Which protocol to choose for chat?

Question

Chats

Hello. I decided to try to write a chat, but after reading, I did not find any recommendations on which protocol to use. The idea is simple: There are users and they have 1 on 1 correspondence and can create group chats.
Personally, I understand that IRC is not needed, because it is suitable for connecting geographically separated servers and does not have built-in protection, Websocket also does not have any protection, but the functionality seems to be good, to use socket.io you need to learn Node.js (I like would not mind but still it will not be right away). MQTT seems to be the best (there is no data encryption, but it is easier to write than protection) and yet the question remains - What are your recommendations for choosing a chat protocol?

Answer 1

Large projects use XMPP .
If you just need to raise a chat not for millions of users and as quickly as possible, simply and conveniently, then firebase is perfect, here is an example