Vitalik Buterin focuses on "Big FOCIL" and cryptographic memory pools to prevent the centralization of the block building process.

Ethereum co-founder Vitalik Buterin recently published a series of lengthy technical articles discussing Ethereum's future roadmap. In his latest article, he focuses on analyzing the potential centralization risks in the block building pipeline process and proposes solutions such as expanding the FOCIL mechanism and introducing encrypted mempools to enhance the network's censorship resistance. According to the plan, Ethereum will launch the Glamsterdam upgrade in the first half of 2026, which will introduce the "enshrined Proposer-Builder Separation" (ePBS) mechanism. This mechanism allows block proposers to outsource block building to a permissionless open marketplace to reduce the risk of centralization at the staking level. However, Buterin points out that although ePBS can prevent the concentration of block building power in a few staking pools, block building itself may still concentrate in the hands of a few high-level participants due to specialization and maximizing ranking benefits (MEV), thus creating a new trend of centralization. To address this issue, Ethereum developers plan to introduce the FOCIL (Forward Obligatory Commitment to Inclusion Lists) mechanism concurrently with the Glamsterdam upgrade. The initial version will randomly select 16 witnesses who will enforce that specific transactions must be included in a block; otherwise, the block will be rejected. Buterin stated that even if block building is controlled by a single malicious entity, FOCIL can still ensure that transactions cannot be fully censored. Furthermore, Buterin also explored the possibility of expanding the size of FOCIL (“big FOCIL”) and introducing a cryptographic mempool to further mitigate information asymmetry and power concentration issues during block building. Recently, Buterin has spoken extensively on topics such as the quantum resistance roadmap, execution layer improvements, and block building mechanisms, indicating that the Ethereum core development team is conducting systematic design and risk assessment for the next phase of the protocol upgrade.