Lightweight FPGA-Based Number-Theoretic Transform for ML-KEM in Post-Quantum Cryptography
Mohammed O. Alshomrany, Muhammad Al-Hashimi, Fawaz Alsolami, Mostafa Saleh, Osama Abulnaja, Turki F. Al-Somani, Abdullah Altuwaijri · IEEE Access · 2025
This paper introduces a lightweight, energy-efficient Number Theoretic Transform (NTT) implementation tailored for the ML-KEM scheme in post-quantum cryptography. Unlike prior efforts focusing mainly on multipliers and modular reduction, the proposed design emphasizes the address generator, a critical yet often overlooked component. A compact counter-based mechanism integrated with XOR logic and multiplexing eliminates large lookup tables, reduces redundant operations, and ensures efficient memory access for both NTT and INTT. The unified butterfly unit and a LUT-based modular reduction circuit enable multi-cycle modular operations without requiring digital signal processing (DSP) or block RAM (BRAM) resources. The complete architecture occupies only 147 slices and 557 LUTs, achieving very low power consumption. Implemented on a Virtex-7 platform, the design demonstrates up to 88.8% reduction in area, 22% decrease in dynamic power, and a 17.57× improvement in A²T efficiency compared with state-of-the-art implementations. These results highlight the significance of optimizing address generation to achieve compact, power-aware accelerators. The architecture’s elimination of memory-intensive components and reliance on LUT-based logic make it highly portable and suitable for resource-constrained devices.