A simple fully homomorphic encryption scheme available in cloud computing

With continuous expansion of cloud computing, problems of third-party data security become increasingly prominent. However, effective retrieval of encrypted data and other operations are difficult to achieve by traditional cryptogram systems. Thus, a practical simple fully homomorphic encryption scheme, using only elementary modular arithmetic, derived from Gentry cryptosystem is put forward to ensure the privacy-preserving in cloud storage, in which encrypted data can be operated directly without affecting the confidentiality of the encryption systems, so that it can excellently realize the need of cipertext retrieval and other processing in untrusted servers. Compared with the previous protocols Marten van Dijk et al. proposed at Advances in Cryptology-EUROCRYPT 2010 and Craig Gentry proposed in the March 2010 issue of Communications of the ACM, especially in the aspect of cipertext retrieval, the proposed scheme is much more secure and feasible. And the performance evaluation and security analysis demonstrate the practice and validity of the proposed scheme.