Aptos charges double the minimum gas price to hide a trade from sandwich bots
Aptos made its opt-in encrypted mempool live on mainnet at twice the base minimum gas price and about 20 ms of added latency per block. The premium falls on every encrypted transaction, so opting in turns on how likely a trader is to be sandwiched.
The Investor · Invest desk
Each encrypted transaction incurs an extra 375 gas units for decryption, a charge of 75,000 octas at the 200-octa floor price. Aptos said the system adds around 20 milliseconds per block in tests involving 50 nodes.
| Figure | Value | Note | Claim |
|---|---|---|---|
| Extra gas for decryption, each encrypted transaction | 375 gas units | 4 | |
| Charge at 200-octa floor | 75,000 octas | 17 | |
| Latency added per block | 20 ms, around | 5 |
What happened
- Assets and amounts stay hidden, but the sender's wallet address and the gas fee remain visible throughout.
- Once ordering is finalized, validators decrypt the transactions together, and no single validator can decrypt a pending one alone.
- Bitquery counted nearly 6.9 million sandwich attacks on about 2.2 million Solana wallets over 11 months, worth $29.7 million to the bots.
- Gnosis Chain launched an encrypted mempool using Shutter in July 2024, and Ethereum's Flashbots Protect routes transactions privately to block builders, Cointelegraph noted.
Why it matters
- What it costs cost An encrypted transaction pays at least twice the plain fee at floor prices, and the multiple rises as the transaction uses less gas, so the premium weighs most on small, cheap transfers.
- What it limits constraint The 20 ms is at least 2% of a block that finalizes in under one second, a cost for anyone competing on arrival order and a minor one for a trader placing a single swap.
- Who's exposed exposure Contents stay private only while a stake-weighted validator majority does not decrypt early, the same security assumption Aptos consensus already rests on.
Next story · Invest · yesterday
Bitquery counts $102 million drained from 324 Ledger-linked wallets across six chainsConfirmed6 publishers
Each encrypted transaction swaps a known premium for an uncertain payout. The payout is the chance of being sandwiched times what the sandwich would have taken. Aptos said: "Bots use that visibility to trade against you or copy your strategy." [14] The nearest benchmark is the Solana data, which works out to about $4.30 an attack [19] and about $13.50 a wallet [20] in bot revenue. Cointelegraph's Ethereum figure, about $60 million over the 12 months through October 2025 from its analysis of EigenPhi data, measures what traders lost, so the two are different quantities [10]. Neither report includes an Aptos sandwich-loss figure, and neither converts octas into dollars.
The premium has two parts. The gas price floor doubles from 100 octas per gas unit [16] to 200 [3], and each encrypted transaction also pays for 375 extra gas units of decryption [4], or 75,000 octas at the floor price [17]. Both are charged on gas. A sandwich loss grows with order size. In our view that puts the break-even with large orders, the institutions Aptos listed first among its intended users [15].
ZKSecurity reviewed the encryption before launch [12], and the 20 ms comes from tests involving 50 nodes [5]. Our view fails if Aptos sandwich losses prove small, because almost nobody should then opt in at any multiple. It fails differently if wallets encrypt by default: users then never run the comparison, and apps absorb the premium.
APT fell more than 11% over 24 hours, crypto.news reported [22]. The value of the feature shows up elsewhere, in opt-in share among large orders: if it is high, the break-even holds, and if it is low, large traders have run the numbers and passed.
What to watch
- Opt-in share among large Aptos orders once wallets support encryption. That share will show whether institutions are paying the doubled fee.
- Any measurement of sandwich losses on Aptos itself, since the only loss figures so far come from Solana and Ethereum.
- Whether the 20 ms latency holds at mainnet validator counts beyond the 50-node tests.
Information, not investment advice. This story is general information about companies and markets, drawn from cited reporting. It is not a recommendation to buy, sell or hold any security; check the cited sources before acting.
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- [1]
Aptos said its Encrypted Mempool is live on mainnet, and users opt in to keep pending transactions encrypted until their block ordering is finalized.
- [2]
Encrypted transactions carry a minimum gas price at twice the network's base minimum, according to Aptos' developer documentation.
- [3]
Encrypted transactions must pay a minimum gas price of 200 octas per gas unit.
- [4]
Each encrypted transaction incurs an extra 375 gas units for decryption, separate from the gas consumed by executing its instructions.
- [5]
Aptos said the system adds around 20 milliseconds per block in tests involving 50 nodes, compared with the existing consensus implementation.
- [6]
The production AptosBFT consensus implementation normally finalizes blocks in less than one second.
- [7]
Details such as the assets and amounts involved stay hidden, while the sender's address and gas fee remain visible.
- [8]
Once ordering is finalized, validators collectively decrypt the transactions, which are then executed and recorded onchain; no single validator can decrypt a pending transaction on its own.
- [9]
Bitquery identified nearly 6.9 million sandwich attacks affecting about 2.2 million wallets on Solana, generating $29.7 million for bots over an 11-month period.
- [10]
Sandwich attacks cost Ethereum traders about $60 million over the 12 months through October 2025, according to Cointelegraph's analysis of EigenPhi data.
- [11]
Decryption requires a stake-weighted validator majority, following the security assumptions used by the blockchain's existing consensus mechanism.
- [12]
The encryption system underwent an independent security review by ZKSecurity before launch.
- [13]
Gnosis Chain launched an encrypted mempool using Shutter in July 2024, while Ethereum's Flashbots Protect routes transactions privately to block builders.
- [14]
Aptos said: "Bots use that visibility to trade against you or copy your strategy."
- [15]
Aptos said the feature was built for institutions submitting large transactions, traders wanting to avoid MEV risk, AI agents and builders.
- [16]
The base minimum gas price implied by the doubling is 100 octas per gas unit.
- [17]
The decryption charge is 75,000 octas at the 200-octa floor price.
- [18]
Because 20 ms is added to blocks that finalize in under one second, the added latency is at least 2% of block time.
- [19]
Solana sandwich attacks generated about $4.30 in bot revenue per attack.
- [20]
Solana sandwich attacks generated about $13.50 in bot revenue per affected wallet.
- [21]
At floor prices an encrypted transaction using G gas units pays 2 x (G + 375) / G times the plain fee, which is always above 2 and larger the less gas the transaction uses.
- [22]
Aptos's native APT token fell more than 11% over 24 hours.
Sources
2 independent publishers whose own reporting we read for this story.
- cointelegraph.comAptos rolls out Encrypted Mempool to curb frontrunning, sandwich attacks
1 article · October 12, 2026
- crypto.newsAptos launches Encrypted Mempool: How does it work?
1 article · October 12, 2026
Topics and entities
Topics
- Encrypted mempool
- Layer-1 blockchains
- MEV