Revocable Data Access Control for Secure Data Sharing In Cloud

Cloud computing provides a flexible and convenient way for data sharing, which brings various benefits for both the society and individuals. But there exists a natural resistance for users to directly outsource the shared data to the cloud server since the data often contain valuable information. Thus, it is necessary to place cryptographically enhanced access control on the shared data. Identity-based encryption is a promising crypto graphical primitive to build a practical data sharing system. However, access control isn’t static. That is, when some user’s authorization is expired, there should be a mechanism that can remove him/her from the system. Consequently, the revoked user cannot access both the previously and subsequently shared data. To this end, propose a notion called revocable-storage identity-based encryption (RS-IBE), which can provide the forward/backward security of cipher text by introducing the functionalities of user revocation and cipher text update simultaneously. Furthermore, present a concrete construction of RS-IBE, and prove its security in the defined security model. Furthermore have introduced AES algorithm because the more popular and widely adopted symmetric encryption algorithm likely to be encountered nowadays is the Advanced Encryption Standard (AES). It is found at least six times faster than triple DES. Some features of AES algorithm is Symmetric key symmetric block cipher, 128-bit data, 128/192/256-bit keys, Stronger and faster than Triple-DES, Provide full specification and design details, Software implementable in C and Java. The performance comparisons indicate that the proposers-IBE scheme has advantages in terms of functionality and efficiency, and thus is feasible for a practical and cost-effective data-sharing system.