BibTeX:

@article{IJIRSTV1I7040,
     title={Data Security For Unreliable Clouds Using Reliable Re-Encryption},
     author={Ritesh B. Tandel and Krishnakant Kishor},
     journal={International Journal for Innovative Research in Science & Technology},
     volume={1},
     number={7},
     pages={158--160},
     year={},
     url={http://www.ijirst.org/articles/IJIRSTV1I7040.pdf},
     publisher={IJIRST (International Journal for Innovative Research in Science & Technology)},
}

Data Security is one of the most critical aspects in a cloud computing environment due to the sensitivity and importance of information stored in the cloud. The risk of malicious insiders in the cloud and the failure of cloud services have received a great deal of attention by companies. This paper is related to data security and privacy. The data owner stores the encrypted data in the cloud, and issue decryption keys to authorized users. Then, when a user is revoked, the data owner will issue re-encryption commands to the cloud to re-encrypt the data, to prevent the revoked user from decrypting the data, and to generate new decryption keys to valid users, so that they can continue to access the data. However, since a cloud computing environment is comprised of many cloud servers, such commands may not be received and executed by all of the cloud servers due to unreliable network communications The above problem can be solved by proposing an instant mailing scheme and sending password to the valid user mobile device, which enables the cloud servers to automatically re-encrypt data based on their internal clocks. The solution is to build a new encryption scheme, by sending instant password to the valid data user through their mail and Short Message on Mobile. Every time there will be a different password such that even though the data user get revoked from the system without the knowledge of cloud server he login again with same password. Key terms : data owner, data user, cloud service provider, instant mailing system and instant short message scheme.

Cloud Computing, Re-encryption, Decryption