JP6931331B2 - Blockchain management system, blockchain management method and blockchain management program - Google Patents

Description

The present invention relates to a system, method and program for managing a plurality of blockchains.

Conventionally, a blockchain, which is a distributed database, has been proposed as a data recording method that is difficult to falsify, and is used in various systems (see, for example, Non-Patent Documents 1 to 3).

Satoshi Nakamoto. Bitcoin: A peer-to-peer electronic cash system, 2008. Somplinsky, Y. et al. , Zohar, A. : Accelerating bitcoin's transaction processing. Fast money grows on trees, not chains. IACR Cryptography ePrint Archive 2013 (2013) 881. Lewenberg, Y. et al. , Somplinsky, Y. et al. , Zohar, A. : INCLUSIVE block chain protocols. In: Financial Cryptography and Data Security-19th International Convention, FC2015, San Juan, Puerto Rico, January 26-30, 2015, Selected Paper. (2015) 528-547.

By the way, in blockchain, in order to guarantee the correctness of recorded data, consensus building is usually performed by a predetermined consensus algorithm for all users, but this process requires a large amount of calculation and communication costs.
In addition, when local blockchains are operated by a plurality of organizations, reliability decreases as the scale of each blockchain decreases, and the overall cost increases.

An object of the present invention is to provide a blockchain management system, a blockchain management method, and a blockchain management program that can improve the reliability of each of a plurality of blockchains at low cost.

The blockchain management system according to the present invention is a blockchain management system in which a plurality of nodes form blockchains different from each other, and each node is randomly selected from blocks stored in the blockchains of other nodes. In addition to the selection unit that selects one or more blocks and acquires the hash value of the block and the hash value of the block that it generated immediately before, the hash value of the one or more blocks selected by the selection unit is added. Including, it includes a generation unit that generates a new block.

The selection unit may be selected from blocks generated within a predetermined period.

The blockchain management system may include a buffer unit that temporarily stores the hash value of a block stored in the blockchain of the other node.

The selection unit may select one or more blocks by a selection function in which at least a part of the hash value of the block generated immediately before is input.

The blockchain management method according to the present invention is a blockchain management method in which a plurality of nodes form blockchains different from each other, and each node is randomly selected from blocks stored in the blockchains of other nodes. In addition to the selection step of selecting one or more blocks and acquiring the hash value of the block and the hash value of the block generated immediately before itself, the hash value of the one or more blocks selected in the selection step is added. Including, the generation step to generate a new block, and the execution of.

The blockchain management program according to the present invention is a blockchain management program for a plurality of nodes to form blockchains different from each other, and each node is composed of blocks housed in the blockchains of other nodes. In addition to the selection step of randomly selecting one or more blocks and acquiring the hash value of the block and the hash value of the block generated immediately before itself, the hash of the one or more blocks selected in the selection step. It is for executing a generation step to generate a new block including a value.

According to the present invention, the reliability of each of the plurality of blockchains is improved at low cost.

It is a figure which shows the functional structure of the blockchain management system which concerns on embodiment. It is a figure which shows the structure of the block which concerns on embodiment. It is a figure which illustrates the state of the connection between blocks which concerns on embodiment.

Hereinafter, an example of the embodiment of the present invention will be described.
FIG. 1 is a diagram showing a functional configuration of a node 10 (information processing device or device group) that manages a plurality of blockchains to be managed in the blockchain management system 1 according to the present embodiment.
The nodes 10 of each organization that manages the blockchain form blockchains that are different from each other, and include a buffer unit 11, a selection unit 12, and a generation unit 13.

The buffer unit 11 temporarily stores the hash value of the block stored in the block chain composed of the other nodes 10.
For example, the hash value of the block stored in each blockchain is broadcast and stored in the buffer unit 11 of each node 10 in association with the index.
The buffer unit 11 stores the hash value of the blocks generated within a predetermined period, and for example, the older the block whose time has passed since the generation, the older the block may be deleted with a higher probability.

The function of the buffer unit 11 may be implemented by a buffer function. The buffer function manages the correspondence table between the index and the hash value, and returns the hash value corresponding to the specified index. In addition, the buffer function uses a random FIFO (First In, First Out) method to exclude old blocks from the buffer target each time it is executed, and newly adds a hash value of blocks generated in a certain period of time.

The selection unit 12 randomly selects one or more blocks from the blocks stored in the blockchain of the other node 10, and acquires the hash value of the selected block.
At this time, the selection unit 12 acquires the hash value of the block generated within a predetermined period by selecting from the hash values stored in the buffer unit 11.

Further, the selection unit 12 may select one or more blocks by a selection function in which at least a part of the hash value of the block generated immediately before itself is input. Specifically, the selection unit 12 uniquely determines an index (integer value) by extracting a predetermined bit of the hash value of the block generated immediately before and inputting it to the selection function, and corresponds to this index. Get the hash value of the block.

The generation unit 13 generates a new block by including the hash value of one or more blocks selected by the selection unit 12 in addition to the hash value of the block immediately generated by each node 10 itself.

FIG. 2 is a diagram showing a configuration of blocks housed in the block chain according to the present embodiment.
A plurality of transaction data recorded in each block of the blockchain is managed by a tree structure such as a Merkle hash tree, and the root hash of this tree structure is stored in the block.

In addition, the hash value of the immediately preceding block and the hash value of one or more blocks generated by the other node 10 are stored in the block, and the electronic signature of the creator is given by combining these.
The Nonce used in the normal consensus processing can be omitted, thereby reducing the processing load.

