BoostCom：通过加速逐字比较实现高效通用全同态加密
BoostCom: Towards Efficient Universal Fully Homomorphic Encryption by Boosting the Word-wise Comparisons
AI总结：
针对通用算术全同态加密（uFHE）中非算术比较操作速度慢的问题，本文提出BoostCom方案，通过基础设施加速与算法感知优化，将端到端性能较现有最优CPU方案提升11.1倍。
AI中文摘要：
全同态加密（Fully Homomorphic Encryption, FHE）支持在不解密的前提下对加密数据执行计算，为隐私保护计算操作提供了巨大潜力。新兴的基于算术的FHE方案（ar-FHE）（如BGV）在逐字比较操作上的性能优于非算术FHE（na-FHE）方案（如TFHE），尤其是在数值比较、求最大值和最小值等基础任务中。这体现了ar-FHE的通用性——它无需在算术与非算术FHE之间进行高成本转换，即可有效处理算术和非算术两类操作。我们将这种通用算术全同态加密称为uFHE。uFHE中的算术操作与原始算术FHE保持一致，且已得到显著加速；但其非算术比较操作有所不同，运行速度较慢，尚未得到充分研究或加速。本文提出BoostCom方案，旨在加速逐字比较操作，提升uFHE系统的效率。BoostCom包含多维度优化：基础设施层面的加速（多级异构并行化及GPU相关改进），以及算法感知优化（槽位压缩、非阻塞比较语义）。在多种FHE参数和任务下，与当前最优的基于CPU的uFHE系统相比，BoostCom实现了超过一个数量级的端到端性能提升（速度提升11.1倍）。
英文摘要：
Fully Homomorphic Encryption (FHE) allows for the execution of computations on encrypted data without the need to decrypt it first, offering significant potential for privacy-preserving computational operations. Emerging arithmetic-based FHE schemes (ar-FHE), like BGV, demonstrate even better performance in word-wise comparison operations over non-arithmetic FHE (na-FHE) schemes, such as TFHE, especially for basic tasks like comparing values, finding maximums, and minimums. This shows the universality of ar-FHE in effectively handling both arithmetic and non-arithmetic operations without the expensive conversion between arithmetic and non-arithmetic FHEs. We refer to universal arithmetic Fully Homomorphic Encryption as uFHE. The arithmetic operations in uFHE remain consistent with those in the original arithmetic FHE, which have seen significant acceleration. However, its non-arithmetic comparison operations differ, are slow, and have not been as thoroughly studied or accelerated. In this paper, we introduce BoostCom, a scheme designed to speed up word-wise comparison operations, enhancing the efficiency of uFHE systems. BoostCom involves a multi-prong optimizations including infrastructure acceleration (Multi-level heterogeneous parallelization and GPU-related improvements), and algorithm-aware optimizations (slot compaction, non-blocking comparison semantic). Together, BoostCom achieves an end-to-end performance improvement of more than an order of magnitude (11.1x faster) compared to the state-of-the-art CPU-based uFHE systems, across various FHE parameters and tasks.
