Efficient as Symmetric Key, Flexible as Public Key: A Novel Remote Data Auditing Protocol

Ensuring data integrity in cloud computing is crucial. Symmetric key systems are fast but struggle with secure key exchange, while public key systems allow flexible key sharing but are computationally expensive. Traditional auditing methods require the entire dataset, leading to increased communication overhead. Remote integrity checking (RIC) protocols enable users to verify cloud data without downloading the full dataset. However, existing RIC methods face challenges such as high tagging costs and significant communication overhead. This paper introduces O 2 RIC, an online/offline remote integrity checking method designed to address these challenges. Our scheme combines the efficiency of symmetric key systems with the flexibility of public key systems, significantly reducing storage, communication, and computation overhead. In O 2 RIC, computation-ally intensive tagging operations are performed offline, while efficient operations occur online, offering a balanced trade-off between overhead and flexibility. We prove the security of our proposed scheme under the hardness assumption of the Bilinear Diffie-Hellman (BDH) problem. We evaluate O 2 RIC by developing software that implements our algorithm and testing it with real data. Our findings reveal that O 2 RIC significantly reduces overhead in cloud storage systems, accelerating the tagging and verification process by 100 times compared to current state-of-the-art approaches.