Intel HEXL: Accelerating Homomorphic Encryption with Intel AVX512-IFMA52

TL;DR

Intel HEXL is a C++ library that accelerates homomorphic encryption operations by leveraging Intel AVX512 instructions, significantly improving the speed of polynomial arithmetic crucial for schemes like CKKS, BFV, and BGV.

Contribution

The paper introduces Intel HEXL, an optimized library utilizing AVX512 for polynomial arithmetic, enhancing HE performance over previous implementations.

Findings

Up to 7.2x speedup in forward NTT

Up to 6.7x speedup in inverse NTT

Up to 6.0x speedup in modular multiplication

Abstract

Modern implementations of homomorphic encryption (HE) rely heavily on polynomial arithmetic over a finite field. This is particularly true of the CKKS, BFV, and BGV HE schemes. Two of the biggest performance bottlenecks in HE primitives and applications are polynomial modular multiplication and the forward and inverse number-theoretic transform (NTT). Here, we introduce Intel Homomorphic Encryption Acceleration Library (Intel HEXL), a C++ library which provides optimized implementations of polynomial arithmetic for Intel processors. Intel HEXL takes advantage of the recent Intel Advanced Vector Extensions 512 (Intel AVX512) instruction set to provide state-of-the-art implementations of the NTT and modular multiplication. On the forward and inverse NTT, Intel HEXL provides up to 7.2x and 6.7x speedup, respectively, over a native C++ implementation. Intel HEXL also provides up to 6.0x speedup on the element-wise vector-vector modular multiplication, and 1.7x speedup on the element-wise vector-scalar modular multiplication. Intel HEXL is available open-source at https://github.com/intel/hexl under the Apache 2.0 license and has been adopted by the Microsoft SEAL and PALISADE homomorphic encryption libraries.