Worked on the okx/xlayer-erigon repository to enhance the reliability and security of ZK-EVM contract execution by addressing a critical bug in the modular exponentiation (ModExp) input validation logic. Focused on backend development using Go and cryptography principles, the work involved tightening byte-length checks for base, exponent, and modulus inputs, ensuring that oversized values are rejected early in the process. This approach improved contract safety and execution predictability by preventing downstream errors and refining gas calculation logic. The changes reinforced system robustness and aligned modexp execution with updated validation rules, contributing to more secure and reliable smart contract operations.