Abstract: Cloud computing would be one of technologies which is going to play a vital role in the next generation of computer engineering field. The increased scalability and flexibility provided by the cloud computing has reduced the costs to a greater extent and therefore the technology has gained wide acceptance. The facility of Data outsourcing in the clouds enables the owner of the data to upload the data and other users can access the same. But, the data stored should be secure in the cloud servers. The data owner has lot of concern about security aspects present with the cloud computing. The data owners hesitate to adopt cloud computing services because of privacy protection issues of data and security of data. The proposed research work aims to undertake the critical issue of identity revocation wherein outsourcing computation into IBE has been introduced for the first time and a revocable IBE scheme in the server-aided setting has been proposed. This scheme offloads most of the key generation related operations to a Key Update Cloud Service Provider for key-issuing and key-update processes. Only a constant number of simple operations for PKG and users are left to perform locally. Data security is provided by using encryption, user authentication; re-encryption in the proposed data storage security model. The proposed system has also introduced outsourcing computation into IBE revocation, formalizes the security definition of outsourced revocable IBE for the first time to the best of our knowledge. Finally, experimental results have demonstrated the efficiency of the proposed construction.
Keywords: Cryptography, Cloud, IBE