Research On Provable Data Possession In Cloud Computing Environment

Cloud is coming! An increasing number of person choose to outsource their storage demands to get three-high( high scalability, high reliability, high availability ) cloud storage service. In order to ensure the integrity of the data in the untrusted Cloud, we propose an improved dynamic provable data possession scheme to support data integrity verification and dynamic update. There are two roles in our scheme: User and Server. User pays a fee to get an appropriate storage space on Server and uploads his files. Server is asked to faithfully store the files, without any unauthorized modification. User challenges the Server, ask him to prove the integrity of his files. Server calculates and returns the evidence that he faithfully holds the files. User can update his file online, and after update, the integrity verification can still process. Compared with previous works, it reduces the computational and communication complexity from O(logn) to O(1). Then, we extend our scheme to file sharing situation. Multiple users can simultaneously do integrity verification or updating on a file on the untrusted Server.We use a Demo system to do some experiments to ensure these improvements. Experimental results show that our scheme achieves the desired results.