Building Defense-in-Depth Encryption: A Cascading Cipher System
⚠️ NOTE: This article describes a cascading cipher implementation. The system is actively used in real-world P2P messaging applications. 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.