Research On Blockchain Scheme Basing On BFT Consensus Protocol

Blockchain technology is a new type of decentralized ledger technology,which can build global trust among mutual distrust parties without the participation of a trusted third party.Due to its unique data structure design,transaction information on the blockchain has the characteristics of integrity and immutability.Blockchain technology has a wide range of applications in the fields of finance,the Internet of Things,and credit management et al.The consensus mechanism is the core technology of blockchain.Different consensus nodes use the consensus mechanism to update the global ledger.The Po W(Proof of Work)consensus mechanism is most widely used,but it has the disadvantages of high energy consumption and low transaction throughput.Among the many consensus mechanisms,BFT(Byzantine Fault Tolerance)protocols are widely used in the design of consortium blockchain due to their definite security boundary and fast convergence speed.However,most existing BFT protocols are static BFT protocols,which do not support dynamic joining and quitting of consensus nodes.At the same time,the performance of BFT protocol will decrease sharply when there are many nodes in the system.These problems have limited the application of the BFT protocol in the blockchain system to a certain extent.Based on the limitations of existing BFT protocols,this paper has made design improvements based on the existing scheme and the following are the achievements:1.We propose dynamic enhanced BFT protocol basing on HoneyBadger BFT.The protocol has the fault-tolerant characteristics and communication complexity advantages of the original protocol.By combining a dynamic threshold encryption component and a distributed key generation component,and designing reasonable protocol details,the dynamic enhancement BFT protocol realizes the dynamic characteristics of the BFT protocol.Without the need to reconfigure the system globally,new nodes can join the system by sponsoring join protocol and current consensus nodes can leave the system by sponsoring quit protocol.At the same time,an evaluation scheme for the behavior of consensus nodes in the system and a specific clear protocol are designed to allow enough nodes to initiate clear protocols for malicious or inactive nodes to clear them out of the system.Dynamic properties of the BFT protocol makes our BFT protocol suitable for deployment in consortium blockchain with certain dynamic characteristics requirements,and it is conducive to maintaining the long-term benign working of the system.2.We propose a new layered sharding consortium blockchain scheme basing on dynamically enhanced BFT protocol.In this scheme,consensus nodes are divided into verification nodes and updating nodes to be responsible for transaction verification and new block generation respectively.This layered architecture design can reduce the burden on a single node,while combining the local log mechanism of the consensus node can provide a global audit function.The sharding scheme is used to divide the verification nodes into different consensus groups to form different verification shard.Different verification shards are responsible for verifying disjoint UTXO(Unspent Transaction Output)sets.This solution improves the system transaction throughput while keeping the system security.At the same time,the audit and supervision mechanism in the system combined with the dynamic property of the BFT protocol improves the reliability of the system.