"James Kempf" <[EMAIL PROTECTED]> writes:
> I've submitted a draft on securing neighbor discovery,
> draft-kempf-secure-nd-00.txt.

Hi James.  Thanks for providing the tandem threat-solution for ND.  As
before, I'll make a case against using crypto as a total solution for
a fine-grained problem.  Please note that I think I understand some of
the merits of the ABK crypto-system (I still miss some details).

The threat document points out valid security concerns with ND.  IMHO,
some are easy to deal with and some other are harder, but in any case
not all require total application of the ABK mechanism, noting that
even if ABK's are applied some simple threats still hold.

Threat 3.1. Malicious Last Hop Router fools the victim into using it
as a default router.  If the legitimate AR uses the ABK system then
the attacker AR can also use a similar ABK system, right?  It might be
argued that the attacker AR can not communicate with the MN because it
can't be authenticated by the MN with an attacker NAS, fair enough.
But in that case, if the MN already shares a secret with the NAS, why
not using the same secret to authenticate the ND, thus questioning the
need for a more complex system.

Threat 3.2 Good Router Goes Bad is probably less particular to ND.
When good router goes bad it's too bad.

Threat 3.5 Bogus On-Link Prefix can be addressed by a smart legitimate
access router sending RA's with the attacker-prefix with lifetime 0.
A smart MN could even detect too many RA sequences
infinity-0-infinity-0 and consider that subnet unreliable.

Threat 3.7 DAD seems to be solved by using an ABK system if the
legitimate node will verify the authenticity of RS's.

Threat 3.8 is not addressed by the ABK, I think.

Alex

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