Privacy preserving data auditing protocol for secure storage in mobile cloud computing

In spite of the growing usage of smart mobile devices, the inherent restrictions like resource scarcity, mobility and frequent disconnections makes it difficult to exploit its full potential. Cloud computing simplifies the deployment of large-scale distributed systems and enables advanced computational power with improved storage capabilities. The evolution of Mobile Cloud Computing (MCC) exploits the services of Cloud Service Providers (CSP) by outsourcing the local data storage and computation to the remote servers and thereby relieving the overhead incurred by mobile clients for data storage and processing. In spite of the relief, the clients no longer have control over their outsourced data which demands the purpose of ensuring the data intactness maintained by the Cloud Storage Server (CSS). The resource constrained mobile devices act as a thin client for the cloud server access and hence the computation for ensuring the proof of correctness for secure data storage becomes an overhead with existing solutions. The proposed auditing protocol introduces a trusted third party auditor (TPA) who will be in charge of verifying the correctness of data stored at cloud storage on behalf of the user without the need for retrieving the entire data. The usage of Bilinear pairing and Merkle Hash Trees guarantees Blockless verification by TPA. The verification process in the proposed method reduces the auditing overhead at the mobile device using short signatures. The proposed auditing protocol saves the mobile client's computational resource, thereby achieving cost-effectiveness to gain trust in the Cloud Storage Service.