An Oriented-Group Supporting Multi-user Public Auditing for Data Sharing

Cloud computing is a kind of internet-based computing, it outstanding property is on-demand computing. As an important service, cloud storage is able to provide users and enterprises with various capabilities to store and access their data in the centers. It relies on sharing of resources to achieve coherence and economies of scale. However, in most of data sharing protocols, to update the outsourced data, the data updating operation is only executed by data owner. Obviously, it is far from practical due to the tremendous computational cost on data owner. To support multi-user modification, we propose a novel public auditing for data sharing with multi-user modification by using ring signature in this paper. Our scheme does not only support public checking and efficient user revocation, but provide backward security. Efficiency analysis shows that our scheme is very efficient.