Re: [LinkSec] Notes from meeting 12/10/02
Marcus:
In IEEE 802.11, there are now several security protocols. In trying to
understand how their differences, we made a model of the 802.11 MAC. It is
impossible to get agreement on the internal organization of the MAC. Any
structure that provides the correct interface and correct peer interaction
is acceptable. So, standards are not welcome in this area.
In my opinion, it will be very difficult to provide security of MAc-to-MAC
control traffic without a structure like this for the MAC that is being
protected.
Russ
At 10:44 AM 12/12/2002 -0500, Marcus Leech wrote:
>Russ Housley wrote:
> >
> > Allyn:
> >
> > I would like to clarify one point for the final minutes.
> >
> > >Russ - protection of MAC control track is part of our work, don't know
> > >if replay is important. At the rate things are being added onto MACs,
> > >if replay isn't important today it will be
> >
> > I do not know if protection of the MAC control traffic is important. I
> > hope it can be put out of scope. Otherwise a specific solution will be
> > needed for each MAC. However, it is clear that management protocols that
> > sit on top of the MAC are within scope. Bridge-to-bridge traffic is one
> > example. Further, I do not know if replay protection is important, but I
> > suspect that it is. Even if we were to make study today of each of the
> > protocols and we were to find that replay could not cause a problem, this
> > may not be meaningful. Future changes could introduce a problem.
> >
>Shooting entirely from the hip here, it seems to me that including MAC-layer
> control traffic our security "perimeter" [cone of silence :-) ] wouldn't
> necessarily require a large amount of per-MAC engineering.
>
>I suspect that a higher-layer key management scheme can be shared across
>everything,
> as in 802.10. I *suspect* that the process of extruding SDE into the
> individual
> MAC layers will result in only minor tweakages about where the bits live,
> with largely-similar or identical semantics, and a common set of mandatory
> algorithms.
>
>It seems to me that being able to hijack MAC-layer control traffic can have
> as devastating consequences as being able to hijack user and
> bridging-control
> traffic, so if we don't protect it, we've only done half a job.
>
>--
>----------------------------------------------------------------------
>Marcus Leech Mail: Dept 8M70, MS 012, FITZ
>Advisor Phone: (ESN) 393-9145 +1 613 763
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>Security Architecture and Planning Fax: (ESN) 393-9435 +1 613 763
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>Nortel Networks mleech@nortelnetworks.com
>-----------------Expressed opinions are my own, not my employer's------