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Building Executable Secure Design Models for Smart Contracts with Formal Methods

  • Weifeng Xu
  • Glenn A. FinkEmail author
Conference paper
  • 48 Downloads
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11599)

Abstract

Smart contracts are appealing because they are self-executing business agreements between parties with the predefined and immutable obligations and rights. However, as with all software, smart contracts may contain vulnerabilities because of design flaws, which may be exploited by one of the parties to defraud the others. In this paper, we demonstrate a systematic approach to building secure design models for smart contracts using formal methods. To build the secure models, we first model the behaviors of participating parties as state machines, and then, we model the predefined obligations and rights of contracts, which specify the interactions among state machines for achieving the business goal. After that, we illustrate executable secure model design patterns in TLA+ (Temporal Logic of Actions) to against well-known smart contract vulnerabilities in terms of state machines and obligations and rights at the design level. These vulnerabilities are found in Ethereum contracts, including Call to the unknown, Gasless send, Reentrancy, Lost in the transfer, and Unpredictable state. The resultant TLA+ specifications are called secure models. We illustrate our approach to detect the vulnerabilities using a real-estate contract example at the design level.

Notes

Acknowledgment

This work is supported in part by the Department of Energy and the National Science Foundation under Grant Numbers 1714261.

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Copyright information

© International Financial Cryptography Association 2020

Authors and Affiliations

  1. 1.College of Public AffairsUniversity of BaltimoreBaltimoreUSA
  2. 2.Cyber Security GroupPacific Northwest National LaboratoryRichlandUSA

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