Cloud computing is a rapid growth technology used in much different type of companies in recent times. With the huge demand in cloud computing, security concerns are raised for both service providers and consumers. While open systems still facing many day-to-day security threats or attacks, there is a need to identify the possible security holes that can be made more secure and robust. It’s very important to secure the cloud for business and personal users, the solution that helps in defending cloud computing keeps information safe and secure and that’s what everyone wants for their data storage. In addition that cloud security supports the organizations and enhances trustworthy from their customers. There are many techniques proposed and used for protecting users’ data from outside attackers. The best solution is to secure data and network under many phases. One of these phases used in cloud security is data auditing by a third party which was introduced to monitor the protection of data stored on the cloud. The aim of this report is lightening the role of Third Party Auditor (TPA) in data integrity check while performing activities on the data (generate, concatenate and compare digital signature), receiving requests from data owner and demanding requests to the cloud service provider.