Aptos Turns On Its Encrypted Mempool, Opt-In One Transaction at a Time

Aptos switched on an encrypted mempool on its mainnet on Monday, letting a sender hide what a transaction does until the block carrying it is final. The feature is opt-in and set per transaction, so nothing changes for anyone who ignores it. While a transaction waits, validators order it without being able to read it; once the ordering is settled they combine decryption shares and execute. Aptos says no single validator can open a pending transaction, and that no group below the chain's two-thirds honest-stake threshold can either. The design is specified in AIP-144 and was reviewed by the security firm zkSecurity before launch.

What stays visible

Encryption covers the payload and not the envelope. The sender's address and the fee stay in the clear. The function called, its arguments, the assets and the amounts are hidden until the block closes. A compatible wallet does the encrypting on the user's device, and the Aptos TypeScript SDK from version 7.0.0 fetches the epoch key. Existing Move contracts, the announcement says, "require no changes". Petra is the first wallet to put the option in the signing flow, and Decibel, a perpetual futures venue on the chain, plans to keep pending orders private with it.

The pitch is aimed at anyone whose intentions are worth copying.

"Bots use that visibility to trade against you or copy your strategy," the project said of ordinary public mempools.

The cost of a readable queue shows up elsewhere, as in the session where a trader took $1.28 million out of Papertrade by moving a reference price on Hyperliquid. Gnosis Chain has run an encrypted mempool built on Shutter since July 2024, and Ethereum users can route around the public queue through Flashbots Protect. Aptos' claim to something different is that its own validators handle both ordering and decryption, with no separate committee and no trusted builder.

Two latency numbers, measured differently

Aptos puts the cost at roughly 20 milliseconds of overhead per block in 50-node benchmarks, against blocks that normally finalize in under a second. Cointelegraph and crypto.news both carry that figure as the project gave it. A second number is in circulation. CoinoTag, reading the November 2025 TrX preprint by Rex Fernando, Guru-Vamsi Policharla, Andrei Tonkikh and Zhuolun Xiang, reported 27 milliseconds of added proposal-to-execution latency, a 14% increase over those authors' own baseline. One is per-block overhead in a benchmark, the other is end-to-end latency against an academic baseline. They do not reconcile, and the 27-millisecond reading rests on one outlet's account of a preprint.

What it costs to send one

An encrypted transaction carries a minimum gas price of 200 octas per gas unit, twice the network's base minimum, on crypto.news' reading of the developer docs; Cointelegraph gives the same multiple without the octa figure. crypto.news alone adds 375 gas units per transaction for the decryption work. Underneath is a batch threshold encryption scheme from the TrX paper, which zkSecurity's report describes as combining BLS threshold signatures with witness encryption. That report lists 30 findings across the three components it examined and does not break them out by severity. Threshold cryptography is being weighed on other chains too, where Ethereum researchers have debated an early move off ECDSA.

Nobody has measured sandwiching on Aptos

The numbers quoted around the launch come from other chains. Bitquery counted about 6.9 million sandwich attacks on Solana between 30 October 2025 and 7 October 2026, run by 2,545 bot wallets and extracting about $29.7 million before trading costs. The daily count climbed from about 3,400 in late 2025 to 51,900 in September 2026. Cointelegraph separately put Ethereum sandwich losses near $60 million over the 12 months to October 2025, citing its own analysis of EigenPhi data. None of that research measured Aptos, and crypto.news says so plainly.

So the launch leaves its own central question open. Encryption that doubles the base gas price is a trade every sender has to price, and the venues named so far are one wallet and one exchange. Aptos has published no adoption target, and no third party has benchmarked the feature on mainnet. The figure to watch is the share of blocks carrying encrypted transactions once Decibel switches it on.