-64219

By the way, a user who uses an item, which is a product or service, may want to know what kind of elements the item is composed of. For example, consider the case where an industrial product is manufactured. Industrial products often contain various raw materials (for example, rare metals).

In particular, in recent years, the United Nations has established Sustainable Development Goals (SDGs), demanding the provision of environmentally friendly items. Therefore, if it is possible to verify whether the elements that make up an item are environmentally friendly, the results of that verification can be used as SDGs indicators. However, it is difficult to distinguish the difference from the appearance of processed products or industrial products using the same kind of raw materials. On the other hand, if information about the raw materials of items (or information about the process in which energy is supplied) becomes traceable, it will be possible to set, measure, and evaluate indicators based on such information. It is also possible to restrict the movement of items that do not meet predetermined criteria.

In addition, a supply chain of raw materials and intermediate materials is often formed by multiple business operators before industrial products are supplied to consumers. For example, a business operator A procures a plurality of raw materials a1, a2, and a3, and manufactures an intermediate material _MA from these raw materials a1, a2, and a3. Next, business operator B procures intermediate material _MA from business operator A, adds raw materials b1 and b2 to intermediate material _MA , and manufactures intermediate material _MB . Next, business operator C procures an intermediate material _MB from business operator B, and combines the intermediate material _MB with several other intermediate materials to manufacture industrial products _MC . Then, the industrial product _MC is supplied from the business operator C to the consumer.

In this case, for example, consumers or quality inspection organizations, etc., must consider the origin of the raw materials contained in the industrial products _MC , the content of recycled materials, the purity measured in the refining process, and the components such as elements and molecules. There are cases where you want to know information about the compounding ratio of In addition, consumers or organizations that supervise distribution may also want to know information about the business operators through which the industrial product _MC was manufactured and supplied. Also, each business operator may want to know information about raw materials or parts procured by itself.

If such data related to traded items were made public using network technology such as blockchain, multiple business operators and consumers would be able to freely view information related to traded items. . For example, multiple business operators and consumers view information on the origin of raw materials contained in a part, the content of recycled materials, the purity measured in the refining process, and the blending ratio of components such as elements and molecules. By doing so, you can confirm what kind of raw materials the parts or intermediate materials you have acquired are composed of, and use them for labeling the products you ship or meet the standards you have set as your goals. It can be used to identify incompatible parts or intermediate materials.

However, when such data is recorded on a blockchain and made public, it becomes possible for an unspecified number of third parties to freely view the data. For example, if the data recorded on the blockchain includes data related to know-how for manufacturing industrial products, the competitiveness of the business may be impaired.

For example, a particular business operator may wish to keep information about ingredient ratios confidential from competing businesses, and may disclose that information to business operators with whom it has a direct contractual relationship, but In some cases, we do not want to disclose personal information to third parties that are not covered by the law.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to verify that there is no fraudulent transaction of raw materials contained in an item while keeping the quantity of raw materials contained in the item secret.

In order to achieve the above object, an information processing system according to the present invention includes a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminals include identification information of an item to be generated. , raw material identification data that is identification information of raw materials used when generating the target item, quantity data that represents the quantity of the raw materials, and generation that represents the identification information of the source item original item identification data to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data to calculate the commitment value of the item to be generated, and the raw material transaction data stored in a predetermined data structure of a combination of identification data and the item identification data to be generated, and recorded in a blockchain stored in a storage unit of the blockchain node; First transaction data, which is transaction data in which item identification data is included in output data, is obtained, and an address representing the source of the item to be generated, an address representing the destination of the item to be generated, and the data structure are obtained. second transaction data, wherein the source item identification data is included in input data, and the data structure including the generation target item identification data is included in output data; , and each of a plurality of blockchain nodes reads from the blockchain each first transaction data that is past transaction data linked to the second transaction data broadcast by the server, and the second transaction data and the commitment value of the generation source item included in the first transaction data, the generation target item of the second transaction data is the verifying whether or not the item to be generated of the second transaction data is composed of the material included in the source item of the first transaction data, and determining that the item to be generated of the second transaction data is composed of the material of the first transaction data; If determined, record the second transaction data in the blockchain It is an information processing system that

Further, the server of the present invention is an information processing system including a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminal includes a generation target item identifier representing identification information of a generation target item. data, raw material identification data that is identification information of raw materials used when generating an item to be generated, quantity data that represents the quantity of the raw materials, and source item identification data that represents the identification information of the source item. is sent to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data, thereby calculating the commitment value of the item to be generated, and calculating the raw material identification data and the generation target Transaction data stored in a predetermined data structure in combination with item identification data, recorded in a blockchain stored in a storage unit of the blockchain node, and the generation source item identification data is output Transaction data obtained by obtaining first transaction data, which is transaction data included in the data, and including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure , broadcasting to a plurality of blockchain nodes second transaction data whose input data includes the source item identification data and whose output data includes the data structure including the generation target item identification data; Each of the blockchain nodes reads each of the first transaction data, which is past transaction data linked to the second transaction data broadcast by the server, from the blockchain, and the generation target included in the second transaction data. Based on the relationship between the commitment value of the item and the commitment value of the source item included in the first transaction data, the generation target item of the second transaction data is the It is verified whether or not it is composed of the raw material contained in the source item, and if it is determined that the generation target item of the second transaction data is composed of the raw material of the first transaction data, the A server that records second transaction data to the blockchain be.

