  Cloud computing is the long dreamed vision of computing as a utility, where
users can remotely store their data into the cloud so as to enjoy the on-demand
high quality applications and services from a shared pool of configurable
computing resources. By data outsourcing, users can be relieved from the burden
of local data storage and maintenance. we utilize the public key based
homomorphism authenticator and uniquely integrate it with random mask technique
to achieve a privacy-preserving public auditing system for cloud data storage
security while keeping all above requirements in mind. To support efficient
handling of multiple auditing tasks, we further explore the technique of
bilinear aggregate signature to extend our main result into a multi-user
setting, where TPA can perform multiple auditing tasks simultaneously along
with investigates secure outsourcing of widely applicable linear programming
(LP) computations. In order to achieve practical efficiency, our mechanism
design explicitly decomposes the LP computation outsourcing into public LP
solvers running on the cloud and private LP parameters owned by the customer
Extensive security and performance analysis shows the proposed schemes are
provably secure and highly efficient.
