Efficient Processing of Encrypted Data in Honest-but-Curious Clouds

Encrypted data stored in clouds usually cannot be processed. To address this limitation, we design a practically efficient fully homomorphic encryption (FHE) scheme, which allows encrypted data to be directly processed by the clouds. Our scheme assumes that the clouds are curious to derive information from encrypted data, but not performing any nondeterministic brute-force attacks. We implemented a prototype of our scheme and evaluated its concrete performance by evaluating high-degree polynomials over encrypted data and calculating inner product of high-dimensional encrypted vectors.