Association for Computing Machinery
Both security and efficiency are crucial to the success of cloud storage. So far, security and efficiency of cloud storage have been separately investigated as follows: on one hand, security notions such as Proof of Data Possession (PDP) and Proof Of Retrievability (POR) have been introduced for detecting that the data stored in the cloud has been tampered with. On the other hand, the notion of Proof Of oWnership (POW) has also been proposed to alleviate the cloud server from storing multiple copies of the same data, which could substantially reduce the consumption of both network bandwidth and server storage space. These two aspects are seemingly quite to the opposite of each other.