Publicly verifiable outsourced data migration scheme supporting efficient integrity checking

With the rapid development of cloud storage, an increasing number of data owners prefer to store their large-scale data on the remote cloud for greatly reducing the burden of maintaining the data by themselves. Since different cloud storage service providers offer distinct quality of data storage services, secure outsourced data migration becomes a fundamental requirement for data owners to change their cloud storage service providers. As a result, how to guarantee the correctness and integrity of the outsourced data blocks when they are being migrated from one semi-trusted cloud host to another becomes a primary concern of data owners. To solve this problem, we propose a blockchain-based publicly verifiable data migration scheme supporting efficient data integrity checking for cloud storage in this paper. Specifically, the data owner can dynamically change the cloud storage service providers and securely migrate the outsourced data from one cloud host to another, without retrieving the transferred data from the original cloud host, and checking the transferred data integrity in the target cloud host. By making use of blockchain, our proposed scheme can simultaneously achieve data migration and integrity checking without interacting with a third party auditor, thus avoiding the problems of service interruption and privacy leakage caused by the single-point-of-failure of the third party auditor, which is much better than the previous schemes. Meanwhile, our proposed scheme is provable secure in the random oracle model. Finally, we also develop a prototype implementation of our proposed scheme and compare the efficiency with some existing schemes. The experimental result demonstrates that our proposed scheme is more efficient and practical.