With the rapid development of cloud storage, a growing number of data owners prefer to outsource their large-scale data to the remote cloud data centers, thus effectively avoiding the heavy burden of storing the massive data by themselves in local. Due to the promising market prospect, plenty of companies invest cloud storage and offer data storage services, which equipped with different access speed, using price, security, storage capacity, etc. For enjoying more suitable services, data owners might dynamically change cloud service providers and migrate the outsourced data blocks from a cloud data center to another one. However, the data integrity cannot be guaranteed during the migration process. In this paper, we study the challenge of secure outsourced data migration supporting fair contract signing and efficient data integrity auditing. Subsequently, we propose an efficient and practical solution to address this problem. Specifically, we adopt public blockchain to design a fair three-party contract signing protocol for outsourced data migration, which can effectively prevent data owners and cloud data centers from slandering each other maliciously. Meanwhile, we combine public blockchain and multicopy Merkle hash tree (M2HT) to design a secure data migration protocol with efficient data integrity auditing, which can guarantee the data integrity during the migration process. Next, we provide the formal security analysis, which demonstrates that our scheme can satisfy all of the expected security requirements without trusted third party. Finally, we also develop a prototype implementation and provide the performance evaluation, which can show the high-efficiency and practicality of our scheme.

中文翻译：

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通过公平合同签订和云存储中的高效数据完整性审计进行安全数据迁移


随着云存储的快速发展，越来越多的数据所有者更愿意将其大规模数据外包给远程云数据中心，从而有效避免了自己在本地存储海量数据的沉重负担。由于市场前景广阔，许多公司投资云存储并提供数据存储服务，这些服务配备了不同的访问速度、使用价格、安全性、存储容量等。为了享受更合适的服务，数据所有者可以动态地更换云服务提供商，并将外包的数据块从一个云数据中心迁移到另一个云数据中心。但是，在迁移过程中无法保证数据完整性。在本文中，我们研究了支持公平合同签署和高效数据完整性审计的安全外包数据迁移所面临的挑战。随后，我们提出了一种有效且实用的解决方案来解决这个问题。具体来说，我们采用公有区块链，为外包数据迁移设计了公平的三方合同签署协议，可以有效防止数据所有者和云数据中心相互恶意诽谤。同时，我们将公有区块链和多副本默克尔哈希树 （M2HT） 相结合，设计了具有高效数据完整性审计的安全数据迁移协议，可以保证迁移过程中的数据完整性。接下来，我们提供正式的安全分析，这表明我们的方案可以在没有受信任的第三方的情况下满足所有预期的安全要求。最后，我们还开发了一个原型实现，并提供了性能评估，可以展示我们方案的高效率和实用性。