TF-LB-CLPAS: Trapdoor-Free Lattice-Based Certificateless Public Auditing Scheme for Cloud-Assisted IoT

Abstract

Cloud-assisted IoT systems increasingly rely on certificateless public auditing (CLPA) mechanisms to ensure the integrity of outsourced data stored in the cloud while avoiding certificate management and key escrow issues. However, most existing CLPA schemes are built on conventional cryptographic assumptions and are therefore vulnerable to quantum attacks. To resist quantum adversaries, several lattice-based CLPA schemes (LB-CLPAS) have been proposed. Nevertheless, these schemes typically rely on complex lattice trapdoor constructions and adopt integer or ideal lattices, resulting in high computational overhead and rendering them impractical for resource-constrained IoT systems. To address these limitations, this paper proposes a trapdoor-free lattice-based certificateless public auditing scheme for cloud-assisted IoT (TF-LB-CLPAS). By eliminating complex trapdoors and adopting module lattices, the scheme significantly improves computational efficiency while maintaining strong post-quantum security. Security is formally proven under the Module-SIS and Module-LWE assumptions. Performance evaluations demonstrate lower computational overhead and superior practicality compared to existing trapdoor-based LB-CLPAS, making it well suited for cloud-assisted IoT devices.