Research On The Storage And Repair Of Cloud Data Based On MSBR Coding

With the outbreak of big data and the coming of the era of cloud computing,how to ensure the safety of cloud data is becoming more and more important.For cloud data security,it is mainly reflected in two aspects of secure storage and repair when failure occurs.The existing technologies in cloud storage system are mainly based on encryption,replication and erased code.With the increasing number of data,the existing methods will be more and more difficult to meet the requirements of security and reliable restoration in storage system.At the same time,network coding can reduce the bandwidth of the system and improve the network data throughput.It has become a hot topic in the research of cloud storage.In this thesis,we study the cloud storage system based on network coding.We propose a cloud data security storage model based on MSBR coding and a data block allocation method based on the node synthesis capability value(NCA)algorithm,which improves the security of cloud storage.Firstly,in view of the fact that the MSR coding method only guarantee the minimum storage cost,the MBR coding method can only maximize the reduction of the system's repair bandwidth.In this thesis,a cloud data security storage model based on MSBR coding is proposed.The MSBR based approach selects the coding coefficients according to the bandwidth resources and storage space of the system.The coding methods of MSR and MBR are adopted for the data blocks,and the advantages of the two coding methods are fully utilized.At the same time,on the basis of the maximum utilization of the system bandwidth resources and storage space,the security of the storage is guaranteed,while only the smaller repair bandwidth is used.Secondly,a method of data block placement based on the node integrated capability value(NCA)algorithm is proposed.According to the current storage time,the NCA value of nodes is calculated and the safe storage threshold is obtained.The allocation of coded data blocks and the number of replica placement are compared through the comparison of NCA value and threshold value.From the security performance of the node,the storage of cloud data is provided with a double security guarantee.Finally,simulation experiments prove the effectiveness and rationality of the proposed MSBR coding method and the data allocation method based on NCA algorithm,and compare the performance under different bandwidth resources and storage overhead.At the same time,Markov chain method is applied to evaluate the performance of cloud storage model based on MSBR coding.Statistical analysis of the experimental data shows that the theoretical analysis is consistent with the experimental results,so the method is feasible and effective.