Book Image

Building Blockchain Projects

By : Narayan Prusty
Book Image

Building Blockchain Projects

By: Narayan Prusty

Overview of this book

Blockchain is a decentralized ledger that maintains a continuously growing list of data records that are secured from tampering and revision. Every user is allowed to connect to the network, send new transactions to it, verify transactions, and create new blocks, making it permission-less. This book will teach you what blockchain is, how it maintains data integrity, and how to create real-world blockchain projects using Ethereum. With interesting real-world projects, you will learn how to write smart contracts which run exactly as programmed without any chance of fraud, censorship, or third-party interference, and build end-to-e applications for blockchain. You will learn about concepts such as cryptography in cryptocurrencies, ether security, mining, smart contracts, solidity, and more. You will also learn about web sockets, various API services for Ethereum, and much more. The blockchain is the main technical innovation of bitcoin, where it serves as the public ledger for bitcoin transactions.
Table of Contents (16 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

hooked-web3-provider and ethereumjs-tx libraries

Until now, all the examples of Web3.js library's sendTransaction() method we saw were using the from address that's present in the Ethereum node; therefore, the Ethereum node was able to sign the transactions before broadcasting. But if you have the private key of a wallet stored somewhere else, then geth cannot find it. Therefore, in this case, you will need to use the web3.eth.sendRawTransaction() method to broadcast transactions.

web3.eth.sendRawTransaction() is used to broadcast raw transactions, that is, you will have to write code to create and sign raw transactions. The Ethereum node will directly broadcast it without doing anything else to the transaction. But writing code to broadcast transactions using web3.eth.sendRawTransaction() is difficult because it requires generating the data part, creating raw transactions, and also signing the transactions.

The Hooked-Web3-Provider library provides us with a custom provider, which communicates...