Ph.D. Project: An Efficient NTT Accelerator Supporting Various Lengths for HHE

Hybrid Homomorphic Encryption (HHE) scheme integrates arithmetic FHE and logical FHE to enhance the performance and scalability of privacy-preserving computations. However, the performance of hybrid homomorphic encryption mainly depends on the efficiency of the Number Theoretic Transform (NTT). Consequently, this paper introduces an FPGA-based NTT accelerator for HHE. We have designed a cross-scheme-friendly NTT architecture that supports NTT of varying lengths through the reuse of NTT units. Experimental results demonstrate that proposed architecture achieves a 3.4 times increase in throughput compared to existing state-of-the-art approaches across a range of NTT lengths.