Research On Cloud Data Integrity Audit Mechanism Based On Blockchain

In recent years,with the rapid development of cloud storage technology,more and more users and enterprises choose to store data in cloud servers.Due to the separation of ownership and management rights of data after outsourcing storage,the data outsourcing storage is faced with the threat of malicious tampering and intentional deletion.How to protect the integrity of outsourced data in the cloud environment is the focus of user attention.Researchers have proposed a variety of data integrity audit mechanisms for the integrity of cloud data.The current more efficient and mature cloud data integrity audit scheme is to use a trusted third party(TPA)instead of users to initiate audit challenges to CSP,and verify the proof of ownership of cloud data returned by CSP,so as to ensure the integrity of data.However,in practice,TPA is not completely credible.TPA may be coerced or colluded with CSP to obtain commercial benefits in the process of data audit.In addition,the previous scheme did not consider the issue of fairness,that is,there is no effective mechanism to punish malicious CSP and compensate users whose data integrity has been damaged.Therefore,a secure and reliable cloud data integrity verification scheme is urgently needed.In order to solve the above problems,this paper proposes a cloud data integrity audit system based on blockchain.The system deploys the audit algorithm to the blockchain network in the form of a smart contract,and implements the verification of the integrity of the cloud data by executing the smart contract,which ensures the credibility and non-tampering of the audit results of the TPA under non-trusted conditions.Compared with the traditional data integrity audit mechanism based on trusted third parties,this scheme has the following advantages: 1.In the design of the audit contract,the scheme uses the current block hash value in the blockchain as the random number seed to generate challenge value,so it can effectively resist man-in-themiddle attacks and replay attacks;2.The scheme supports fair arbitration mechanism,that is,the user and CSP pay a certain amount of Ether to the audit contract in advance as the deposit,and the user whose data is damaged can get the deposit of CSP as compensation.This method can not only effectively curb the occurrence of malicious behavior in the audit process,but also make the design more reasonable.Finally,the cloud data integrity audit system based on blockchain is simulated and run on the Ethereum network platform,and the system is tested for functions and performance.The experimental results show that the scheme can make use of the characteristics of smart contract and blockchain to achieve the integrity audit of cloud data while protecting the user's data privacy.