Block chain hybrid consensus method and system based on asynchronous committee

Abstract

The invention discloses a block chain hybrid consensus method and system based on asynchronous committee, and the method comprises the steps: carrying out the election processing of a plurality of block nodes in a block chain system through a Zhonghome consensus algorithm, and obtaining a committee node and a common node; the common node performs checking calculation processing according to the transaction information of the client to obtain a block; and according to the block, the committee node performs consensus processing by executing an asynchronous consensus protocol to obtain a block consensus result. According to the embodiment of the invention, the overall energy consumption of the block chain system can be reduced, and the reliability of the block chain system in a complex network environment is improved. The block chain hybrid consensus method and system based on the asynchronous committee can be widely applied to the technical field of block chains.

Description

Technical Field

[0001] The present invention relates to the field of blockchain technology, and in particular to a blockchain hybrid consensus method and system based on an asynchronous committee. Background Art

[0002] As a decentralized distributed ledger system, the core of blockchain technology lies in the design of the consensus mechanism. The related consensus mechanisms have the following problems. Although the Proof of Work (PoW) mechanism has good decentralization characteristics, it has serious performance bottlenecks. The PoW system represented by Bitcoin requires all nodes in the network to continuously perform a large number of hash calculations, which not only causes huge energy waste, but also due to the long block confirmation time (the average block generation time of Bitcoin is 10 minutes), the transaction processing efficiency is low. In addition, the inherent possibility of fork in the PoW mechanism makes transactions need to wait for multiple confirmations to ensure security, further prolonging the confirmation time. To solve the efficiency problem of PoW, mechanisms such as Proof of Stake (PoS) and Delegated Proof of Stake (DPoS) have been proposed. Although these mechanisms improve the efficiency, they are prone to concentration of rights and interests, affecting the decentralization degree of the system. At the same time, these mechanisms also face security threats such as "nothing at stake". The traditional Byzantine Fault Tolerance (BFT) consensus protocols, such as PBFT, Tendermint, etc., although they can provide instant finality, all rely on strong network synchronization assumptions and are difficult to run reliably in the actual Internet environment. In addition, such protocols usually require multiple rounds of communication between nodes, and the performance drops sharply when the number of nodes increases, making it difficult to support large-scale node networks. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a blockchain hybrid consensus method and system based on an asynchronous committee, which can reduce the overall energy consumption of the blockchain system and improve the reliability of the blockchain system in a complex network environment.

[0004] The first technical solution adopted by the present invention is: a blockchain hybrid consensus method based on an asynchronous committee, including the following steps:

[0005] Perform an election process on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes;

[0006] The ordinary nodes perform verification processing according to the transaction information of the client to obtain a block;

[0007] According to the block, the committee nodes perform consensus processing by executing an asynchronous consensus protocol to obtain a block consensus result.

[0008] Further, the step of performing an election process on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes specifically includes:

[0009] Obtain several block nodes in the blockchain system;

[0010] Perform a weight amplitude process according to the parameter information corresponding to the block nodes to obtain block nodes with weights, where the parameter information includes online time and coin holdings;

[0011] Conduct an election vote on the block nodes with weights through the Nakamoto consensus algorithm, and select the top N block nodes with the highest weights as committee nodes, and the remaining nodes as ordinary nodes.

[0012] Further, it also includes that each committee node is replaced after serving a term of epoch, and the term of epoch includes time points of several preset block rounds.

[0013] Further, the step of the ordinary nodes performing a verification process according to the transaction information of the client to obtain a block specifically includes:

[0014] Store the transaction information broadcast by the client in the network to the blockchain network to construct a transaction pool;

[0015] The ordinary nodes package the transaction information in the transaction pool to obtain the corresponding hash calculation value to get a block.

