With the rapid growth of data, limited by the storage capacity, more and more IoT applications choose to outsource data to Cloud Service Providers (CSPs). But, in such scenarios, outsourced data in cloud storage can be easily corrupted and difficult to be found in time, which brings about potential security issues. Thus, Provable Data Possession (PDP) protocol has been extensively researched due to its capability of supporting efficient audit for outsourced data in cloud. However, most PDP schemes require the Third-Party Auditor (TPA) to audit data for Data Owners (DOs), which requires the TPA to be trustworthy and fair. To eliminate the TPA, we present a Public Mutual Audit Blockchain (PMAB) for outsourced data in cloud storage. We first propose an audit chain architecture based on Ouroboros and an incentive mechanism based on credit to allow CSPs to audit each other mutually with anticollusion (any CSP is not willing to help other CSPs conceal data problems). Then, we design an audit protocol to achieve public audit efficiently with low cost of audit verification. Rigorous analysis explains the security of PMAB using game theory, and performance analysis shows the efficiency of PMAB using the real-world dataset.

中文翻译：

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PMAB：云存储中外包数据的公共互助审计区块链

随着数据的快速增长，受存储容量的限制，越来越多的物联网应用选择将数据外包给云服务提供商（CSP）。但是，在这种情况下，云存储中的外包数据容易损坏且难以及时发现，从而带来潜在的安全问题。因此，可证明数据拥有 (PDP) 协议因其支持对云中外包数据进行高效审计的能力而得到广泛研究。然而，大多数 PDP 方案都需要第三方审计员 (TPA) 来审计数据所有者 (DO) 的数据，这就要求 TPA 是值得信赖和公平的。为了消除 TPA，我们为云存储中的外包数据提供了公共互助审计区块链 (PMAB)。我们首先提出了基于Ouroboros的审计链架构和基于信用的激励机制，允许CSP相互审计，反共谋（任何CSP都不愿意帮助其他CSP隐瞒数据问题）。然后，我们设计了一个审计协议，以较低的审计验证成本有效地实现公共审计。严谨的分析使用博弈论解释了 PMAB 的安全性，性能分析显示了使用真实世界数据集的 PMAB 的效率。