keyboard-interactive and challenge-response

From: - (
Date: 02/28/05

Date: 28 Feb 2005 04:32:31 -0800

I'm confused about the newer keyboard-interactive and
challenge-response authentication types.

The current version of OpenSSH does not seem to have the
KbdInteractiveAuthentication keyword (although I think it used to),
and now has ChallengeResponseAuthentication.

The commercial SSH seems to have BOTH keywords, and the current
Solaris 10 version of SSH only has KbdInteractiveAuthentication.

What is the difference between these two?

Also, which non public key authentication method is likely to be the
most compatible with GUI clients such as PuTTY, Exceed etc - Password,
Keyboard Interactive or Challenge Response?