[0016] Further, the block includes a block header, a block body, consensus verification information, and additional information, where:

[0017] The block header includes the block height, the hash value of the parent block, the list of committee members, the block producer, and the block hash;

[0018] The block body includes the information of the transaction list, the PoW proof information, and the block content summary information, and the information of the transaction list is packaged into the block by the generating node of the block;

[0019] The consensus verification information includes the signature information of the committee nodes on this block during the consensus process. Among them, the consensus nodes will verify the correctness of the block and verify the correctness of each transaction one by one, and then sign the block hash with the private key and append it to the consensus verification information part to ensure that the block is officially added to the blockchain after reaching consensus;

[0020] The additional information is used to replace the committee or record the reward information.

[0021] Further, the step of the committee nodes performing a consensus process through the execution of an asynchronous consensus protocol according to the block to obtain a block consensus result specifically includes:

[0022] Obtain the hash value of the block and use it as input data;

[0023] Select the corresponding asynchronous consensus engine according to the dimensional characteristics of the transaction;

[0024] If the dimensional characteristic of the transaction is to focus on the security of the transaction, select the message authentication mechanism to perform consensus processing on the input data to obtain the first block consensus result;

[0025] If the dimensional characteristic of the transaction is to focus on the efficiency of the transaction, select the lightweight cryptography primitive mechanism to perform consensus processing on the input data to obtain the second block consensus result;

[0026] Integrate the first block consensus result and the second block consensus result to obtain the block consensus result.

[0027] Furthermore, it further includes that the block consensus result is broadcast by the consensus node as the latest block of the blockchain to all nodes of the blockchain.

[0028] The second technical solution adopted by the present invention is: a blockchain hybrid consensus system based on an asynchronous committee, including:

[0029] The first module is used to perform election processing on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes;

[0030] The second module is used for the ordinary nodes to perform verification processing according to the transaction information of the client to obtain the block;

[0031] The third module is used to perform consensus processing through the execution of the asynchronous consensus protocol by the committee nodes according to the block to obtain the block consensus result.

[0032] The beneficial effects of the method and system of the present invention are: the present invention performs election processing on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes. Further, the ordinary nodes perform verification processing according to the transaction information of the client to obtain the block. The first layer uses PoW with a higher difficulty to elect committee members, and the second layer uses PoW with a lower difficulty to generate ordinary blocks, significantly reducing the overall energy consumption of the system and maintaining the decentralized characteristics of PoW. Also, the committee mechanism provides fast block confirmation ability. Finally, according to the block, the committee nodes perform consensus processing through the execution of the asynchronous consensus protocol to obtain the block consensus result. The asynchronous consensus protocol adopted by the committee does not make any assumptions about network synchronization, improving the reliability of the system in a complex network environment. Description of the Drawings

[0033] Figure 1It is a flowchart of the steps of a blockchain hybrid consensus method based on an asynchronous committee according to the present invention;

[0034] Figure 2 It is a block diagram of the structure of a blockchain hybrid consensus system based on an asynchronous committee according to the present invention;

[0035] Figure 3 It is a schematic diagram of the protocol architecture of blockchain hybrid consensus provided by a specific embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram of the algorithm composition of the consensus mechanism provided by a specific embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of the process of a blockchain hybrid consensus protocol provided by a specific embodiment of the present invention;

[0038] Figure 6 It is a schematic diagram of the process of the protocol by rounds provided by a specific embodiment of the present invention;

[0039] Figure 7 It is a schematic diagram of the block composition structure provided by a specific embodiment of the present invention;

[0040] Figure 8 It is a schematic diagram of the consensus node mechanism within the committee provided by a specific embodiment of the present invention;

[0041] Figure 9 It is a schematic diagram of the transaction pool Txpool provided by a specific embodiment of the present invention;

[0042] Figure 10 It is a schematic diagram of consensus based on the hash of the block provided by a specific embodiment of the present invention. Detailed implementation manners

