Elliptical curve asymmetrical keys for the actual encryption. No encryption by proxy by default. Basically think of a shared database where you don't know who inserts data or who selects data. Making all payloads the same size, and constantly transmitting/receiving at a set rate ensures that even your isp can't tell if you are the sender or receiver of a message. The security/anonymity levels are adjustable so you don't have to use the features if you'd rather not. Also with shared asymetrical keys, users can communicate without having to sign/identify themselves within the message. This also provides plausible deniability. There are a lot more layers, but I'll keep it brief here.