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

Older hashing functions

We began this book by promising that we wouldn't be covering older cryptographic functions, so it seems appropriate to break that promise as early as in the third chapter.

The reason why we are not apologizing for our "misdeed" is that there are lots of hashing functions that are broken and yet are still too widely used and talked about, so it is worth taking a quick look at what's wrong with them and why they should be avoided.

Among the hashing functions that you should not use, we need to highlight the following:

  • MD5 and SHA-1 are considered precursors to SHA-2. Researchers have found vulnerabilities in them that allow attackers to generate collisions in minutes (more on that shortly), so these algorithms are considered effectively broken.
  • PBKDF2 is an older key derivation function that was used for password hashing too. While not broken, it's not recommended to be used as a key derivation function anymore.

    At a high...