Decentralized Data Integrity Auditing in Vehicular Cloud Computing

As Vehicular Cloud Computing (VCC) evolves, ensuring data integrity and availability becomes a critical challenge due to the vast amount of data being shared and stored. These properties are vital for preserving confidence in cloud services, guaranteeing that data is kept intact and readily available when needed. Traditional data auditing mechanisms, such as Proofs of Retrievability (PoR) and Provable Data Possession (PDP), are effective but often rely on centralized models that pose risks like single-point failures and susceptibility to collusion. To mitigate these risks, we introduce a blockchain-assisted protocol that leverages the decentralized and tamper-proof characteristics of blockchain to enhance the security of data auditing in VCC. Our approach incorporates a dynamic key update mechanism to counter key exposure issues prevalent in VCC and introduces a multi-replica mechanism to ensure data redundancy and reliability across different storage nodes. This feature significantly reduces the risk of data loss and improves trust in cloud services by distributing data storage responsibilities and preventing single-point failures. We conduct formal security analysis and implement a prototype of our protocol on the Ethereum blockchain. Experimental evaluations on both Ganache and Sepolia testnets validate its feasibility in decentralized environments. The results demonstrate that our scheme supports stable challenge-response latency, moderate gas consumption, and reliable multi-replica consistency—making it well-suited for VCC deployments with dynamic conditions and limited resources.