Privacy Preserving Provable Data Possession: A FHE-based Hash Approach

The data privacy nowadays is of importance for every user of cloud service. Meanwhile, proof of data possession (PDP) is also a well-known security issue. In our work, we propose a PDP framework that contains 1) a PDP procedure combine with Fully Homomorphic Encryption (FHE) over Hash (such as MD5 and SHA256) that has capability to check integrity of single file efficiently. 2) A FHE merkle hash tree uses FHE hash function to check the integrity of multiple files under encryption. The proposed approach has been implemented using TFHE library. In the experiment stage, though it takes longer time to do our PDP process, the time complexity is polynomial and thus it is an usable work.