Blockchain-based auditing with data self-repair: From centralized system to distributed storage

Cloud storage provides data owners with massive storage and computing resources. To release from heavy data management and maintenance, more and more data owners are willing to outsource data to cloud. However, the data stored in cloud are out of the control of data owners, and may be corrupted and unretrievable. To solve the above problem, this paper proposes a decentralized auditing scheme BVA for the single cloud storage server, and an extended batch auditing scheme E-BVA for distributed storage. Firstly, BVA and E-BVA utilize vector commitment technology to realize lightweight data integrity auditing for outsourced data. Secondly, to avoid privacy and performance risks caused by the third party auditor, both BVA and E-BVA employ a smart contract on the blockchain as an auditor to perform data integrity auditing. Thirdly, both schemes support the verifiability between outsourced data and their corresponding authenticators, which prevents malicious data owners framing cloud storage servers and avoid subsequent dispute arbitration. Finally, based on regenerating code, E-BVA supports data self-repair of corrupted servers, while protecting the privacy of outsourced data and realizing the lightweight computation. The security and performance analyses demonstrate the security and efficiency of BVA and E-BVA.