Blockchain-based verification framework for data integrity in edge-cloud storage

With the popularity of the Internet of Things (IoT), data integrity verification in the edge cloud storage attracts attentions from many researchers. Due to the over dependence of the Third Party Auditor (TPA) and the dynamical nature of the IoT data, the traditional data integrity verification framework for cloud storage can hardly work. To satisfy the characteristics of the IoT and avoid the over dependence of the TPA, we propose a blockchain-based framework without TPA for data integrity verification in a decentralized edge-cloud storage (ECS) scenario in this paper. In our framework, we employ the Merkle tree with random challenging numbers for data integrity verification and analyze different Merkle tree structures to optimize the system performance. To solve the problem of limited resources and high real-time requirements, we further propose sampling verification and develop rational sampling strategies to make sampling verification more effective. The overhead and precision of the verification in ECS are studied by an optimal sample size strategy. Finally, a prototype system is implemented based on our framework. We conduct a series of experiments to evaluate the effectiveness of the proposed schemes. The experimental results show that our schemes can effectively improve the performance of data integrity verification. (C) 2020 Elsevier Inc. All rights reserved.