An Efficient and Secure Dynamic Auditing Protocol for Data Storage in Cloud Computing

Currently, there has been an increasing trend in outsourcing data
to remote cloud, where the people outsource their data at Cloud
Service Provider(CSP) who offers huge storage space with low
cost. Thus users can reduce the maintenance and burden of local
data storage. Meanwhile, once data goes into cloud they lose
control of their data, which inevitably brings new security risks
toward integrity and confidentiality. Hence, efficient and
effective methods are needed to ensure the data integrity and
confidentiality of outsource data on untrusted cloud servers. The
previously proposed protocols fail to provide strong security
assurance to the users. In this paper, we propose an efficient and
secure protocol to address these issues. Our design is based on
Elliptic Curve Cryptography and Sobol Sequence (random
sampling). Our method allows third party auditor to periodically
verify the data integrity stored at CSP without retrieving original
data. It generates probabilistic proofs of integrity by challenging
random sets of blocks from the server, which drastically reduces
the communication and I/O costs. The challenge-response
protocol transmits a small, constant amount of data, which
minimizes network communication. Most importantly, our
protocol is confidential: it never reveals the data contents to the
malicious parties. The proposed scheme also considers the
dynamic data operations at block level while maintaining the
same security assurance. Our solution removes the burden of
verification from the user, alleviates both the user’s and storage
service’s fear about data leakage and data corruptions. Through
security analysis, we prove that our method is secure and
through performance and experimental results, we also prove
that our method is efficient. To compare with existing schemes,
our scheme is more secure and efficien