Cloud Data Integrity Using a Designated Public Verifier

Cloud computing presents many advantages over previous computing paradigms such as rapid data processing and increased storage capacity. In addition, there are many cloud service providers (CSPs) that ensures for easy and an efficient migration and provide varying levels of security with respect to information or assets contained in the storage. However, the average cloud service user (CSU) may not have the auditing expertise and sufficient computing power to perform the necessary auditing of cloud data storage and an accurate security evaluation which facilitates to maintain the trust deficit between CSUs and CSPs. Therefore, the use of a trusted third party (TTP) to perform the required auditing tasks is inevitable since it provides several advantages to both CSUs and CSPs in terms of efficiency, fairness, trust, etc. -- which is essential to achieve the economies of scale for the cloud computing. Motivated with this, we present a new data security scheme which allows a CSU to enable a public verifier (e.g., a third-party auditor) to perform the necessary auditing tasks at the cloud data. Our proposed scheme is the extension of the TTP based encryption scheme proposed in [7]. Specifically, the auditing tasks include the checking of cloud data integrity on cloud user´s request employing a public verifier. The simulation results demonstrate the effectiveness and the efficiency of our proposed scheme when auditing the cloud data integrity in terms of reliability of CSPs and the trust-level between the CSUs and a public verifier.