The cloud storage offers users with infrastructure flexibility, faster deployment of applications and data, cost control, adaptation of cloud resources to real needs, improved productivity, etc. Inspite of these advantageous factors, there are several deterrents to the widespread adoption of cloud computing remain. Among them, security towards the correctness of the outsourced data and issues of privacy lead a major role. In order to avoid security risk for the outsourced data, we propose the dynamic audit services that enables integrity verification of untrusted and outsourced storages. An interactive proof system (IPS) with the zero knowledge property is introduced to provide public auditability without downloading raw data and protect privacy of the data. In the proposed system data owner stores the large number of data in cloud after e encrypting the data with private key and also send public key to third party auditor (TPA) for auditing purpose. TPA in clouds and it’s maintained by CSP. An Authorized Application (AA), which holds a data owners secret key (sk) and manipulate the outsourced data and update the associated IHT stored in TPA. Finally Cloud users access the services through the AA. Our system also provides secure auditing while the data owner outsourcing the data in the cloud. And after performing auditing operations, security solutions are enhanced for the purpose of detecting malicious users with the help of Certificate Authority.