Re: Re[2]: [SAGE] The danger of SSH keys..

[Dave Close <dave@compata.com>]

With properly implemented password verification (such as including,
for example, three wrong attempts requires manual intervention), there
is really no way to crack a password from the outside, almost no matter
how "weak" it might be. The weakness of passwords is a function of the
weakness of the server: steal the data base and crack at your leisure.
Making passwords "stronger" doesn't really have much impact on an
attack of that sort. Changing passwords periodically also has almost
no value against an offline crack (no attacker will wait three months
before trying to use a discovered password). Your only defense is to
keep the server itself secure.

Some might respond that no security is perfect and the server might
well be broken, so why not make the offline cracking take a little
longer? But "stronger" passwords /don't/ make it take any longer, given
the ability to use pre-computed dictionaries of any size. So you're back
to trying to keep the server secure, which is the right approach anyway.

Where a passwordless SSH key really presents a problem is that the
"server" you need to secure is the client machine. It's the one with
the password "data base", the private key itself. If you don't think
securing that is possible, maybe you should require SSH users to use
passwords, instead of or in addition to keys.
-- 
Dave Close, Compata, Costa Mesa CA  "There is no security on this earth.
dave@compata.com, +1 714 434 7359    There is only opportunity."
dhclose@alumni.caltech.edu             -- Douglas MacArthur