
Briefing
This paper addresses the critical challenge of designing effective transaction fee mechanisms for a new generation of leaderless blockchain protocols, such as those based on Directed Acyclic Graphs (DAGs), where multiple participants concurrently contribute to block production. It proposes a novel extensive-form game model to analyze these complex multi-proposer environments and introduces the “strongly Block Producer Incentive Compatible (BPIC)” property, ensuring that block producers are economically motivated to adhere to the protocol’s intended allocation rules. The foundational breakthrough is the First-Price Auction with Equal Sharing (FPA-EQ) mechanism, proven to be strongly BPIC and capable of achieving significant welfare guarantees, thereby laying the groundwork for more robust and economically secure decentralized systems.

Context
Prior to this research, the prevailing models for blockchain transaction fee mechanisms primarily focused on single-leader architectures, like those found in traditional Proof-of-Work or Proof-of-Stake systems where a single miner or validator proposes a block. This established theoretical framework proved inadequate for emerging leaderless blockchain designs, which allow multiple block producers to contribute simultaneously. The unsolved foundational problem was the absence of a robust mechanism design that could ensure incentive compatibility and optimize welfare in such multi-proposer settings, risking inefficient resource allocation and potential adversarial behavior among block producers.

Analysis
The paper’s core mechanism revolves around the “First-Price Auction with Equal Sharing (FPA-EQ)” for transaction fees within leaderless blockchain protocols. Conceptually, users submit bids for transaction inclusion, similar to a standard first-price auction. However, in a leaderless environment where multiple block producers might contribute to a single block, the FPA-EQ mechanism dictates that the winning bids (transaction fees) are collected and then equally shared among all block producers who contributed to that block. This design fundamentally differs from previous approaches by explicitly modeling and incentivizing cooperative behavior among multiple block producers through its “strongly BPIC” property, ensuring that following the intended allocation rule is a Nash equilibrium that dominates other potential strategies for block producers.

Parameters
- Core Concept ∞ Transaction Fee Mechanism Design
- New System/Protocol ∞ First-Price Auction with Equal Sharing (FPA-EQ)
- Key Property ∞ Strongly Block Producer Incentive Compatible (BPIC)
- Target Protocols ∞ Leaderless Blockchain Protocols (e.g. DAG-based consensus)
- Welfare Guarantee ∞ At least 63.2% of maximum-possible expected welfare
- Authors ∞ Not explicitly stated in snippets, but the paper is from arXiv:2505.17885

Outlook
This research opens significant avenues for advancing the economic security and efficiency of next-generation blockchain architectures, particularly those leveraging leaderless or DAG-based consensus. The FPA-EQ mechanism and the strongly BPIC property provide a foundational framework for designing incentive-compatible protocols, potentially unlocking real-world applications in 3-5 years that require high throughput and decentralized block production without compromising economic stability. Future research will likely focus on extending these mechanism design principles to incorporate dynamic network conditions, explore different sharing rules, and integrate with broader tokenomics models to further optimize for decentralization and resilience against various attack vectors.