Even with UDP it's still not hard. Sure getting it right might be hard, but getting it somehow good enough to not be obviously bad is much less so. Not only a

Even with UDP it's still not hard. Sure getting it right might be hard, but getting it somehow good enough to not be obviously bad is much less so. Not only are there thinks like DTLS, in the worst case you could just "ship" a AES key when you login over TCP/TLS and then you encrypt any udp message with that key or something like that. Sure there are many ways you can get it wrong but it's easy to setup and better then plaintext.