5 posts tagged with "cryptography"

⚠️ NOTE: This document and related project is not finished. The details in this document are subject to change.

What if you could combine multiple encryption algorithms like layers of an onion, where each layer provides independent protection? What if breaking one encryption layer still left your data protected by two or three more?

In this article, we'll explore how to build a cascading cipher system that chains multiple encryption algorithms together for defense-in-depth security. We'll walk through a browser-based JavaScript implementation that combines MLS (Message Layer Security), Signal Protocol's Double Ratchet, Diffie-Hellman key exchange, and AES-GCM encryption—all working together to create a robust, multi-layered encryption solution.

In the ever-evolving landscape of digital communication, decentralization has emerged as a powerful concept with diverse interpretations and applications. This article explores our unique approach to decentralization in the context of a chat application, pushing the boundaries of what it means to be truly self-hosted and user-centric.

Our decentralized chat application reimagines the traditional centralized model by leveraging cutting-edge web technologies. Built as a Progressive Web App (PWA), it combines the best of both worlds - the accessibility of web applications and the rich functionality of native apps. What sets our approach apart is its commitment to operating independently of central servers, placing control firmly in the hands of users.

By prioritizing user privacy and data security, we've created an architecture that challenges conventional notions of chat applications. This article will take you on a deep dive into the innovative components and architectural decisions that form the backbone of our truly decentralized chat app, showcasing how we're redefining digital communication for the privacy-conscious era.

⚠️ WARNING: This document is not finished. The details in this document are subject to change.

End-to-end encrypted messaging for two people is a solved problem—Signal Protocol has set the gold standard. But what happens when you want to scale that security to group chats with dozens or hundreds of participants? Traditional pairwise encryption becomes a nightmare: N participants require N(N-1)/2 encrypted channels, each with its own key management overhead.

Enter MLS (Message Layer Security), the IETF's RFC 9420 standard designed specifically for scalable group messaging. MLS provides the same strong security guarantees as Signal Protocol—forward secrecy, post-compromise security, authentication—but does so efficiently for groups of any size.

In this article, we'll explore how MLS works, why it's a game-changer for group messaging, and walk through a complete browser-based implementation using the ts-mls library. We'll cover everything from the TreeKEM algorithm to practical P2P integration with WebRTC.

⚠️ WARNING: This document is not finished. The details in this document are subject to change.

The Signal Protocol has become the gold standard for end-to-end encrypted messaging, powering applications like WhatsApp, Signal, and Facebook Messenger. But what happens when you want to implement the same level of security in a truly peer-to-peer environment—one without centralized servers managing pre-keys and message routing?

In this article, we'll explore how to adapt the Signal Protocol's X3DH (Extended Triple Diffie-Hellman) key agreement and Double Ratchet algorithm for direct peer-to-peer communication over WebRTC. We'll discuss the challenges unique to P2P environments, propose practical solutions, and walk through a browser-based JavaScript implementation that maintains the security guarantees of the original protocol.

In digital communication, security and privacy are the major initials. Our latest project—a chat application built with JavaScript—aims to provide a robust communication platform fortified with industry-grade encryption. While we aspire to offer one of the most secure chat experiences available, declaring it "the most secure chat app in the world" might be premature. This article delves into the technology behind our app, current security measures, and the remaining challenges. We also welcome feedback to help refine our approach.