Double Encryption Based Auditing Protocol in Dynamic Cloud Storage

Cloud storage is a model of data storage in which the digital data is stored in logical pools, the cloud storage providers are responsible for keeping the data available, accessible and security. A privacy-preserving public auditing protocol allows a third party auditor to check the integrity of the outsourced data on behalf of the users without violating the privacy of the data. However, existing privacy-preserving public auditing protocols assume the end devices of users are powerful enough to compute all costly operations in real time when the data to be outsourced is given. In fact, the end devices may also be those with low computation capabilities. This paper provides the data security and data integrity checking in dynamic cloud storage. Merkle Hash Tree authentication structure with partial signatures to used. The User level privacy can be implemented using double encryption scheme at the time of data storage in the cloud. Experiments show that our protocols based on online/offline signatures are hundreds of times more efficient than a recent proposal and we include the batch auditing protocol to improve the efficiency.