LEAP: Lightweight and Efficient Accelerator for Sparse Polynomial Multiplication of HQC

The Hamming quasi-cyclic (HQC) code-based encryption scheme is one of the fourth-round algorithms selected by the National Institute of Standards and Technology (NIST) postquantum cryptography (PQC) standardization process. However, very few hardware implementations have been reported for HQC to date. In this brief, we propose a novel Lightweight and Efficient Accelerator for sparse Polynomial multiplication (LEAP) of HQC, compatible with different parameters, on the field-programmable gate array (FPGA) platform. First, we give a mathematical derivation process for the sparse polynomial multiplication deployed in HQC. Then, we explain the proposed hardware structure in detail. Finally, we present the FPGA implementation results to confirm the efficiency of the proposed LEAP, for example, the proposed design for hqc-192 has at least 31.03% less area-delay product (ADP) than the existing design. LEAP can be extended further to construct efficient HQC cryptoprocessors.