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. For the step numbers in the following embodiments, they are only set for the convenience of explanation and illustration, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0044] First of all, it should be noted that compared with the prior art, in the embodiments of the present invention, traditional blockchain consensus mechanisms either rely on the computationally intensive PoW mechanism, resulting in energy waste and confirmation delays, or rely on the BFT protocol that requires strong network synchronization assumptions and is difficult to operate reliably in a real network environment. The present invention successfully solves these problems through a hybrid consensus design: First, only the high-difficulty PoW is used in the committee election stage, significantly reducing the overall energy consumption of the system; Second, the asynchronous consensus protocol adopted by the committee does not require any assumptions about network synchronization, improving the reliability of the system in a complex network environment; Finally, the deterministic feature of the committee consensus result avoids blockchain forks and provides a reliable finality guarantee for upper-layer applications.

[0045] Specifically, the present invention adopts a two-layer proof-of-work mechanism. In the first layer, a higher-difficulty PoW is used for the election of committee members, and in the second layer, a lower-difficulty PoW is used for the generation of ordinary blocks. Committee members are responsible for executing the asynchronous consensus protocol, verifying the blocks generated by ordinary nodes, and generating verifiable consensus proofs. This hierarchical design not only maintains the decentralized feature of PoW but also provides fast block confirmation capabilities through the committee mechanism.

[0046] Based on this, as Figure 3 shown, the protocol of the embodiments of the present invention is applicable to the blockchain public chain environment where nodes can enter or leave the system arbitrarily. A separate client sends transaction information to all nodes. All nodes in the blockchain are divided into two parts: committee nodes and ordinary nodes. The consensus algorithm adopts the Nakamoto consensus + distributed asynchronous algorithm. Ordinary nodes are responsible for packing transactions and performing PoW calculations to generate blocks; consensus nodes belong to the consensus committee and are responsible for verifying the blocks mined by ordinary nodes, including checking whether there are conflicting transactions, correct format, correct signature, etc., and reaching a consensus at a certain block height and saving it as the latest block in the current blockchain. The generation of each block is a consensus round. To avoid frequent view conversions, each blockchain committee has a tenure epoch that contains multiple consensus rounds.

[0047] Referring to Figure 1 , the present invention provides a blockchain hybrid consensus method based on an asynchronous committee, and the method includes the following steps:

[0048] S100. Perform election processing on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes;

[0049] Specifically, obtain several block nodes in the blockchain system; perform weight amplitude processing according to the parameter information corresponding to the block nodes to obtain block nodes with weights, where the parameter information includes online time and coin holding amount; conduct an election vote on the block nodes with weights through the Nakamoto consensus algorithm, and select the top N block nodes with the highest weights as committee nodes, and the remaining nodes as ordinary nodes.

[0050] S200. The ordinary nodes perform verification processing on the transaction information of the client to obtain a block.

[0051] Specifically, store the transaction information broadcast by the client in the network to the blockchain network to construct a transaction pool; the ordinary nodes package the transaction information in the transaction pool to obtain the corresponding hash calculation value to obtain a block.

[0052] In this embodiment, as Figure 4 shown, computing power is the basis for each node to continuously run this protocol. Similar to the verification process of Bitcoin, ordinary nodes generate new blocks by solving hash puzzles and submit them to the current committee for consensus. Solving this kind of hash puzzle is difficult but the verification speed is relatively fast. Therefore, the committee nodes can quickly verify these blocks and use the blocks that pass the verification as their consensus proposals.

[0053] It should be further noted that each block in the blockchain is the result of consensus by each round of consensus committee. Each block is generated by the ordinary node group through verification and is attached with the signature of the committee node during the consensus process. After the block receives enough n-f consensus signatures, it is marked as valid and broadcast to all nodes to be recorded in the local ledger. In this protocol, a block consists of four parts, including a block header, a block body, consensus verification information, and additional information. As Figure 7 shown, the block header contains information such as block height, hash value of the parent block, list of committee members, block producer, block hash, etc. The block body contains information of the transaction list, which is packaged into the block by the block generation node, as well as information such as PoW proof and block content summary. The consensus verification information contains the signature information of the committee node on this block during the consensus process. After the consensus node verifies the correctness of the block and verifies the correctness of each transaction one by one, it signs the block hash with the private key and attaches it to the consensus verification information part to ensure that the block is officially added to the blockchain after reaching consensus. The additional information is used for other processes such as replacing the committee or recording reward information.

