Now a day’s everyone storing there data in cloud because we can’t depends on hard drives if they crash one can’t have backup for ever data. Famous Cloud storage applications are Drop box, Google drive, Sky drive, Box, Amazon cloud drive, Surdoc and Apple icloud. In cloud data security is provided by various security algorithms. In our research we have chosen attribute based encryption technique...

In this short paper we formally prove that designing attribute-based encryption schemes cannot be easier than designing identity-based encryption schemes. In more detail, we show how an attribute-based encryption scheme which admits, at least, AND policies can be combined with a collision-resistant hash function to obtain an identity-based encryption scheme. Even if this result may seem natural...