@strypey So there's a lot to unpack in that document. The # onion routing protocol involves using a # called # to make it difficult for an adversary to control a significant fraction of the nodes and prevent exposing the IP addresses (and therefore identities) of a user and his/her contacts to the same person or group. (As you noticed, Session is not yet using onion requests.)

There's also swarms and attachments and message storage (including attachments), online vs offline messages, multiple device support, spam resistance, a modified version of #'s encryption protocol, group chats (3-500 member "closed" groups are end-to-end encrypted like the rest of Session; "open" groups are not, and require an account on a special group server [self-hostable])

Note that all this stuff happens under the covers. It seems that Session will handle most of it without the user ever seeing it. I'm going to query some family members and see whether any would be willing to try this as a secondary channel (for now # is our primary channel). Just adding offline messages is a clear advantage over #, but the lack of audio & video chats is going to limit its usefulness.