Aptos Turns On Encrypted Mempool on Mainnet

Aptos switched on an encrypted mempool on its mainnet on October 12, the network announced. Users can now submit a transaction in encrypted form: validators place it in a block without seeing what it contains and decrypt it only after the order of transactions in the block is final. The goal is to protect trades from MEV attacks, where bots watch the transaction queue and jump ahead of someone else's trade.

The details

The design is laid out in AIP-144, which has "Accepted" status. The transaction payload is encrypted client-side before submission. The block leader orders these transactions blind, and decryption happens after consensus, just before execution. Validators reconstruct the decryption key through a stake-weighted threshold — the same threshold used for block production — so, according to the authors, the system adds no new trust assumptions. The encryption key rotates every epoch.

Encryption is opt-in, per transaction. The function being called and its arguments are hidden, while the sender address and gas fee stay public: hiding the sender and other metadata is out of scope for the first version. According to TokenPost, a 50-node benchmark showed about 20 milliseconds of added latency per block, and the system passed a security review by ZKSecurity. The Petra wallet already supports the feature, and Decibel, a perpetuals exchange on Aptos, plans to use it to keep orders private. AIP-144 targets more than 1,000 transactions per second for the encrypted mempool at launch.

Aptos says the feature is aimed at institutions, traders and AI agents, so that large orders do not reveal intent before they execute.

What it means for the market

MEV is one of the main hidden costs of on-chain trading: "sandwich" bots buy just ahead of a large trade and sell right after it, skimming part of the price from the trader. On Ethereum, users protect themselves with private transaction relays such as Flashbots, which means trusting an intermediary. Aptos builds the protection into the protocol itself. The limits are clear too: only transactions a user chooses to encrypt are covered, and the scheme assumes most validators by stake behave honestly.

The launch has not lifted the token so far: as of 1:40 PM ET, APT traded near $0.82, down 10.8% over 24 hours, per CoinGecko. For the Bitcoin and market brief, see the home page.