Encrypted Mempools Cause Funding Rate Distortions in DeFi
New paper reveals how transaction privacy creates economic reaction gaps.
A new academic paper by Benjamin Marsh, posted on arXiv (ID: 2607.13832), explores a novel class of attack in blockchain systems using encrypted mempools. While encrypted mempools hide transaction contents until execution order is fixed to prevent maximal extractable value (MEV), Marsh identifies that this very privacy can create an 'economic reaction gap'. In perpetual futures funding, where the funding rate determines transfer between longs and shorts, the inability to insert corrective transactions after commit leads to distortions. The paper models correction as executable arbitrage, showing that the closed-stage correction rate is lower than the adaptive rate, with a response factor multiplying the distortion entering a funding window.
Marsh also identifies a second amplification channel: transaction privacy reduces the capitalization of predictable funding into entry prices. The paper derives a 'local security index' separating attacker blindness, correction shielding, and capitalization shielding. These findings have practical implications for DeFi protocols considering encrypted mempools (e.g., Flashbots, Ethereum PBS). While privacy protects against frontrunning, it may inadvertently enable self-authored manipulation of funding rates. Protocol designers must carefully balance MEV prevention with market efficiency.
- Encrypted mempools prevent adaptive corrective arbitrage after commit, creating a funding rate distortion.
- The distortion is multiplied by a response factor, with a second amplification through reduced capitalization of predictable funding.
- The paper introduces a local security index quantifying attacker blindness, correction shielding, and capitalization shielding.
Why It Matters
Privacy in DeFi may trade off against market efficiency, introducing new risks for perpetual futures protocols.