Research On Block Storage Methods Of Consortium Blockchain Based On Erasure Codes

Blockchain technology adopts redundant storage methods to ensure data consistency,it is decentralized and immutable.Blockchain is widely used in Finance,Medical care,Supply chain and other fields.With the continuous development of blockchain application technology,the scale of data during system operation will increase exponentially,resulting in the occurrence of block bloating.To resolve this problem,some scholars proposed to apply erasure code technology to blockchain systems with the purpose of reducing the storage pressure of nodes.However,only a little research has existed on this scheme and these studies are not mature yet.This thesis studies the block storage methods based on erasure codes in the consortium blockchain environment.The main work is as follows:(1)A Multi-group Chain Model Based on Coordinator Node(MGCM)is proposed.After block generation,the block is propagated by the anchor node to the full nodes during the coordinator node performs block coding and coded blocks placement,so as to effectively improve system operation efficiency.The selection of the coordinator node is implemented by the Random Selection Strategy Based on TOPSIS to ensure that the coordinator node has sufficient hardware performance to process block data.On this basis,the number and sequence of coded blocks stored by the coding nodes are determined by the proposed Coded Blocks Placement Strategy,which can reduce the occurrence of unavailability of system data due to the association failure of coding nodes.Finally,the model is implemented and verified on Hyperledger Fabric,and the results show that MGCM can further improve the availability of block data under the condition that MGCM has the same redundancy as Fabric.(2)A Block Storage Method Based on Trusted Group View is proposed,which can implement block storage based on erasure codes in MGCM.Firstly,the trusted group view was proposed to record the trusted group status in MGCM,including the member node list,node type,encoding scheme,number and sequence of coded blocks in the current group,so as to facilitate the parameter acquisition during system operation.Then,In view of the dynamic change of trusted groups in consortium blockchain due to joining,quitting or failure of nodes,the algorithm of node joining and the algorithm of node quitting is proposed to realize the dynamic adjustment of block coding.On this basis,the whole process of block storage is described.Finally,the throughput,transaction latency,transaction query time,and storage space occupation of MGCM and Fabric are compared and tested.The results show that the method proposed in this thesis can promote the storage efficiency of nodes in the system without reducing the performance of consortium blockchain.