Re: [homenet] Ted's security talk at IETF99: DNCP Security

Michael Richardson <> Tue, 01 August 2017 20:48 UTC

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From: Michael Richardson <>
To: Ted Lemon <>
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Date: Tue, 01 Aug 2017 16:48:22 -0400
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Subject: Re: [homenet] Ted's security talk at IETF99: DNCP Security
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Ted Lemon <>; wrote:
    > You agree that it's a different problem right?

    mcr> The common part is that one might have a similar set of external
    mcr> (physical) signals.

    mcr> Should Dave bring his printer to the IETF network, and they happen to
    mcr> discovery each other via privacy-enhanced dnssd magic (cf: Arthur Clark's
    mcr> definition of magic), then it would be good that they can prove that it's
    mcr> really them.

    > To be honest, I probably missed the point you were making—I just went back
    > and reviewed this exchange, and I don't actually understand what the
    > distinction is that you are making between ephemeral and long-lived
    > relationships.

This thread started by being about the problem of getting devices in the home
to securely join the homenet.  One sees a list of possible routers in the
home, and identifies one that should belong, and tells your homenet that it
should be allowed to join.  (And the router also is told to join your

The short-term exchange is where you discover the new router and do the
out-of-band secured exchange to establish initial trust.  Within that initial
trust, longer-term credentials (asymmetric keys) are exchanged.

Michael Richardson <>;, Sandelman Software Works
 -= IPv6 IoT consulting =-