Blockchain-based Cloud Data Integrity Public Auditing Schemes Against Malicious Attackers

In recent years,cloud storage services have been developed rapidly.It has brought users a lot of convenience,such as reducing the cost of users' devices,storage burden,and users can quickly access storage services through the network.However,outsourced data on cloud servers is not completely controlled and managed by users.Cloud services are not fully trusted,and users are concerned about outsourced data.Therefore,cloud data integrity auditing is a very important research area.To verify cloud data integrity,researchers have proposed many solutions.In practice,users often use public auditing schemes to verify data integrity.In public auditing schemes,the user delegates the task to a third-party auditor(TPA)to review the cloud data periodically.However,existing public auditing schemes have the following problems: Firstl y,many traditional audit schemes assume that the TPA is credible,but the TPA may be malicious in reality;Secondly,the randomness of the challenge information is affected by the malicious miners and the security of the system is in doubt.To solve these problems,it is necessary to design a more secure and efficient scheme against malicious attackers.The paper studies the public audit scheme and blockchain technology,and designs the audit schemes from two security angles.On the one hand,to resist the malicious auditor,we design a blockchain-based scheme against malicious auditors.We investigate traditional schemes,and focuses on how to use the blockchain platform to realize the audit process against malicious TPA under different security assumptions.On the other hand,we use RANDAO contract in Ethereum to resist malicious miners.At the same time,we have the security analysis and demonstration of the proposed scheme.Specifically,we deduce the security of protocols to famous hard problems,and simulation experiments prove that the schemes are safe and feasible.In addition,by comparing the computational cost and communication cost of the relevant audit scheme,we show that the audit schemes designed in this paper performs well against malicious attackers.