An Efficient Privacy Preserving Public Auditing Mechanism for Secure Cloud Storage

one of the services provided by the cloud environment is cloud storage which allows users to store, remotely manage and access their data over the internet. However, the limited control granted to users over remote cloud nodes makes users worry about the integrity of their data as the user’ data can be accessed or modified by external attackers. Therefore, a new terminology called data auditing has been evolved to allow users to use cloud storage as they use their local storage without worrying about the integrity of their data. In order to achieve the auditing task, users can resort to an independent entity called Third Party Auditor (TPA) rather than putting the burden of the auditing task on the users themselves. The job of the TPA is to monitor the modifications, deletions, and insertions made on the user’s data. However, using a TPA can endanger the data privacy and hence a privacy preserving TPA is required. In this paper, we have designed and implemented a cloud storage framework which includes an efficient TPA with main objective is to provide the public data auditing service while preserving the data privacy. Also, it can act as an intermediary between the data owner and the cloud service provider through which the users can upload, access, modify, delete, and audit their data while maintaining its privacy. The proposed auditing protocol is based on using two well-known encryption techniques, namely, message digest algorithm 5 (MD5) and advanced encryption standard (AES). Also, the TPA allows the users to store their data on multiple clouds to enhance the availability of data. A set of experiments have been conducted to evaluate the performance of the proposed public auditing mechanism.