Secure and efficient parallel hash function construction and its application on cloud audit

Rapid development of cloud computing has created enormous security challenges on authenticity, integrity, availability and reliability of outsourced data. Cloud audit is an effective solution for massive data verification and provides reliable and credible authentication results. High efficiency of audit is needed because real-time verification of data is necessary for most of applications on cloud. Since hashing operation is an essential function in audit scheme which occupies most of audit overhead, this paper proposes a parallel iterative structure and a message padding procedure to construct a novel parallel lattice hash function (PLHF). Moreover, inside the parallel iterative structure, a lattice-based hash compression function is proposed to reduce the hardness of PLHF cracking into the solution of shortest vector problem. Based on experimental results and security analysis, the cloud audit scheme with PLHF does not only perform significant higher efficiency, but also has stronger security.