Malicious MEV continues to undermine fair execution on Ethereum due to the public visibility of transactions before they are finalized, enabling bots and validators to front-run, reorder, and execute sandwich attacks that systematically extract value from users. Research estimates suggest nearly 2,000 sandwich attacks occur daily, draining more than $2 million each month from traders. While mempool encryption has emerged as a potential mitigation strategy, early batch- and epoch-based designs proved insufficient, as transaction data could still be exposed if inclusion was delayed. The Flash Freezing Flash Boys (F3B) proposal introduces a more robust approach through per-transaction encryption, ensuring transactions remain private until finality and eliminating pre-execution visibility. Although F3B has not yet been deployed due to execution-layer complexity, it establishes a clear benchmark for MEV-resistant transaction design, encrypted mempools, and future applications such as sealed-bid auctions.
