Aptos launches encrypted mempool on mainnet to limit MEV
Aptos made its optional encrypted transaction feature live on mainnet Oct. 12, hiding trade details until block ordering is final to limit frontrunning and sandwich attacks.
The Blocktape Editors 2 min read 00e225
Aptos launched its optional Encrypted Mempool on mainnet on Oct. 12, allowing users to hide transaction contents while validators set their order, a move aimed at reducing frontrunning and sandwich attacks. The Aptos announcement says the feature is opt-in for each transaction and built into the network’s consensus process.
Cointelegraph also reported the mainnet launch, describing the feature as protection against maximal extractable value, or MEV, attacks that exploit visible pending trades.
What does the encrypted mempool hide?
A user’s wallet encrypts a transaction’s contents on the device before submission, according to Aptos. The function being called and its arguments stay hidden, while the sender’s address and gas fee remain visible.
Validators order encrypted transactions before they can read their contents. After the block is finalized, validators collectively reconstruct the decryption key and the transactions execute, Aptos said. No single validator can decrypt a pending transaction on its own.
How much delay does encryption add?
Aptos said its batched threshold encryption scheme added about 20 milliseconds per block in benchmarks involving 50 nodes. The network said the scheme decrypts a full block with constant-size communication per validator, regardless of the batch size.
The feature uses the same validator set that orders transactions to hold the decryption shares. Aptos said decryption requires the same stake-weighted majority used to produce blocks, so the system does not introduce a separate committee.
How can users and apps access it?
Encryption is optional for each transaction. Aptos said Petra is the first wallet to offer the option in its signing flow, while the Aptos TypeScript SDK version 7.0.0 and later can fetch an epoch encryption key and encrypt payloads on the client.
Aptos said existing Move smart contracts do not need changes. The network said Decibel, a perpetual futures exchange built on Aptos, plans to use the feature to keep orders private until execution.
Source material
- Aptos announcement — aptosnetwork.com
- reported the mainnet launch — cointelegraph.com