
Briefing
The foundational problem of Maximal Extractable Value (MEV) in Automated Market Makers (AMMs) is addressed by proposing a novel mechanism design solution at the application layer, shifting the focus from complex consensus-level fixes to provable smart contract guarantees. This breakthrough introduces a new AMM mechanism that processes a batch of transactions by enforcing pre-defined rules to maintain a constant potential function, thereby eliminating opportunities for block producers to extract risk-free arbitrage profit. The single most important implication is the establishment of a mathematically formal paradigm for truly strategy-proof decentralized finance (DeFi), where users are incentivized to report their true demands and cannot be exploited by strategic transaction ordering.

Context
The prevailing theoretical limitation in decentralized finance has been the inability to fully mitigate MEV, which block producers extract by front-running and back-running user transactions, leading to centralized off-chain economies and consensus instability. Prior research primarily focused on augmenting the underlying consensus protocol with properties like sequencing fairness, but these attempts often relied on heuristic arguments and failed to provide comprehensive, provable guarantees against all forms of MEV extraction. This left the core problem of designing an incentive-compatible trading environment largely unsolved, with AMMs inherently creating arbitrage opportunities exploitable by those who control transaction ordering.

Analysis
The paper’s core mechanism, referred to as DROPS, fundamentally differs from previous approaches by applying mechanism design principles directly within the smart contract logic of the AMM itself. The new primitive is a batch-processing rule set that mandates all transactions within a block be processed in a manner that ensures the AMM’s state maintains a constant potential function. Conceptually, this function acts as a mathematical invariant that must hold true after any batch of trades is executed, effectively closing the arbitrage window that MEV extractors rely on. This approach yields two tiers of provable security ∞ it guarantees arbitrage resilience for legacy blockchain architectures and, more powerfully, guarantees strategy proofness for systems that offer sequencing fairness, meaning a user’s best response is always to follow the honest trading strategy.

Parameters
- Provable Guarantee ∞ Strategy Proofness. This is the strongest game-theoretic property achieved, ensuring that no individual user can gain an advantage through strategic, dishonest behavior.
- Core Mechanism ∞ Constant Potential Function. The mathematical invariant maintained by the batch-processing rule set, which is the foundation of the mechanism’s security guarantee.
- Security Tiers ∞ Arbitrage Resilience and Strategy Proofness. The mechanism’s security scales depending on the underlying blockchain’s transaction sequencing properties.

Outlook
This research opens a critical new avenue for securing decentralized systems by proving that core economic security can be guaranteed at the application layer, independent of the consensus protocol’s complexity. The immediate next step involves the real-world deployment and formal verification of this mechanism in high-volume AMMs. In the next three to five years, this principle could unlock a new generation of DeFi primitives ∞ including lending protocols and stablecoin mechanisms ∞ that are strategy-proof by construction. This shift will fundamentally re-architect the relationship between users, block producers, and smart contracts, leading to a more equitable and stable on-chain financial ecosystem.
