Research On Cloud Data Integrity Auditing Based On Blockchain

With the development of cloud computing technology,more users choose to outsource and store data in the cloud.As a result,users losing physical control over the data and cannot guarantee data integrity.At present,the cloud data integrity auditing scheme mainly uses auditors(Aud)to verify whether the data possession certificate is credible,and then judge the integrity of the corresponding cloud data.Aud is often a single institution or organization with a single point of failure,and may conspire with a cloud service provider(CSP)to carry out malicious attacks.Therefore,a blockchain-based cloud data integrity auditing application has emerged to solve the problem of correctly completing data integrity auditing even with untrusted Aud participation.In addition,to address issues such as invalid or incorrect auditing results in blockchain,the modification of invalid auditing results of the blockchain at the fine-grained level of transactions has been realized.The specific research content of this article is as follows:(1)Aiming at the low efficiency of cloud data integrity auditing,on the basis of Proof of Data Possession(PDP),a blockchain based cloud data integrity auditing scheme(BCDIAS)is proposed.Aud randomly extracts data blocks through the local confidence rates corresponding evidence for challenge.In the state channel,Aud completes the integrity auditing verification according to the auxiliary evidence information in the verification information tree(EIB).The auditing results are packaged into transactions by smart contracts,and saved in the blockchain through blockchain miner nodes.Experiments have showed that the BCDIAS scheme provides data privacy protection,can resist various individual attacks,and improves the overall auditing efficiency by 12.14%,which has certain reference value for practical application scenarios.(2)Aiming at the failure or error of auditing results in the blockchain,a modifiable blockchain scheme based on Chameleon hash(MBSC)based on the Chameleon hash function is proposed.Utilizing multiple committee members instead of a single member to generate,manage,and distribute modification keys,thus solving the problem of key leakage caused by attacks in traditional solution where a single member generates modification keys;Using the smallest pseudo-random number to select a modifier,thereby solving the problem of slow speed caused by multiple rounds of voting to select a modifier;By dynamically binding the relationship between the number of keys owned by committee members and the deposit,the problem of some transactions being unable to be modified due to the withdrawal of malicious committee members without reason is solved.Experiments have shown that the MBSC scheme can modify invalid auditing results at the fine-grained level of transactions,and the system’s key modification management is more secure and reliable.It can achieve accountability after modification,and the efficiency of blockchain data modification is improved by 21.4%.