Ethereum's Centralization Risk: Vitalik Buterin Proposes FOCIL Framework to Restore Network Independence

The Challenge of Block Builder Dominance

While Ethereum has built its reputation on censorship resistance, a growing structural weakness is emerging. The power concentrated in the hands of a small number of block builders—entities responsible for assembling transactions into blocks—poses a fundamental threat to the network’s core principle of neutrality. This concentration creates a chokepoint where a handful of players could, intentionally or through regulatory pressure, influence which transactions get included on-chain.

Why This Matters for Ethereum’s Future

The current architecture has inadvertently created dependencies that undermine decentralization. When block construction becomes centralized, the network loses its most critical feature: the guarantee that any valid transaction can be processed regardless of origin or content. Vitalik Buterin has been sounding the alarm about this architectural vulnerability, recognizing that true censorship resistance requires distributing power across the consensus layer.

FOCIL: A Transformative Solution

To address these concerns, Buterin has outlined multiple approaches, with FOCIL (Fair Ordering and Censorship-resistant Inclusion List) standing as the most comprehensive. This framework aims to fundamentally reshape how transactions are selected and ordered, moving the critical decision-making power away from centralized block builders toward the broader validator set.

FOCIL’s potential lies in its design: by establishing a transparent, decentralized mechanism for transaction inclusion, it could restore Ethereum’s original promise of neutrality while maintaining network efficiency. The proposal represents more than a technical adjustment—it signals Ethereum’s commitment to evolving its consensus model to prevent institutional chokepoints.

What’s Next

As the network matures, addressing builder concentration has become essential. Whether through FOCIL or complementary mechanisms, Ethereum’s community faces a critical decision about prioritizing long-term neutrality over short-term optimization.