International Journal for Innovative Research in Science and Technology (IJIRST)
In cloud computing, data sharing is the important functionality. Secure distributed data storage was developed to reduce the burden of data owner from managing numerous files, by transferring the files from data owner to proxy servers. Proxy servers can convert encrypted files for the owner to encrypted files for the receiver without the necessity of knowing the content of the original files. In practice, the original files will be removed by the owner for the sake of space efficiency. Therefore, there is no guarantee that the outsourced files are not accessed by the unauthorized users and not modified by proxy servers is an important problem that has been considered.