In cloud storage environment, data owners host their data on cloud servers and users can access the data from cloud servers. Due to the data outsourcing, this process of data hosting service introduces new security challenges, which requires an independent auditing service to check the data integrity in the cloud. Because, owner need to be convinced that the data are correctly stored in the cloud. Two-Party storage auditing system could not be guaranteed to provide proper auditing result thus Third-Party auditing is the better choice for the storage auditing in cloud computing. In this we try to evaluate ECC algorithm for encryption and decryption.A Third-Party auditor is capable to do a more efficient work and convinces both the cloud serviceproviders and the owner. There are chances of data being lost or get misplaced in cloud storage environment. For this we propose replication mechanism to third party auditing such that it will enhance the data availability. We divide a data file into fragments and replicate the fragmented data over the cloud nodes. Each of the nodes stores only a single fragment of a particular data file that ensures that even in case of a successful attack, no meaningful information is revealed to the attacker.Furthermore, the nodes storing the fragments are separated with certain distance to prohibit an attacker of guessing the locations of the fragments. Hence user will get the belief that his data is safely stored on the cloud and could retrieve data without any modification.To better protect data security, the first attempt to formally address the problem of authorized data deduplication.