Encrypted mempool vs private RPC for MEV protection

There are three ways to stop a pending trade from being front-run: hand it to someone you trust to keep quiet, let one sequencer see everything and promise to behave, or encrypt it so that nobody can read it until its place is fixed. They protect you in very different ways.

protocol reference

Three ways to hide a pending trade

	private RPC	private sequencer	encrypted mempool
examples	Flashbots Protect, MEV Blocker	a rollup whose single sequencer keeps pending transactions to itself	Shutter on Gnosis Chain; Peal's encrypted lane
who can read your trade before it lands	the RPC operator and the builders it forwards to	the sequencer operator	nobody, until a threshold of the committee opens it
what stops front-running	rules and reputation: builders and searchers agree not to	the operator's policy	cryptography: there is nothing readable to front-run
if the trusted party misbehaves	it can front-run or leak, and you may never know	it can reorder or leak	a threshold of committee members must collude to read early
what it needs from the chain	nothing; you change your RPC URL	it is the chain's own design	an integration: validators that include encrypted transactions, or a contract that settles a revealed batch
cost to you	usually nothing; often a rebate	nothing extra	latency until the batch or slot opens

Private RPCs: privacy by agreement

Flashbots Protect sends your transaction to a private mempool instead of the public one, so sandwich bots never see it, and it adds refunds and reverts protection. Its own documentation is clear about the trust: when you send a transaction to a builder, "you trust them not to frontrun your transaction or disclose it to third-party MEV searchers." Fast mode shares it with every registered builder. MEV Blocker works on the same principle with different economics: searchers may backrun you and return 90% of the profit, but are not allowed to front-run or sandwich, and its data becomes public after a 30-second delay.

These services protect a great deal of volume, and they are easy to adopt. But the protection is an agreement, not encryption: your transaction is readable by every party you send it to, and if one of them breaks the agreement you may never find out.

Private sequencers: privacy by position

On a rollup with one sequencer, there is no public mempool to watch, so outsiders cannot front-run you. The sequencer itself sees every transaction in the clear and decides the order. You are trusting one operator, and the privacy stops at that chain's edge.

Encrypted mempools: privacy by encryption

An encrypted mempool has users encrypt a transaction to a committee, the order is fixed while it is still unreadable, and only then is it decrypted and executed. Front-running stops working because there is nothing to read in time.

Shutter on Gnosis Chain is the live example. It has been running since July 2024 as an alternative RPC endpoint, with keypers holding shares from a distributed key generation. It depends on validators opting in: around 4% of Gnosis validators at launch, and in October 2025 Shutter reported an average of about three minutes to inclusion because of the limited number of Shutterized validators and keypers. Each chain needs its own integration; Shutter runs an OP Stack testnet and has proposed EIP-8105, an encrypted mempool enshrined in Ethereum itself.
Peal's encrypted lane is a testnet demonstration. An order enters PealMempool as a commitment to a ciphertext hash, which is all a searcher watching the chain can see. At the cue, the committee opens the whole batch at once, and executeBatch settles the orders in their committed order after re-deriving the batch's merkle root, so it cannot execute anything but the revealed batch. Validators change nothing: a chain needs only that contract. In v0 the coordinator is the address that settles, and the committee's key shares are distributed among five operators run by Peal during testnet; v1 adds distributed key generation.

You can watch both lanes side by side, with a real searcher bot, on the encrypted mempool page.

Why Peal's approach

Nothing to front-run. An order is unreadable to everyone, the coordinator and the operators included, until a threshold of the committee opens its batch.
Every order opens together. One set of operator shares opens a batch of 64, in an order derived from the ciphertext hashes, so nobody sees another order first and nobody chooses their position.
No validators to recruit. A chain needs one contract that accepts ciphertext commitments and settles a revealed batch. Nothing changes in its clients or its consensus.
Settlement you can check. executeBatch re-derives the batch's merkle root before it settles, so it can only execute the batch that was revealed.

Which one to use

A venue, an auction or an intent system you control: an encrypted batch, which is what Peal provides, with protection that comes from cryptography rather than promises.
Transactions on Gnosis Chain specifically: Shutter, which is integrated with Gnosis validators.
A wallet that needs something on Ethereum mainnet this week: a private RPC, accepting that the builders it forwards to can read every transaction.

Questions

What is the difference between an encrypted mempool and a private RPC like Flashbots Protect?

A private RPC hides your transaction from the public mempool but sends it in the clear to builders you must trust not to front-run. An encrypted mempool encrypts the transaction so that nobody can read it until its position is fixed, which replaces that trust with a threshold committee.

Do encrypted mempools need changes to the chain?

Some form of integration, yes. Shutter on Gnosis needs validators running Shutterized clients. Peal's approach needs a contract that accepts ciphertext commitments and settles a revealed batch, and no changes to validators.

Is Peal's encrypted mempool live on mainnet?

Not yet. It runs on testnet, with key shares distributed among five operators; v1 adds distributed key generation.

Sources: Flashbots Protect, overview · Flashbots Protect, quick start · MEV Blocker · Shutterized Gnosis Chain (Jul 2024) · Shutter, Applied MEV protection (Oct 2025) · EIP-8105 proposal.