High-Throughput Secure Multiparty Computation with an Honest Majority in Various Network Settings
Christopher Harth-Kitzerow, Ajith Suresh, Yongqin Wang, Hossein Yalame, Georg Carle, Murali Annavaram
TL;DR
This paper tackles the challenge of achieving high-throughput honest-majority MPC over rings in practical, heterogeneous networks. It introduces two protocols, Trio (3PC) and Quad (4PC), that maintain low per-multiplication communication (3 and 5 ring elements, respectively) while tolerating weak links and leveraging preprocessing to shift computation away from latency-sensitive online phases. The authors implement a comprehensive open-source C++ framework and demonstrate unprecedented throughput, sustaining billions of gates per second on realistic hardware and network configurations, including heterogeneous WAN settings. The results underscore the critical role of balancing computation, preprocessing, and network utilization, and they provide concrete tools and methodologies to scale MPC to large, real-world workloads, including privacy-preserving machine learning. The work also maps network settings to protocol choices via a nuanced Category I–III link taxonomy and confirms substantial gains through hardware-friendly optimizations like bitslicing and load balancing. The open-source framework and extensive benchmarking position this work as a practical milestone for deploying MPC at scale in real-world distributed systems.
Abstract
In this work, we present novel protocols over rings for semi-honest secure three-party computation (3PC) and malicious four-party computation (4PC) with one corruption. While most existing works focus on improving total communication complexity, challenges such as network heterogeneity and computational complexity, which impact MPC performance in practice, remain underexplored. Our protocols address these issues by tolerating multiple arbitrarily weak network links between parties without any substantial decrease in performance. Additionally, they significantly reduce computational complexity by requiring up to half the number of basic instructions per gate compared to related work. These improvements lead to up to twice the throughput of state-of-the-art protocols in homogeneous network settings and up to eight times higher throughput in real-world heterogeneous settings. These advantages come at no additional cost: Our protocols maintain the best-known total communication complexity per multiplication, requiring 3 elements for 3PC and 5 elements for 4PC. We implemented our protocols alongside several state-of-the-art protocols (Replicated 3PC, ASTRA, Fantastic Four, Tetrad) in a novel open-source C++ framework optimized for high throughput. Five out of six implemented 3PC and 4PC protocols achieve more than one billion 32-bit multiplications or over 32 billion AND gates per second using our implementation in a 25 Gbit/s LAN environment. This represents the highest throughput achieved in 3PC and 4PC so far, outperforming existing frameworks like MP-SPDZ, ABY3, MPyC, and MOTION by two to three orders of magnitude.