Ascina: Efficient Proof of Retrievability for Industrial Cloud Storage Systems

Industrial cloud storage systems enhance data availability and offer intelligent services to enterprises. However, they also bring significant concerns about data integrity since the cloud space provider may not consistently retain the outsourced data. Existing cloud storage verification methods impose a significant computational burden on edge devices, so they are unsuitable for industrial cloud storage systems. Although the light-weight homomorphic authenticator somewhat alleviates the computational load on the fog node, its effectiveness remains limited and it further complicates proof generation and verification. To address these problems, we propose Ascina, a new proof of retrievability framework for industrial cloud storage systems. We employ verifiable secret sharing to delegate tag computation tasks to the computing server without disclosing the signing key. Once the fog node completes its initial configuration, no further computations are required. Additionally, we propose the improved Ascina by utilizing Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) technology to further alleviate the computational burden on the fog node. Furthermore, we propose a batch verification algorithm that simultaneously validates the integrity of multiple files while maintaining the same security assurances as single auditing. We evaluate the performance of Ascina through experiments and compare it with state-of-the-art methods. Experimental results demonstrate that the computational overhead on the fog node in Ascina is 5×-251× lower than that of Edasvic and our proof verification time and proof size are reduced by 5×-16× and 977×-3285×, respectively. As the size and quantity of files grow, Ascina demonstrates greater efficiency in both time and space.