cronokirby

(2026-04) Faster Logical Operations from Discrete CKKS

2026-04-14

Abstract

We study efficient non-arithmetic operations in (G)BFV with arbitrary plaintext modulus. We design scheme conversions between (G)BFV and Discrete CKKS, allowing (G)BFV ciphertexts to use radix-based integer computation in the Discrete CKKS setting. This gives asymptotically faster logical operations: for plaintext modulus pp, homomorphic comparison runs in O(\logp\log\logp)O(\log p \log\log p) for BFV and O(\log\logp)O(\log\log p) for GBFV.