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

Understanding public-key and hybrid cryptosystems

Before we dive into the code and learn about using asymmetric and hybrid encryption schemes with Node.js, it's worth spending a few moments understanding why we need these algorithms, what kinds of real-world problems we're trying to solve, and how they work, at least conceptually.

The need for public-key cryptography

We briefly mentioned this in the first section of Chapter 4, Symmetric Encryption in Node.js, when we explained the difference between symmetric and asymmetric ciphers, and how the latter helps solve the problem of transmitting keys to another party over an insecure channel.

For example, let's imagine that Alice needs to send Bob some confidential information via email (cryptographers have a predilection for those two names when they want to describe a situation with two parties); this is a very common problem in real life and is something you may have had to deal with yourself too on occasion!