Also, a blockchain node of the present invention is the blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminals represent identification information of an item to be generated. identification data of the item to be generated, raw material identification data that is identification information of raw materials used when generating the item to be generated, quantity data representing the quantity of the raw material, and source item that represents the identification information of the source item and the identification data to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data to calculate the commitment value of the item to be generated, and the raw material identification data. and the generation target item identification data are stored in a predetermined data structure, transaction data recorded in the blockchain stored in the storage unit of the blockchain node, and the generation source item identification A transaction that acquires first transaction data whose data is transaction data included in output data, and that includes an address representing the source of the item to be generated, an address representing the destination of the item to be generated, and the data structure. Broadcast second transaction data, wherein input data includes the source item identification data, and output data includes the data structure including the generation target item identification data, to a plurality of blockchain nodes. and each of the plurality of blockchain nodes reads from the blockchain each of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server, and included in the second transaction data. based on the relationship between the commitment value of the item to be generated of the second transaction data and the commitment value of the item to be generated included in the first transaction data, the item to be generated of the second transaction data verifying whether or not the item to be generated of the second transaction data is composed of the raw material contained in the source item of the transaction data, and determining that the item to be generated of the second transaction data is composed of the raw material of the first transaction data; the second transaction data in the block It is a blockchain node that records to the blockchain.

Further, an information processing method of the present invention is an information processing method executed by an information processing system including a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminal receives identification information of an item to be generated. raw material identification data that is identification information of raw materials used when generating the target item; quantity data that represents the quantity of the raw material; and item identification data to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data to calculate the commitment value of the item to be generated, and the raw material identification. transaction data stored in a predetermined data structure of a combination of data and the generation target item identification data, and recorded in a blockchain stored in a storage unit of the blockchain node, and the generation source item; First transaction data, which is transaction data whose identification data is included in output data, is obtained, and includes an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure. second transaction data, wherein input data includes the source item identification data, and output data includes the data structure including the generation target item identification data, to a plurality of blockchain nodes; broadcast, and each of a plurality of blockchain nodes reads from the blockchain each first transaction data that is past transaction data linked to the second transaction data broadcast by the server, and converts the second transaction data to the second transaction data Based on the relationship between the commitment value of the item to be generated included and the commitment value of the source item included in the first transaction data, the item to be generated of the second transaction data Verifies whether or not the item to be generated of the second transaction data is composed of the raw material contained in the source item of the first transaction data, and determines that the item to be generated of the second transaction data is composed of the raw material of the first transaction data. recording the second transaction data to the blockchain when It is an information processing method.

A program of the present invention is a program to be executed by the server in an information processing system including a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminal represents identification information of an item to be generated. identification data of the item to be generated, raw material identification data that is identification information of raw materials used when generating the item to be generated, quantity data representing the quantity of the raw material, and source item that represents the identification information of the source item and the identification data to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data to calculate the commitment value of the item to be generated, and the raw material identification data. and the generation target item identification data are stored in a predetermined data structure, transaction data recorded in the blockchain stored in the storage unit of the blockchain node, and the generation source item identification A transaction that acquires first transaction data whose data is transaction data included in output data, and that includes an address representing the source of the item to be generated, an address representing the destination of the item to be generated, and the data structure. Broadcast second transaction data, wherein input data includes the source item identification data, and output data includes the data structure including the generation target item identification data, to a plurality of blockchain nodes. and each of the plurality of blockchain nodes reads from the blockchain each of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server, and included in the second transaction data. based on the relationship between the commitment value of the item to be generated of the second transaction data and the commitment value of the item to be generated included in the first transaction data, the item to be generated of the second transaction data verifying whether or not the item to be generated of the second transaction data is composed of the raw material contained in the source item of the transaction data, and determining that the item to be generated of the second transaction data is composed of the raw material of the first transaction data; the second transaction data in the block chain It is a program that records to the screen.

A program of the present invention is a program to be executed by the blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a plurality of terminals, wherein the terminal includes identification information of an item to be generated. , raw material identification data that is identification information of raw materials used when generating the target item, quantity data that represents the quantity of the raw materials, and generation that represents the identification information of the source item original item identification data to the server, and the server performs secure calculation based on the parameter value corresponding to the raw material and the quantity data to calculate the commitment value of the item to be generated, and the raw material transaction data stored in a predetermined data structure of a combination of identification data and the item identification data to be generated, and recorded in a blockchain stored in a storage unit of the blockchain node; First transaction data, which is transaction data in which item identification data is included in output data, is obtained, and an address representing the source of the item to be generated, an address representing the destination of the item to be generated, and the data structure are obtained. second transaction data, wherein the source item identification data is included in input data, and the data structure including the generation target item identification data is included in output data; , and each of a plurality of blockchain nodes reads from the blockchain each first transaction data that is past transaction data linked to the second transaction data broadcast by the server, and the second transaction data and the commitment value of the generation source item included in the first transaction data, the generation target item of the second transaction data is the verifying whether or not the item to be generated of the second transaction data is composed of the material included in the source item of the first transaction data, and determining that the item to be generated of the second transaction data is composed of the material of the first transaction data; If determined, the second transaction data It is a program that records to the blockchain.

