A swift Cloud-Paillier scheme to protect sensitive data confidentiality in cloud computing

Concerns over the confidentiality of sensitive data are still the main obstacles limiting the wide-spread adoption of cloud services. Actually, scientists have suggested a new encryption form, called homomorphic encryption (HE), which can offer a third-party having the ability to perform operations on encrypted data. The HE property can be considered as a useful method to get over these concerns. Since cloud environments are threatened by outsider/insider security attacks and since the cloud consumers oftentimes access to cloud services utilizing resource-limited devices, the HE schemes need to be promoted in terms of security level and running time to work effectively. At BDAW'16, we boosted a Paillier scheme at the security level, we refer to as Cloud-Paillier. In this paper, we propose a fast variant of Cloud-Paillier scheme to accelerate its decryption process. The variant employs the Chinese remaindering to decrypt. Simulation results show that the proposed variant provides a large decryption speedup over Cloud-Paillier scheme while preserves the same security level.