Re: Update to BCP-38?

[William Herrin <bill () herrin us>]

On Tue, Oct 8, 2019 at 6:51 AM Rich Kulawiec <rsk () gsp org> wrote:
> On Tue, Oct 08, 2019 at 01:35:16PM +0100, Mike Meredith via NANOG wrote:
> > You've ignored step 1 - identifying critical information that needs
> > protecting. It makes sense to protect information that needs protecting
and
> > don't lose sleep over information that doesn't need protecting. Not
many of
> > us are planning an invasion of a Nazi-infected Europe any time soon.
>
> We are heading toward a restatement of Kerckhoff's principle/Shannon's
maxim,
> the latter of which can be paraphrased as "design systems assuming that
> your adversary will know as much about them as you do".

They aren't mutually exclusive concepts. A strong security architecture has
multiple layers an adversary must penetrate. No layer has to be sufficient
on its own, it just has to reduce vulnerability more than it increases cost.

Limiting the server banner so it doesn't tell an adversary the exact
OS-specific binary you're using has a near-zero cost and forces an
adversary to expend more effort searching for a vulnerability. It doesn't
magically protect you from hacking on its own. As you say, your security
must not be breached just because the adversary figures out what version
you're running. But viewed as one layer in an overall plan, limiting that
information enhances your security at negligible cost. That's security
smart.

Regards,
Bill Herrin


-- 
William Herrin
bill () herrin us
https://bill.herrin.us/