An end-to-end encrypted chat suite implementing libsignal and Message Layer Security (MLS). It supports multiple devices per user, so a conversation follows its participants across platforms without the server ever holding readable messages.
Alice/phone Alice/laptop Bob/phone Bob/desktop
| | | |
+-------+-------+---- MLS group -----+------+------+
| |
v ciphertext only v
+---------------------------------------------------+
| delivery service: stores and forwards blobs |
+---------------------------------------------------+
Figure 1: Every device is a member; the server is not