Vitalik Buterin presents strategy to reduce centralization among Ethereum block builders.

Another emphasis of his post is the concept of “toxic MEV,” where traders take advantage of insight into pending transactions to front-run or “sandwich” users’ trades.

What to know:

• Vitalik Buterin is focusing on who determines which transactions are included in a block.
• He has proposed several ideas designed to prevent the block building process, which involves assembling transactions before they are confirmed onchain, from becoming overly centralized.

Vitalik Buterin is concentrating on an aspect of Ethereum that most users overlook but has quietly emerged as a significant pressure point: who has the authority to decide which transactions are incorporated into a block.

In a recent blog entry on Monday, the Ethereum co-founder presents a collection of ideas aimed at ensuring that the block building process, which entails the assembly of transactions prior to their finalization onchain, does not become excessively centralized.

While Ethereum’s forthcoming “Glamsterdam” update will implement proposer-builder separation, enabling validators to delegate block construction to a competitive market, Buterin contends that merely establishing a builder marketplace does not address all issues. If a limited number of builders dominate, they may still have the capacity to censor transactions or derive excessive profits from users.

One suggestion, termed FOCIL, would serve as a sort of anti-censorship measure. According to this design, a small group of randomly chosen participants would each select transactions that must be included in the next block. Should those transactions be absent, the block would be rejected. The concept is that even if a single adversarial builder monopolized the market, they could not permanently exclude particular users.

Another area of focus in his post is the concept of “toxic MEV,” where traders leverage visibility into pending transactions to front-run or “sandwich” users’ trades. A potential solution is to encrypt transactions until they are confirmed, thereby preventing opportunistic actors from accessing them beforehand.

Buterin also highlights threats at the networking level, where transactions can be observed by intermediaries before they reach a block, suggesting that anonymized routing systems could serve as a vital line of defense.

In the long term, he outlines a vision for more distributed block building, where not every transaction necessitates full global coordination. He posits that much of Ethereum’s activity may not require processing in a single, tightly coordinated bundle, thus paving the way for designs that alleviate central chokepoints.

Overall, Buterin appears to emphasize that as Ethereum expands, the challenges of decentralization are shifting from validators to the infrastructure that determines which users’ transactions are actually executed onchain.

Read more: Vitalik Buterin reveals his bold new plan to fix Ethereum’s scaling problem