A Study On Scalable Distributed Consensus Algorithm Based On Sharding Technology

Since the advent of Bitcoin in 2008,blockchain as the underlying technology of cryptocurrency such as Bitcoin,has attracted widespread attention in many fields such as finance and academia.Blockchain is essentially a distributed database system,which provides an open distributed consensus algorithm.Although blockchain is a fully decentralized and securely designed protocol,it still faces scalability bottlenecks: low transaction throughput and high confirmation delay.These factors greatly limit the practical application of blockchain.Therefore,it is very meaningful to design a scalable distributed consensus algorithm.Sharding technology is a major method to improve the scalability and performance of the blockchain.It maintains the distributed ledger by running the classic Byzantine Fault Tolerance(BFT)protocol in parallel through several relatively small committees.In response to the scalability bottleneck of the blockchain,a scalable distributed consensus protocol-Hot DAG is implemented by employing the sharding technology,the parallel Nakamoto consensus model,the scalable BFT protocol and the directed acyclic block structure(block DAG).The Hot DAG protocol uses the parallel Nakamoto consensus algorithm to implement the node sharding,ensuring that each committee is strongly biasresistant without relying on any honest third party.Secondly,by introducing a scalable BFT protocol and an inter-committee consensus mechanism based on block DAG,the transaction confirmation has a linear communication complexity.At the same time,the Hot DAG protocol implements the leader rotation,which can effectively prevent transaction censorship attacks.Finally,the Hot DAG protocol provides an incentive mechanism based on the epoch reputation.The rewards are distributed through the committee's dynamic block reward coefficient and the node's contribution to processing transactions,which avoids the issues of selfish nodes' collusive behaviors and resource monopoly.The experimental results on performance and incentive mechanism show that Hot DAG protocol achieves a linear increase in transaction throughput with the increase in the number of participating nodes,and Hot DAG protocol has better incentives.