Cloud storage system enabling secure privacy preserving third party audit

Cloud computing is a revolutionary new approach to how computing services are produced and consumed. It is an abstraction of the concept of pooling resources and presenting them as virtual resources. Using cloud computing resources, data, computations, and services can be shared over scalable network of nodes; these nodes may represent the datacenters, end user computers and web services. On the same note cloud storage refers to storing the data on a remote storage located at other organization's infrastructure. The data storage is maintained and managed by the organization; the user will pay for the storage space which is used. Outsourcing data ultimately relinquishes the control of data from user and the fate of data is in control of the cloud server. As the data is stored on cloud server, the storage correctness of data is put on risk. The cloud server is managed by cloud service provider which is a different administrative entity, so ensuring the data integrity is of prime importance. This article studies the problems of ensuring data storage correctness and proposes an efficient and secure method to address these issues. A third party auditor is introduced securely, who will on behalf of users request will periodically verify the data integrity of the data stored on cloud server. There will not be any online burden on user and security of data will be maintained as the data will not be shared directly with the third party auditor. A homomorphic encryption scheme is used to encrypt the data which will be shared with the TPA. The results can be further extended to enable the third party auditor to do multiple auditing.