2 posts tagged with "end-to-end encryption"

⚠️ 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.