According to the present invention, it is possible to obtain the effect that it is possible to verify that there is no fraudulent transaction of the raw materials contained in the item while keeping the quantity of the raw materials contained in the item secret.

It is a figure showing an example of a schematic structure of an information processing system of this embodiment. 1 is a schematic block diagram of a computer functioning as each device constituting an information processing system; FIG. It is an explanatory view for explaining processing of an information processing system of this embodiment. It is a figure for explaining this embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings.

<System configuration of information processing system>

FIG. 1 is a block diagram showing an information processing system 10 of this embodiment. As shown in FIG. 1 , an information processing system 10 of this embodiment includes a terminal 12 , a server 14 and a blockchain node 16 . Each device of the information processing system 10 is connected by a network 20 such as the Internet. Note that the blockchain node is simply referred to as "blockchain node 16" except when describing a specific node among the plurality of blockchain nodes 16A, 16B, and 16C. In addition, the terminal is simply referred to as "terminal 12" except when describing a specific terminal among the plurality of terminals 12A, 12B, 12C, . . . , 12X.

Although three blockchain nodes are shown in FIG. 1, more blockchain nodes may be included. Also, although four terminals are shown in FIG. 1, more terminals may be included.

In recent years, there have been an increasing number of cases in which disclosure of some of the events that occur in the process of production or distribution of goods or services (hereinafter also simply referred to as "items") is required. For example, as evidence of efforts to address environmental issues, each business operator should disclose the utilization rate of renewable energy, the amount of _CO2 emissions, or the recycling rate of the raw materials used in the item when it provides the item. may be required.

Currently, such information disclosure is often reported as the sum of corporate activities over a period of time (eg, one year). On the other hand, if details are added to individual items, such information can also be regarded as added value of the item. In addition, by adding a description to an item, it becomes possible to prove that the item conforms to distribution regulations in the international community.

Therefore, when an item X is handed over from a certain business operator U1 to another business operator U2, and the business operator U2 manufactures a new item Y based on the item X, the series of events is data representing one transaction slip. Consider the case of expressing as Then, the data representing the transaction slip is recorded on the blockchain. Since the data representing the transaction slip is stored in the storage units (not shown) of the multiple blockchain nodes 16A, 16B, and 16C, the transaction data recorded in the blockchain is disclosed. Third parties can view the transaction data. This allows the item to be specified and a set of information to be published when the item is manufactured or provided.

However, on the other hand, there is information that should be kept secret among the information when the item is manufactured or provided. For example, a company that manufactures an intermediate material by mixing a plurality of raw materials may want to keep information about the mixing ratio of the raw materials confidential because it is their own know-how. Since the information on these know-hows is also the intellectual property of each business operator, it is common for each business operator to avoid disclosing the intellectual property to third parties free of charge.

Therefore, in the information processing system 10 of the present embodiment, the information about the quantity of raw materials contained in the item is not recorded in the blockchain, but the quantity of raw materials contained in the item is kept secret. Verify that raw material transactions are not fraudulent.

Specifically, in the information processing system 10 of the present embodiment, predetermined secure calculation is executed based on quantity data representing the quantity of raw materials contained in the item and parameter values set for each raw material. to calculate the commitment value for each item. In the information processing system 10 of the present embodiment, this commitment value is recorded in the block chain, and based on the commitment value, it is verified that there is no fraudulent transaction of raw materials included in each item. As a result, information about the quantity of raw materials contained in the item is not recorded on the blockchain, and the quantity of raw materials contained in the item is kept secret, while ensuring that there is no fraudulent transaction of raw materials contained in the item. Verification is possible.

Each device included in the information processing system 10 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs and the like for realizing each processing routine, and a RAM (Random Access Memory) that temporarily stores data. ), a memory as storage means, a network interface, and the like.

Terminal 12, server 14, and blockchain node 16 may be implemented, for example, by computer 70 shown in FIG. The computer 70 includes a CPU 71 , a memory 72 as a temporary storage area, and a non-volatile storage section 73 . The computer 70 also includes an input/output interface (I/F) 74 to which an input/output device (not shown) is connected, and a read/write (R/W) unit 75 for controlling reading and writing of data to and from a recording medium. Prepare. The computer 70 also has a network I/F 76 connected to a network such as the Internet. The CPU 71 , memory 72 , storage section 73 , input/output I/F 74 , R/W section 75 and network I/F 76 are connected to each other via a bus 77 .

The storage unit 73 can be implemented by a hard disk drive (HDD), solid state drive (SSD), flash memory, or the like. A program for causing the computer 70 to function is stored in the storage unit 73 as a storage medium. The CPU 71 reads out the program from the storage unit 73, develops it in the memory 72, and sequentially executes the processes of the program.

<Action of information processing system 10>

Next, the operation of the information processing system 10 of this embodiment will be described. In this embodiment, an example will be described in which the information processing system 10 records the details of the product C in the blockchain.

