Vitalik Buterin Focuses on "Big FOCIL" and Encrypted Mempools to Prevent Centralization in Block Building Pipeline

Odaily News Ethereum co-founder Vitalik Buterin recently published a series of in-depth technical articles discussing Ethereum's future roadmap. In his latest post, he focused on analyzing the potential centralization risks within the block building pipeline and proposed 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 market, aiming to reduce centralization risks at the staking level.

However, Buterin pointed out that while ePBS can prevent block building rights from concentrating among a few staking pools, block building itself could still become centralized among a small number of sophisticated participants due to specialization and the pursuit of maximal extractable value (MEV), potentially creating a new centralization trend.

To address this issue, Ethereum developers plan to simultaneously launch the FOCIL (Forward Obligatory Commitment to Inclusion Lists) mechanism with the Glamsterdam upgrade. The initial version will randomly select 16 witnesses to mandate 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 transactions cannot be fully censored.

Furthermore, Buterin explored the possibility of scaling up FOCIL ("big FOCIL") and introducing encrypted mempools to further mitigate information asymmetry and power concentration issues during the block building process.

Recently, Buterin has been actively commenting on topics including the quantum resistance roadmap, execution layer improvements, and block building mechanisms, indicating that Ethereum's core development team is conducting systematic design and risk assessments for the next phase of protocol upgrades.