> > I don't believe anyone has done any testing on the cost of
> > authentication. Truth of the matter is if it is near instance I doubt
> > anyone really cares (I sure never have =).

> I care! Not a whole lot because we generally see the authentication
> process as sunk cost. It matters a lot on low bandwidth long delay
> connections involving small transfers. Its more difficult to amortize
> the cost of authentication in those instances.

I agree. If the authentication time is too long, users will feel nervous.
I have found some of users evaluate the performance mostly from their
first login remote server. If the time spent in login is too long, they will
believe the performance of whole ssh is too low. Here, the time of first login
is determined mostly by authentication module.
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