It is assumed that product C contains cobalt, nickel, and manganese as its raw materials. In the following, an example will be described in which cobalt, nickel, and manganese, which are raw materials for product C, are extracted from product A and product B, and product C is produced using the extracted raw materials. In the process of producing product C, some (or all) of the raw materials that make up product A or some (or all) of the raw materials that make up product B are not consumed, and correspond to surplus raw materials that are not consumed. An example will be described in which a product D is generated. Therefore, products A and B are examples of source items, and product C is an example of items to be created.

In this embodiment, a combination of a product as an item and its raw materials (for example, product C is composed of raw materials cobalt: 5, nickel: 4, manganese: 9) can be tracked. In that case, the raw material quantity data must be kept confidential. On the other hand, it is necessary to prove to a third party that product C is generated from product A and product B, for example.

Therefore, in this embodiment, it is possible to prove that the item is properly manufactured while concealing the quantity data of the raw materials that make up the item. A specific description will be given below.

When the user operating the terminal 12 inputs information about the product C, which is the item to be generated, to the terminal 12, the sequence shown in FIG. 3 is executed.

In step S100, the terminal 12 receives information about items input by the user. Note that this item information includes, for example, quantity data representing the quantity of raw materials that constitute product C, which is the item to be generated. For example, it is assumed that the quantities (or composition ratios) of raw materials constituting product C are as follows.

Cobalt: 5
Nickel: 4
Manganese: 9

Also, assume that the quantities of raw materials that make up the product A, which is the source item, are as follows.

Cobalt: 3
Nickel: 7
Manganese: 5

Also, assume that the quantities of raw materials that make up the product B, which is the originating item, are as follows.

Cobalt: 4
Manganese: 8

Also, assume that the quantity of raw materials constituting product D corresponding to surplus raw materials that are not consumed is as follows.

Cobalt: 2
Nickel: 3
Manganese: 4

In step S102, the terminal 12 receives item identification data representing identification information of product C to be generated (hereinafter simply referred to as "item ID"), the item ID of product A as the generation source, and the item ID of product B as the generation source. item ID, raw material identification data (hereinafter simply referred to as "raw material ID") that is identification information of raw materials that make up product C, and the quantity (or ratio) of raw materials consumed when producing product C to the server 14.

At step S104, the server 14 receives the data transmitted from the terminal 12 at step S102. Further, in step S104, the server 14 acquires a parameter value corresponding to the raw material of the received raw material ID, a blind parameter value G corresponding to the blind factor, and a random coefficient r for the blind parameter value G. The blind factor rG is data representing a virtual raw material that is not actually contained in the product C. The random coefficient r for the blind parameter value G is also the blind quantity data value corresponding to the blind factor quantity.

Note that this parameter value and the blind parameter value G are obtained by calculation using a commitment scheme with additive homomorphism. For example, the Pedersen commitment, which is an example of a known technique (see, e.g., Section 3 of https://link.springer.com/content/pdf/10.1007%2F3-540-46766-1_9.pdf#page=3!). is used to calculate the parameter value and the blind parameter value G. When the Pedersen commitment is used to calculate the parameter value and the blind parameter value G, points (coordinates) of unknown discrete logarithms on the elliptic curve are selected as the parameter value and the blind parameter value G corresponding to each raw material. As a result, parameter values and blind parameter values G having additive homomorphism are obtained. For example, the following are obtained as parameter values for each raw material.

Cobalt: _HC
Nickel: _HN
Manganese: _HM
Blind parameter value: G

Note that the commitment value _CA of product A, which is the originating item, and the commitment value _CB of product B, which is the originating item, are calculated according to the following equations. r ₁ , r ₂ are random coefficients for the blind parameter value G; These commitment values C _A and C _B are recorded in past transaction data in the blockchain as described later.

In step S106, the server 14 generates the parameter values H _C , H _N , and H _M and the blind parameter value G corresponding to each raw material, and the quantity data and blind parameter value of each raw material, as shown in the following equations. Commitment value C _C of product C is calculated by performing a secure computation of multiplying G with a random coefficient r ₃ .

Note that the above commitment value corresponds to one point on the elliptic curve whose discrete logarithm is unknown. Therefore, it is not possible to calculate how much raw material is included in product C from the commitment value C _C described above.

Further, in step S106, the server 14 generates parameter values H _C , H _N , H _M and blind parameter values G corresponding to each raw material, quantity data of each raw material and blinds, as shown in the following equations. Commitment value C _D of product D is calculated by performing a secure calculation of multiplying and adding random coefficient _r4 to parameter value G.

If the commitment value is calculated without introducing the blind factor rG, the commitment value will be the same value if different items are made up of the same quantity of raw materials or the same ratio of raw materials. By introducing the blind factor rG, it is possible to have different commitment values for different items even if they are made up of the same quantity of raw materials or the same ratio of raw materials.

In order to establish the following formula (A), which will be described later, the random coefficients r ₁ , r ₂ , r ₃ , r ₄ are adjusted and set in advance so that the following formula (B) is satisfied. .

