Book Image

Blockchain for Enterprise

By : Narayan Prusty
Book Image

Blockchain for Enterprise

By: Narayan Prusty

Overview of this book

The increasing growth in blockchain use is enormous, and it is changing the way business is done. Many leading organizations are already exploring the potential of blockchain. With this book, you will learn to build end-to-end enterprise-level decentralized applications and scale them across your organization to meet your company's needs. This book will help you understand what DApps are and how the blockchain ecosystem works, via real-world examples. This extensive end-to-end book covers every blockchain aspect for business and for developers. You will master process flows and incorporate them into your own enterprise. You will learn how to use J.P. Morgan’s Quorum to build blockchain-based applications. You will also learn how to write applications that can help communicate enterprise blockchain solutions. You will learn how to write smart contracts that run without censorship and third-party interference. Once you've grasped what a blockchain is and have learned about Quorum, you will jump into building real-world practical blockchain applications for sectors such as payment and money transfer, healthcare, cloud computing, supply chain management, and much more.
Table of Contents (14 chapters)
Title Page
Packt Upsell

Building the network

Before we proceed to writing smart contracts, let's create Quorum networks for USD currency for the +1 ISD code. We will make sure that these networks are permissioned and protected using node IDs.

So far with, all the networks we have created in this book, we have assumed that they are protected using whitelisted IPs. But Quorum provides a way to whitelist node IDs. You can apply the same practice to other networks built in this book. A cell phone number shouldn't be leaked outside of the network, and therefore it's important to protect the network at all costs.

Network permissioning in Quorum

Network permissioning is enabled at the individual node level by adding the --permissioned flag as the command-line parameter during node startup. When the flag is added, the node looks for a file named permissioned-nodes.json in the node's data directory folder.

The permissioned-nodes.json file contains a list of node identifiers (enode://nodeID@ip:port) that this specific node will...