An Efficient Unified Polynomial Arithmetic Unit for CRYSTALS-Dilithium

The CRYSTALS-Dilithium protocol is considered as one of the most promising digital signature schemes in NIST’s post-quantum cryptography standardization process. While separating arithmetic computation units can be advantageous in some cases, it can lead to increased hardware resource consumption and performance degradation. To overcome this issue, this paper proposes a novel architecture called the Unified Polynomial Arithmetic Unit (UniPAU), specifically designed for the Dilithium signature scheme. The proposed UniPAU offers a unique hardware module that can execute all the polynomial operations required for the Dilithium signature scheme. To demonstrate the effectiveness of our design, we implemented it on the Xilinx Zynq UltraScale+ ZCU102 (xczu9eg-ffvb1156-2-e) FPGA platform and evaluated its hardware efficiency and performance. Our implementation results indicate that the proposed UniPAU can achieve comparable throughput while consuming fewer hardware resources compared to state-of-the-art studies. These findings suggest that our UniPAU can provide an optimized and efficient hardware solution for polynomial arithmetic operations in the Dilithium signature scheme.