Aptos Makes Encrypted Mempool Optional on Mainnet

Aptos crypto has activated its optional Encrypted Mempool on mainnet, letting compatible wallets and apps conceal pending transaction instructions, assets and amounts until validators finalize transaction ordering. The feature targets maximal extractable value (MEV), including frontrunning and sandwich attacks, but it is not free: encrypted transactions have a minimum gas price twice the network’s base minimum, while sender addresses and gas-fee information remain visible.

When you send a transaction on any major chain today, anyone watching the network can see the details before it executes, the function you’re calling, the assets and amounts involved, and the contracts you’re interacting with.

The network announced the mainnet feature on Monday, October 12, describing it as an option for institutions submitting large transactions, traders seeking to limit MEV exposure, AI agents and builders.

I think we underestimate how much traders lose because transactions are visible before execution.@Aptos finally launched an optional Encrypted Mempool on mainnet.

The idea is simple: transactions stay encrypted until validators finalize their order, making it much harder for… pic.twitter.com/8Mit9Cv8Vo

A compatible wallet or app encrypts the transaction contents on the user’s device before submitting it to Aptos. The transaction then waits in the mempool-the queue for transactions awaiting inclusion in a block-while validators agree on its order without seeing its contents.

Once ordering is finalized, validators collectively decrypt the transaction, which is then executed and recorded onchain. No individual validator can decrypt a pending transaction alone. Aptos said the feature is designed to prevent bots from reading pending orders and inserting trades ahead of or around them; in its words, “Bots use that visibility to trade against you or copy your strategy.”

In tests involving 50 nodes, Aptos reported that the process added about 20 milliseconds per block compared with its existing consensus implementation. That is a modest reported delay, but the higher minimum gas price means traders must weigh the added protection against the extra transaction cost.

The encrypted payload hides the instructions, assets, amounts and contract interactions while a transaction is pending. It does not hide the sender’s address or gas-fee information, so the feature protects transaction contents rather than making users anonymous.

That distinction matters for anyone assessing what the feature can-and cannot-shield. The design aims to prevent bots from exploiting visible orders through frontrunning or sandwich attacks that profit from price movements around user transactions. Aptos’s reported two-times-base-minimum gas price and roughly 20-millisecond per-block test impact are the concrete costs attached to that protection.

The change is a protocol infrastructure update, in the same broad category as work on validator performance and network design, such as Ethereum’s Glamsterdam test on Sepolia. On Aptos, however, use remains optional and requires a compatible wallet or application.

mev bots are getting blinded. @Aptos just flipped the script on sandwich attacks with its encrypted mempool.

how it works: your transaction details (assets, amounts) are encrypted on your device. validators order the block *blindly*, then jointly decrypt it only after the… https://t.co/tgd2YXWxEW

The launch responds to a recorded trading risk across networks. Ethereum traders experienced sandwich-attack losses of roughly $60 million during the 12 months ending October 2025. Bitquery noted nearly 6.9 million sandwich attacks on Solana over 11 months, affecting about 2.2 million wallets and producing $29.7 million for bots.

Gnosis Chain introduced an encrypted mempool with Shutter in July 2024, whereas Ethereum’s Flashbots Protect directs transactions privately to block builders. Aptos crypto claims its method differs because current validators manage both ordering and decryption, avoiding a separate committee or trusted builders. Users can access this protection by opting in via a compatible wallet or app, and a gas-price floor applies to encrypted submissions.

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Alex is a seasoned cryptocurrency trader and market analyst with over seven years of active experience in the digital asset space. Since entering the markets in 2017, Alex has specialized in identifying emerging "meta" trends and high-volatility narratives. Notably, Alex... Read More