Practical and Efficient FHE-Based MPC

We present a reactive MPC protocol built from FHE which is robust in the presence of active adversaries. In addition the protocol enables reduced bandwidth via means of transciphering, and also enables more expressive/efficient programs via means of a \(\textsf{Declassify}\) operation. All sub-components of the protocol can be efficiently realised using existing technology. We prove our protocol secure in the UC framework.