Paper 2026/1314 Original: eprint.iacr.org/2026/1314 ↗

HHE Kombat: Benchmarking Hybrid Homomorphic Encryption Schemes

Abstract

Hybrid Homomorphic Encryption (HHE) is emerging as a practical alternative to fully homomorphic encryption by offloading computational overhead to the cloud. Despite the growing number of HHE schemes and implementations, no unified evaluation methodology currently exists. In this work, we present a comprehensive and reproducible benchmarking framework covering both standard and HE-friendly HHE schemes. We analyze and evaluate 19 open-source HHE frameworks, comprising 218 distinct ciphers' benchmarks, across diverse HE libraries and programming languages. To ensure fair comparison, we interpret the main results under an HHE-128 security target, separating standardized or author-claimed 128-bit settings from below-target measurements. Our contributions include a unified repository, a language-agnostic benchmarking tool, and detailed metrics on runtime and memory usage. The results offer actionable insights into the security-aware performance trade-offs of each design and lay the groundwork for standardizing future HHE evaluations.