GasChecker: Scalable Analysis for Discovering Gas-Inefficient Smart Contracts

Ting Chen, Youzheng Feng, Zihao Li, Hao Zhou, Xiapu Luo, Xiaoqi Li, Xiuzhuo Xiao, Jiachi Chen, Xiaosong Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)

Abstract

Ethereum, the largest blockchain for running smart contracts, charges the people who send transactions to deploy or invoke smart contracts for thwarting resource abuse. The amount of transaction fee depends on the size of that contract and the operations executed by that contract. Consequently, smart contracts with inefficient code will waste money. In this paper, we propose and develop the first tool, named GasChecker, for automatically identifying gas-inefficient code in smart contracts, and conduct the first empirical study on the prevalence of gas-inefficient code in the deployed smart contracts. More precisely, we first summarize ten gas-inefficient programming patterns and propose a new approach based on symbolic execution (SE) to detect them in the bytecode of smart contracts.To make our approach scalable to analyze millions of smart contracts, we parallelize SE by tailoring it to the MapReduce programming model, and propose a new feedback-based load balancing strategy to effectively utilize cloud resources. Extensive experiments show that GasChecker scales well with the increase of workers. The empirical study demonstrates that lots of real smart contracts contain various inefficient code. Manual investigation demonstrates that only 2.5% of discovered gas-inefficient instances are false positives.

Original languageEnglish
JournalIEEE Transactions on Emerging Topics in Computing
DOIs
Publication statusAccepted/In press - Mar 2020

Keywords

  • Contracts
  • gas-inefficient pattern
  • Load management
  • Load modeling
  • MapReduce
  • parallelization
  • Programming
  • scalable analysis
  • Smart contract
  • symbolic execution
  • Task analysis
  • Tools

ASJC Scopus subject areas

  • Computer Science (miscellaneous)
  • Information Systems
  • Human-Computer Interaction
  • Computer Science Applications

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