Subject: Re: [OPSAWG] "Secure Device Install" - draft-wkumari-opsawg-sdi

From: Bill Fenner <[email-masked]>
Date: Sat, 30 Mar 2019 10:16:18 +0100

Hi Warren,

The idea is interesting.  I definitely like the idea of having a
lightweight mechanism for this - certainly customers have been asking for
"secure no touch provisioning", whatever that means.  I'd like to throw out
a couple of things for discussion:

1. Vendors (speaking as one) don't necessarily want it to be easy to find
out what serial numbers we've built.  You may say "well change your serial
number allocation", but, we have a whole logistics team that has way more
input to that.  Also see https://en.wikipedia.org/wiki/German_tank_problem .

2. If we create an identifier divorced from the serial number (e.g., a
UUID) to avoid problem 1, we still need to provide that identifier to the
customer somehow. The serial number is nice because it's written on the
device, so you can tell which one you've got when you have a stack of 150
that you just received.  Perhaps there can be a service provided by the
vendor that performs the dynamic mapping, but then that service is
vulnerable to the dictionary attack to discover serial numbers (or needs to
have countermeasures).

3. The vendor is now responsible for maintaining the public key until the
user needs it.  Sure, storage is cheap, sure, I can back it up on Google
Cloud, but that's still a new burden on the vendor (no matter how light
weight it sounds).

  Bill