RACE: RISC-V SoC for En/decryption Acceleration on the Edge for Homomorphic Computation

As more and more edge devices connect to the cloud to use its storage and compute capabilities, they bring in security and data privacy concerns. Homomorphic Encryption (HE) is a promising solution to maintain data privacy by enabling computations on the encrypted user data in the cloud. While there has been a lot of work on accelerating HE computation in the cloud, little attention has been paid to optimize the en/decryption on the edge. Therefore, in this paper, we present RACE, a custom-designed area- and energy-efficient SoC for en/decryption of data for HE. Owing to similar operations in en/decryption, RACE unifies the en/decryption datapath to save area. RACE efficiently exploits techniques like memory reuse and data reordering to utilize minimal amount of on-chip memory. We evaluate RACE using a complete RTL design containing a RISC-V processor and our unified accelerator. Our analysis shows that, for the end-to-end en/decryption, using RACE leads to, on average, 48x to 39729x (for a wide range of security parameters) more energy-efficient solution than purely using a processor.