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

Symmetric encryption with AES

The Advanced Encryption Standard (AES) is one of the most widely used symmetric ciphers, and it's been like that since its standardization in the early 2000s. It's safe (approved by the US government for encrypting "top secret" documents) and fast, with support available in all operating systems and programming languages.

Additionally, hardware acceleration for AES is available in all modern desktop and server CPUs (for example, the AES-NI instructions in Intel and AMD processors), as well as in a large number of mobile/embedded chips, making executing AES rather cheap in terms of computing power. A regular consumer-grade CPU can easily encrypt or decrypt AES streams at the speed of multiple gigabits per second. Many consumer operating systems are now encrypting hard drives by default, transparently to the user, using AES – that's the case of BitLocker on Windows and FileVault on macOS, for example.

To use AES, you...