Book Image

Ethereum Smart Contract Development

By : Mayukh Mukhopadhyay
Book Image

Ethereum Smart Contract Development

By: Mayukh Mukhopadhyay

Overview of this book

Ethereum is a public, blockchain-based distributed computing platform featuring smart contract functionality. This book is your one-stop guide to blockchain and Ethereum smart contract development. We start by introducing you to the basics of blockchain. You'll learn about hash functions, Merkle trees, forking, mining, and much more. Then you'll learn about Ethereum and smart contracts, and we'll cover Ethereum virtual machine (EVM) in detail. Next, you'll get acquainted with DApps and DAOs and see how they work. We'll also delve into the mechanisms of advanced smart contracts, taking a practical approach. You'll also learn how to develop your own cryptocurrency from scratch in order to understand the business behind ICO. Further on, you'll get to know the key concepts of the Solidity programming language, enabling you to build decentralized blockchain-based applications. We'll also look at enterprise use cases, where you'll build a decentralized microblogging site. At the end of this book, we discuss blockchain-as-a-service, the dark web marketplace, and various advanced topics so you can get well versed with the blockchain principles and ecosystem.
Table of Contents (18 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Parity hack demystified


Parity (https://parity.io/) is a UK-based, venture capitalist-funded, tech start-up company. They provide an Ethereum client, also called Parity, which has an extensive Ethereum wallet and DApp environment for contract deployment. The entire application is written and compiled in the RUST language. The wallets are multi-sig. Multi-sig wallets, in simple words, are wallets that require at least two separate agreements to spend a token from the wallet. These wallets are supposed to be more secure than normal single-sig wallets.

Unfortunately, on July 19, 2017, three multi-sig wallets were exploited from a total of 596 wallets with similar vulnerabilities. Figure 6.10 shows these compromised accounts in Etherscan, the public Ethereum block explorer. When the Parity team got alerted of this hack, they tackled this situation by forming a "White Hat Group" and used the same vulnerability to siphon all the tokens from the remaining 593 wallets into a safe repository so that...