A Survey on Smart Contract Vulnerabilities and Safeguards in Blockchain

Abstract

Blockchain technology is developing rapidly as a result of its numerous applications, security features and smart contracts embedded in it. Smart contracts are software codes written in a programming language. They get automatically executed on the Blockchain network when certain condition is met written in that program code. The distinctive characteristics of smart contracts led Blockchain technology to be used in applications beyond cryptocurrencies, including healthcare, IoT, supply chain, digital identification, digital asset exchange, crowdfunding, intellectual property, and many more. Millions were stolen and lost as a result of technical flaws and various vulnerabilities present in smart contracts. Many tools and methodologies have been proposed to address these challenges, and additional research is underway to build unique tools that enable the discovery of vulnerabilities in smart contract code. Ethereum is a well-known public Blockchain platform supporting smart contracts. Additionally, Hyperledger Fabric is private Blockchain platform featuring smart contracts in private sector. This survey presents, a bird’s eye view of smart contract languages, vulnerabilities and security tools in Public and Private Blockchain. The paper also looks at the different formal verification approaches used to identify the vulnerabilities present in the smart contract. The intent of the paper is to focus on smart contract challenges and vulnerabilities, Security tools in Public and private Blockchain and Formal verification Methods for validation of smart contracts.