ssh clarification needed

[Kevin Kofler]

Anne Wilson wrote:
> Is a ssh key specific to a computer, or to a user?  That is, does my key
> pertain to any box on the lan, as long as I'm the user?  Or is it machine
> specific - in which case I would think that every user would have the same
> key, which seems unlikely.  Then again, is it a combination of user and
> computer, in which case every user needs a specific key on every box he
> uses (assuming that he may want to ssh to other boxes).

There's 2 kinds of keys:
* host keys - those are the keys which are on the server, they're generated
once per server (unless you explicitly regenerate them) and they're what
the fingerprint you see when connecting to an SSH server the first time
corresponds to. Those are one per machine (server).
* authentication keys - those are what you use to log in instead of a
password. They're one per user and machine unless you explicitly copy the
private key to a different machine or user account (something you normally
shouldn't do, but some servers allow you to upload only one public key, so
you'll have to copy the matching private key around if you want to be able
to log in from multiple machines).

        Kevin Kofler