（Ａ）

（Ｂ）

(A)

(B)

In step S108, the server 14 stores the combination of the item ID of product C and the raw material ID of each raw material in the accumulator disclosed in Japanese Unexamined Patent Application Publication No. 2021-064219, for example. By storing various data in the accumulator, it is possible to record the item tracking information on the blockchain while reducing the data amount of the item tracking information. Similarly, the server 14 also stores the combination of the item ID of the product D and the raw material ID of each raw material in a predetermined data structure.

Note that the server 14 sets the parameter values H _C , H _N , H _M and the blind parameter value G, as described above. The commitment value calculated based on the parameter values H _C , H _N , and H _M and the blind parameter value G, and the quantity data and random coefficients corresponding to the raw material combination is the commitment calculated for the other raw material combination. Unique unlike the value. Therefore, the commitment value can also be used as identification data. The parameter values H _C , H _N , H _M and the blind parameter value G used when calculating the commitment value are stored and managed in a storage unit (not shown) of the server 14 .

Next, the server 14 accesses the blockchain node 16 to obtain the transaction data in which the accumulator including the item ID of the product A that is the origin of the generation is recorded in the output data, and the item ID of the product B that is the origin of the generation. Acquire the transaction data in which the accumulator included in the output data is recorded. The server 14 acquires transaction data based on the transaction ID assigned to the transaction data.

Specifically, in step S110, the server 14 acquires the transaction data in which the accumulator containing the item ID of the product A and the item ID of the product B in the output data is recorded. , sends a request signal to the blockchain node 16 .

In step S112, when the block chain node 16 receives the request signal transmitted from the server 14 in step S110, the past transaction data in which the item ID of product A is recorded as output information and the item of product B The past transaction data in which the ID is recorded as output data are transmitted to the server 14 . In this embodiment, such past transaction data is also referred to as first transaction data.

At step S<b>114 , the server 14 obtains first transaction data output from the blockchain node 16 .

In step S116, the server 14 generates second transaction data, which is transaction data including the address representing the source of the product C, which is the item to be generated, the address representing the destination of the product C, and the above data structure.

Specifically, the server 14 includes the past output data of the first transaction data in the input data of the second transaction data. In addition, the server 14 generates the second transaction data so that the transaction ID on the block chain related to the past first transaction data is also included in the input data of the second transaction data. In addition, the server 14 includes the item ID, raw material ID, and commitment value of product C in the output data constituting the second transaction data. As described above, the item ID and raw material ID of product C are stored in the accumulator, which is a predetermined data structure. Note that the commitment value may be further stored in the accumulator. In the present embodiment, the case where the item ID and raw material ID are stored in the accumulator will be described as an example. may be recorded in the

As described above, if some (or all) of the raw materials are not consumed in the process of generating product C, the accumulator also contains data on product D corresponding to the surplus raw materials that are not consumed. This recording method is one of the implementation examples of expressing the conservation law between the raw material represented by the input data and the raw material represented by the output data within one transaction data. As another method, it is possible to record the waste, which is the surplus raw material generated when generating the item to be generated, in another blockchain and refer to it between different blockchains.

FIG. 4 shows a diagram for explaining the data structure of transaction data. As shown in FIG. 4, transaction data TX2 includes an address representing the source of the product and an address representing the destination of the product.

Furthermore, as shown in FIG. 4, the input data of the transaction data TX2 includes the output data of the past transaction data TX1-1 and the output data of the past transaction data TX1-2. there is

On the other hand, as shown in FIG. 4, the output data of transaction data TX2 includes an accumulator containing the item ID and raw material ID of product C to be produced. In addition, this accumulator also contains the Item ID and Ingredient ID of Product D produced from the surplus ingredients. The output data of the transaction data TX1-1 and the transaction data TX1-2, which are the transaction data of the source item, store the item ID and raw material ID of the products A and B that have been generated in the past. It contains an accumulator with

At step S<b>118 , the server 14 broadcasts the second transaction data generated at step S<b>118 to the plurality of blockchain nodes 16 .

At step S120, each of the plurality of blockchain nodes 16 receives the second transaction data. In step S120, each of the plurality of blockchain nodes 16 reads each of the first transaction data, which are past transaction data linked to the second transaction data, from the blockchain. Specifically, each of the plurality of blockchain nodes 16 blocks in accordance with a predetermined protocol based on the identification data on the blockchain related to the past first transaction data, which is included in the second transaction data. Read each of the first transaction data from the chain.

In step S122, each of the plurality of blockchain nodes 16 exchanges the commitment value CC of product C and the remaining commitment value _CD of product _D included in the second transaction data TX2 with the commitment value CD included in the first transaction data TX1-1. Based on the relationship between the commitment value C A of product _A included in the first transaction data TX1-2 and the commitment value C _B of product B included in the first transaction data TX1-2, the product C that is the target item for generating the second transaction data TX2 is , is composed of raw materials of products A and B, which are origin items of the first transaction data TX1-1 and TX1-2.

As described above, when each parameter value and blind factor are generated by Pedersen commitment, the commitment value of the past transaction data included in the input data in the second transaction data and the commitment included in the output data should be equal to the value For this reason, for example, if the total commitment value included in the input data in the second transaction data is not equal to the total commitment value included in the output data in the second transaction data, the item to be generated is not generated properly for some reason.