FIG. 3 is a diagram illustrating a state of connection between blocks in the blockchain management system 1 according to the present embodiment.
In this example, three nodes A, B, and C each operate a blockchain, node A generates blocks in the order of numbers 1, 4, and 7, and node B generates blocks in the order of numbers 2, 5, and 8. Blocks are generated, and node C generates blocks in the order of numbers 3, 6 and 9.

For example, the fourth block stores the hash value of the second block of the blockchain operated by the node B in addition to the hash value of the immediately preceding first block in the same blockchain.
Similarly, for example, the 8th block stores the hash value of the 1st block of the blockchain operated by the node A in addition to the hash value of the 5th block immediately before in the same blockchain.

In this way, the blocks stored in the plurality of blockchains are connected to each other by including the hash values of the blocks of the other blockchains. Over time, this interconnection becomes denser throughout the system, increasing the reliability of each block.
The timing of generating blocks in each blockchain does not necessarily have to be synchronized, and the hash value of the blocks generated in each node 10 at its own cycle is held in the buffer unit 11 for a certain period of time.

According to the present embodiment, the blockchain management system 1 is configured by distributing a plurality of blockchains by a plurality of nodes 10. In the block of each blockchain, in addition to the hash value of the immediately preceding block, the hash value of any block generated by the other node 10 is randomly selected and stored.
Therefore, the blockchain management system 1 can suppress falsification in a single blockchain by mutually referencing the blocks of a plurality of blockchains. Since each blockchain refers to all other blockchains in the system over time, the effect of mutual checking can improve the reliability of each of the plurality of blockchains at low cost. As a result, a consensus process using a normal Nonce becomes unnecessary, and a blockchain capable of high-speed and distributed processing is realized.

Furthermore, even if the number of blockchains increases, the cost of a single blockchain does not increase, so increasing the degree of parallelism improves efficiency.
In addition, since the only data that is cross-referenced between blockchains is the hash value, it is possible to prevent leakage of confidential information and ensure security.

The blockchain management system 1 temporarily stores the hash value of the block generated by the other node 10 in the buffer unit 11, thereby randomly selecting a past block other than the latest block and including the hash value in the block. can.
Therefore, the blockchain management system 1 can make the interconnection of blockchains more complicated and improve the reliability. Furthermore, by selecting a plurality of blocks, a closer connection is possible, and improvement in reliability can be expected.

Further, the blockchain management system 1 can suppress the capacity and processing load of the buffer unit 11 by limiting the blocks of the other nodes 10 to be selected to the blocks generated within a predetermined period.

In the blockchain management system 1, when selecting a block of another node 10, each node 10 obtains a unique index by inputting at least a part of the hash value of the block generated immediately before.
Therefore, the selected block is uniquely determined from the immediately preceding block, which facilitates verification.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Moreover, the effects described in the above-described embodiments are merely a list of the most preferable effects arising from the present invention, and the effects according to the present invention are not limited to those described in the embodiments.

In the above-described embodiment, the broadcast hash value is stored in the buffer unit 11, but the buffer unit 11 may be omitted by limiting the block to be selected to, for example, the latest block. In this case as well, a rule for selecting the immediately preceding block is determined for the index obtained by the selection function.

Further, in the above-described embodiment, the Nonce used for the processing of the consensus is not required, but a blockchain composed of blocks including the Nonce may be included. The blockchain management system 1 can improve the overall reliability by interconnecting the blockchains operated by each of the plurality of nodes 10 according to their own policies.

The blockchain management method by the blockchain management system 1 is realized by software. When realized by software, the programs that make up this software are installed in the information processing device (computer). Further, these programs may be recorded on a removable medium such as a CD-ROM and distributed to the user, or may be distributed by being downloaded to the user's computer via a network. Further, these programs may be provided to the user's computer as a Web service via a network without being downloaded.

1 Blockchain management system 10 nodes 11 buffer part 12 selection part 13 generation part

Claims (6)

A blockchain management system in which multiple nodes form different blockchains from each other.
Each node, respectively,
A selection unit that randomly selects one or more blocks from the blocks stored in the block chain of another one or more nodes and acquires the hash value of the block.
Itself in addition to the hash value of the block generated immediately before, including a hash value of the one or more blocks selected by the selection unit, by providing a generator for generating a new block, a plurality A blockchain management system in which the nodes of are cross-referenced. The blockchain management system according to claim 1, wherein the selection unit selects from blocks generated within a predetermined period. The blockchain management system according to claim 1 or 2, further comprising a buffer unit for temporarily storing a hash value of a block stored in the blockchain of the other node. The blockchain management according to any one of claims 1 to 3, wherein the selection unit selects one or more blocks by a selection function in which at least a part of the hash value of the block generated immediately before is input. system. A blockchain management method in which multiple nodes form different blockchains from each other.
Each node, respectively,
A selection step of randomly selecting one or more blocks from the blocks stored in the blockchain of another one or more nodes and acquiring the hash value of the block, and
Itself in addition to the hash value of the block generated immediately before, including the hash value of the selected the one or more blocks in the selecting step, by executing the a generation step of generating a new block, the A blockchain management method in which multiple nodes are cross-referenced. A blockchain management program for multiple nodes to configure different blockchains from each other.
For each node ,
A selection step of randomly selecting one or more blocks from the blocks stored in the blockchain of another one or more nodes and acquiring the hash value of the block, and
Itself in addition to the hash value of the block generated immediately before, including the hash value of the selected the one or more blocks in the selecting step, by executing the a generation step of generating a new block, the A blockchain management program for cross-referencing multiple nodes.

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