Blockchain Based Data Integrity Verification In Cloud Storage

Due to the rapid growth of information sharing and exchange,more and more companies and individual users choose to store data in the cloud.In order to use the data correctly,users need to ensure that the data obtained from the cloud is complete.Therefore,how to verify the integrity of the data stored in the cloud has become an important issue.The traditional cloud storage data integrity verification framework introduces a third-party auditor(TPA)to complete the verification work.This framework completely relies on the TPA,which requires extremely high credibility of the TPA.Moreover,the TPA is equivalent to a centralized organization,if the cloud colludes with the TPA maliciously,the result of data integrity verification may not be credible.The emergence of P2P(Peer to Peer,P2P)technology accelerated the speed of information sharing,and cut the cost of storing data.In this paper,we first propose blockchain-based data integrity verification framework in P2 P cloud storage.The Merkle tree with random challenging numbers is used in this framework.By introducing blockchain,we remove the dependence on the TPA.Aiming at the problem of limited resources and high real-time requirement,we propose a sampling verification scheme,formulate a reasonable sampling strategy,and study the optimal sample size to comprehensively consider the cost and precison of verification.Considering the cloud edge integration architecture is being applied to more and more scenarios,we further propose a blockchain-based data integrity verification framework for edge-cloud storage.Based on the verification scheme,we implement a prototype system,design the concrete smart contract,and carry out a series of experiments to evaluate the effectiveness of the proposed scheme.The experimental results show that in the process of sampling verification,there is an optimal sample size to achieve the best performance of data integrity verification.Compared with the traditional TPA-based verification scheme,our scheme can achieve more reliable data integrity verification.