Aptos Launches Optional Encrypted Transactions to Hide Traders From MEV Bots
Encrypted mempool goes live on Aptos mainnet
Layer-1 blockchain Aptos has launched an optional feature called the Encrypted Mempool on its mainnet. When a user opts in, their pending transactions are encrypted before they are sent to the network, hiding key details from anyone watching the chain.
The mempool is the public waiting area where transactions sit before being added to a block. Normally, bots can see what transactions are waiting and try to profit by placing trades ahead of or around them. Aptos' feature aims to stop that by keeping transaction contents hidden until the block ordering is finalized.
The feature was announced on Monday, October 13, 2026. Aptos says it was built with institutions submitting large transactions, traders who want to avoid MEV risk, AI agents, and builders in mind.
What Aptos confirmed
- The Encrypted Mempool is optional. Users can choose whether to use it.
- Compatible wallets or apps encrypt transactions on the user's device before sending.
- Asset types and amounts stay hidden. The sender's address and gas fee remain visible.
- Validators agree on transaction order while unable to see transaction contents.
- After ordering is finalized, validators collectively decrypt the transactions for execution on chain.
- No single validator can decrypt a pending transaction on its own.
- Encrypted transactions have a minimum gas price at twice the network's base minimum.
- In tests with 50 nodes, the system added around 20 milliseconds per block.
Why bots target pending trades
Maximal extractable value (MEV) is a term for profits that validators or bots extract by reordering, including, or excluding pending transactions. Sandwich attacks are one common form: a bot places a trade right before and right after a victim's trade to profit from the price movement they cause.
According to Cointelegraph's analysis of EigenPhi data, sandwich attacks cost Ethereum traders about $60 million over the 12 months ending October 2025. On Solana, Bitquery identified nearly 6.9 million sandwich attacks over an 11-month period that generated about $29.7 million for bots and affected roughly 2.2 million wallets.
How Aptos compares to other MEV protections
Other blockchains have also addressed MEV attacks. Gnosis Chain launched an encrypted mempool using Shutter, a threshold encryption protocol, in July 2024. On Ethereum, Flashbots Protect routes transactions privately to block builders.
Aptos says its distinction is that its existing validators handle both the transaction ordering and the decryption. The network does not rely on a separate decryption committee or a group of trusted builders.
Costs and trade-offs
The protection comes with two trade-offs. Encrypted transactions require a minimum gas price at double the network's standard base minimum. The system also adds a small delay of about 20 milliseconds per block in the 50-node test described in Aptos' developer documentation.
What this means in practice
By keeping transaction details hidden until block order is set, the Encrypted Mempool prevents bots from reading pending orders and front-running or sandwiching users. Users who need privacy for large or sensitive transactions can opt in without changing their wallet, provided the wallet supports the feature.
The feature is optional, so users who do not want the higher gas cost or added latency can continue using the standard mempool.
Sources
Newisty Editorial Team covers technology, cryptocurrency, digital products, online platforms, developer tools and the wider digital economy. Our content is researched from official sources, company announcements, public documentation, market data and other primary or reputable sources. Articles are reviewed and edited before publication for clarity, accuracy and useful context.