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 6: Digital Signatures with Node.js and Trust

In the previous chapter, we learned about asymmetric cryptography, also called public-key cryptography because it relies on pairs of public/private keys, and we used that to encrypt messages.

In this chapter, we'll begin by looking at public key cryptography's other main use, which is calculating digital signatures. When attached to a message (encrypted or not), these offer a guarantee that the content is intact and that the sender is indeed the person they're claiming to be. Digital signatures are the last class of cryptographic operations we'll be analyzing in this book.

Before we end this chapter, we'll also learn how to deal with the problem of trusting public keys. We'll look at some techniques that are commonly used to bind keys to a real identity, such as an individual or an organization, and why that matters.

In this chapter, we're going to cover the following main topics: