Boost+: Equitable, Incentive-Compatible Block Building

2026-02-03

AI Summary

This work addresses the excessive centralization induced by Ethereum’s current MEV-Boost mechanism, which undermines fairness, efficiency, and transparency in block construction. To mitigate this, the authors propose M_Boost+, a novel mechanism that decouples block building into two distinct phases: transaction collection and transaction ordering. This design ensures all builders have equal access to transactions and introduces an incentive-compatible default ordering algorithm that encourages both searchers and builders to act honestly. Theoretical analysis demonstrates that, under scenarios with conflict-free transactions, truthful behavior constitutes a dominant equilibrium. Empirical backtesting using historical data further validates that M_Boost+ enhances both fairness and block space utilization, showing that even non-integrated participants are incentivized to participate honestly despite the presence of integration advantages.

Technology Category

• Multiagent Systems: Mechanism Design
• Game Theory and Economic Paradigms: Mechanism Design
• Machine Learning: Ethics, Bias, and Fairness

Application Category

• Economics, Online Markets and Human Computation: Fairness and ethical considerations in crowd work and in human-in-the-loop AI systems
• Security and Privacy: Blockchains and distributed ledgers
• User Modeling, Personalization and Recommendation: Accountability, Transparency, and Ethics for personalization

Abstract

Block space on the blockchain is scarce and must be allocated efficiently through block building. However, Ethereum's current block-building ecosystem, MEV-Boost, has become highly centralized due to integration, which distorts competition, reduces blockspace efficiency, and obscures MEV flow transparency. To guarantee equitability and economic efficiency in block building, we propose $\mathrm{Boost+}$, a system that decouples the process into collecting and ordering transactions, and ensures equal access to all collected transactions. The core of $\mathrm{Boost+}$ is the mechanism $\mathit{M}_{\mathrm{Boost+}}$, built around a default algorithm. $\mathit{M}_{\mathrm{Boost+}}$ aligns incentives for both searchers (intermediaries that generate or route transactions) and builders: Truthful bidding is a dominant strategy for all builders. For searchers, truthful reporting is dominant whenever the default algorithm dominates competing builders, and it remains dominant for all conflict-free transactions, even when builders may win. We further show that even if a searcher can technically integrate with a builder, non-integration combined with truthful bidding still dominates any deviation for conflict-free transactions. We also implement a concrete default algorithm informed by empirical analysis of real-world transactions and evaluate its efficacy using historical transaction data.

Problem

• blockchain
• MEV
• block building
• centralization
• equitability

Innovation

• Boost+
• MEV
• incentive compatibility
• block building
• transaction ordering