Briefing
The core research problem in blockchain economics is the impossibility of designing a Transaction Fee Mechanism (TFM) that simultaneously guarantees Dominant Strategy Incentive Compatibility (DSIC) for users, collusion-proofness, and non-zero miner revenue. This paper resolves the dilemma by relaxing the stringent DSIC requirement to Bayesian-Nash-Incentive-Compatibility (BNIC), introducing the novel auxiliary mechanism method which connects the properties of BNIC and DSIC through an auxiliary-variation decomposition. This foundational breakthrough enables the construction of a TFM that is both collusion-proof and BNIC, achieving a constant-ratio approximation of optimal miner revenue, which fundamentally secures the long-term economic stability of decentralized protocol architecture.
Context
The established theoretical landscape for transaction fee mechanisms was defined by a critical impossibility result. This result demonstrated that any TFM satisfying the gold standard of incentive alignment ∞ Dominant Strategy Incentive Compatibility (DSIC) ∞ while also being collusion-proof, must necessarily yield zero revenue to the miner. This “zero-revenue barrier” presents a foundational threat to protocol security, as it removes the economic incentive required to motivate honest miner or validator participation, thereby compromising the network’s stability and liveness. This academic challenge necessitates a new theoretical framework to reconcile incentive compatibility with economic viability.
Analysis
The paper’s core mechanism shifts the game-theoretic model from a dominant strategy setting to a Bayesian-Nash equilibrium setting, relaxing the user incentive requirement to BNIC. The central innovation is the auxiliary mechanism method , a new theoretical primitive that decomposes a BNIC mechanism into two components ∞ a related DSIC mechanism and an auxiliary mechanism representing the variation between the two. The BNIC TFM is constructed using a soft second-price model based on the multinomial logit choice model. This structure allows the TFM to preserve the crucial collusion-proof property, which protects against off-chain agreements, while the BNIC property ensures users bid truthfully based on their probabilistic knowledge of other users’ valuations, thereby breaking the zero-revenue barrier.
Parameters
- Revenue Approximation ∞ Constant-ratio approximation of optimal miner revenue. This metric confirms the mechanism’s ability to generate positive, near-optimal revenue while maintaining truthfulness and collusion resistance.
- Incentive Compatibility ∞ Bayesian-Nash-Incentive-Compatibility (BNIC). This is the key relaxation from the Dominant Strategy Incentive Compatibility (DSIC) standard that enables non-zero revenue.
Outlook
The introduction of the auxiliary mechanism method is a significant advance for mechanism design in decentralized systems. In the near term, it provides a blueprint for designing more robust and economically stable transaction fee markets, directly impacting layer-one and rollup fee structures. Looking forward, the method’s general applicability to connecting BNIC and DSIC properties opens new avenues for mechanism design across all blockchain applications, including fair sequencing, decentralized governance, and oracle design, where incentives must be aligned under conditions of incomplete information.
Verdict
This research provides a fundamental game-theoretic tool that overcomes a long-standing impossibility result, securing the economic foundation of blockchain transaction fee mechanisms and advancing the field of mechanism design.