[0054] S300. According to the block, the committee nodes perform consensus processing through the execution of an asynchronous consensus protocol to obtain a block consensus result.

[0055] Specifically, obtain the hash value of the block and use it as input data; according to the dimensional characteristics of the transaction, select the corresponding asynchronous consensus mechanism; if the dimensional characteristic of the transaction is to focus on transaction security, select the message authentication mechanism to perform consensus processing on the input data to obtain the first block consensus result; if the dimensional characteristic of the transaction is to focus on transaction efficiency, select the lightweight cryptography primitive mechanism to perform consensus processing on the input data to obtain the second block consensus result; integrate the first block consensus result and the second block consensus result to obtain the block consensus result.

[0056] In this embodiment, as Figure 8 shown, within the committee, the committee nodes will, according to the rules, take a certain block received as the proposal of the consensus node in this round of consensus and use it as the input of the consensus algorithm. After the consensus algorithm ends, the output is the consensus result of this round. This consensus result is broadcast by the consensus node as the latest block of the blockchain to all nodes of the blockchain.

[0057] As Figure 9 shown, each committee node has its own transaction pool Txpool and the list of received blocks, which contains the information of the block. Different committee nodes may receive different blocks because the ordinary node group uses the PoW consensus algorithm and may produce forks. As a result, multiple ordinary nodes have mined blocks and submitted them to the consensus committee. The consensus nodes within the committee will perform consensus on these blocks, and the consensus result is submitted to the blockchain as the only determined block at this block height, avoiding forks. Therefore, this protocol is a deterministic consensus.

[0058] Furthermore, it should be noted that, as Figure 10 shown, the asynchronous consensus protocol is sensitive to the input size. Therefore, the input size of the asynchronous consensus mechanism should be minimized as much as possible. Since the blocks mined by the nodes will be broadcast to all consensus nodes, the consensus nodes often store the specific contents of multiple blocks. Therefore, during the consensus process, only the hash of the corresponding block needs to be used as the input of the asynchronous consensus mechanism for consensus to accelerate the consensus process.

[0059] The selection of the asynchronous consensus mechanism within the committee is a key flexible point in the present invention, which can be customized according to the specific application scenarios and requirements of the blockchain. Specifically, the selection of asynchronous consensus can be considered from the following dimensions: (1) When the blockchain system places more emphasis on security, an asynchronous consensus scheme with the following characteristics can be selected: introducing additional cryptographic proof mechanisms, increasing the number of verification rounds to provide stronger certainty guarantees, and using more stringent message authentication mechanisms, etc. (2) When the blockchain system places more emphasis on transaction processing efficiency, an asynchronous consensus scheme with the following characteristics can be selected: optimizing message complexity, reducing the number of communication rounds, adopting a batch processing mechanism to increase parallelism, or using lightweight cryptographic primitives. Therefore, the specific implementation of the asynchronous consensus mechanism can choose different paradigms of asynchronous consensus protocols to achieve. The present invention supports the adoption of two mainstream asynchronous consensus paradigms: including the BKR paradigm and the CKPS paradigm.

[0060] In summary, as Figure 5 shown, the step process of the embodiment of the present invention can be summarized as follows:

[0061] 1) All nodes conduct a high-difficulty verification election through the Nakamoto consensus PoW to elect committee nodes for the subsequent asynchronous consensus process, and the remaining nodes become ordinary nodes for processing transactions and verifying block production.

