Cloud computing encourages users to outsource their data to cloud storage. Data outsourcing means that users lose physical autonomy on their own data, which makes remote data integrity verification become a critical challenge for potential cloud users. To free user from the burden incurred by frequent integrity verifications, Third Party Auditor (TPA) is introduced to perform verifications on behalf of user for data integrity assurance. However, existing public auditing schemes rely on the assumption that TPA is trusted, thus these schemes cannot be directly extended to support the outsourced auditing model, where TPA might be dishonest and any two of the three involved entities (i.e. user, TPA, and cloud service provider) might be in collusion. In this paper, we propose a dynamic outsourced auditing scheme which cannot only protect against any dishonest entity and collision, but also support verifiable dynamic updates to outsourced data. We present a new approach, based on batch-leaves-authenticated Merkle Hash Tree (MHT), to batch-verify multiple leaf nodes and their own indexes all together, which is more appropriate for the dynamic outsourced auditing system than traditional MHT-based dynamism approaches that can only verify many leaf nodes one by one. Experimental results show that our solution minimizes the costs of initialization for both user and TPA (compared to existing static outsourced auditing scheme), and incurs a lower price of dynamism at user side.

中文翻译：

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基于Batch-Leaves-Authenticated Merkle Hash Tree的云存储动态外包审计服务

云计算鼓励用户将他们的数据外包给云存储。数据外包意味着用户失去了对自己数据的物理自主权，这使得远程数据完整性验证成为潜在云用户面临的关键挑战。为了使用户免于频繁进行完整性验证所带来的负担，引入了第三方审核员 (TPA) 来代表用户执行验证以保证数据完整性。然而，现有的公共审计方案依赖于 TPA 是可信的假设，因此这些方案不能直接扩展以支持外包审计模型，其中 TPA 可能是不诚实的，并且涉及三个实体（即用户、TPA 和云）中的任何两个实体。服务提供商）可能串通。在本文中，我们提出了一种动态外包审计方案，它不仅可以防止任何不诚实的实体和冲突，而且还支持对外包数据进行可验证的动态更新。我们提出了一种新的方法，基于批量叶子认证的默克尔哈希树（MHT），来批量验证多个叶子节点和它们自己的索引，这比传统的基于 MHT 的动态更适合动态外包审计系统只能一一验证多个叶节点的方法。实验结果表明，我们的解决方案最大限度地减少了用户和 TPA 的初始化成本（与现有的静态外包审计方案相比），并在用户端产生了更低的动态成本。基于批量叶子认证的默克尔哈希树（MHT），将多个叶子节点和它们自己的索引一起批量验证，这比传统的基于 MHT 的动态方法更适合动态外包审计系统，它只能验证许多叶节点一一。实验结果表明，我们的解决方案最大限度地减少了用户和 TPA 的初始化成本（与现有的静态外包审计方案相比），并在用户端产生了更低的动态成本。基于批量叶子认证的默克尔哈希树（MHT），将多个叶子节点和它们自己的索引一起批量验证，这比传统的基于 MHT 的动态方法更适合动态外包审计系统，它只能验证许多叶节点一一。实验结果表明，我们的解决方案最大限度地减少了用户和 TPA 的初始化成本（与现有的静态外包审计方案相比），并在用户端产生了更低的动态成本。