The HHE Land: Exploring the Landscape of Hybrid Homomorphic Encryption

Hybrid Homomorphic Encryption (HHE) addresses key challenges in Homomorphic Encryption (HE), such as communication, computation, and storage overheads, by combining symmetric cryptography with HE schemes. Despite progress, enhancing HHE’s usability, performance, and security remains critical. This work analyzes prominent HHE schemes, evaluating their performance in a client-server setting using Go. Our implementation is publicly available on GitHub. We categorize and study attacks on HHE schemes, revealing vulnerabilities to practical threats despite meeting theoretical security. This study highlights the need for standardized parameters and improved countermeasures, guiding the development of secure, efficient HHE systems for real-world applications.