High-precision RNS-CKKS on fixed but smaller word-size architectures: theory and application

Abstract

A prevalent issue in the residue number system (RNS) variant of the Cheon-Kim-Kim-Song (CKKS) homomorphic encryption (HE) scheme is the challenge of efficiently achieving high precision on hardware architectures with a fixed, yet smaller, word-size of bit length W , especially when the scaling factor satisfies log Δ > W