Re: [Homenet-babel-sec] [babel] What's up with HNCP security?

Ted Lemon <mellon@fugue.com> Mon, 29 May 2017 01:27 UTC

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From: Ted Lemon <mellon@fugue.com>
In-Reply-To: <87shjoihnz.wl-jch@irif.fr>
Date: Sun, 28 May 2017 21:27:09 -0400
Cc: Markus Stenberg <markus.stenberg@iki.fi>, homenet-babel-sec@ietf.org, babel@ietf.org
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Subject: Re: [Homenet-babel-sec] [babel] What's up with HNCP security?
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> I was under the (perhaps mistaken) impression that asymmetric signing can
> be done just as well over multicast.  The reasons people want unicast
> hellos are multiple:

We concluded that asymmetric signing was too expensive, IIRC.

> Even for Stenberg-Schinazi security, it's not obvious to me why we need
> unicast Hellos -- it's only Updates that really need to be protected, if
> an attacker manages to fake a Hello he'll only be able to disrupt the
> link-quality estimation algorithm (which is only a DoS vector).

I will rely on your expertise here.   However, if the point is to identify the attacker, then being able to identify the attacker in a DoS attack is just as important.

>> Network wide keys are useless.
> 
> Depends on the size of the network, I guess.

Yes.   For networks with only two hosts, network-wide keys are adequate...

;)