Two major attacks on the Ethereum smart contract application layer

Abstract

Ethereum is a decentralized open-source, public blockchain platform with smart contract functionality. As of December 2021, Ether is the second highest cryptocurrency in the world by market capitalization, after Bitcoin. Also, Ether is one of the most used blockchain platforms. As a second-generation blockchain platform, Ethernet supports a new computing paradigm - decentralized applications (DApps) running on top of the blockchain. While DApps bring rich and flexible application semantics and functions, they also inevitably bring more security risks and vulnerabilities. And Ethereum, as a blockchain that carries a large amount of value in virtual currency, has attracted a large number of unsuspecting attackers to target Ethereum security vulnerability attacks for profit. Among them, there have been numerous attacks against the application layer of Ether in the past few years. This article will review several serious attacks on Ethereum at the application level in the past few years and analyse the vulnerabilities exploited by these attacks, the methods of attack, and the improvements made by Ethereum after the attacks in order to provide some insight into the future security of virtual currencies and blockchains.