Despite revolutionizing financial transactions, blockchain technology faces critical scalability challenges, impeding its global adoption. Optimistic rollup, a state-of-the-art Layer 2 (L2) scaling solution, addresses scalability issues by assuming transaction validity unless challenged. Through this work, we formally identify that interactions within optimistic rollup systems inherently constitute an inspection game between aggregators and verifiers, which is vulnerable to adversarial behaviors, as rational aggregators may act dishonestly for illicit gains, while verifiers often avoid challenges to prevent slashing penalties. To address these vulnerabilities, we propose OptiGame, an enhanced protocol incorporating a Bayesian game model and a reputation mechanism to strengthen optimistic rollup systems. Our approach incentivizes honest aggregator behavior and mitigates verifier losses (due to slashing) by aligning economic incentives with security requirements. The proposed model leverages symbolic mathematics to construct an initial mutable payoff matrix based on system parameters and dynamically updates it in response to players’ interactions. To validate OptiGame ’s effectiveness in real-world scenarios, we deploy it on the Optimism Sepolia testnet and analyze various performance metrics.
