Defeating front-runners with Submarine Sends
Duration: 00:06:09
Speaker: Lorenz Breidenbach, Tyler Kell
Type: Talk
Expertise: Intermediate
Event: Devcon
Date: Jun 2026
Front-running is a fundamental problem in blockchain-based markets in which miners reorder, censor, and/or insert their own (or the highest gas bidder's) transactions to directly profit from markets running on blockchain economic mechanisms. Submarine Sends (first introduced here: http://hackingdistributed.com/2017/08/28/submarine-sends/) are a powerful general-purpose mechanism to prevent front-running on Ethereum by hiding the very existence of a transaction until it is no longer front-runnable. Unfortunately, so far no practical (in terms of gas) Submarine Send constructions were known. In this talk, I will introduce: a freshly discovered, practical Submarine Send construction that works on the Ethereum mainnet today.LibSubmarine, an open source project implementing it.