The security risks associated with each cloud delivery model vary and are dependent on a wide range of factors including the sensitivity of information assets, cloud architectures and security controls involved in a particular cloud environment. With public audit ability, a trusted entity with expertise and capabilities data owners do not possess can be delegated as an external audit party to assess the risk of outsourced data when needed. Such an auditing service not only helps save data owners’ computation resources but also provides a transparent yet cost-effective method for data owners to gain trust in the cloud. All types of users who require the secure transmission or storage of data in any kind of media or network. Since the data transmission on the inter net or over any networks are vulnerable to the hackers attack. We present information risk management framework for better understanding critical to support scalable and efficient trusted third party auditing in Cloud Computing. We propose a new model–driven methodology for the security testing of cloud environments, to support batch auditing for TPA upon delegations from multi-user’s. We also propose new scheme that enables the data owner to delegate tasks of Cloud storage data file encryption and trusted user secret key update to cloud servers without disclosing security data contents or user access privilege information. The trusted third party auditing process will bring in no new vulnerabilities towards user cloud storage data privacy. Our new method combined the secret key based homomorphic authenticator with random masking to achieve the privacy-preserving public cloud data auditing system.