RE: [LinkSec] linksec roadmap
> give the bad player the new key too. In a sizable group,
> this can take quite a long time.
Not necessarily ... existing cable and satillte distribution system provide fairly rapid updates of 'group keys' to millions of users.
> -----Original Message-----
> From: Russ Housley [mailto:housley@vigilsec.com]
> Sent: Tuesday, December 10, 2002 11:14 AM
> To: Dennis Volpano
> Cc: stds-802-linksec@ieee.org
> Subject: Re: [LinkSec] linksec roadmap
>
>
>
> Dennis:
>
> One problem with an architecture like this is removing a bad
> player. It
> forces you to change the key that everyone is using, taking
> care to not
> give the bad player the new key too. In a sizable group,
> this can take
> quite a long time.
>
> Russ
>
> At 10:59 AM 12/10/2002 -0800, Dennis Volpano wrote:
>
>
> >On Tue, 10 Dec 2002, Marcus Leech wrote:
> >
> > > The roadmap had me somewhat confused, and maybe it's
> because I don't really
> > > understand what the *application space* of VLANs is.
> But it seems to me
> > > that a LAN segment with a group-shared key suffers from
> the same
> > problems as
> > > a completely unsecured LAN segment--I can spy on my
> neighbours, and forge
> > > traffic. Having a single key that is shared among 500
> of my nearest and
> > > dearest is like having no key at all. Granted, I won't
> be able to forge
> > > traffic on a *different* VLAN, but that's only slightly
> better than
> > nothing
> > > at all. But maybe that's not what Dennis intended?
> > >
> >
> >In my trust model, group members trust each other because
> the group is
> >a "security group", in the sense that it requires
> authentication to join.
> >Once the group leader has taken the steps needed to be convinced
> >that a station and perhaps its user is trustworthy, it may admit the
> >station, depending on whether the station is authorized to join.
> >
> >Granted, a station may misbehave after being given membership, in
> >which case group members are at *some* risk. Precisely,
> they need only
> >be at risk with respect to link layer integrity because
> stations can still
> >take other steps at upper layers to protect privacy if they
> wish. Limiting
> >the consequences of the misbehavior to the group is the best
> one can do.
> >
> >Dennis
> >
> > >
> > > --
> > >
> ----------------------------------------------------------------------
> > > Marcus Leech Mail: Dept
> 8M70, MS 012, FITZ
> > > Advisor Phone: (ESN)
> 393-9145 +1 613
> > 763 9145
> > > Security Architecture and Planning Fax: (ESN)
> 393-9435 +1 613
> > 763 9435
> > > Nortel Networks mleech@nortelnetworks.com
> > > -----------------Expressed opinions are my own, not my
> employer's------
> > >
>
>