Many people are curious about the difference between Keychat and White Noise.

Keychat encrypts one-to-one chats and small groups with the Signal protocol, while large groups use MLS encryption. White Noise, by contrast, encrypts every message solely with MLS.

Think of each message as a letter: both Keychat and White Noise rely on OpenMLS to encrypt the content inside. The main distinction lies in the envelope—the format of the recipient address and how that address rotates.

For large-group messages, Keychat adopts exactly the same envelope as a Nostr direct message (NIP-17), blending the traffic so thoroughly that an outside observer cannot distinguish a Keychat message from a Nostr DM.

Why does Keychat choose the Signal protocol over MLS for one-to-one chats? Because Signal’s ratchet advances more frequently than MLS’s, providing stronger post-compromise security.

Could Keychat’s large groups interoperate with White Noise’s groups in the future? Quite possible—after all, the two are already 90 % identical.