For this reason, each of the plurality of blockchain nodes 16 includes the sum of the commitment values included in the output data in the first transaction data (the sum of the commitment values included in the input data in the second transaction data) and the second Second transaction data is recorded in the blockchain when the sum of the commitment values included in the output data in the transaction data is equal.

On the other hand, each of the plurality of blockchain nodes 16 is the sum of the commitment values included in the output data in the first transaction data (the sum of the commitment values included in the input data in the second transaction data) and the second transaction If the sum of the commitment values included in the output data in the data is not equal, the second transaction data is discarded without being recorded in the blockchain.

Note that, for example, when multiple item IDs are included in the output data, the total value of multiple commitment values included in the output data of the transaction data is published on the blockchain.

Specifically, when each of the plurality of blockchain nodes 16 generates the commitment value _CC of product C and product C included in the second transaction data TX2, as shown in the following formula: The sum of the commitment value C _D corresponding to the surplus of the generated raw materials is equal to the sum of the commitment values of the raw materials (the sum of C _A and C _B ) included in the plurality of first transaction data TX1-1, TX-2. In this case, it is determined that the product C of the second transaction data TX2 is composed of a plurality of raw materials of the first transaction data TX1-1 and TX-2.

In step S124, if each of the plurality of blockchain nodes 16 determines that the product C of the second transaction data TX2 is composed of the raw materials of the first transaction data TX1-1 and TX-2, the second Record the transaction data TX2 to the blockchain.

Depending on the commitment value described in the transaction data, an overflow may occur during the addition process of the commitment value performed by each blockchain node 16, resulting in an erroneous calculation result. Therefore, it is preferable to include proof that the commitment value is within the proper range. This implementation can include, for example, Range proofs. Examples of known techniques include Borromean Ring Signatures (https://www.semanticscholar.org/paper/Borromean-Ring-Signatures-%E2%88%97-Maxwell-Poelstra/4160470c7f6cf05ffc81a98e8fd67fb0c84836ea) and Bulletproofs (https:// eprint.iacr.org/2017/1066.pdf) can be used.

When the server 14 receives from the terminal 12 a request signal indicating a request to disclose the parameter value corresponding to the raw material ID, the server 14 performs authentication processing with the terminal 12 that has sent the request signal. Then, the server 14 discloses the parameter values to the terminal 12, which is the source of the request signal, when the terminal 12, which is the source of the request signal, is a terminal permitted to disclose the parameter values in advance. This terminal 12 verifies whether or not the product C has been manufactured appropriately based on the disclosed parameter values and the commitment values recorded in the transaction data.

For example, a user who has received product C to be generated decommits using the commitment value recorded in the blockchain in order to confirm whether product C was manufactured based on appropriate raw materials.

Note that when Pedersen commitment is used to calculate the commitment value, decommitment can be performed according to the following procedure.

Specifically, for example, the terminal 12X operated by the user who received the product C or a third party user transmits a predetermined request signal to the server 14 according to the user's operation. In response to the request signal, the server 14 passes through the authentication process described above, the parameter values _HC , _HN , and _HM , raw material quantity data (cobalt: 5, nickel: 4, manganese: 9), blind and the factor rG to the terminal 12X operated by the user. Also, the terminal 12X accesses the blockchain node 16 and acquires the commitment value _CC of the product C recorded in the second transaction data.

The terminal 12X receives the parameter values H _C , H _N , and H _M , raw material quantity data (cobalt: 5, nickel: 4, manganese: 9), blind factor rG, and the second transaction recorded in the block chain. Based on the data commitment values C and _C , a known decommit method is used to generate a verification result indicating whether or not product C was properly manufactured from products A and B. The terminal 12X confirms that the commitment value _CC of the product C recorded in the second transaction data is calculated based on the raw material quantity data, and that the product C is properly manufactured from the products A and B ( hereinafter simply referred to as "product C is properly generated"), the verification result to that effect is displayed on the display unit (not shown). On the other hand, if the product C is not properly generated, the terminal 12X displays the verification result to that effect on the display unit (not shown).

It is highly probable that the user who received the product C received the ingredient list of the product C from the user who generated the product C. Therefore, the terminal 12X operated by the user who received the product C displays the raw material quantity data (cobalt: 5, nickel: 4, manganese: 9) recorded in the composition table, etc., and the parameter values H _C , H _N , It is also possible to calculate the commitment value C _C ' for the product C itself based on H _M and the blind factor rG. Therefore, the terminal 12X operated by the user who received the product _C compares the commitment value C C ' calculated by itself with the commitment value C _C recorded in the block chain, and confirms that the product C has been properly generated. It is possible to generate a verification result indicating whether or not the object is true.

Note that the blind factor rG may be generated by the terminal 12X operated by the user who receives the product C, and each generated value may be transmitted to the server . In this case, the terminal 12X operated by the user who receives the product C transmits the blind factor rG to the server 14 in step S104.

Also, without disclosing the blind factor rG to the terminal 12X, using a known decommit method, based on a subtraction value obtained by subtracting the blind factor rG from each commitment value and a digital signature generated from the blind factor rG, It is also possible to generate a verification result indicating whether or not product C was properly generated.

