The Research On Consensus Scheme Based On Proof Of Stake Mechanism In Public Chain

With the rapid development of Internet,the demand for decentralization and multi-party data sharing increases quickly.Traditional distributed databases have some problems such as centralization and “information islands”,thus the security and reliability of data cannot be guaranteed.Public chian is a new distributed database with excellent features such as decentralization,detrustness,and non-tamperability,it has great prospects in areas with centralization problems such as medical care,finance,and supply chain.The consensus mechanism is the foundation of public chain.However,the current public chain consensus schemes have problems such as security and scalability,which makes the public chain unable to be applied to real-life scenarios.The prevailing public chain consensus schemes are based on proof of work or proof of stake.Proof of work became popular because of its simplicity,practicality and provable security earlier.However,its huge energy consumption and performance bottleneck makes it difficult to increase the scalability of the public chain,thus makes public chain cannot be applied to extendable application scenarios.Proof of stake is an energy-saving consensus framework.It uses stake instead of computing power for consensus,which greatly reduces computational consumption and consensus time,and avoids the performance bottleneck of proof of work.However,the security of it has not been fully proven,and the scalability of its system performance is also a problem.To solve the problems of the current public chain consensus scheme,this thesis combines the stake mechanism,Verifiable Random Function(VRF)and the longest chain rule to propose a scalable and secure consensus scheme based on proof of stake,which increases scalability on the premise of its security,thus the public chain based on the scheme can be applied to practical application scenarios.In order to ensure security,it combines a Verifiable Random Function(VRF)to design a block generation protocol,which improves the decentralization property by ensuring the randomness and fairness of generated blocks,and designs a block synchronization protocol based on a new chain selection rule,which supports dynamic availability without relying on third parties,and further ensure the security of the scheme.As for scalability,it combines an independent stake mechanism to design a node registration protocol,which supports dynamic stake through stake transactions,it also proposes a block compression method to reduce the communication consumption of the consensus,which further improves the scalability of the solution by improving the efficiency of the consensus.Finally,according to the overall design above,this thesis implements the prototype system of the public chain consensus scheme,and tests its compressed block size,block broadcast time and system performance in a simulation environment,the results show that it does have better scalability.In addition,this thesis also analyzes the security of the scheme,and proves that it satisfies the three standard security attributes of blockchain and can resist general security threats.The above results show that the scheme is indeed feasible,which is of great significance for the development of public chain technology and its application in practical scenarios.