Aptos Launches Opt‑In Encrypted Mempool on Mainnet

Overview

• Aptos launched the opt-in Encrypted Mempool on October 12, 2026, letting users encrypt transaction payloads so validators agree on order without seeing the instructions.
• The system uses a stake-weighted threshold encryption where a validator majority must combine decryption shares to reveal batched transactions.
• A four-week zkSecurity audit in March 2026 flagged seven high-severity cryptographic issues that were mostly patched before launch, including problems with range proofs and key-generation transcripts.
• Encrypted transactions pay higher costs and add modest delay because they must meet a 200-octas-per-gas minimum, incur an extra 375 gas units for decryption, and showed about 20 milliseconds of added latency in 50-node tests.
• Early integrations from Petra wallet and Decibel exchange are live, but the feature’s real impact will depend on user opt-in rates, whether bots infer intent from visible sender or fee data, and wider wallet and exchange adoption; other chains use different trust models to fight MEV, and Bitquery found roughly 6.9 million sandwich attacks on Solana over the past year.