Cloud computing is defined as a type of computing that relies on sharing computing resources rather than having local servers or personal devices to handle the applications. User can easily modify the shared and stored data in the cloud. To overcome this data modification in cloud the signature is provided to each individual user who accesses the data in cloud. Once the data is modified by the user on a block, the user must ensure that the signature is provided on that specific block. When user misbehaves or misuses the system the admin has authority to revoke that particular user from the group. After revoking that user, the existing user must re-sign the data signed by the revoked user. In addition to this, the security of the data is also enhanced with the help of public Auditor who is always able to audit the integrity of shared data without retrieving the entire data from the cloud