By default it's no more encrypted than HN (as in, traffic to their servers uses TLS, messages on the server are not encrypted at all).
There's Secret Chats feature which they claim to be end-to-end encrypted, meaning that it's no more secure than Facebook's Messenger (also end-to-end encrypted in Secret Conversations). Even less so considering that they roll their own encryption (MTProto), while Facebook's Messenger uses Signal's protocol.
There's Secret Chats feature which they claim to be end-to-end encrypted, meaning that it's no more secure than Facebook's Messenger (also end-to-end encrypted in Secret Conversations). Even less so considering that they roll their own encryption (MTProto), while Facebook's Messenger uses Signal's protocol.
Further info (which will also lead you to problems with their MTProto protocol, if you're interested): https://security.stackexchange.com/questions/49782/is-telegr...