[0062] 2) Ordinary nodes execute a low-difficulty PoW verification process, package the transactions, and generate a block.

[0063] 3) Ordinary nodes submit the generated block to the committee member nodes in the protocol.

[0064] 4) Committee nodes conduct an asynchronous consensus protocol within the committee to reach a consensus on the generated block.

[0065] 5) After reaching a consensus, the committee nodes broadcast the consensus result to all nodes.

[0066] 6) The protocol proceeds in rounds. The process from the generation of each block to its being added to the chain requires the processes of steps 2) to 5). After reaching a consensus by the committee nodes and broadcasting it to all nodes, a deterministic consensus is formed.

[0067] As Figure 6As shown in the figure, the protocol of the embodiment of the present invention runs in rounds, which is the same as the traditional distributed consensus protocol. The protocol of the present invention runs in rounds. Ordinary nodes send their block generation to all consensus committee nodes. After internal consensus within the committee, the consensus result will be submitted to the blockchain network and broadcast to all nodes. Each round is a process of consensus for a block, and the consensus result of this round is the latest block on the blockchain. To prevent frequent view conversions, the internal consensus of the committee designs a leaderless consensus protocol. At the same time, each consensus committee serves for one term of epoch before being replaced. Each term of epoch contains the time of multiple block rounds. The consensus committee is only replaced until the consensus cannot be advanced due to an excessive number of malicious nodes or network reasons.

[0068] In summary, the embodiment of the present invention has the following differences compared with the traditional consensus mechanism:

[0069] 1) Deterministic consensus: The traditional blockchain public chain consensus PoW implements a probabilistic confirmation consensus mechanism. The consensus of each block is only a probabilistic consensus, and the security depends on the computing power held by malicious parties. If the adversary holds more computing power resources, the consensus is no longer secure.

[0070] 2) Faster consensus speed: In the Bitcoin network using PoW consensus, it often takes about one hour to confirm a transaction (because it is necessary to wait for 6 blocks to probabilistically confirm that the transaction has been submitted to the chain). The generation interval and size of transaction blocks also limit the throughput of the blockchain. As a solution to accelerate the blockchain consensus performance, the committee-based consensus protocol was initially implemented by PeerCensus, which has since sparked a research boom in blockchain committee-based consensus. PeerCensus adopts the consensus form of PoW+PBFT, forming a deterministic consensus (strong consensus) by running the distributed system consistency protocol PBFT within the committee on the probabilistic consensus (weak consensus) in the previous blockchain. Most of the subsequent research on committee-based consensus protocols also adopts the form of PoX-based consensus + distributed system consistency protocol, but they are all limited under the assumptions of synchronous and semi-synchronous networks.

[0071] 3) Wider application environment: Considering that when applied to the public chain environment, the committee nodes may be in a relatively poor environment, and the real situation should be an asynchronous network. Therefore, the traditional committee-based consensus protocol may not be able to advance in this case, and an attack on the node network may lead to the paralysis of the entire system. The introduction of the committee in blockchain consensus has improved performance, but it has also brought other problems, including centralization risks, security risks, etc. Designing a more practical and efficient committee-based consensus mechanism is of great significance.

[0072] Therefore, the embodiments of the present invention have the following advantages compared with traditional consensus mechanisms:

[0073] 1) Significantly reduce the consensus overhead of the entire network, improving the overall efficiency and scalability of the system;

[0074] 2) Ensure consensus security even in an asynchronous network environment, improving the practicality of the system;

[0075] 3) Achieve fast block confirmation and deterministic finality through the committee mechanism;

[0076] 4) Maintain an appropriate degree of decentralization while optimizing system performance.

[0077] Refer to Figure 2 , a blockchain hybrid consensus system based on an asynchronous committee, including:

[0078] The first module 201 is used to perform an election process on several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes;

[0079] The second module 202 is used for ordinary nodes to perform verification processing according to the transaction information of the client to obtain a block;

[0080] The third module 203 is used to perform consensus processing through an asynchronous consensus protocol according to the block by the committee nodes to obtain a block consensus result.