It is also possible to use KZG commitment (see, for example, https://www.iacr.org/archive/asiacrypt2010/6477178/6477178.pdf) to calculate the commitment value. When using the Pedersen commitment, when decommitting, it is necessary to disclose the quantity data of raw materials included in the commitment value. On the other hand, by using the KZG commitment, which is a commitment scheme using polynomials, it is possible to disclose only the quantity data of some raw materials.

In the above example, the Pedersen commitment and KZG commitment are used to calculate the commitment value, but any commitment scheme with additive homomorphism can be used. be able to.

As described above, the terminal of the information processing system according to the present embodiment has the generation target item identification data representing the identification information of the generation target item and the identification information of the raw material used when generating the generation target item. Raw material identification data, quantity data representing the quantity of raw materials, and source item identification data representing the identification information of the source item are transmitted to the server. The server calculates the commitment value of the item to be produced by performing secure calculations based on the parameter values corresponding to the raw materials and quantity data. The server stores the combination of the commitment value, raw material identification data, and generation target item identification data in a predetermined data structure. The server provides first transaction data, which is transaction data recorded in the blockchain stored in the storage unit of the blockchain node and in which the generation source item identification data is included in the output data. to get Then, the server provides transaction data including an address representing the source of the item to be generated, an address representing the destination of the item to be generated, and a data structure, wherein the input data includes identification data of the item to be generated, and Broadcast second transaction data, wherein the output data includes a data structure containing item identification data, to a plurality of blockchain nodes. Each of the plurality of blockchain nodes reads from the blockchain each first transaction data, which is past transaction data linked to the second transaction data broadcast by the server. Each of the plurality of blockchain nodes performs the second transaction based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data Verifies whether or not the item of data is composed of raw materials included in the source item of the first transaction data, and determines that the item to be generated of the second transaction data is composed of the raw materials of the first transaction data. If so, record the second transaction data to the blockchain. As a result, it is possible to verify that the transaction of the raw materials contained in the item is not fraudulent while keeping the quantity of the raw materials contained in the item secret.

Also, by introducing the blind factor rG when calculating the commitment value of an item, it is possible to prevent the commitment values of different items from becoming the same value.

The present invention is not limited to the above-described embodiments, and various modifications and applications are possible without departing from the gist of the present invention.

For example, items include not only actual objects but also specific data.

Further, in the above embodiment, the case of introducing the blind factor rG when calculating the commitment value has been described as an example, but the present invention is not limited to this. The commitment value may be calculated without introducing the blind factor rG.

Further, in the above embodiment, the random coefficients r ₁ , r ₂ , r ₃ , r ₄ are adjusted in advance so that the above formula (B) is satisfied. not a thing If the random coefficients r ₁ , r ₂ , r ₃ , and r ₄ do not satisfy the above formula (B), a known method is can also be used to verify whether the product to be generated is properly manufactured from the original product.

In this case, as described above, the server 14 calculates the commitment value CC of the product C to be generated using the blind factor rG when calculating the commitment value of the product _C to be generated. Then, the server 14 generates the sum (C _C +C _{D ) of the commitment value C C of the product C to be generated included in the second transaction data and the commitment value C D corresponding to} the surplus of raw materials, and a plurality of first transactions A digital signature of the server 14 is generated for the information representing the difference between the sum of the commitment values (C _A +C _B ) of the products A and B of the generation source contained in the data, and the digital signature is used in the second transaction. Add to data. As a result, even if the operation result of (C _A +C _B )-(C _C +C _D ) does not become 0, since the operation result has a digital signature attached, it is generated based on the digital signature. It is possible to verify whether the target product is properly manufactured from the original product.

Further, in the above embodiment, the case where the product D corresponding to the surplus material that is not consumed when the product C is produced has been described as an example, but the present invention is not limited to this, and the surplus material is generated. It is possible to apply this embodiment even if it does not.

In the above embodiment, the server 14 executes various processes as an example, but the terminal 12 or the blockchain node 16 may execute part or all of the various processes.

Further, in the specification of the present application, an embodiment in which the program is pre-installed has been described, but it is also possible to store the program in a computer-readable recording medium and provide it. For example, the program is stored in non-transitory storage media such as CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), and USB (Universal Serial Bus) memory. may be provided in any form. Also, the program may be downloaded from an external device via a network.

Note that the processing executed by the CPU by reading the software (program) in the above embodiment may be executed by various processors other than the CPU. In this case, the processor is a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit) for executing specific processing. A dedicated electric circuit or the like, which is a processor having a specially designed circuit configuration, is exemplified. Alternatively, a GPGPU (General-purpose graphics processing UNIT) may be used as the processor. Also, each process may be executed by one of these various processors, or a combination of two or more processors of the same or different type (for example, a plurality of FPGAs, a combination of a CPU and an FPGA, etc.). ) can be run. More specifically, the hardware structure of these various processors is an electric circuit in which circuit elements such as semiconductor elements are combined.

