On October 12, Aptos rolled out its Encrypted Mempool feature, bringing optional transaction privacy to the mainnet while its native APT token experienced an 11% drop over a 24-hour period. The upgrade hides pending transaction details until validators lock in their sequence, which helps curb frontrunning and sandwich attacks. The network designed this mechanism to safeguard individual users, institutional traders, automated trading agents, and decentralized applications.
By encrypting transaction instructions prior to their entry into the blockchain network, the system prevents validators from reading hidden trading data while they determine the processing order.
Network fees and wallet addresses stay visible, however. Once validators settle the ordering sequence, they collaboratively decrypt the instructions to carry out the transactions.
Aptos Introduces Encrypted Transactions to Prevent MEV Attacks
The Encrypted Mempool focuses on maximal extractable value (MEV), a practice where trading bots exploit pending user transactions for financial gain. These bots regularly scan public transaction queues to spot substantial trades, positioning their own orders ahead of users or sandwiching targets with preceding and succeeding transactions.
Aptos noted that this visibility allows bots to copy strategies or trade against users. The new framework seeks to mitigate those risks by keeping transaction instructions hidden prior to execution. Rather than depending on external security committees or private transaction builders, Aptos utilizes its current validator network to sort and decrypt transactions.
Additionally, the encryption model demands participation from a stake-weighted majority of validators, meaning no single validator can independently decrypt pending transaction data. This technology aligns with AIP-144, which details how the network processes encrypted transactions. Aptos initially shared its roadmap in May 2026 prior to deploying the technology to the mainnet in October.
Encrypted Mempool Adds Gas Costs but Maintains Fast Processing
Using encrypted transactions requires higher fees than standard network operations. According to Aptos developer guidelines, users must supply at least 200 octas per gas unit—double the network’s baseline minimum gas price. Every encrypted transaction also tacks on 375 extra gas units for decryption, separate from standard execution costs.
Even with these demands, network testing demonstrated minimal processing overhead. Aptos documented roughly 20 milliseconds of added latency per block during evaluations involving 50 nodes, running on its production AptosBFT consensus framework that typically finalizes blocks in under one second.
Prior to the rollout, cybersecurity organization ZKSecurity performed an independent review of the encryption system. For developers, Aptos added support for encrypted transactions in version 7.0.0 of its TypeScript software development kit.
Current Move smart contracts do not require any modifications to support the upgrade. Petra integrated encryption as the first wallet to back it during transaction signing, while the decentralized perpetual futures exchange Decibel intends to use the feature to shield pending trading orders.
Read More: 10 Leading Aptos Ecosystem Tokens Ranked by Market Cap (2026)
Aptos Targets Sandwich Attacks After Millions in Trading Losses
The deployment arrives on the heels of research highlighting widespread sandwich attacks across blockchain networks. Bitquery recorded approximately 6.9 million such attacks on Solana between October 30, 2025, and October 7, 2026.
The data connected 2,545 bot wallets to attacks involving roughly 2.2 million user wallets, pulling in $29.7 million prior to trading expenses. Roughly 96% of the tracked attacks involved memecoins tied to Pump.fun markets.
Daily attack volumes climbed from about 3,400 in late 2025 to 51,900 by September 2026. Although that study centered on Solana, it highlights the predatory behavior Aptos aims to block. Aptos preserves public auditability following execution while keeping pending instructions concealed.
The network also provides alternative privacy features like Confidential APT and Keyless Accounts. In May, the Aptos Foundation and Aptos Labs pledged over $50 million toward growing the ecosystem around AI agents, trading infrastructure, and blockchain research.
That effort included Shelby, which concentrates on data-heavy applications, and Decibel. Aptos also noted that Decibel crossed $1 billion in cumulative trading volume during its development phase.
Conclusion
Aptos has launched the Encrypted Mempool to safeguard pending transactions from sandwich attacks and frontrunning, while keeping transaction histories public after execution. Though the upgrade raises gas expenses, testing confirmed minimal latency impact. Petra already accommodates the capability, and Decibel prepares to implement encrypted orders as APT deals with selling momentum.
