Gas Fee Drain Loops (Grief Attacks): Economic Exhaustion Attacks in Proof-of-Stake and DeFi Systems

Transaction fees are a core economic mechanism in blockchain systems, intended to price scarce blockspace and align resource consumption with economic cost. However, in Proof-of-Stake (PoS) and decentralized finance (DeFi) environments, fee mechanisms can be exploited to impose asymmetric and persistent economic harm without violating protocol rules. This paper defines Gas Fee Drain Loops, commonly referred to as grief attacks, as a class of economic exhaustion attacks that weaponize execution costs, transaction ordering, and revert semantics to drain capital from targeted participants. We analyze the structural conditions that enable such attacks, demonstrate why conventional fee market assumptions fail under adversarial strategies, and show how gas griefing degrades security through economic exclusion rather than consensus failure. Finally, we propose a logic-layer mitigation model that bounds execution costs, restores economic symmetry, and preserves open participation under adversarial conditions.