Source code obfuscation for smart contracts

State-of-the-art work of evaluating smart contract static analysis tools faces a major problem: most test cases (i.e., labeled buggy contracts) are too simple and lack complexity, which makes the evaluation unable to show the real performance of the analysis tools when complex contracts are analyzed. To fill the gap, we propose a novel source code obfuscation approach for Ethereum smart contracts. We use the buggy contracts in the public dataset11 https://github.com/smartbugs/smartbugs/tree/master/dataset to evaluate our approach. The evaluation result shows that our approach can effectively increase the complexity of a contract. Besides, we use obfuscated contracts to evaluate the static analysis tools. The evaluation result shows that the performance of most smart contract static analysis tools decreases in different degree when the original contracts are obfuscated.