Lightweight Proofs of Storage with Public Verifiability from Lattices

Proof of storage (POS) is a useful cryptographic primitive that enables users to efficiently verify the integrity of their data outsourced in the cloud. Usually, users prefer to utilize POS schemes with public verifiability for integrity checking tasks, since such schemes allow a third-party on behalf of a user to implement these tasks without disclosure of any secret information of the user. However, most of the existing publicly verifiable POS schemes are somehow cumbersome because they involve a great deal of heavy operations especially on the user side so that they may not be competent for some applications.To compensate for this defect, we explore a simple and lightweight POS scheme with public verifiability from hardness problems relative to lattices. Our scheme only requires simple cryptographic computations and, in particular, significantly decreases the computation overhead of users. We prove our scheme is secure assuming the ring small integer solution problem is intractable. Moreover, we also conduct extensive simulations to evaluate the performance of our scheme, and the experimental results do speak volumes about its effectiveness.