An Introduction To Utilizing Public-Key Cryptography In Javascript

Open Cryptochat - A Tutorial

Cryptography is important. Without encryption, the internet as we know it would not be possible - data sent online would be as vulnerable to interception as a message shouted across a crowded room. Cryptography is also a major topic in current events, increasingly playing a central role in law enforcement investigations and government legislation.

Encryption is an invaluable tool for journalists, activists, nation-states, businesses, and everyday people who need to protect their data from the ever-present threat of hackers, spies, and advertising agencies.

An understanding of how to utilize strong encryption is essential for modern software development. We will not be delving much into the underlying math and theory of cryptography for this tutorial; instead, the focus will be on how to harness these techniques for your own applications.

In this tutorial, we will walk through the basic concepts and implementation of an end-to-end 2048-bit RSA encrypted messenger. We'll be utilizing Vue.js for coordinating the frontend functionality along with a Node.js backend using Socket.io for sending messages between users.

• Live Preview - https://chat.patricktriest.com
• Github Repository - https://github.com/triestpa/Open-Cryptochat

The concepts that we are covering in this tutorial are implemented in Javascript and are mostly intended to be platform-agnostic. We will be building a traditional browser-based web app, but you can adapt this code to work within a pre-built desktop (using Electron) or mobile ( React Native, Ionic, Cordova) application binary if you are concerned about browser-based application security.[^1] Likewise, implementing similar functionality in another programming language should be relatively straightforward since most languages have reputable open-source encryption libraries available; the base syntax will change but the core concepts remain universal.

Disclaimer - This is meant to be a primer in end-to-end encryption implementation, not a definitive guide to building the Fort Knox of browser chat applications. I've worked to provide useful information on adding cryptography to your Javascript applications, but I cannot 100% guarantee the security of the resulting app. There's a lot that can go wrong at all stages of the process, especially at the stages not covered by this tutorial such as setting up web hosting and securing the server(s). If you are a security expert, and you find vulnerabilities in the tutorial code, please feel free to reach out to me by email ([email protected]) or in the comments section below.

To read more, visit - https://github.com/triestpa/Open-Cryptochat

This app is 100% open-source, feel free to utilize the code however you would like.

The MIT License (MIT)

Copyright (c) 2018 Patrick Triest

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