[0081] The content in the above method embodiments is applicable to the system embodiments of the present invention. The functions specifically implemented by the system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0082] The above is a specific description of the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A blockchain hybrid consensus method based on asynchronous committee, characterized in that: The following steps are involved: The Nakamoto consensus algorithm is used to elect several block nodes in the blockchain system to obtain committee nodes and ordinary nodes; Ordinary nodes verify and process the transaction information of the client to obtain blocks; According to the block, the committee nodes perform consensus processing by executing the asynchronous consensus protocol to obtain the block consensus result.

2. According to claim 1, a blockchain hybrid consensus method based on an asynchronous committee is characterized in that: The step of electing several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes specifically includes: Get several block nodes in the blockchain system; Perform weight amplitude processing according to the parameter information corresponding to the block node to obtain a block node with weight, wherein the parameter information includes online time and currency holding amount; The Nakamoto consensus algorithm is used to elect and vote on weighted block nodes, and the top N block nodes with the highest weights are selected as committee nodes, and the remaining nodes are used as ordinary nodes.

3. According to claim 2, a blockchain hybrid consensus method based on an asynchronous committee is characterized in that: It also includes replacing each committee node after serving for one epoch, and the epoch includes several time points of preset block rounds.

4. According to claim 3, a blockchain hybrid consensus method based on asynchronous committee is characterized in that: The ordinary node verifies and processes the transaction information of the client to obtain the block, which specifically includes: Store the transaction information broadcast by the clients in the network to the blockchain network and build a transaction pool; Ordinary nodes package the transaction information in the transaction pool, obtain the corresponding hash calculation value, and obtain the block.

5. According to claim 4, a blockchain hybrid consensus method based on asynchronous committee is characterized in that: The block includes a block header, a block body, consensus verification information and additional information, where: The block header includes the block height, the hash value of the parent block, the committee member list, the block generator and the block hash; The block body includes transaction list information, PoW proof information and block content summary information. The transaction list information is packaged into the block by the block generation node; The consensus verification information includes the signature information of the committee node on the block during the consensus process. The consensus node will verify the correctness of the block and the correctness of the transactions one by one, and then use the private key to sign the block hash and attach it to the consensus verification information part, ensuring that the block is officially added to the blockchain after reaching a consensus; The additional information is used to replace the committee or record award information.

6. According to claim 5, a blockchain hybrid consensus method based on asynchronous committee is characterized in that: The step of obtaining the block consensus result by the committee node executing the asynchronous consensus protocol according to the block specifically includes: Get the hash value of the block and use it as input data; Select the corresponding asynchronous consensus device according to the dimensional characteristics of the transaction; If the dimension feature of the transaction is to focus on the security of the transaction, the message authentication mechanism is selected to perform consensus processing on the input data to obtain the consensus result of the first block; If the dimensional feature of the transaction is to focus on the efficiency of the transaction, a lightweight cryptographic primitive mechanism is selected to perform consensus processing on the input data to obtain the consensus result of the second block; Integrate the consensus result of the first block and the consensus result of the second block to obtain the block consensus result.

7. According to claim 6, a blockchain hybrid consensus method based on asynchronous committees is characterized in that: It also includes that the block consensus result is broadcasted by the consensus node to all nodes in the blockchain as the latest block of the blockchain.

8. A blockchain hybrid consensus system based on asynchronous committee, characterized in that: Includes the following modules: The first module is used to elect several block nodes in the blockchain system through the Nakamoto consensus algorithm to obtain committee nodes and ordinary nodes; The second module is used by ordinary nodes to verify and process the transaction information of the client to obtain blocks; The third module is used to perform consensus processing based on the block and the committee node by executing the asynchronous consensus protocol to obtain the block consensus result.

Images