HLS design of a hardware accelerator for Homomorphic Encryption

Modular polynomial multiplication is the most computationally intensive operation in many homomorphic encryption schemes. In order to accelerate homomorphic computations, we propose a software/hardware (SW/HW) co-designed accelerator integrating fast software algorithms with a configurable hardware polynomial multiplier. The hardware accelerator is implemented through a High-Level Synthesis (HLS) flow. We show that our approach is highly flexible, since the same generic high-level description can be configured and re-used to generate a new design with different parameters and very large sizes in negligible time. We show that flexibility does not preclude efficiency: the proposed solution is competitive in comparison with hand-made designs and can provide good performance at low cost.