Proof of cloud data integrity based on blockchain

With the development of cloud storage technology, the advantages of cloud storage technology such as easy expansion, fast computing and controllable resources are favored by users. More and more users choose to store data in the cloud, but at the same time, they also lose the control over the data. Many schemes implement data integrity verification by introducing third-party auditors (TPA), but TPA is not completely trusted. There may be collusion with CSPS to steal user data or damage data. Traditional table structure can not solve the problem of dynamic update of remote data block, while Merkle hash tree data structure can solve the problem of dynamic update, but the efficiency is not optimal. Therefore, this paper proposes a cloud data integrity audit scheme based on blockchain, which introduces blockchain, realizes data integrity verification through its decentralization, immutable and other characteristics, and proposes a set of credit-based consensus strategy based on the license chain to ensure the security of the system. In addition, a multi-branch path tree (LP-MBT) based on local priority is proposed. LP-MBT enables users to quickly locate data blocks to be updated and optimizes the dynamic update scheme. Finally, the safety analysis shows that the scheme is provably safe, and the performance evaluation shows the effectiveness of the scheme.