Paper 2025/2032 Original: eprint.iacr.org/2025/2032 ↗

TrX: Encrypted Mempools in High Performance BFT Protocols

Abstract

MEV (Maximal Extractable Value) remains one of the most corrosive forces in blockchain systems, enabling frontrunning, sandwiching, and other manipulations that directly exploit users. The core culprit is the transparent mempool: validators see transactions before they are ordered. Encrypted mempools are a promising solution by hiding transaction contents until after ordering. We present the first integration of encrypted mempools with a high-performance BFT protocol. Our system uses a cryptographic scheme based on recent work on batched threshold encryption, and improves on the cryptographic state of the art in this line of work. The system ensures confidentiality of transactions during ordering while sustaining performance on par with leading BFT designs. Specifically, the proposal-to-execution latency of our system yields only a 27 ms overhead (14%) compared to the baseline. The result is a practical consensus layer that simultaneously defends against MEV and delivers the throughput and latency needed for real deployments. This work closes the gap between cryptographic defenses and production-ready consensus, showing that robust MEV protection and high performance can, in fact, coexist.