Secure Cloud Storage Research Based On The Hybrid Storage Srategy

Cloud storage,as a new mode based on network, provides cost-effective andconvenient storage services.But, its security and reliability are all hotspots that arousewide concern and been searched. To ensure the reliability and integrity of the data,Cloud storages mainly adopt two kinds of measures to ensure the security of the data:for one thing, they save users’ data in the method of redundancy to avoid data losscaused by software and hardware; for another thing, they provide the service ofintegrity checking and recovery data efficiently when errors or failures are found.Redundancy storage mainly includes multi-replication and erasure codes thesetwo kinds of storage strategy. Multi-replication can be simply designed and supportconcurrent access,but it costs multiple space consumption; erasure codes has strongfault tolerant ability and highutilization of the space, but the computational cost andthe access latencybe broughtand encoding and decoding will reduce the experiencevalue of users. At first, researching on the shortage of single redundancy storage, adynamic replication based on erasure code redundancy storage solution-DRBEC ispresented. Thinking about the overhead of repairing bandwidth,DRBEC stores filesafter codding themusingregenerating codes.And thenit predicts popularity by curvefitting method toadjust the number of replication dynamically, which exploits theadvantages of I/O of multi-copy. Secondly, as forthe filling date that in low dynamics,combining regenerating codes with MD5,because of the uniqueness ofMD5,achecking schemefor regenerating codes and date recovery strategy basedDRBEC is provided and achieved.Itcalculates the MD5of the regenerating codes andthensavesthem in the nodesof the filerandomly after encrypted.Users can test theintegrity of remote-data without downloading the source file.At last, designing cluster storage experimental prototype system based on Xenvirtual machineto test the performance of the storage system of DBREC, includingthe storage space consumption and the access performance,alsoto test the feasibilityand reliability of the system and date recovery strategy inregenerating codes based on MD5. Results show that it has a high space utilization and short access latency, andimproving the success rate of user access in mixed storage strategy.Moreover, itshows the checking strategy for regenerating codes based on MD5is reliable andreducing the consumption of storage and communication. Besides, it locates thefailure node positions accurately, and recoveriesdata effectively in lowbroadband,protecting the integrity and validity of the data.