
Briefing
The core research problem addresses the hidden vulnerabilities in Transaction Fee Mechanism (TFM) designs like EIP-1559, which are theoretically sound on-chain but susceptible to off-chain manipulation. The foundational breakthrough is the introduction of Off-Chain Influence Proofness , a new desideratum ensuring a block producer cannot gain additional revenue by running a separate, coercive auction off-chain. This new theory’s single most important implication is a strong impossibility result, proving that no TFM can satisfy all previously established desirable properties ∞ such as incentive compatibility and simplicity ∞ alongside this new requirement for censorship resistance.

Context
Prior to this work, the academic focus in TFM design centered on achieving properties like incentive-compatibility for users and simplicity for block producers, with EIP-1559 often considered the gold standard based on these criteria. The prevailing theoretical limitation was an incomplete model that assumed the block producer’s revenue was derived solely from on-chain transactions, failing to account for the strategic threat of censorship used to solicit private, off-chain side payments or tips.

Analysis
The paper’s core mechanism is the rigorous formalization of Off-Chain Influence Proofness to model the threat of a Bayesian revenue-maximizing block producer. The mechanism fundamentally differs from previous approaches by explicitly integrating the block producer’s ability to persuasively threaten to censor transactions that do not transfer a tip directly off-chain. This analysis demonstrates that EIP-1559 fails this new property because the block producer can strictly increase profits by coercing off-chain payments. The research then reconsiders a Cryptographic Second Price Auction, showing that a modified version, where the block producer can set the reserve directly, can satisfy off-chain influence proofness and simplicity for both users and the block producer.

Parameters
- New Desideratum Introduced ∞ Off-Chain Influence Proofness (A TFM property where the miner cannot achieve additional revenue by running a separate auction off-chain.)
- Mechanism Shown to Fail ∞ EIP-1559 (The current gold-standard TFM that is vulnerable to a block producer’s coercive off-chain influence.)
- Impossibility Condition ∞ Unlimited Supply (A condition under which the paper proves no mechanism can satisfy all desirable properties, including off-chain influence proofness.)

Outlook
This research opens a new avenue for mechanism design, shifting the focus from purely on-chain incentive alignment to holistic, cross-layer security against coercive censorship. Future work must concentrate on designing TFMs that strategically trade off certain properties ∞ such as simplicity or maximum welfare ∞ to achieve the non-negotiable goal of off-chain influence proofness, leading to a new generation of more robust and censorship-resistant fee markets in the next 3-5 years.

Verdict
The introduction of off-chain influence proofness establishes a new, non-negotiable security primitive that fundamentally redefines the theoretical boundaries of decentralized transaction fee mechanism design.
