Building Team Projects

Abstract

When the Ethereum blockchain was first built, there was no chainId in the blocks. The concept of chainId was introduced after a DAO attack in 2016 that resulted in 3.6 million ethers stolen and made Ethereum blockchain to fork into two blockchains, that is, Ethereum mainnet (ETH) and Ethereum Classic. In this chapter, a crosschain id service project is developed from specification, architecture, design, smart contract coding, to Web client implementations.