Question about insecure server

[Bingrui Foo]

Hi all,

I coded a simple chat server that allows people to remotely connect to
port 9999 and chat with other people who connect. It uses basic C socket
code to do it.

People use telnet to connect, and have to input a password at the start
when creating an account.

I'm wondering is there a way to use ssh instead of telnet to connect to my
chat server to make the connection secure?

Do I have to modify the C socket code to somehow allow people to ssh into
it? Or is there another way. I have no idea how to make it secure.

If anybody could help, it would be greatly appreciated.

Thanks,
Foo