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


In this chapter, we covered hashing, the first of the cryptographic operations we will be exploring in this book. Hashing functions can be used by developers for a variety of purposes: in particular, we've looked at SHA-2 as the recommended function for calculating digests of files and messages (to verify their integrity or to generate identifiers), and Argon2 and scrypt for storing passwords and deriving encryption keys. We've also looked at the issues that impact hashing functions, and why older algorithms are to be avoided.

In the next chapter, we're going to cover encryption and decryption using symmetric ciphers, the first of the two kinds we'll be studying in this book, using two popular algorithms – AES and ChaCha20-Poly1305. We'll also put what we saw in this chapter into practice and use hashing functions to derive symmetric encryption keys safely.