Moreover, each process of the present embodiment may be configured by a computer or server having a general-purpose arithmetic processing unit, a storage device, or the like, and each process may be executed by a program. This program is stored in a storage device, and can be recorded on a recording medium such as a magnetic disk, optical disk, or semiconductor memory, or can be provided through a network. Of course, any other component does not have to be realized by a single computer or server, but may be distributed and realized by a plurality of computers connected by a network.

All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

It should be noted that, in the above embodiment, if there is no description of "only" such as "based only on XX", "only in response to XX", or "only in the case of XX", in this specification Note that it is assumed that , may also consider additional information. As an example, the statement "when a, do b" does not necessarily mean "when a, do b", unless explicitly stated.

In addition, even if there is an aspect in which some method, program, terminal, device, server, or system (hereinafter "method, etc.") performs operations different from those described in this specification, each aspect of the disclosed technology is The existence of operations that are the same as any of the operations described herein and that differ from the operations described herein indicate that the methods, etc. is not outside the scope of

10 information processing system 12, 12A, 12B, 12C, 12X terminal 14 server 16, 16A, 16B, 16C block chain node 20 network 70 computer 72 memory 73 storage unit

Claims (13)

An information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
Information processing system. An information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
Information processing system. When the server receives a request signal representing a request for disclosing the parameter value, the server performs authentication processing with the terminal that has transmitted the request signal, and the terminal that has transmitted the request signal confirms the parameter value. Disclosing the parameter value to the terminal that sent the request signal if the terminal is pre-permitted for disclosure;
The information processing system according to claim 1 or 2. The server in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
server. The server in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
server. The blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
blockchain node. The blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
blockchain node. An information processing method executed by an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
Information processing methods. An information processing method executed by an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
Information processing methods. A program to be executed by the server in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
program. A program to be executed by the server in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
program. A program for execution by the blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material that is not actually included in the item to be generated and blind quantity data representing a random pre-adjusted blind factor quantity, calculating the commitment value of the item to be generated by adding it to the sum-of-products operation result of the parameter value and the quantity data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when generating the item to be generated is included in the plurality of first transaction data. determining that the generation target item of the second transaction data is composed of a plurality of the raw materials of the first transaction data when equal to the sum of the commitment values of the generation source item;
program. A program for execution by the blockchain node in an information processing system including a server, a plurality of blockchain nodes, and a terminal operated by a user ,
When an item is traded between a plurality of users, a first user generates an item to be generated, and from the first user who is the source of the item to be generated, the second user who is the destination of the item to be generated When the item to be generated is sent to the user,
In response to an operation by the first user, the terminal operated by the first user outputs generation target item identification data representing identification information of the generation target item and identification of raw materials used when generating the generation target item. transmitting raw material identification data, which is information, quantity data representing the quantity of the raw material, and source item identification data representing the identification information of the source item to the server;
the server
calculating a commitment value of the item to be generated by performing secure calculation using a commitment scheme with additive homomorphism based on the parameter value corresponding to the raw material and the quantity data;
storing a combination of the raw material identification data and the generation target item identification data in a predetermined data structure;
Transaction data recorded in the blockchain stored in the storage unit of the blockchain node, wherein the source item identification data and the commitment value of the source item are included in the output data. Acquiring first transaction data, which is transaction data;
Transaction data including an address representing a source of the item to be generated, an address representing a destination of the item to be generated, and the data structure, wherein the source item identification data is included in input data, and the object to be generated obtaining second transaction data in which output data includes the data structure including item identification data and the commitment value of the item to be generated , and broadcasting the second transaction data to a plurality of blockchain nodes;
Each of the multiple blockchain nodes
reading from the blockchain each piece of first transaction data, which is past transaction data linked to the second transaction data broadcast by the server;
the generation of the second transaction data based on the relationship between the commitment value of the generation target item included in the second transaction data and the commitment value of the generation source item included in the first transaction data; verifying whether or not the target item is composed of the raw material included in the source item of the first transaction data, and verifying whether the target item of the second transaction data is composed of the raw material of the first transaction data; If determined to be configured, record the second transaction data to the blockchain ;
When the server calculates the commitment value of the item to be generated,
The result of a product-sum operation between a blind parameter value corresponding to a blind factor representing a raw material not actually contained in the item to be generated and blind quantity data representing a random quantity of the blind factor is defined as the parameter value. calculating the commitment value of the item to be generated by adding it to the result of the sum-of-products operation with the quantity data;
The sum of the commitment value of the item to be generated included in the second transaction data and the commitment value corresponding to the surplus of raw materials generated when the item to be generated is generated, and the sum is included in the plurality of first transaction data. generating a digital signature of the server for information representing a difference between the sum of commitment values of the originating item and adding the digital signature to the second transaction data;
When verifying whether the generation target item of the second transaction data is composed of the raw materials of the plurality of first transaction data, the plurality of blockchain nodes:
information representing the digital signature and the difference in the second transaction data; a commitment value of the item to be generated included in the second transaction data; By referring to the sum of the corresponding commitment values and the sum of the commitment values of the generation source items included in the plurality of the first transaction data, the generation target item of the second transaction data is the first transaction data. 1 verifying whether or not it is composed of the raw material contained in the originating item of transaction data;
program.

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