TFHE-SBC: Software Designs for Fully Homomorphic Encryption over the Torus on Single Board Computers

2025-03-04

AI Summary

This work addresses critical bottlenecks—low computational efficiency, high energy consumption, and excessive communication overhead—of Torus Fully Homomorphic Encryption (TFHE) on resource-constrained single-board computers (SBCs). To this end, we propose the first lightweight TFHE software architecture specifically optimized for SBCs. Our approach introduces: (i) a novel TLWE-based single-bit encryption acceleration scheme; (ii) SBC-customized memory layout and instruction-level optimizations; (iii) bit-level parallel scheduling; and (iv) a low-overhead ciphertext compression and transmission protocol—all implemented without hardware acceleration. Experimental results demonstrate substantial improvements: encryption throughput increases by up to 2486×, ciphertext communication volume reduces to 1/512 of the baseline, and energy efficiency improves by 12–2004×. This is the first work to enable high-energy-efficiency, low-bandwidth FHE client deployment on SBCs, thereby supporting secure cloud-based statistical analysis and machine learning over embedded sensitive data.

Technology Category

• Machine Learning: Hardware-aware ML
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Search and Optimization: Distributed Search

Application Category

• Security and Privacy: Applications of cryptography
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments

Abstract

Fully homomorphic encryption (FHE) is a technique that enables statistical processing and machine learning while protecting data including sensitive information collected by such single board computers (SBCs) on a cloud server. Among FHE schemes, the TFHE scheme is capable of homomorphic NAND operation, and unlike other FHE schemes, it can perform any operation, such as minimum, maximum, and comparison operations. However, TFHE requires Torus Learning With Error (TLWE) encryption, which encrypts one bit at a time, resulting in less efficient encryption and larger ciphertext size than the other schemes. In addition, SBCs have a limited number of hardware accelerators compared to servers, making it difficult to perform the same optimization as servers. In this study, we propose a novel SBC-specific design TFHE-SBC to accelerate the client-side TFHE operations and achieve communication and energy efficiency. Experimental results show that the TFHE-SBC encryption is up to 2486 times faster, communication efficiency improves 512 times higher, and 12 to 2004 times more energy efficiency than the state-of-the-art.

Problem

• Enhance TFHE encryption efficiency on single board computers.
• Reduce communication overhead in homomorphic encryption processes.
• Improve energy efficiency for client-side TFHE operations.

Innovation

• Accelerates client-side TFHE operations on SBCs
• Enhances communication efficiency by 512 times
• Improves energy efficiency up to 2004 times