Achieving Availability and Efficient Audit Services in Cloud Computing

Abstract

— Cloud computing is the long dreamed version of computing as a utility in IT industry. By data outsourcing, users can be relieved from the burden of local data storage and maintenance. As cloud provides many advantages, it also brings certain challenges. Here, as the clients no longer have the physical possession of the data, they can face formidable risk for missing data  without clients knowledge, cloud providers can modify or delete data which are either not used by client from long-time which occupies large space. Hence, audit services are important for ensuring the integrity and availability of outsourced data in order to reduce the security risks and to achieve credibility on cloud computing. Many schemes have been proposed to achieve audit services, such as PDP protocol, which is used to prevent dishonest of prover and the leakage of verified data. In this audit service, the third party auditor (TPA), known as the agent of the data owners, can issues a periodic verification to monitor the change of outsourced data by providing an optimized scheduled. Even though they have addressed various aspects such as Public verifiability, Dynamics, Scalability and Privacy preservation, they still lack in providing assurance of data when they experience data leakage attack and tag forgery attacks and also existing schemes are designed for public cloud. The existing schemes are not applicable for hybrid clouds. Hybrid cloud is a cloud computing environment in which organization provides and manages some internal resources and external. This new enviormnet cloud brings irretrievable losses to the clients due to a lack of data integrity and verification mechanism for distributed data outsourcing. Hence, we propose a collaborative provable data possession (CPDP) method for providing data integrity in hybrid cloud and provides dynamic scalability and data migration in hybrid cloud.