Blockchain-Based Integrity Auditing with Secure Deduplication in Cloud Storage

Abstract

AbstractPublic auditing technology has currently been proposed to ensure the integrity of the cloud data and reduce users’ overheads, which, enables users to hire a third-party auditor (TPA) for cloud data auditing. However, most existing public auditing schemes are exposed to security problems of not completely reliable TPAs, easily manipulated challenge messages, and the convenience for external adversaries to launch side-channel attacks based on audit parameters. Additionally, a large number of redundant integrity tags caused by the auditing mechanism increase the storage burden of cloud servers, and reduce the searching and auditing efficiency. Hence, aiming to solve the concern of data security and storage efficiency in cloud storage, this paper proposes a blockchain-based cloud storage integrity auditing with secure deduplication (BIAD). We distribute a random file key between different users by employing the ciphertext-policy attribute encryption (CP-ABE), and conduct secure public auditing through the blockchain combined with a bloom filter-based random challenge generation method. In particular, by applying the random key to encrypt ciphertext and integrity tags, the existence and ownership privacy of the requested file in the auditing process can be protected. The security analysis and experimental results demonstrate that compared with the state-of-the arts, the proposed scheme achieves public auditing and deduplication in a secure and lightweight way.KeywordsCloud storage serviceBlockchainIntegrity auditingData deduplicationSide-channel attack