Research On The Algorithm Of Shard Node Recombination With Security Mechanism

At present,the shard-based blockchain technology can enable the blockchain system to effectively process transactions in parallel and improve the scalability of the blockchain system,which is also the main method to break the trilemma of decentralization,security and scalability in the traditional blockchain system.In a network without permission,nodes can join or leave the system at any time,and malicious nodes in the blockchain system can attack and destroy a constant number of honest nodes in each epoch,resulting in malicious nodes in a shard exceeding the security threshold,thus affecting the blockchain system and reducing the security of the blockchain.Some classic shard schemes randomly allocate nodes to different shards,such as Elastico,by means of reorganization to reduce the possibility of shard control by malicious nodes.However,these schemes do not consider the node performance in the reorganization process and have weak security guarantee,resulting in a large performance gap between different shards and affecting the blockchain system performance.In order to solve the above problems,a Recombination scheme based on node performance evaluation(RSNPE)is proposed from the perspectives of node performance and node recombination scheme.To solve the performance problem of each node,RSNPE scheme adopts a scoring mechanism to evaluate the node performance according to the average performance of nodes,so as to judge the overall performance of shards and the necessity of node reorganization.To solve the problem of node reconfiguration,the cuckoo rule is improved,and only the shards with malicious nodes exceeding the acceptable proportion are reorganized to achieve the minimum number of nodes.RSNPE scheme combines the scoring mechanism with cuckoo rule,and only carries out node recombination for shards with low performance,so as to balance the performance of each shards and reduce the aggregation rate of malicious nodes,avoiding huge data migration and large amount of bandwidth consumption caused by all nodes recombination.At the same time,the decentralization mechanism is set in the scheme.The sub Leader node is selected by sorting the committee nodes,so that the sub Leader and the Leader process transactions in parallel,improving the transaction throughput and ensuring the effectiveness of the consensus process.Experimental results show that RSNPE scheme has better performance than Elastico and Omniledger scheme in terms of data throughput and consensus delay,and has significant resistance to node attacks.