HermHD: Enhancing smart contract security based on code obfuscation

Abstract

Abstract. Due to the transparent nature of blockchain, all transaction information and smart contract code is recorded on the public blockchain. It is easy for existing static analysis tools to analyze and exploit vulnerabilities in smart contract code. To mitigate this risk, we propose HermHD, an automated security enhancement tool that protects smart contracts on the Ethereum network. HermHD employs six obfuscation patterns that can rewrite the bytecode of a smart contract without affecting its functionality. By applying these obfuscation techniques, we aim to prevent reverse static analysis tools from cracking the contract and thereby enhance the security of smart contracts. To validate the effectiveness of HermHD, we conducted experiments on 121 smart contracts from a public dataset. 54The evaluation results demonstrate that all the protected smart contracts are resistant to two popular reverse engineering tools, and the additional gas cost incurred is minimal.