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 2: Dealing with Binary and Random Data

When building solutions that leverage cryptography, we're almost always faced with two issues.

The first is managing binary data, which is a sequence of bytes, including characters that can't be represented as text. Most people have the experience of opening a binary file (such as an image and an executable application) in a text editor such as Notepad and being presented with a sequence of random, garbled symbols that can't be read, let alone edited.

In cryptography, encrypted messages, hashes, keys, and sometimes even decrypted messages are guaranteed to contain non-printable, binary data. This introduces challenges for developers as binary data often requires special handling to be visualized (such as while debugging our applications), stored, and transferred.

In this chapter, we'll explore how we can use encodings such as base64 and hex (short for hexadecimal) with Node.js to make binary data representable...