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 DApp

Let's write the smart contracts for digitalizing fiat currency and storing cell phone numbers linked to bank accounts. Here is the smart contract for digitalizing fiat currency:

pragma solidity ^0.4.18;

contract USD {
    address centralBank;

    mapping (address => uint256) balances;
    uint256 totalDestroyed;
    uint256 totalIssued;

    event usdIssued(uint256 amount, address to);
    event usdDestroyed(uint256 amount, address from);
    event usdTransferred(uint256 amount, address from, address to,
      string description);

    function USD() {
        centralBank = msg.sender;

    function issueUSD(uint256 amount, address to) {
        if(msg.sender == centralBank) {
            balances[to] += amount; 
            totalIssued += amount;
            usdIssued(amount, to);

    function destroyUSD(uint256 amount) {
        balances[msg.sender] -= amount;
        totalDestroyed += amount;
        usdDestroyed(amount, msg.sender);