A C/C++ Smart Contract Vulnerability Detection Method Based on Intermediate Value Transformation

Smart contracts have brought new developments to Blockchain technology, quickly finding widespread application in finance, law, and business sectors upon their emergence. However, security vulnerabilities in smart contracts have limited their growth. The existing methods for detecting vulnerabilities in smart contracts primarily focus on Ethereum's Solidity, lacking of vulnerability detection tools based on other smart contract languages such as C/C++. Therefore, this paper investigates the current state of vulnerability detection research for smart contract languages other than Ethereum's Solidity and proposes a vulnerability detection method for C/C++ smart contracts based on intermediate value transformation. This method combines Clang technology with the symbolic execution tool KLEE[l], utilizing the Intermediate Representation (IR) from LLVM (Low Level Virtual Machine) for research, andproduces a detection method capable of identifying eight types of code level vulnerabilities. Finally, it summarizes the current shortcomings of smart contract vulnerability detection methods and future research directions.

I. Introduction

With the rapid development of blockchain technology, we have transitioned from the era of programmable currency to the era of smart contracts. In 1995, cryp tographer Nick Szabo[2] first proposed the concept of a ‘smart contract’, defining it as ‘a set of promises, specified in digital form, including protocols within which the parties perform on these promises’. When Szabo introduced smart contracts, they did not gain widespread application due to the lack of a trusted execution environment. However, the emergence of blockchain technology has brought a new opportunity. Smart contracts have become one of the key applications of blockchain technology, characterized by automatic execution, decentralization, and immutability. They provide a new solution for businesses in various fields. Nevertheless, the complexity and security challenges in the writing and execution processes of smart contracts may result in potential vulnerabilities and risks.