A Remote File Possession Checking Protocol in a Cloud Storage

Outsourcing a file to a remote cloud storage provides several benefits, including scalability, accessibility, data replication and considerable cost saving. Unfortunately, when we send a file to a remote cloud storage server, we do not know if this file is intact. To address this problem, we present a remote file possession checking protocol. In this protocol, we use three technologies: Firstly, we design a kind of file block tag whose security is based on the discrete logarithm problem (DLP); secondly, we use probability checking method to improve its effectiveness; thirdly, we use tag aggregation method to reduce its communication cost. Our theory analysis and experiment results show that our protocol is practical and secure.