Comment by sneak

Worth noting: The Google Authenticator app lets _anyone_ generate a shared secret seed that can be added to the app (which, afaict, does not communicate with the network at all).

I'm confused as to why you'd need a third-party for this.

Example of how to generate a seed and share it with an ssh server: https://scottlinux.com/2013/06/02/use-google-authenticator-f...