Signal Double Ratchet: Messenger Encryption (2D)

This 2D companion to the 3D Double Ratchet visualizer drives the exact same session model: end-to-end encrypted messengers such as Signal and WhatsApp don't reuse one secret key for a whole conversation — they derive a brand-new key for every single message from a one-way hash chain, and periodically fold in a fresh Diffie-Hellman exchange. Sending messages advances the symmetric-key ratchet and spins off a new key node on the helix, a Diffie-Hellman ratchet step mints a fresh root key shown as a gold marker, and a simulated key-compromise event demonstrates forward secrecy (past keys stay unrecoverable because the hash chain can't run backward) and post-compromise security (the very next ratchet step heals the session even after a leak) — drawn here as a flat, draggable and zoomable key-helix instead of a rotating 3D scene.