Book excerpt: Discover how to take advantage of common cryptographic operations to build safer apps that respect users' privacy with the help of examples in JavaScript for Node.js and browsers Key FeaturesUnderstand how to implement common cryptographic operations in your code with practical examplesLearn about picking modern safe algorithms, which libraries you should rely on, and how to use them correctlyBuild modern and secure applications that respect your users' privacy with cryptographyBook Description 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. What you will learnWrite JavaScript code that uses cryptography running within a Node.js environment for the server-side or in frontend applications for web browsersUse modern, safe hashing functions for calculating digests and key derivation, including SHA-2 and Argon2Practice encrypting messages and files with a symmetric key using AES and ChaCha20-Poly1305Use asymmetric and hybrid encryption, leveraging RSA and Elliptic Curve Cryptography with ECDH and ECIESCalculate and verify digital signatures using RSA and ECDSA/EdDSAManage passwords and encryption keys safelyWho this book is for This cryptography book is an introductory guide for software developers who don't necessarily have a background in cryptography but are interested in learning how to integrate it in their solutions, correctly and safely. You'll need to have at least intermediate-level knowledge of building apps with JavaScript and familiarity with Node.js to make the most of this book.