Cross-Cloud Associated Multireplica Auditing for Lightweight Devices in the IoT

Cloud storage has become prevalent in Internet of Things (IoT) systems, attributed to its robust storage capabilities and user convenience. However, the cloud-based storage model, which separates data ownership from management, introduces integrity challenges due to the vulnerability of data to tampering. To address the risk of data loss and ensure recoverability, the implementation of multiple replicas is a common strategy. Nonetheless, traditional multireplica auditing schemes are not well suited for IoT environments that employ lightweight devices with limited computational capabilities. In response to the aforementioned challenges, we propose a novel multireplica auditing scheme named CCMR, aimed at alleviating the heavy computation cost on the device side. Our scheme leverages an efficient aggregated multisignature algorithm, offloading computationally intensive tasks associated with data tags from lightweight devices to cloud service providers (CSPs) equipped with advanced computational power. The innovative cross-cloud multireplica hash tree structure, named CC-MHT, facilitates the secure and efficient verification of data block structures and ensures consistency of replicas across multicloud environments. Furthermore, by utilizing blockchain as a public random source, a robust challenge-response protocol is established to guard against potential audit failures that could arise from collusion between the third-party auditor and CSPs. The experimental results indicate the high efficiency of the proposed scheme in terms of computation cost.