Efficient and Secure Auditing of Cloud Data with Key -Updating

Cloud storage auditing is the process of verifying the integrity of the data stored in public cloud. The existing auditing protocols are based on the assumption that the clients secret key for auditing is secure. In practical the secret key is not absolutely secure due to weak security settings at the client. If secret key for auditing is exposed, most of the current auditing protocols become unable to work. This paper focus on how to solve the problem of key-exposure in public cloud and give the practical solution for it. In the proposed design, use a binary tree structure and the preorder traversal technique to update the clients secret keys. Also develop a novel authenticator construction for forward security and the property of blockless verifiability. The secret key updating is done by a trusted authority and the updating process is done automatically. If the verification result is negative then it is possible to retrieve the original data.