High-Throughput Key Switching Accelerator for Homomorphic Encryption
Zeyu Wang, Makoto Ikeda · 2023
We propose an ASIC architecture for key switching in RNS-CKKS Homomorphic Encryption scheme. With the pipeline design, the frequent RAM access is avoided and high throughput is achieved. This key switching design is a general architecture for several operations in RNS-CKKS, such as reliearization, rotation and conjugation. Furthermore, we show the flexibility of the design in changing the degree of parallelism. Increasing parallelism leads to an almost quadratic growth in throughput, which further accelerates the calculation. Compared to previous design, the throughput is increased to 1.7 times for key switching operation.