A survey on auditing techniques used for preserving privacy of data stored on cloud

Providing security to the stored data on the cloud is one of the important challenges in cloud computing. Encrypted data which is stored on the cloud may be viewed or modified by the cloud service provider. To overcome this problem many techniques have been developed but, those cannot guarantee accurately about the security of the stored data. These modifications of the data by the service provider or by others should also be known to the data owner. For such purpose, data tagging technique can be used to audit the data. Auditing is done by using Third Party Auditor (TPA). TPA stores data information of the data owner and challenges to the cloud server, depending upon the data owner request. With the help of such mechanism, TPA can convince both, data owner and cloud server.