An Efficient Implementation of the NewHope Key Exchange on FPGAs

Lattice based cryptography plays an important role in the construction of post-quantum cryptography, including key exchange, public key encryption as well as digital signature schemes. Dating back to 2016, a new key exchange scheme called NewHope was proposed by Alkim, Ducas, Poppelmann, and Schwabe that based security on the quantum hardness of Ring Learning with Errors (RLWE) problem, and was later submitted to the NIST public competition of standard post-quantum cryptography. The new scheme is attractive as it is designed to achieve high performance. In this work, we concentrate on its performance on hardware platforms and propose an efficient implementation of NewHope on Xilinx Artix-7 7020 FPGA platform that consumes 3158 slices, 10285 LUTs, 6623 registers in the server side, and 3042 slices, 10345 LUTs, 6704 registers in the client side, achieving a 45% reduction in LUT, 30% reduction in FF while the total time utilization also decreases by 16% compared with the up to date and directly related work. Specifically, we can accomplish three phases of the key exchange in 39.8/61.7/ $21.4~\mu \text{s}$ respectively, operating in 153/152 MHz in server/client side.