Book Image

Blockchain Developer's Guide

By : Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty
Book Image

Blockchain Developer's Guide

By: Brenn Hill, Samanyu Chopra, Paul Valencourt, Narayan Prusty

Overview of this book

Blockchain applications provide a single-shared ledger to eliminate trust issues involving multiple stakeholders. It is the main technical innovation of Bitcoin, where it serves as the public ledger for Bitcoin transactions. Blockchain Developer's Guide takes you through the electrifying world of blockchain technology. It begins with the basic design of a blockchain and elaborates concepts, such as Initial Coin Offerings (ICOs), tokens, smart contracts, and other related terminologies. You will then explore the components of Ethereum, such as Ether tokens, transactions, and smart contracts that you need to build simple DApps. Blockchain Developer's Guide also explains why you must specifically use Solidity for Ethereum-based projects and lets you explore different blockchains with easy-to-follow examples. You will learn a wide range of concepts - beginning with cryptography in cryptocurrencies and including ether security, mining, and smart contracts. You will learn how to use web sockets and various API services for Ethereum. By the end of this Learning Path, you will be able to build efficient decentralized applications. This Learning Path includes content from the following Packt products: • Blockchain Quick Reference by Brenn Hill, Samanyu Chopra, Paul Valencourt • Building Blockchain Projects by Narayan Prusty
Table of Contents (37 chapters)
Title Page
About Packt

Digital signatures

Now that we've covered hashing, it's time to go over a related concept: digital signatures. Digital signatures use the properties of hashing to not only prove that data hasn't changed but to provide assurances of who created it. Digital signatures work off the concept of hashing but add a new concept as well: digital keys.

What are digital keys?

All common approaches to digital signatures use what is called Public Key Cryptography. In Public Key Cryptography, there are two keys: one public and one private. To create a signature, the first hash is produced of the original data, and then the private key is used to encrypt that hash. That encrypted hash, along with other information, such as the encryption method used to become part of the signature, are attached to the original data.

This is where the public key comes into play. The mathematical link between the public key and the private key allows the public key to decrypt the hash, and then the hash can be used to check...