Improved Provable Data Transfer from Provable Data Possession and Deletion in Cloud Storage

Due to the limited computational resources of data owners and the developments in cloud computing, more and more data owners choose to store data on the cloud to reduce their own storage burden. When the data owner wants to re-select a new cloud service provider, the data needs to be transmitted from Cloud A to Cloud B. How to ensure that data has been safely transferred to Cloud B and Cloud A honestly implementing data deletion has become a hot topic for many scholars. To solve these problems, Liang et al. proposed a provable data transfer protocol based on provable data possession and deletion for secure cloud storage. However, we find a security flaw in their scheme. In this paper, we first review their scheme and then present our attack in detail. Finally, we propose an improved scheme which can resist the attack well.