Aptos Adds Optional Encrypted Mempool to Block Front-Running

Aptos has introduced an optional encrypted mempool, a feature that hides transaction details while they are waiting to be ordered. The aim is to stop bots from using visible pending trades to jump ahead of users or sandwich their transactions.

A mempool is the pool of transactions awaiting processing. By concealing trade details until ordering is finalized, Aptos seeks to reduce the opportunity for automated traders to exploit what they can see before a transaction executes.

How does Aptos’ encrypted mempool protect trades?

In a typical public mempool, bots may inspect pending transactions and react before those transactions are confirmed. A sandwich attack is one such tactic: a bot places trades around a user’s pending trade to try to profit from the price movement it causes.

Aptos’ feature changes when transaction details become visible: they are hidden until the transaction’s order is finalized. That can remove the advance warning bots rely on, but the rollout is described as optional—not a blanket change to every Aptos transaction.

What should Aptos users know?

The immediate practical point is that protection depends on whether the encrypted option is enabled and supported by the way a user submits a transaction. The announcement does not establish that every app or trade on Aptos will use it automatically, nor does it claim to eliminate every kind of trading loss or manipulation.

This is a narrower intervention than changing how a blockchain processes every transaction: Aptos is offering a way to shield pending trades rather than making all transaction data private. For users, the useful next step is to check whether their wallet or trading app supports the option before assuming a swap is protected. The feature’s real-world value will depend on that support and adoption.