Cryptanalysis and Improvement of a Provable Data Possession Scheme in Public Cloud Storage

For validating the data integrity in the cloud storage, several provable data possession (PDP) schemes have been proposed to concern with this issue. However, these schemes are either inefficient or insecure under some circumstances. In 2015, Ren et al. Proposed an efficient mutual verifiable PDP (MV-PDP) scheme with stateless property. In this article, we will show that their scheme cannot provide data integrity checking by presenting a universal forgery attack on the verification procedure. In addition, an improvement is proposed to resist this attack. Under the computational Diffie-Hellman (CDH) and discrete logarithm (DL) assumptions, we formally prove that the improved PDP scheme is secure against forgery attacks while achieving better performance than Ren et al.'s scheme.