Boost+: Equitable, Incentive-Compatible Block Building

TL;DR

Boost+ proposes a novel block-building framework that decouples transaction collection from ordering and uses a VCG based mechanism to allocate value truthfully among searchers, builders, and proposers. It introduces a default algorithm and a trusted execution environment to run algorithmic blocks securely, ensuring DSIC for builders and, when the default dominates, DSIC for searchers, while rewarding builders when their algorithms win. The mechanism handles conflict free bundles to resist integration and demonstrates practical performance with empirical evaluation showing the default algorithm yields the optimal block in about $53.2\%$ of cases and reveals actionable insights for future improvement. Overall, Boost+ offers a principled approach to reducing MEV related centralization and improving block space efficiency while fostering algorithmic innovation and maintaining incentive compatibility.

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.

Figures (7)

• Figure 1: High-level comparison between Boost+ and MEV-Boost.
• Figure 2: Illustration of block building and MEV-Boost.
• Figure 3: Our mechanism $\mathcal{M}_{\textsf{Boost+}\xspace}$
• Figure 4: Searcher's two-step decision: first, choose whether to integrate or participate; conditional on participation, choose between truthful bidding or misreporting. Each path leads to a terminal outcome.
• Figure 5: Frequency of large CGs where $|CG| \geq 8$.

Theorems & Definitions (26)

• Example 1: State-dependent proportional bid
• Definition 1
• Remark 1: Integration under Boost+
• Definition 2: Searcher Utility Function
• Definition 3: Builder Utility Function
• Remark 2: Integration-resistance vs. Searcher-DSIC
• Example 2
• Theorem 1: vickrey1961counterspeculationclarke1971multipartgroves1973incentives
• Theorem 2
• proof