Configurable number theoretic transform (ntt) butterfly circuit for homomorphic encryption

Abstract

Fully homomorphic encryption integrated circuit (IC) chips, systems and associated methods are disclosed. In one embodiment, a number theoretic transform (NTT) butterfly circuit is disclosed. The (NTT) butterfly circuit includes a high input word path cross-coupled with a low word path. The high input word path includes a first adder/subtractor, a first multiplier, and first selection circuitry coupled to the first adder/subtractor and the first multiplier. Respective bypass paths selectively bypass the first adder/subtractor and the first multiplier. The low input word path includes a second adder/subtractor, a second multiplier, and second selection circuitry coupled to the second adder/subtractor and the second multiplier. Respective bypass paths selectively bypass the second adder/subtractor and the second multiplier. The first and second selection circuitry is responsive to different mode control signals to reconfigure the low and high input word paths into different logic processing units.