Integrity Checking Research Of Data In Cloud Storage

In recent years, cloud storage services are being embraced by users both from the private and public sectors, due to the fact that cloud storage provides a convenient approach for users to store and access their data. However, the cloud platform may not be trusted by professional users; the data outsourced to the cloud is subject to data security risks, e.g. the data may be deleted or maliciously modified due to the poor management of cloud service providers. Data integrity checking is one important problem of them.Currently, a lot of data integrity checking schemes have been proposed; however, most of them cannot apply to real-life cloud storage services. The reason is that the compute capability of the cloud storage service is not provided, which is assumed in those proposed schemes. From the cloud's perspective, although many public cloud storage services can return MD5 value of a file to help a user to verify data integrity, however, the cloud may not be trusted by professional users; thus, the MD5 returned cannot serve as a trustable verification result. Therefore, in view of the present situation of the cloud storage service and in order to ensure the availability and reliability of real-word data integrity checking schemes, we conclude that we still need to download(partial) data from the cloud to perform cloud data integrity checking.Another disadvantage of the proposed cloud data integrity checking schemes is that economical cost of the proposed protocols is not considered. In contrast, nowadays the majority of storage service providers charge the professional cloud storage users for storage cost, communication cost, and data request cost, etc. We argue that economical cost of cloud data integrity checking needs to be considered when designing a solution to this problem.Different form previous approaches, in this paper, we aim to design real-world-oriented and economical cloud data integrity checking schemes. Our main works are as follows:First, we architect a cloud data integrity checking system that contains a user and a cloud. Our system is based on the technique of Hash and MAC. We also list four kinds of cloud data integrity checking schemes.Second, we model economical cost of cloud data integrity checking schemes by combining the PDP sampling and on-demand charge standard employed by mainstream cloud platforms. Our model guides us to determine the total number of blocks that a cloud data integrity checking scheme should adopt to keep the integrity checking cost minimal.Third, we implement our cloud data integrity checking scheme(named as ICA) on top of Ali OSS(Object Storage Service) which is provided by Aliyun. Our implementation has taken into account the economic cost model and features with four specific integrity checking methods. Experimental results prove that our protocol is efficient in practice.