(2026-06) RondoMPC; Asynchronous MPC with G.O.D. made More Practical
2026-06-15
Asynchronous multi-party computation (AMPC) en- ables a set of mutually distrustful parties to securely compute any joint function on their private inputs under arbitrary network delays. The guaranteed output delivery (i.e., G.O.D.) property is essential for availability, but can be very challenging to achieve in practice. HoneyBadgerMPC (CCS 2019), the first practical AMPC protocol, follows Beaver’s paradigm that generates Beaver triples offline to simplify online computation. One of the underlying building blocks, the random double sharing protocol that generates random double shares, how- ever, implicitly assumes a synchronous network. DumboMPC (Usenix Sec 2025) overcomes the issue by adopting a two-phase workflow where the underlying consensus protocol has to be executed twice, and thus incurs high latency. Velox (CCS 2025) achieves lower latency and weaker cryptographic assumptions at the cost of sacrificing G.O.D. It remains an open question whether there exists a more practical AMPC protocol with the G.O.D. property. In this paper, we present RondoMPC, a practical AMPC protocol with G.O.D. with only one phase of consensus. To achieve this goal, we build a practical asynchronous and complete random double sharing (ACRDS) protocol. Our ACRDS protocol supports batching, so a batch of random double shares can be generated simultaneously. Furthermore, ACRDS supports efficient verification of aggregated secret shares, allowing the random double shares to be used for Beaver triple generation using only one phase of consensus. Our experimentation results show that RondoMPC is highly practical, achieving both higher throughput and lower latency for Beaver triple generation compared to existing protocols.