Aptos (@Aptos) has made its native Encrypted Mempool available on mainnet, and users can now access it through the Petra Wallet (@PetraWallet) browser extension. The opt-in feature lets users
Aptos (@Aptos) has made its native Encrypted Mempool available on mainnet, and users can now access it through the Petra Wallet (@PetraWallet) browser extension. The opt-in feature lets users encrypt transaction inputs, including amounts, before submission. Details stay hidden until the block is finalized, which is designed to reduce exposure to maximal extractable value (MEV) attacks on the $APT network.
A mempool is the waiting area for transactions before they are included in a block. When transaction details are readable at this stage, attackers can use that information to trade ahead of other users.In a sandwich attack, a bot buys ahead of a pending purchase and sells after it, leaving the user with a worse execution price.
Under the new system, a compatible wallet or app encrypts an opted-in transaction's contents on the user's device before sending it to Aptos.Validators agree on transaction ordering without seeing the contents, then collectively decrypt the transactions once ordering is finalized.A single validator, or a group representing less than two-thirds of the network's staked voting power, cannot decrypt pending transactions on its own.
The feature is opt-in and enabled per transaction.Petra's browser extension is the first wallet to support it at signing, according to Aptos Labs.Aptos-based perpetuals exchange Decibel plans to use the encrypted mempool to protect order privacy. The mechanism is defined in Aptos Improvement Proposal 144 (AIP-144). Developers can submit encrypted transactions through the Aptos TypeScript SDK version 7.0.0 and later without modifying existing Move contracts.
The protection covers transaction payloads, not the whole transaction. Clients may still see metadata such as the sender, gas parameters, expiration and signatures, and the AIP says hiding the sender and other metadata is out of scope for the first version.
Privacy also carries a fee. According to Aptos developer documentation, encrypted transactions must pay a minimum gas price of 200 octas per gas unit, twice the network's base minimum, plus an extra 375 gas units for decryption.Aptos says the upgrade adds roughly 20 milliseconds of latency per block in 50-node benchmarks.The system also passed a security review by ZKSecurity.
It is too early to measure the impact. Actual reductions in attacks have not yet been independently established. Aptos also offers Confidential APT, which encrypts balances and transfer amounts while leaving addresses visible.
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