Ensuring Dynamic Data Integrity with Public Auditability for Cloud Storage

Cloud computing brings about not only the improvement of resources utilization efficiency and conveniences, but also great challenges in the field of data security and privacy protection. One major challenge is to verify data integrity at untrusted server under the condition of supporting public audit ability and dynamic data operation. This paper analyzes the efficiency issues and security loophole of a current scheme, constructs dynamic Merkle hash tree with relative index to compute the index of leaf node quickly, and proposes an improved dynamic data integrity scheme based on this tree structure for cloud storage. The performances and security analysis show that our scheme is efficient and secure, the computation complexity of dynamic data operation and integrity verification reaches O (log n) definitely.