SSH hank attempts bad?

Chris Carey chris.carey at
Wed Apr 12 10:38:02 MDT 2006

On 4/12/06, Michael Halcrow <mike at> wrote:
> On Wed, Apr 12, 2006 at 08:22:16AM -0600, Chris Carey wrote:
> > Though, you could spend your whole life fighting this losing battle.
> > My opinion is to set your security in place, and forget about it.
> Some of the tactics suggested in this thread *are* setting security in
> place. And you should *never* just forget about it, because more
> likely than not, your adversaries are cleverer than you are. Good
> attacks are rarely conventional; if history has taught us anything,
> attackers will always ``cheat.'' Security is a hard problem -- in
> fact, it reduces to the same problem as the correctness problem, which
> any CS student knows is intractable.
> When it comes to system security, what we have to rely on is basic
> economics. If someone wants to ``get to'' your system, and if they
> have the willpower and enough resources to do it, you're screwed.
> So what you need to do is make it *more costly* for an attacker to get
> to your resources than whatever benefits the attacker would obtain by
> compromising your resources. For most run-of-the-mill systems on the
> Internet, the ``low-hanging'' fruit principle applies, just as it
> applies to the security tactics of home burglar alarm signs, walking
> down the sidewalk with confidence, and so forth. Criminals also
> understand the concept of opportunity cost.
> The moral of the story is to employ as many (layered) security
> mechanisms as you can while minimizing the inconvenience to the
> legitimate users. There are no one-shot silver bullets (although SE
> Linux comes close), and so you should be using a wide variety of
> tactics -- the more unique the approach, the less likely they will be
> compromised via a ``class break.''
> Mike
> .___________________________________________________________________.
>                          Michael A. Halcrow
>        Security Software Engineer, IBM Linux Technology Center
> GnuPG Fingerprint: 419C 5B1E 948A FA73 A54C  20F5 DB40 8531 6DCA 8769
> Natural selection is a theory, just like gravity. If you don't
> believe it, go jump off a bridge!
> Version: GnuPG v1.4.1 (GNU/Linux)
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I agree wholeheartedly. What I meant is that its futile to block
individual IPs. For every one you block, two more will appear. For an
Internet connected device, one should put a policy for security in
place that covers all IPs.

Chris Carey

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