Book Image

Essential Cryptography for JavaScript Developers

By : Alessandro Segala
Book Image

Essential Cryptography for JavaScript Developers

By: Alessandro Segala

Overview of this book

If you’re a software developer, this book will give you an introduction to cryptography, helping you understand how to make the most of it for your applications. The book contains extensive code samples in JavaScript, both for Node.js and for frontend apps running in a web browser, although the core concepts can be used by developers working with any programming language and framework. With a purely hands-on approach that is focused on sharing actionable knowledge, you’ll learn about the common categories of cryptographic operations that you can leverage in all apps you’re developing, including hashing, encryption with symmetric, asymmetric and hybrid ciphers, and digital signatures. You’ll learn when to use these operations and how to choose and implement the most popular algorithms to perform them, including SHA-2, Argon2, AES, ChaCha20-Poly1305, RSA, and Elliptic Curve Cryptography. Later, you’ll learn how to deal with password and key management. All code in this book is written in JavaScript and designed to run in Node.js or as part of frontend apps for web browsers. By the end of this book, you'll be able to build solutions that leverage cryptography to protect user privacy, offer better security against an expanding and more complex threat landscape, help meet data protection requirements, and unlock new opportunities.
Table of Contents (13 chapters)
Part 1 – Getting Started
Part 2 – Using Common Cryptographic Operations with Node.js
Part 3 – Cryptography in the Browser

Chapter 4: Symmetric Encryption in Node.js

If you stopped a random person on the street and asked them what is the first thing that comes to their mind when they think of cryptography, chances are they'd talk about encrypting their data and protecting it with a password or PIN. This class of operations is called symmetric encryption, and it's arguably the most widely known, even among not particularly tech-savvy consumers.

In Chapter 3, File and Password Hashing with Node.js, we began looking at classes of cryptographic operations. starting with hashing functions, and we explained how they're different from encryption. While hashing is a one-way operation, encryption is reversible: you can obtain the plaintext back from an encrypted message (also called ciphertext).

In this chapter, we'll look at data encryption using symmetric algorithms, specifically AES and ChaCha20-Poly1305, by covering the following topics:

  • The difference between symmetric and...