Re: [Rats] About (E)UID's

Michael Richardson <mcr+ietf@sandelman.ca> Fri, 14 February 2020 07:26 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
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Comments: In-reply-to Laurence Lundblade <lgl@island-resort.com> message dated "Wed, 12 Feb 2020 17:16:43 +0000."
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Date: Fri, 14 Feb 2020 07:26:48 +0000
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Subject: Re: [Rats] About (E)UID's
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Laurence Lundblade <lgl@island-resort.com> wrote:
    > Here’s some text we might add:

    > UEID’s are intended to be globally unique permanent device identifiers,
    > but these characteristics rely on the implementors of device following
    > the specification well. A relying party, particularly one dealing with
    > a very broad variety of devices from different manufacturers, may wish
    > to take into account other data in the token to uniquely identify the
    > device. For example they might consider a hash some or all of the UEID
    > + oemid + hw_version + signing_key as the unique identifier of the
    > device. Note these are all values that are permanently set for a device
    > at time of manufacturer.

Since the Relying Party needs to vest trust in the Verifier, it seems that
the verifier out to calculate this hash, and it should be a new claim.

a) it has access to this information.
b) there are fewer Verifiers than Manufacturers
c) the OEMID/HW_Version may well be personally identifier information which
   should not be passed on to the Relying Party.
   (Although I guess, if we are forming a hash over it, it becomes trackable)

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