Efficient and Privacy-Preserving Ideal Lattice-based Public Auditing Scheme for Cloud Storage

The proliferation of cloud computing has rendered reliable data integrity auditing a paramount challenge within the domain of cloud storage security. This necessity is particularly urgent in the post-quantum era, given the severe threat posed by quantum computers to traditional public-key cryptosystems. However, extant solutions for data integrity are often predicated upon classical cryptographic hardness problems susceptible to quantum attacks. To this end, this paper proposes an efficient and privacy-preserving identity-based integrity auditing scheme founded on ideal lattices. The scheme leverages homomorphic signature technology to generate integrity authentication tags, allowing a third-party auditor to efficiently verify data integrity without retrieving the entire dataset. The cloud service provider can efficiently aggregate evidence using the homomorphic property of the signatures to respond to audit challenges, achieving efficient and privacy-preserving outsourced auditing. Rigorous security proofs demonstrate that the integrity auditing scheme is existentially unforgeable under chosen-message attacks (EUF-CMA) under the Ring-SIS assumption. The efficiency of the scheme is due to its effective utilization of the algebraic structure of the ideal lattice, which accelerates polynomial operations through Number Theoretic Transformations (NTT). Comparative analysis and experimental results show that the scheme has significant advantages in computing efficiency and communication cost, thereby underscoring its practical feasibility for high-throughput cloud environments.