Public Integrity Checking for Dynamic Data Sharing among Multi Groups

Cloud is un-trusted file storage, and there is still a challenging issue, i. e. , frequent change of the data in an un-trusted cloud. For that a number of techniques have been proposed for data integrity auditing to ensure users confidence of their shared data on cloud. Most of the paper focus on the original data owner who will create the data can modify the data, and the other users have only the reading permission. To enhance this work to multi-user modification therefore any user (in group) can modify the data in the cloud. Main issues of multi-user modification is used revocation, here a user can revocate, just delete the user information no need to update the signature, because the data in depend to the user. Multi file auditing is also efficiently supported in our scheme by mechanism of batch auditing. So it reduces the computational/communication cost. This work enhanced to multiple groups to access the data. This paper concluded as, a efficient integrity auditing scheme for cloud data characterized by multi-user modification, public auditing, high error detection probability, efficient user revocation, resist user impersonation attack, Multi file auditing.