TEEMRDA: Leveraging trusted execution environments for multi-replica data auditing in cloud storage

Driven by the rising popularity of multi-replica backups for enhanced data reliability and availability in cloud storage, multi-replica data auditing, which guarantees that cloud service providers (CSPs) securely store all designated replicas, has become a prominent research area in cloud data security. However, existing multi-replica auditing schemes pose a notable challenge: users incur additional computation and communication overheads to generate and upload multiple replicas. This approach also diverges from the conventional multi-replica storage model, where users typically submit a single copy and the CSP handles replica creation. To address this issue, this paper presents a novel multi-replica data auditing scheme based on Trusted execution environments (TEEs), named TEEMRDA. TEEMRDA is designed to align with real-world practices where users upload a single copy, significantly reducing user burden. To guarantee reliable multi-replica storage, we propose a random mask-based strategy implemented by TEEs to securely generate a predetermined number of data copies. For auditability, we introduce an impartial dual authentication mechanism using replica and data block index-independent signatures, employing both online and offline procedures. This approach substantially reduces the TEE’s computation overhead in generating tags for multiple-replica blocks and enhances efficiency for third-party auditors conducting data audits. Finally, we conduct comprehensive security validation and performance comparison of TEEMRDA with state-of-the-art schemes. The results demonstrate that TEEMRDA achieves secure and efficient auditing for multi-replica data, outperforming existing schemes in terms of computation and communication overheads.