Re: [6tisch] Extending CoJP (minimal-security) for non-6TiSCH 802.15.4 networks

Christian Amsüss <> Mon, 20 September 2021 10:54 UTC

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Date: Mon, 20 Sep 2021 12:54:22 +0200
From: Christian =?iso-8859-1?Q?Ams=FCss?= <>
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Subject: Re: [6tisch] Extending CoJP (minimal-security) for non-6TiSCH 802.15.4 networks
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On Mon, Sep 20, 2021 at 12:15:27PM +0200, Mališa Vučinić wrote:
> As you could probably see from RFC9031, we did make an attempt to
> separate TSCH-specific from generally-applicable text,

yes, thanks for that -- if that were not done, the endeavour would be a
lot harder.

> The use cases you mention are bound to 15.4 radios. Do you see this
> effort potentially useful for other low-power radio technologies?

I'm not sufficiently familiar with other technologies' security
mechanisms; I'm struggling enough with in-15.4 use.

I originally thought I'd just take a K1 and K2 and the existing key
usage table, but these are actually 6TiSCH specific. It'd be quite a
waste to repeat the 14 modes to say the same about any other MAC
(especially as using the K1/K2 separation probably makes sense there
too); maybe the other parameters can skew the semantics. ("If this
parameter is present, keys are used for 802.15.4 as in the given 6TiSCH-
key usage, but with the adaptations described in this document").

A non-802.15.4 network would certainly need new values there, I hope to
manage without to keep overhead low.


To use raw power is to make yourself infinitely vulnerable to greater powers.
  -- Bene Gesserit axiom