MEV bots have skimmed value from Ethereum trades for years, and one pattern explains why developers are finally moving to shut them down: sandwich attacks, where a bot spots your pending trade and jumps in front of it, have cost traders real money on every major decentralized exchange. Ethereum developers are now weighing a proposal that goes after the root cause instead of patching around it: an Ethereum encrypted mempool.
How an Ethereum Encrypted Mempool Would Work
Known as EIP-8184, or LUCID, the design keeps transaction contents hidden from block builders until after they have already committed to including them. Instead of submitting a transaction anyone can read, a sender would submit a sealed payload alongside a “ticket” proving it is valid and pays its fees. Builders would agree to slot the transaction into a block without ever seeing what is inside it. Only after that commitment locks in would the decryption key get released, revealing what the transaction actually does.
The elegance here is simple: a bot cannot sandwich a trade it cannot read. Ethereum developers are set to discuss the proposal on a developer call, and if it advances, it is expected to pair with FOCIL (EIP-7805), a related mechanism for guaranteeing transaction inclusion, as part of the network’s 2027 “Hegotá” upgrade. That follows the earlier Glamsterdam upgrade, which is already rewriting how Ethereum charges gas.
What This Means for Your Next Trade
Picture a rideshare driver in Phoenix who swaps a few hundred dollars of stablecoins into ETH every week to cover gas for a side project. On a bad day, a sandwich bot can quietly cost that kind of trader one to three percent of a swap’s value, money that just vanishes into the bot’s profit instead of staying in the driver’s wallet. Multiply that across thousands of small traders and the number gets large fast. A protocol-level fix that removes the information bots need would put those percentage points back where they belong.
The Hard Problems Still Unsolved
Getting there is not trivial. The team behind LUCID has flagged a genuinely hard cryptography problem: no existing scheme fully satisfies Ethereum’s requirements for small public keys, non-interactive decryption, no trusted setup, manageable ciphertext sizes, strong security guarantees, and resistance to future quantum computers, all at once, at Ethereum’s scale. There are open governance questions too, like how to tell a sender who maliciously withholds a decryption key apart from one who just suffers a technical failure.
MEV extraction has already declined from its earlier peaks as tooling and awareness have improved, but building an encrypted mempool into the protocol itself would be a structural fix rather than a stopgap. It is the difference between telling users to be careful in a bad neighborhood and redesigning the street so the neighborhood is not dangerous anymore. You can read more in CryptoSlate’s coverage of the proposal.