NEON PQCryto: Fast and Parallel Ring-LWE Encryption on ARM NEON Architecture

Recently, ARM NEON architecture has occupied a significant share of tablet and smartphone markets due to its low cost and high performance. This paper studies efficient techniques of lattice-based cryptography on ARM processor and presents the first implementation of ring-LWE encryption on ARM NEON architecture. In particular, we propose a vectorized version of Iterative Number Theoretic Transform (NTT) for high-speed computation. We present a 32-bit variant of SAMS2 technique, original proposed in CHES’15, for fast reduction. A combination of proposed and previous optimizations results in a very efficient implementation. For 128-bit security level, our ring-LWE implementation requires only 145, 200 clock cycles for encryption and 32, 800 cycles for decryption. These result are more than 17.6 times faster than the fastest ECC implementation on ARM NEON with same security level.