Researcher Advocates for Reintroduction of Public Mempool on Solana
Discussions about sandwich attacks on Solana, where advanced traders exploit less sophisticated users by front-running and back-running trades, have resurfaced. There is general agreement that sandwiching is detrimental, but solutions remain elusive.
This week, Solana researcher Ben Coverston reported that the leading sandwich bot, arsc, is generating millions daily through these attacks. He predicts arsc could become the largest staker on Solana within 1-2 years. One proposed solution involves reintroducing a public “mempool” for transactions, which was eliminated by Jito earlier this year to combat sandwiching.
Sandwich attackers leverage slippage — the difference between expected and executed trade prices. They first execute their trade to manipulate the price favorably, then follow up with another trade to secure profits from the altered price. Consequently, original traders often receive worse execution prices, effectively funding the attacker’s gains.
This practice represents maximal extractable value (MEV), allowing sandwichers to derive profits from Solana blocks at the expense of less knowledgeable users. Recent measures by Solana include Jito Labs discontinuing its public mempool in March to hinder MEV revenue generation for validators. However, sandwiching persisted as some validators created private mempools.
In response, the Solana Foundation ceased financial support for validators using private mempools and Jito blacklisted certain private validators from its stake pool. Critics argue that this approach is ineffective since blacklisted validators can establish new ones to continue sandwiching.
Coverston's proposal suggests reinstating a public mempool, which may increase sandwiching activity but could also enhance competition among validators, leading to a more equitable distribution of MEV profits. This would counteract the centralization of staked Solana among a few malicious validators.
Despite concerns, the long-term impact of sandwiching may be negligible. High-frequency trading strategies in traditional markets often employ similar tactics, yet equities trading volumes continue to reach record highs.