Research On Blockchain Sharding Technology Considering Node Difference

The blockchain technology has broad development prospects with its characteristics of decentralization,openness,tamper-proof,anonymity,traceability,etc.However,the scalability of blockchain is one of the key technologies which blockchain needs to solve.With a maximum throughput of 7 transactions per second for Bitcoin and only a few hundred transactions per second for Ethereum,it is clear that typical blockchain applications are far from being able to meet the demand for tens of thousands of transactions per second in Internet applications,and the scalability of blockchain is seriously affecting and restricting the implementation of blockchain technology.In this paper,the research revolves around the scalability of blockchain and adopts the sharding technology to build a blockchain sharding model,which divides the original single chain structure of blockchain into multiple sub-chains to improve the transaction throughput of the system by processing transactions in a parallel mode.Based on this model,this paper focuses on the network sharding algorithm from the perspective of blockchain security,and proposes a blockchain network sharding algorithm considering node power(NPNS)and a blockchain network sharding algorithm considering node credibility(NCNS).The major research contents of this paper are as follows:(1)In order to optimize the blockchain performance,this paper adopts the sharding technology and constructs a blockchain sharding model.This paper focuses on network sharding,analyzes the factors and the objectives of network sharding.Based on this,the performance of the blockchain sharding model is analyzed in terms of system throughput and system security.The analysis shows that the system throughput has a linear positive growth relationship with the shard size,and the system security has an inverse relationship with the shard size.(2)In order to solve the problem of unbalanced power distribution in network sharding,which leads to poor system security,this paper proposes a network sharding algorithm considering node power from the perspective of system security.The algorithm not only considers the randomness of node distribution in network sharding,but also considers the difference of node power,which effectively avoids the emergence of low power sharding.The experimental results show that the NPNS algorithm under different shard size outperforms the existing Monoxide,Omniledger and Zilliqa algorithms in terms of the power ratio in blockchain,the diversity factor of shard nodes,the diversity factor of shard power and other performance indicators.Therefore,the NPNS algorithm can guarantee both the power balance of nodes within a shard and the power balance between shards,which effectively avoids the problem of poor system security caused by unbalanced power.(3)In order to avoid the collusion attack problem caused by malicious nodes divided in the same shard,this paper proposes a network sharding algorithm considering node credibility.The algorithm introduces the concept of node credibility due to node behavior characteristics in network sharding,and comprehensively considers node credibility and node power during sharding to improve the security of network sharding.The experimental results show that the NCNS algorithm under different shard size outperforms the existing Monoxide,Omniledger and Zilliqa algorithms in terms of the shard credibility,the diversity factor of shard nodes,the diversity factor of shard power and other performance indicators.Therefore,this algorithm can balance the creditability between shards and effectively solve the problem of power attacks caused by the aggregation of malicious nodes within shards.