Secured document management through a third party auditor scheme in Cloud Computing Cloud Computing has been envisioned as the next-generation architecture of IT Enterprise. Cloudstorage moves the user’s data to large data centers, which are remotely located, on which user does not have any control. However, this unique paradigm of the cloud poses many new security challenges which need to be clearly understood and resolved. This work studies the problem of ensuring the integrity of data storage in Cloud Computing. The Cloud Server provides a platform for the Cloud Client to manage their documents. In particular, we consider the task of allowing a third party auditor (TPA), on behalf of the cloud client, to verify the integrity of the dynamic data stored in the cloud. The introduction of TPA eliminates the involvement of the client through the auditing of whether his data stored in the cloud are indeed intact, which can be important in achieving economies of scale for CloudComputing.