Poster: SigRec - Automatic Recovery of Function Signatures in Smart Contracts

Millions of contracts deployed onto Ethereum provide various services that can be invoked. For this purpose, blockchain users need to know and specify the function signature of a callee, which includes its function id and the parameter types. Function signatures are crucial in several applications, such as recognizing the services that contracts provide. In this poster, we propose a novel solution that leverages how functions are handled by Ethereum virtual machine (EVM) to automatically recover function signatures from contract bytecode, without the need of source code and function signature databases. The extensive experimental results show that our solution outperforms all existing tools, achieving an unprecedented 98.7% accuracy within 0.074 seconds. We further demonstrate the usefulness of our solution in attack detection, fuzzing and reverse engineering of contract bytecode.